MAX3243C各脚功能电路原理芯片引脚定义引脚图及功能IC贸易商-中国IC网-芯三七

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产品型号MAX3243C的概述

芯片MAX3243C的概述 MAX3243C是一款高性能、低功耗的RS-232串口通信转换器，广泛应用于各种电子设备中。此芯片的设计旨在满足现代信息技术和通信设备对传输速度和可靠性的高要求。MAX3243C能将TTL/CMOS逻辑电平转换为RS-232标准，解决了不兼容的问题。该芯片适用于串行通信的场合，如计算机、微控制器和其他数字设备之间的连接。 MAX3243C的设计特色包括较高的传输速率、较宽的工作电压范围以及内置的电源管理功能。它能够在-15V到+15V的电源范围内工作，满足大多数工业和消费电子的需求。此外，MAX3243C配备有多种故障保护特性，确保其在极端工作条件下的稳定性。芯片MAX3243C的详细参数在了解MAX3243C的概述之后，我们可以深入其详细参数。这些参数对于应用工程师在设计电路时非常重要，确保所选芯片能够满足特定设计的需求。 1. 电源电压(Vcc): ...

产品型号MAX3243CAI的Datasheet PDF文件预览

19-0306; Rev 6; 3/99

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

_______________General Description

____________________________Features

ꢀ 1µA Supply Current Achieved with AutoShutdown

ꢀ Small 0.1µF Capacitors

The MAX3221/MAX3223/MAX3243 achieve 1µA supply

current with Maxim’s revolutionary AutoShutdown™ fea-

ture. When the MAX3221/MAX3223/MAX3243 do not

sense a valid signal level on their receiver inputs, the

on-board power supply and drivers shut down. This

occurs if the RS-232 cable is disconnected or if the

transmitters of the connected peripheral are turned off.

The system turns on again when a valid level is applied

to any RS-232 receiver input. As a result, the system

saves power without changes to the existing BIOS or

operating system.

ꢀ True RS-232 Operation from V

= +3.0V to +5.5V

ꢀ Meets EIA/TIA-562 Specifications Down to 2.7V

ꢀ Guaranteed 120kbps Data Rate

ꢀ 6V/µs Min Guaranteed Slew Rate

ꢀ Smallest Single-Supply RS-232 Transceiver

(MAX3221)

The MAX3221/MAX3223/MAX3243 transceivers are 3V-

powered EIA/TIA-232 and V.28/V.24 communications

interfaces intended for notebook computer applica-

tions. A proprietary, high-efficiency, dual charge-pump

power supply and a low-dropout transmitter combine to

deliver true RS-232 performance from a single +3.0V to

+5.5V supply. A guaranteed data rate of 120kbps pro-

vides compatibility with popular software for communi-

cating with personal computers.

ꢀ Guaranteed Mouse Driveability (MAX3243)

ꢀ Small TSSOP Package (MAX3223/MAX3243)

________________________Applications

Notebook, Subnotebook, and Palmtop Computers

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

The MAX3221/MAX3223/MAX3243 require only 0.1µF

capacitors in 3.3V operation, and can operate from input

voltages ranging from +3.0V to +5.5V. They are ideal for

3.3V-only systems, mixed 3.3V and 5.0V systems, or

5.0V-only systems that require true RS-232 performance.

Printers

The MAX3221 is a 1-driver/1-receiver 16-pin SSOP ver-

sion of the 20-pin MAX3223 (2-driver/2-receiver). The

MAX3243 3-driver/5-receiver, complete serial port is

ideal for notebook or subnotebook computers. The

MAX3243 includes one complementary always-active

receiver. This receiver can monitor an external device

(such as a modem) in shutdown, without forward bias-

______________Ordering Information

PART

TEMP. RANGE

0°C to +70°C

-40°C to +85°C

0°C to +70°C

-40°C to +85°C

0°C to +70°C

-40°C to +85°C

PIN-PACKAGE

16 SSOP

MAX3221CAE

MAX3221CUE†

MAX3221EAE

MAX3221EUE†

MAX3223CPP

MAX3223CAP

MAX3223CUP

MAX3223EPP

MAX3223EAP

MAX3223EUP

MAX3243CWI

MAX3243CAI

MAX3243CUI

MAX3243EWI

MAX3243EAI

MAX3243EUI

ing the protection diodes in a UART that may have V

completely removed.

