TPS61045DRBR全新原装原理图各脚功能电路原理芯片引脚定义-中国IC网-芯三七

当前位置：IC37首页_>T字母起始型号索引_>T字母起始型号索引第444页更新时间：2024-10-25 17:03:16

产品型号TPS61045DRBR的概述

TPS61045DRBR的概述 TPS61045DRBR是一款由德州仪器（Texas Instruments）推出的高效升压转换器，广泛用于需要将低电压提升至更高电压的应用场景。该芯片能够处理多种输入电压范围，因此其适用性很广，尤为适合手持电子设备、便携式设备以及类似小型电子产品中，尤其在移动应用中表现出色。TPS61045DRBR的设计极为灵活，支持多种输出电压设置，使得其在电源管理领域成为一种理想选择。该器件具有出色的宽输入范围，能够在2.3V至5.5V之间正常工作，适应多种电源输入场景。此外，该芯片的最大输出电流可达1A，表明其在功率输出方面的强大性能。在设计时，TPS61045DRBR的功率效率也值得关注，能够在负载范围内保持高效，避免了由于过热导致的能量损耗。其内置的补偿网络和低电阻开关，无疑为提升转换效率提供了良好的基础。 TPS61045DRBR的详细参数 1. 输入电...

产品型号TPS61045DRBR的Datasheet PDF文件预览

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

DIGITALLY ADJUSTABLE LCD BOOST CONVERTER

FEATURES

DESCRIPTION

•

Input Voltage Range . . . 1.8 V to 6.0 V

The TPS61045 is a high frequency boost converter with

digitally programmable output voltage and true shut-

down. During shutdown the output is disconnected

from the input by opening the internal input switch. This

allows a controlled power up/down sequencing of the

display. The output voltage can be increased or de-

creased in digital steps by applying a logic signal to the

CTRL pin. The output voltage range, as well as the

output voltage step size, can be programmed with the

feedback divider network. With a high switching fre-

quency of up to 1 MHz the TPS61045 allows the use of

small external components and together, with the small

8-pin QFN package, a miminum system solution size is

achieved.

Up to 85% Efficiency

Digitally Adjustable Output Voltage Control

Disconnects Output From Input During Shut-

down

•

Switching Frequency . . . Up to 1 MHz

No Load Quiescent Current . . . 40 µA Typ

Thermal Shutdown Mode

Shutdown Current . . . 0.1 µA Typ

Available in Small 3mm × 3mm QFN package

APPLICATIONS

•

LCD Bias Supply For Small to Medium LCD

Displays

•

OLED Display Power Supply

– PDA, Pocket PC, Smart Phones

– Handheld Devices

– Cellular Phones

MBR0530

4.7 mH

16.2 V to 18.9 V/ 10 mA

4.7uF

2.2 MW

1 mF

Cff

22 pF

1 MW

= 1.8 V to 6 V

VIN

CTRL

PGND

GND

100 nF

180 kW

Enable / LCD bias control

Figure 1. Typical Application

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments

semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily in-

cludetestingofallparameters.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

(1)

ORDERING INFORMATION

T_A

8 PIN QFN PACKAGE (DRB)

PACKAGE MARKING

-40°C to 85°C

TPS61045DRB

BHT

(1)

The DRB package is available taped and reeled. Add R suffix (TPS61045DRBR) to order quantities of 3000 units per reel. Add T suffix

(TPS61045DBRT) to order quaqntities of 250 units per reel.

ABSOLUTE MAXIMUM RATINGS

(1)

over operating free-air temperature range (unless otherwise noted)

TPS61045

-0.3 V to 7 V

(2)

Supply voltage, V_(VIN)

Voltages, V_(CTRL), V_(FB), V_(L), V_(DO)

(2)

-0.3 V to V_I+ 0.3 V

30 V

Voltage, V_(SW)

Continuous power dissipation

See Dissipation Rating Table

-40°C to 150°C

-65°C to 150°C

260°C

Operating junction temperature range

Storage temperature range, T_STG

Lead temperature (soldering, 10 sec)

(1)

Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings

only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating

conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

All voltage values are with respect to network ground terminal.