16 TSSOP

16 SSOP

16 TSSOP

20 Plastic DIP

20 SSOP

_____________________Selector Guide

20 TSSOP

20 Plastic DIP

20 SSOP

PART

RANGE (V) AutoShutdown

MAX3221

MAX3223

MAX3243

3.0 to 5.5

Yes

20 TSSOP

28 Wide SO

28 SSOP

Pin Configurations appear at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

28 TSSOP

28 Wide SO

28 SSOP

†Future product—contact factory for availability.

AutoShutdown is a trademark of Maxim Integrated Products.

28 TSSOP

* Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.

________________________________________________________________ Maxim Integrated Products

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

ABSOLUTE MAXIMUM RATINGS

...........................................................................-0.3V to +6V

16-Pin SSOP (derate 7.14mW/°C above +70°C) ...........571mW

16-Pin TSSOP (derate 6.70mW/°C above +70°C) .........533mW

20-Pin Plastic DIP (derate 11.11mW/°C above +70°C)....889mW

20-Pin SSOP (derate 8.00mW/°C above +70°C) ...........640mW

20-Pin TSSOP DIP (derate 7.00mW/°C above +70°C).....559mW

28-Pin Wide SO (derate 12.50mW/°C above +70°C) ............1W

28-Pin SSOP (derate 9.52mW/°C above +70°C) ...........762mW

28-Pin TSSOP (derate 8.70mW/°C above +70°C) .........696mW

Operating Temperature Ranges

V+ (Note 1)...............................................................-0.3V to +7V

V- (Note 1) ...............................................................+0.3V to -7V

V+ + |V-| (Note 1).................................................................+13V

Input Voltages

T_IN, FORCEOFF, FORCEON, EN (MAX3223) ......-0.3V to +6V

R_IN ................................................................................... 25V

Output Voltages

T_OUT............................................................................. 13.2V

R_OUT, INVALID ......................................-0.3V to (V

Short-Circuit Duration

+ 0.3V)

MAX32_ _C_ _.......................................................0°C to +70°C

MAX32_ _E_ _....................................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +150°C

Lead Temperature (soldering, 10sec) .............................+300°C

T_OUT ......................................................................Continuous

Continuous Power Dissipation (T = +70°C)

Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.

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 in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T

to T

, unless otherwise noted. Typical values are at T = +25°C.)

MAX A

MIN

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

DC CHARACTERISTICS

Supply Current, AutoShutdown

Supply Current, Shutdown

All R_IN open, FORCEON = GND,

1.0

0.3

µA

FORCEOFF = V

= 3.3V

or 5.0V,

= +25°C

FORCEOFF = GND

Supply Current,

AutoShutdown Disabled

FORCEON = FORCEOFF = V

1.0

no load

LOGIC INPUTS AND RECEIVER OUTPUTS

Input Logic Threshold Low

0.8

T_IN, FORCEON, FORCEOFF, EN (MAX3223)

= 3.3V

= 5.0V

2.0

2.4

Input Logic Threshold High

T_IN, EN, FORCEON, FORCEOFF

Input Leakage Current

Output Leakage Current

Output Voltage Low

Output Voltage High

0.01

0.05

1.0

µA

T_IN, EN, FORCEON, FORCEOFF

Receivers disabled

= 1.6mA

= -1.0mA

0.4

OUT

- 0.6

- 0.1

AUTOSHUTDOWN (FORCEON = GND, FORCEOFF = V

)

Positive threshold

Negative threshold

1µA supply current, Figure 5

2.7

Receiver Input Thresholds to

Figure 5

Transmitters Enabled

-2.7

-0.3

Receiver Input Thresholds to

Transmitters Disabled

0.3

0.4

= 1.6mA

= -1.0mA

INVALID Output Voltage Low

OUT

- 0.6

INVALID Output Voltage High

OUT

Receiver Threshold to

Transmitters Enabled (t

Receiver Positive or Negative

Threshold to INVALID High (t

Receiver Positive or Negative

Threshold to INVALID Low (t

Figure 5

250

µs

)

INVH

INVL

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

ELECTRICAL CHARACTERISTICS (continued)

= +3.0V to +5.5V, C1–C4 = 0.1µF (Note 2), T = T

to T

, unless otherwise noted. Typical values are at T = +25°C.)