(2)

DISSIPATION RATING

PACKAGE

T_A≤25°C POWER

DERATING FACTOR

T_A= 70°C POWER

T_A= 85°C POWER

RATING

ABOVE T_A= 25°C

RATING

(1)

8 pin QFN (DRB)

(1)

370 mW

3.7 mW/°C

204 mW

148 mW

The thermal resistance junction to ambient of the 8 pin QFN package is 270°C/W. Standard 2 layer PCB without vias for the thermal

pad. See the appliction section on how to improve the thermal resistance R_ΘJA

RECOMMENDED OPERATING CONDITIONS

MIN

1.8

TYP

MAX

6.0

UNIT

V_(VIN)

V_(SW)

Input voltage range

Switch voltage

(1)

Inductor

4.7

µH

MHz

µF

(1)

Switching frequency

Input capacitor (C2)

C_I(C2)

C_O(C3)

T_A

4.7

(1)

Output capacitor (C3)

µF

Operating ambient temperature

Operating junction temperature

-40

°C

T_J

125

°C

(1)

See application section for further information.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

ELECTRICAL CHARACTERISTICS

V_I= 2.4 V, CTRL = V_I, V_O= 18.0 V, I_O= 10 mA, T_A= -40°C to 85°C, typical values are at T_A= 25°C (unless otherwise noted)

PARAMETER

SUPPLY CURRENT

TEST CONDITIONS

MIN

TYP

MAX

UNIT

V_I

Input voltage range

1.8

6.0

µA

I_Q

Operating quiescent current

Shutdown current

I_O= 0 mA, not switching

I_O(SD)

V_UVLO

CTRL = GND

V_Ifalling

0.1

1.5

Under-voltage lockout threshold

1.7

CTRL AND DAC OUTPUT

V_IH

CTRL high level input voltage

1.3

V_IL

CTRL low level input voltage

CTRL input leakage current

DAC output voltage range

DAC resolution

0.3

0.1

I_lkg

CTRL = GND or VIN

µA

V_O(DO)

1.233

6 Bit

19.6

607

µA

µs

V_O(DO)

DAC center output voltage

CTRL = high

I_O(SINK)Maximum DAC sink current

t_(UP)

t_(DWN)

t_d1

Increase output voltage one step

Decrease the output voltage one step

Delay time between up/down steps

Shutdown

CTRL = high to low

CTRL = low to high

CTRL = high to low

140

240

t_(OFF)

560

INPUT SWITCH (Q1), MAIN SWITCH (Q2) AND CURRENT LIMIT

V_SW(Q2)Main switch maximum voltage (Q2)

800

mΩ

µA

Ω

r_ds(ON)

Main switch MOSFET on-resistance

V_I= 2.4 V; I_S= 200 mA

V_S= 28 V

400

0.1

375

I_lkg(MAIN)Main switch MOSFET leakage current

I_(LIM)

Main switch MOSFET current limit

Input switch MOSFET on-resistance

Input switch MOSFET leakage current

300

450

r_ds(ON)

I_lkg(IN)

OUTPUT

V_O

V_I= 2.4 V; I_S= 200 mA

VL = GND, V_I= 6 V

0.1

µA

Output voltage range

Vin

V_ref

Internal voltage reference

Feedback input bias current

Feedback trip point voltage

1.233

I_(FB)

VFB = 1.3 V

100

V_(FB)

1.8 V ≤ V_I≤ 6.0 V; V_O= 18 V, I_(LOAD)= 10

1.208

1.233

1.258

DRB PACKAGE

(TOP VIEW)

Exposed

Thermal

Die Pad

VIN 2

DO 3

PGND

GND

CTRL

(A) The Exposed Thermal Die Pad is connected to PGND. Connect this pad directly with the GND pin.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

TERMINAL FUNCTIONS

TERMINAL

I/O

DESCRIPTION

NAME

NO.

CTRL

Combined enable and digital output voltage programming pin. Pulling CTRL constantly high enables

the device. When CTRL is pulled to GND, the device is disabled and the input is disconnected from

the output by opening the integrated switch Q1. Pulsing CTRL low increases or decreases the output

voltage. Refer to the application information section for further information.

Internal DAC output. DO programs the output voltage via the CTRL pin. Refer to the application

information section for further information.

Feedback. FB must be connected to the output voltage-feedback divider.

GND

Analog ground. GND must be directly connected to the PGND pin. Refer to the application

information section for further information.

Drain of the internal switch (Q1). Connect L to the inductor.

Power ground

PGND

Drain of the integrated switch Q2. SW is connected to the inductor and anode of the Schottky rectifier

diode.