MAX A

MIN

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

RECEIVER INPUTS

Input Voltage Range

-25

0.6

0.8

= 3.3V

= 5.0V

= 3.3V

= 5.0V

1.2

1.5

1.8

0.3

Input Threshold Low

Input Threshold High

= +25°C

2.4

Input Hysteresis

Input Resistance

= +25°C

kΩ

TRANSMITTER OUTPUTS

Output Voltage Swing

Output Resistance

All transmitter outputs loaded with 3kΩ to ground

5.0

5.4

10M

Ω

= V+ = V- = 0V, transmitter output = 2V

300

Output Short-Circuit Current

OUT

12V, V

= 0V or 3.0V to 5.5V,

Output Leakage Current

µA

transmitters disabled

MOUSE DRIVEABILITY (MAX3243)

T1IN = T2IN = GND, T3IN = V

Transmitter Output Voltage

T3OUT loaded with 3kΩ to GND, T1OUT and

T2OUT loaded with 2.5mA each

TIMING CHARACTERISTICS

Maximum Data Rate

R = 3kΩ, C = 1000pF, one transmitter switching

120

235

0.3

kbps

µs

PHL

PLH

Receiver input to receiver output,

Receiver Propagation Delay

C = 150pF

0.3

Receiver Output Enable Time

Receiver Output Disable Time

Normal operation

200

100

MAX3221/MAX3223

MAX3243

Transmitter Skew

Receiver Skew

- t

PHL PLH



1000

MAX3221/MAX3223

MAX3243

- t

PHL PLH



500

= 3.3V,

C = 200pF to 2500pF

8.0

R = 3kΩ to 7kΩ,

Transition-Region Slew Rate

T = +25°C,

V/µs

measured from +3V to

-3V or -3V to +3V

C = 200pF to 1000pF

Note 2: C1–C4 = 0.1µF, tested at 3.3V 10%. C1 = 0.047µF, C2–C4 = 0.33µF, tested at 5.0V 10%.

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

__________________________________________Typical Operating Characteristics

= +3.3V, 235kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ, T = +25°C, unless otherwise noted.)

MAX3221/MAX3223

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3221/MAX3223

SUPPLY CURRENT vs. LOAD CAPACITANCE

MAX3221/MAX3223

SLEW RATE

vs. LOAD CAPACITANCE

WHEN TRANSMITTING DATA

MAX3221/3223-03

OUT+

235kbps

-SLEW

+SLEW

120kbps

20kbps

-1

-2

-3

-4

-5

-6

FOR DATA RATES UP TO 235kbps

OUT-

1000

2000

3000

4000

5000

1000

2000

3000 4000

5000

150 500 1000

2000

3000

4000

5000

LOAD CAPACITANCE (pF)

MAX3243

SUPPLY CURRENT vs. LOAD

CAPACITANCE WHEN TRANSMITTING DATA

MAX3243

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3243

SLEW RATE

vs. LOAD CAPACITANCE

7.5

5.0

2.5

235kbps

OUT

120kbps

20kbps

-SLEW

+SLEW

1 TRANSMITTER AT 235kbps

2 TRANSMITTERS AT 30kbps

-2.5

-5.0

-7.5

OUT

ALL OUTPUTS LOADED WITH 3kΩ +C

0.1µF CHARGE-PUMP CAPACITORS

FOR ALL DATA RATES UP TO 235kbps

1000

2000

3000 4000

5000

1000

2000

3000 4000

5000

1000

2000

3000

4000

5000

LOAD CAPACITANCE (pF)

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

______________________________________________________________Pin Description

NAME

FUNCTION

MAX3221

MAX3223

MAX3243

Receiver Enable Control. Drive low for normal operation. Drive high to force

the receiver outputs into a high-Z state.

—

C2+

C2-

Positive terminal of inverting charge-pump capacitor

Negative terminal of inverting charge-pump capacitor

-5.5V generated by the charge pump

RS-232 Receiver Inputs

V-

9, 16

8, 17

12, 13

10, 15

—

4–8

R_IN

9, 10, 11

12, 13, 14

15–19

T_OUT

T_IN

RS-232 Transmitter Outputs

TTL/CMOS Transmitter Inputs

R_OUT

R2OUTB

TTL/CMOS Receiver Outputs

—

Noninverting Receiver Output—active in shutdown

Output of the valid signal detector. Indicates if a valid RS-232 level is pres-

ent on receiver inputs logic “1”.

INVALID

FORCEOFF

FORCEON

Drive low to shut down transmitters and on-board power supply. This over-

rides all automatic circuitry and FORCEON (Table 1).

Drive high to override automatic circuitry keeping transmitters on

(FORCEOFF must be high) (Table 1).

C1-

Negative terminal of the voltage doubler charge-pump capacitor

Ground

GND

+3.0V to +5.5V Supply Voltage

V+

+5.5V generated by the charge pump

Positive terminal of the voltage doubler charge-pump capacitor

C1+

RS-232 Transmitters

_______________Detailed Description

The transmitters are inverting level translators that con-

vert CMOS-logic levels to 5.0V EIA/TIA-232 levels. They

guarantee a 120kbps data rate with worst-case loads of

3kΩ in parallel with 1000pF, providing compatibility with

PC-to-PC communication software (such as Laplink™).

Typically, the MAX3221/MAX3223/MAX3243 can oper-

ate at data rates of 235kbps. Transmitters can be paral-

leled to drive multiple receivers or mice (MAX3243).

Figure 1 shows a complete system connection.

Dual Charge-Pump Voltage Converter

The MAX3221/MAX3223/MAX3243’s internal power

supply consists of a regulated dual charge pump that

provides output voltages of +5.5V (doubling charge

pump) and -5.5V (inverting charge pump), regardless

of the input voltage (V ) over the +3.0V to +5.5V

range. The charge pumps operate in a discontinuous

mode: if the output voltages are less than 5.5V, the

charge pumps are enabled; if the output voltages

exceed 5.5V, the charge pumps are disabled. Each

charge pump requires a flying capacitor (C1, C2) and

a reservoir capacitor (C3, C4) to generate the V+ and

V- supplies.

When FORCEOFF is driven to ground, or the Auto-

Shutdown circuitry senses invalid voltage levels at all

receiver inputs, the transmitters are disabled and the

outputs are forced into a high-impedance state.

LapLink is a trademark of Traveling Software.

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

POWER

MANAGEMENT

UNIT OR

KEYBOARD

CONTROLLER

FORCEOFF

FORCEON

INVALID

PROTECTION

DIODE

RS-232

MAX3243

UART

I/O

GND

SHDN = GND

CHIP

WITH

UART

CPU

RS-232

(a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE

RECEIVER OUTPUT IN SHUTDOWN.

µP

LOGIC

TRANSITION

DETECTOR

Figure 1. Interface Under Control of PMU

MAX3243

PROTECTION

DIODE

R2OUTB

RS-232 Receivers

The MAX3221/MAX3223/MAX3243’s receivers convert

RS-232 signals to CMOS-logic output levels. All

receivers have one inverting three-state output. In shut-

down (FORCEOFF = low) or in AutoShutdown, the

MAX3221/MAX3223’s receivers are active (Table 1).

Driving EN high places the receiver(s) in a high-imped-

ance state. The MAX3243’s receivers are high imped-

ance when the part is shut down.

R2IN

R2OUT

THREE-STATED

UART

T1OUT

T1IN

GND

FORCEOFF = GND

The MAX3243 has an always-active complementary

output (R2OUTB). R2OUTB is an extra output that mon-

itors receiver activity while the other receivers are high

impedance. This allows Ring Indicator to be monitored

without forward biasing other devices connected to the

(b) NEW MAX3243: IN SHUTDOWN, R2OUTB IS USED TO MONITOR EXTERNAL

DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT PATH

THROUGH THE UART'S PROTECTION DIODE.

receiver outputs. This is ideal for systems where V

set to 0V in shutdown to accommodate peripherals,

such as UARTs (Figure 2).

Figure 2. The MAX3243 detects RS-232 activity when the

UART and interface are shut down.

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

FORCEOFF

Table 1a. MAX3221/MAX3223

Enable Control Truth Table

and

+0.3V

TO MAX32_ _

POWER SUPPLY

R_IN

-0.3V

FORCEOFF

T_OUT

R_OUT

Active

AND TRANSMITTERS

30µs

COUNTER

INVALID

High-Z

Active*

High-Z

Active

High-Z

* TRANSMITTERS ARE DISABLED, REDUCING SUPPLY CURRENT TO 1µA IF

ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µs.

Figure 3a. MAX32_ _ Entering 1µA Supply Mode via

AutoShutdown

FORCEOFF

Table 1b. MAX3243

Truth Table

Control

+2.7V

TO MAX32_ _

FORCEOFF

T_OUT

R_OUT

R2OUTB

R_IN

POWER SUPPLY

30µs

COUNTER

INVALID

High-Z

Active*

High-Z

Active*

Active

-2.7V

*Note: If the part is in AutoShutdown mode (FORCEOFF = V

FORCEON = GND), it is shut down if no valid RS-232

levels are present on all receiver inputs.