VIN

Input supply pin

FUNCTIONAL BLOCK DIAGRAM

Input switch

400 ns Min

Off Time

Undervoltage

Lockout

Bias Supply

Gate

Driver

CTRL

Main Switch

ErrorComparator

Gate

Driver

RS Latch

Logic

6 ms Max

= 1.233 V

Digital

ref

On Time

Current Limit

sense

6 Bit DAC

CTRL

Interface

Soft

Start

GND

PGND

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

TYPICAL CHARACTERISTICS

Table #IMPLIED. Table of Graphs

FIGURE

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Efficiency

vs Load current

vs Input voltage

vs Temperature

vs Input voltage

vs Temperature

vs Input voltage

vs CTRL input step

I_DD(Q)

V_(FB)

I_(FB)

Quiescent current

Feedback voltage

Feedback current

r_ds(on)Main switch Q2

r_ds(on)

r_ds(on)Input switch Q1

V_(DO)

V_(DO)Voltage

Line transient response

Load transient response

PFM operation

Soft start

Efficiency

Load Current

Efficiency

Input Voltage

L = 4.7 µH

V = 5 V

= 18 V

= 10 mA

V = 3.6 V

V = 2.4 V

L = 4.7 µH

= 18 V

= 5 mA

0.1

100

V - Input Voltage - V

- Output Current - mA

Figure 2.

Figure 3.

Quiescent Current

Input Voltage

Feedback Voltage

Temperature

1.238

1.237

1.236

1.235

1.234

1.233

V = 2.4 V

= 85°C

= 25°C

= -40°C

-40

-15

1.8

2.4

3.0

3.6

4.2

4.8

5.4

6.0

- Free-Air Temperature - °C

V - Input Voltage - V

Figure 4.

Figure 5.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

Typical Characteristics (continued)

Feedback Current

r_ds(ON)Main Switch Q2

Temperature

100

700

600

500

400

300

200

100

V = 2.4 V

V = 3.6 V

V = 2.4 V

V = 5 V

-40

1.8

-15

6.0

-40

-15

- Free-Air Temperature - ° C

Figure 6.

Figure 7.

r_ds(ON)Main Switch Q2

r_ds(ON)Input Switch Q1

Input Voltage

Temperature

600

500

400

300

200

100

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

V = 2.4 V

= 25° C

2.4

3.0

3.6

4.2

4.8

5.4

-15

V - Input Voltage - V

- Free-Air Temperature - ° C

Figure 8.

Figure 9.

r_ds(ON)Input Switch Q1

V_(DO)Voltage

CTRL Input Step

Input Voltage

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0.0

= 25° C

V = 2.4 V

2.4

3.0

3.6

4.2

4.8

5.4

V - Input Voltage - V

Input Step Number

Figure 10.

Figure 11.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

Typical Characteristics (continued)

V = 2.4 V to 3.4 V Step

= 100 mV/Div

250 µs/Div

Figure 12 . Line Transient Response

= 50 mV/Div

= 1 mA to 11 mA Step

(Load)

50 µs/Div

Figure 13 . Load Transient Response

(SW)

= 10 V/Div

= 50 mV/Div

I = 200 mA/Div

1 µs/Div

Figure 14 . PFM Operation

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

Typical Characteristics (continued)

= 5 V/Div

CTRL 2 V/Div

I = 50 mA/Div

500 µs/Div

Figure 15 . Soft Start

DETAILED DESCRIPTION

OPERATION

The TPS61045 operates with an input voltage range of 1.8 V to 6.0 V and generates output voltages up to 28 V.

The device operates in a pulse frequency modulation (PFM) scheme with constant peak current control. This

control scheme maintains high efficiency over the entire load current range and, with a switching frequency of up

to 1 MHz, the device enables the use of small external components.

The converter monitors the output voltage and when the feedback voltage falls below the reference voltage of

1.233 V (typ) the main switch turns on and the current ramps up. The main switch turns off when the inductor

current reaches the internally set peak current of 375 mA (typ). Refer to the peak current controlsection for more

information. The second criteria that turns off the main switch is the maximum on-time of 6 µs (typ). This limits

the maximum on-time of the converter in extreme conditions. As the switch is turned off, the external Schottky

diode is forward biased delivering the current to the output. The main switch remains off until the minimum off

time of 400 ns (typ) has passed and the feedback voltage is below the reference voltage again. Using this PFM

peak current control scheme, the converter operates in discontinuous conduction mode (DCM) where the

switching frequency depends on the input voltage, output voltage and output current. This gives a high efficiency

over the entire load current range. This regulation scheme is inherently stable which allows a wider range for the

selection of the inductor and output capacitor.

PEAK CURRENT CONTROL

The internal switch is turned on until the inductor current reaches the typical dc current limit (I_LIM) of 375 mA. Due

to the internal current limit delay of 100 ns (typ) the actual current exceeds the dc current limit threshold by a

small amount. The typical peak current limit can be calculated:

+ I

)

100 ns

P(typ)

(LIM)

(1)

+ 400 mA ) 100 ns

P(typ)

The higher the input voltage and the lower the inductor value, the greater the current limit overshoot.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

DETAILED DESCRIPTION (continued)

SOFTSTART

All inductive step-up converters exhibit high inrush current during start up if no special precautions are taken.

This can cause voltage drops at the input rail during start-up, which may result in an unwanted or premature

system shut down.

When the device is enabled, the internal input switch (Q1) is slowly turned on to reduce the in-rush current

charging the capacitor (C2) connected to pin L. Furthermore, the TPS61045 limits this in-rush current during

start-up by increasing the current limit in two steps starting from I_LIM/4 for 256 switch cycles to I_LIM/2 for the next

256 switch cycles.

ENABLE (CTRL PIN)

The CTRL pin serves two functions. One is the enable and disable of the device. The other is the output voltage

programming of the device. If the digital interface is not required, the CTRL pin is used as a standard enable pin

for the device.

Pulling the CTRL pin high enables the device beginning with the softstart cycle.

Pulling the CTRL pin to ground for a period of ≥ 560 µs shuts down the device, reducing the shutdown current to

0.1 µA (typ). During shutdown the internal input switch (Q1) remains open and disconnects the load from the

input supply of the device.

This pin must be terminated.

DAC OUTPUT (DO)

The TPS61045 allows digital adjustment of the output voltage using the digital CTRL interface as described in

the next section. The DAC output pin (DO) drives an external resistor (R3) connected to the external feedback

divider. The DO output has a typical output voltage range from 0 V to V_ref(1.233V). If the DO output voltage is

set to 0 V, the external resistor (R3) is more or less in parallel to the lower feedback resistor (R2) giving the

highest output voltage. Programming the DO output to V_refgives the lowest output voltage. Internally, a 6-bit DAC

is used with 64-steps and 0 as the first step. This gives a typical voltage step of 19.6 mV which is calculated as:

ref

ǒ Ǔ

O(DO)

2 –1

See the sectionsetting the output voltage for further information.

After start-up, when the CTRL pin is pulled high, the DO output voltage is set to its center voltage which is the

32nd step of typically V_(DO)= 607mV.

DIGITAL INTERFACE (CTRL)

When the CTRL pin is pulled high the device starts up with softstart and the DAC output voltage (DO) sets to its

center voltage with a typical output voltage of 607 mV.

The output voltage can be programmed by pulling the CTRL pin low for a certain period of time. Depending on

this time period the internal DAC voltage increases or decreases one digital step, as outlined in Table 1 and

Figure 16. Programming the DAC output V_(DO)to 0 V places R3 in parallel to R2, which gives the maximum

output voltage. If the DAC is programmed to its maximum output voltage equal to the internal reference voltage,

typically V_(DO)=1.233 V, then the output has its minimum output voltage.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

DETAILED DESCRIPTION (continued)

Table 1. Timing Table

DAC OUTPUT DO

TIME

LOGIC LEVEL

Increase one step

Decrease one step

Shutdown

t_(UP)= 1 µs to 60 µs

t_(DWN)= 140 µs to 240 µs

t_(OFF)≥ 560 µs

Low

High

Delay between steps

t_d1= 1 µs

High

Low

(UP)

(OFF)

(DWN)

Device Enabled

Device Disabled

Figure 16. CTRL Timing Diagram

UNDERVOLTAGE LOCKOUT

An undervoltage lockout feature prevents misoperation of the device at input voltages below 1.5 V (typ). As long

as the input voltage is below the undervoltage threshold the device remains off, with the input switch (Q1) and

the main switch (Q2) open.

THERMAL SHUTDOWN

An internal thermal shutdown is implemented in the TPS61045 that shuts down the device if the typical junction

temperature of 160°C is exceeded. If the device is in thermal shutdown mode, the input switch (Q1) and the main

switch (Q2) are open.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

APPLICATION INFORMATION

INDUCTOR SELECTION, MAXIMUM LOAD CURRENT

Since the PFM peak current control scheme is inherently stable the inductor and capacitor value does not affect

the stability of the regulator. The selection of the inductor together with the nominal load current, input, and

output voltage of the application determines the switching frequency of the converter. Depending on the

application, inductor values between 2.2 µH up to 47 µH are recommended. The maximum inductor value is

determined by the maximum switch on-time of 6 µs (typ). The peak current limit of 375 mA (typ) must be reached

within this 6 µs for proper operation.

The inductor value determines the maximum switching frequency of the converter. Therefore, the inductor value

must be selected for the maximum switching frequency, at maximum load current of the converter and should not

be exceeded. A good inductor value to start with is 4.7 µH. The maximum switching frequency is calculated as:

_VIǒ_VO_* VǓ

(max)

L V

with:

I_P= peak current as described in the previous peak current control section.

+ 375 mA ) 100 ns

P(typ)

(2)

L = selected inductor value

If the selected inductor does not exceed the maximum switching frequency of the converter, as a next step, the

switching frequency at the nominal load current is estimated as follows:

ǒ_{VO–V )}_VFǓ

2 I

LOAD

(ILOAD)

with:

I_P= peak current as described in the previous chapter peak current control section

+ 375 mA ) 100 ns

P(typ)

(3)

L = selected inductor value

I_(LOAD)= nominal load current

V_F= rectifier diode forward voltage (typically 0.3 V)

The smaller the inductor value, the higher the switching frequency of the converter but the lower the efficiency.

The maximum load current of the converter is determined at the operation point where the converter starts to

enter continuous conduction mode. The converter must always operate in discontinuous conduction mode to

maintain regulation.

Two conditions exist for determining the maximum output current of the converter. One is when the inductor

current fall time is <400 ns, and the other is when the inductor current fall time is >400 ns.

One way to calculate the maximum available load current under certain operation conditions is to estimate the

expected converter efficiency at the maximum load current. This number can be taken out of the efficiency

graphs shown in Figure 2 and Figure 3. Then the maximum load current can be estimated:

Inductor fall time:

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

APPLICATION INFORMATION (continued)

fall

V –V

For t_f≥ 400 ns

+ h

load max

2 V

(4)

(5)

t_f≤ 400 ns

L V

+ h

load max

ǒ_{2 I L ) 2 400 ns V}Ǔ

ǒ_VO–VIǓ

with:

L = selected inductor value

η = expected converter efficiency (typically between 70% to 85%)

I_P= peak current as described in the previous peak current control section.

+ 300 mA ) 100 ns

(6)

The above formula contains the expected converter efficiency that allows calculating the expected maximum load

current the converter can support. The efficiency can be taken out of the efficiency graphs shown in Figures 2

and 3 or 80% can be used as a good estimation.

The selected inductor must have a saturation current which meets the maximum peak current of the converter as

calculated in the peak current control section. Use the maximum value for I_Lim(450mA) for this calculation.

Another important inductor parameter is the dc resistance. The lower the dc resistance, the higher the efficiency

of the converter. Refer to the Table 1 and the inductor selection section under typical applications.

Table 2. Possible Inductor Selection

INDUCTOR VALUE

COMPONENT SUPPLIER

Sumida CR32-100

COMMENTS

10 µH

High efficiency

Sumida CDRH3D16-100

Murata LQH43CN100K01

Sumida CDRH3D16-4R7

muRata LQH32CN4R7M51

4.7 µH

Small solution size

SETTING THE OUTPUT VOLTAGE

When the converter is programmed to the minimum output voltage, the DAC output (DO) equals the reference

voltage of 1.233 V (typ). Therefore, only the feedback resistor network (R1) and (R2) determines the output

voltage under these conditions. This gives the minimum output voltage possible and can be calculated as:

ǒ Ǔ

+ V

) 1

O(min)

(FB)

The maximum output voltage is determined as the DAC output (DO) is set to 0 V:

ǒ Ǔ

+ V

) V

) 1

O(max)

(FB)

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

APPLICATION INFORMATION (continued)

The output voltage can be digitally programmed by pulling the CTRL pin low for a certain period of time as

described in the Digital Interface section. Pulling the signal applied to the CTRL pin low increases or decreases

the DAC output DO (pin 3) one-step where one step is typically 19.6 mV. A voltage step on DO of 19.6mV (typ)

changes the output voltage by one step and is calculated as:

19.6 mV R1

O(step)

The possible output voltage range is determined by selecting R1, R2 and R3. A possible larger output voltage

range gives a larger output voltage step size. The smaller the possible output voltage range, the smaller the

output voltage step size.

To reduce the overall operating quiescent current in battery powered applications a high impedance voltage

divider must be used with a typical value for R2 of ≤ 200 kΩ and a maximum value for R1 of 2.2 MΩ.

Some applications may not need the digital interface to program the output voltage. In this case the output DO

can be left open as shown in Figure 18 and the output voltage is calculated as for any standard boost converter:

_{+ 1.233 V}ǒ_{1 )}Ǔ

In such a configuration a high impedance voltage divider must also be used to minimize ground current and a

typical value for R2 of ≤ 200 kΩ and a maximum value for R1 of 2.2 MΩ are recommended.

A feed-forward capacitor (C_(FF)), across the upper feedback resistor (R1), is required to provide sufficient

overdrive for the error comparator. Without a feed-forward capacitor or a too small feed-forward capacitor value,

the device shows double pulses or a pulse burst instead of single pulses at the switch node (SW). This can

cause higher output voltage ripple. If a higher output voltage ripple is acceptable, the feedforward capacitor can

be left out too.

The lower the switching frequency of the converter, the larger the feed-forward capacitor value needs to be. A

good starting point is the use of a 10 pF feed-forward capacitor. As a first estimation, the required value for the

feed-forward capacitor can be calculated at the operation point:

[

2 p

with:

R1 = upper resistor of voltage divider

f_S= switching frequency of the converter at the nominal load current. (For the calculation of the switching

frequency see previous section)

For C_(FF)choose a value which comes closest to the calculation result.

The larger the feed-forward capacitor, the worse the line regulation of the device. Therefore, the feed-forward

capacitor must be selected as small as possible if good line regulation is of concern.

OUTPUT CAPACITOR SELECTION

For better output voltage filtering a low ESR output capacitor is recommended. Ceramic capacitors have low

ESR values but depending on the application, tantalum capacitors can also be used. Refer to Table 2 and typical

applications for the selection of the output capacitor.

Assuming the converter does not show double pulses or pulse bursts on the switch node (SW) the output voltage

ripple is calculated as:

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

APPLICATION INFORMATION (continued)

) I ESR

) V * V

s(ILOAD)

with:

I_P= peak current as described in the previous section peak current control

+ 375 mA ) 100 ns

(7)

L = selected inductor value

I_O(LOAD)=Nominal load current

f_S(ILoad)= switching frequency at the nominal load current as calaculated previously.

V_F= rectifier diode forward voltage (typically 0.3 V)

C_O= selected output capacitor

ESR = output capacitor ESR value

INPUT CAPACITOR SELECTION

The input capacitor (C1) filters the high frequency noise to the control circuit and must be directly connected to

the input pin (VIN) of the device. The capacitor (C2) connected to the L pin of the device is the input capacitor for

the power stage.

The main purpose of the capacitor (C2), that is connected directly to the L pin, is to smooth the inductor current.

A larger capacitor reduces the inductor ripple current present at the L pin. The smaller the ripple current at the L

pin, the higher the efficiency of the converter. If a sufficiently large capacitor is used, the input switch must carry

only the DC current, filtered by the capacitor (C2), and not the high switching currents of the converter. A 4.7 µF

or 10-µF ceramic capacitor (C2) is sufficient for most applications. For better filtering, this value can be increased

without limit. Refer to Table 2 and typical applications for input capacitor recommendations.

Table 3. Possible Input and Output Capacitor Selection

CAPACITOR

4.7 F/X5R/0805

VOLTAGE RATING

6.3 V

COMPONENT SUPPLIER

Tayo Yuden JMK212BY475MG

COMMENTS

C_I/C_O

10 µF/X5R/0805

1.0 µF/X7R/1206

4.7 µF/X5R/1210

6.3 V

25 V

35 V

25 V

Tayo Yuden JMK212BJ106MG

Tayo Yuden TMK316BJ105KL

Tayo Yuden GMK316BJ105KL

Tayo Yuden TMK325BJ475MG

C_I/C_O

C_O

DIODE SELECTION

To achieve high efficiency a Schottky diode must be used. The current rating of the diode must meet the peak

current rating of the converter as it is calculated in the peak current control section. Use the maximum value for

I_(LIM)(450mA) for this calculation. Refer to Table 3 and the typical applications for the selection of the Schottky

diode.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

APPLICATION INFORMATION (continued)

Table 4. Possible Schottky Diode Selection

COMPONENT SUPPLIER

ON Semiconductor MBR0530

ON Semiconductor MBR0520

ON Semiconductor MBRM120L

Toshiba CRS02

REVERSE VOLTAGE

30 V

20 V

30 V

40 V

Zetex CHZS400

LAYOUT CONSIDERATIONS

As for all switching power supplies the layout is an important step in the design, especially at high peak currents

and switching frequencies. If the layout is not carefully implemented the regulator can show noise problems and

duty cycle jitter.

The input capacitor must be placed as close as possible to the input pin for good input-voltage filtering. The

inductor and diode must be placed as close as possible to the switch pin (SW) to minimize noise coupling into

other circuits. Since the feedback pin and network is a high impedance circuit, the feedback network must be

routed away from the inductor.

THERMAL CONSIDERATIONS

The TPS61045 is available in a thermally enhanced QFN package. The package includes a thermal pad,

improving the thermal capabilities of the package. See QFN/SON PCB attachment application note (SLUA271).

The thermal resistance junction to ambient (R_ΘJA) of the QFN package depends on the PCB layout. By using

thermal vias and wide PCB, traces improve thermal resistance (R_ΘJA). Under normal operation conditions no

PCB vias are required for the thermal pad. However, the thermal pad must be soldered to the PCB.

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

TYPICAL APPLICATIONS

4.7 µH

Zetex ZHZS400

LQH32CN4R7M11

16.2 V to 18.9 V/ 10 mA

4.7 µF

Cff

22 pF

1 µF

2.2 M

1 M

= 1.8 V to 6 V

Vin

CTRL

100 nF

GND PGND

180 kΩ

Enable / LCD

Bias Control

Figure 17. Typical Application With Digital Adjusted Output Voltage

4.7 µH

Zetex ZHZS400

LQH32CN4R7M11

15 V to 18 V

Adjustable / 10 mA

4.7 µF

Cff

22 pF

1 µF

2.2 M

= 1.8 V to 6 V

Vin

CTRL

DAC or Analog Voltage

0 V = 25 V

1.233 V = 18 V

100 nF

390 kΩ

GND PGND

160 kΩ

Enable

Figure 18. Typical Application With Analog Adjusted Output Voltage

TPS61045

www.ti.com

SLVS440A–JANUARY 2003–REVISED SEPTEMBER 2003

TYPICAL APPLICATIONS (continued)

4.7 µH

Zetex ZHZS400

LQH32CN4R7M23

16.2 V to 18.9 V/

20 mA

4.7 µF

Cff

22 pF

1 µF

2.2 M

1 M

= 2.7 V to 6 V

Vin

CTRL

100 nF

GND PGND

180 kΩ

Enable / LCD

Bias Control

Figure 19. OLED Supply Providing Higher Output Current

PACKAGE OPTION ADDENDUM

www.ti.com

11-Feb-2005

PACKAGING INFORMATION

Orderable Device

Status ⁽¹⁾

Package Package

Pins Package Eco Plan ⁽²⁾Lead/Ball Finish MSL Peak Temp ⁽³⁾

Qty

Type

SON

Drawing

TPS61045DRBR

TPS61045DRBT

ACTIVE

DRB

3000

250

None

CU NIPDAU Level-2-235C-1 YEAR

DRB

⁽¹⁾The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in

a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional

product content details.

None: Not yet available Lead (Pb-Free).

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered

at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,

including bromine (Br) or antimony (Sb) above 0.1% of total product weight.

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder

temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is

provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the

accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take

reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on

incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited

information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI

to Customer on an annual basis.

Addendum-Page 1

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,

enhancements, improvements, and other changes to its products and services at any time and to discontinue

any product or service without notice. Customers should obtain the latest relevant information before placing

orders and should verify that such information is current and complete. All products are sold subject to TI’s terms

and conditions of sale supplied at the time of order acknowledgment.

TI warrants performance of its hardware products to the specifications applicable at the time of sale in

accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI

deems necessary to support this warranty. Except where mandated by government requirements, testing of all

parameters of each product is not necessarily performed.

TI assumes no liability for applications assistance or customer product design. Customers are responsible for

their products and applications using TI components. To minimize the risks associated with customer products

and applications, customers should provide adequate design and operating safeguards.

TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,

in which TI products or services are used. Information published by TI regarding third-party products or services

does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.

Use of such information may require a license from a third party under the patents or other intellectual property

of the third party, or a license from TI under the patents or other intellectual property of TI.

Reproduction of information in TI data books or data sheets is permissible only if reproduction is without

alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction

of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for

such altered documentation.

Resale of TI products or services with statements different from or beyond the parameters stated by TI for that

product or service voids all express and any implied warranties for the associated TI product or service and

is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.

Following are URLs where you can obtain information on other Texas Instruments products and application

solutions:

Products

Applications

Audio

Amplifiers

amplifier.ti.com

www.ti.com/audio

Data Converters

dataconverter.ti.com

Automotive

www.ti.com/automotive

DSP

dsp.ti.com

Broadband

Digital Control

Military

www.ti.com/broadband

www.ti.com/digitalcontrol

www.ti.com/military

Interface

Logic

interface.ti.com

logic.ti.com

Power Mgmt

Microcontrollers

power.ti.com

Optical Networking

Security

www.ti.com/opticalnetwork

www.ti.com/security

www.ti.com/telephony

www.ti.com/video

microcontroller.ti.com

Telephony

Video & Imaging

Wireless

www.ti.com/wireless

Mailing Address:

Texas Instruments

Post Office Box 655303 Dallas, Texas 75265

TPS61045DRBR相关文章

配单直通车

首天国际（深圳）科技有限公司服务专线: 0755-82807802/82807803 在线联系:

QQ：528164397 复制

QQ：1318502189 复制

北京元坤伟业科技有限公司服务专线: 010-62104931621064316210489162104791 在线联系:

QQ：857273081 复制

QQ：1594462451 复制

深圳市芯福林电子有限公司服务专线: 13418564337 在线联系:

QQ：2881495808 复制

QQ：308365177 复制

柒号芯城电子商务（深圳）有限公司服务专线: 0755-83209937 在线联系:

QQ：2881677436 复制

QQ：2881620402 复制

深圳市中利达电子科技有限公司服务专线: 0755-83200645/13686833545 在线联系:

QQ：1902134819 复制

QQ：2881689472 复制

TPS61045DRBRG4产品参数

型号:	TPS61045DRBRG4
Brand Name：	Texas Instruments
是否无铅：	不含铅
是否Rohs认证：	符合
生命周期：	Active
IHS 制造商：	TEXAS INSTRUMENTS INC
零件包装代码：	SON
包装说明：	SON-8
针数：	8
Reach Compliance Code：	compliant
ECCN代码：	EAR99
HTS代码：	8542.39.00.01
Factory Lead Time：	1 week
风险等级：	0.89
Is Samacsys：	N
模拟集成电路 - 其他类型：	SWITCHING REGULATOR
控制模式：	CURRENT-MODE
控制技术：	PULSE FREQUENCY MODULATION
最大输入电压：	6 V
最小输入电压：	1.8 V
标称输入电压：	2.4 V
JESD-30 代码：	S-PDSO-N8
JESD-609代码：	e4
长度：	3 mm
湿度敏感等级：	2
功能数量：	1
端子数量：	8
最高工作温度：	85 °C
最低工作温度：	-40 °C
最大输出电流：	0.45 A
最大输出电压：	28 V
最小输出电压：	1.8 V
封装主体材料：	PLASTIC/EPOXY
封装代码：	HVSON
封装等效代码：	SOLCC8,.12,25
封装形状：	SQUARE
封装形式：	SMALL OUTLINE, HEAT SINK/SLUG, VERY THIN PROFILE
峰值回流温度（摄氏度）：	260
认证状态：	Not Qualified
座面最大高度：	1 mm
子类别：	Switching Regulator or Controllers
表面贴装：	YES
切换器配置：	BOOST
最大切换频率：	1000 kHz
温度等级：	INDUSTRIAL
端子面层：	Nickel/Palladium/Gold (Ni/Pd/Au)
端子形式：	NO LEAD
端子节距：	0.65 mm
端子位置：	DUAL
处于峰值回流温度下的最长时间：	NOT SPECIFIED
宽度：	3 mm
Base Number Matches：	1

电子百科

产品导航

产品型号TPS61045DRBR的概述

产品型号TPS61045DRBR的Datasheet PDF文件预览

TPS61045DRBR相关产品

TPS61045DRBR相关文章

IC37:专业IC行业平台