* TRANSMITTERS ARE ENABLED IF:

ANY RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.

ANY RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30µs.

Figure 3b. MAX32_ _ with Transmitters Enabled Using

AutoShutdown

A 1µA supply current is achieved with Maxim’s new

AutoShutdown feature, which operates when

FORCEON is low and FORCEOFF is high. When the

MAX3221/MAX3223/MAX3243 sense no valid signal

levels on all receiver inputs for 30µs, the on-board

power supply and drivers are shut off, reducing supply

current to 1µA. This occurs if the RS-232 cable is dis-

connected or the connected peripheral transmitters are

turned off. The system turns on again when a valid level

is applied to any RS-232 receiver input. As a result, the

system saves power without changes to the existing

BIOS or operating system. When using AutoShutdown,

the INVALID output is high when the device is on and

low when the device is shut down. Because INVALID

indicates the receiver inputs’ condition, it can be used

in any mode (Figure 3).

FORCEOFF

POWER DOWN

FORCEON

INVALID

INVALID IS AN INTERNALLY GENERATED SIGNAL

THAT IS USED BY THE AUTOSHUTDOWN LOGIC

AND APPEARS AS AN OUTPUT OF THE DEVICE.

POWER DOWN IS ONLY AN INTERNAL SIGNAL.

IT CONTROLS THE OPERATIONAL STATUS OF

THE TRANSMITTERS AND THE POWER SUPPLIES.

Figure 3c. AutoShutdown Logic

POWER

MANAGEMENT

UNIT

MASTER SHDN LINE

Table 2 and Figure 3c summarize the MAX3221/

MAX3223/MAX3243 operating modes. FORCEON and

FORCEOFF override the automatic circuitry and force

the transceiver into its normal operating state or into its

low-power standby state. When neither control is assert-

ed, the IC selects between these states automatically

based on receiver input levels. Figures 3a, 3b, and 5a

depict valid and invalid RS-232 receiver levels.

0.1µF

FORCEOFF FORCEON

MAX3221

MAX3223

MAX3243

A mouse or other system with AutoShutdown may need

time to wake up. Figure 4 shows a circuit that forces the

transmitters on for 100ms, allowing enough time for the

Figure 4. AutoShutdown with Initial Turn-On to Wake Up a

Mouse or Another System

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

Table 2. AutoShutdown Logic

RS-232 SIGNAL

FORCEON

PRESENT AT

FORCEOFF INPUT

INVALID OUTPUT

TRANSCEIVER STATUS

INPUT

RECEIVER INPUT

Yes

Normal Operation

Normal Operation (Forced On)

Shutdown (AutoShutdown)

Shutdown (Forced Off)

Yes

Shutdown (Forced Off)

other system to realize that the MAX3221/MAX3223/

MAX3243 is awake. If the other system outputs valid

RS-232 signals within that time, the RS-232 ports on

both systems remain enabled.

TRANSMITTERS ENABLED, INVALID HIGH

+2.7V

INDETERMINATE

When shut down, the device’s charge pumps are turned

off, V+ decays to V , V- decays to ground, and the

+0.3V

transmitter outputs are disabled (high impedance). The

time required to exit shutdown is typically 100µs (Figure

5b).

AUTOSHUTDOWN, TRANSMITTERS DISABLED,

1µA SUPPLY CURRENT, INVALID LOW

-0.3V

INDETERMINATE

Software-Controlled Shutdown

If direct software control is desired, INVALID can be

used to indicate DTR or Ring Indicator signal. Tie

FORCEOFF and FORCEON together to bypass Auto-

Shutdown so the line acts like a SHDN input.

-2.7V

TRANSMITTERS ENABLED, INVALID HIGH

(a)

___________Applications Information

Capacitor Selection

The capacitor type used for C1–C4 is not critical for

proper operation; either polarized or nonpolarized

capacitors may be used. The charge pump requires

0.1µF capacitors for 3.3V operation. For other supply

voltages, refer to Table 3 for required capacitor values.

Do not use values smaller than those listed in Table 3.

Increasing the capacitor values (e.g., by a factor of 2)

reduces ripple on the transmitter outputs and slightly

reduces power consumption. C2, C3, and C4 can be

increased without changing C1’s value. However, do

not increase C1 without also increasing the values

of C2, C3, and C4 to maintain the proper ratios (C1

to the other capacitors).

RECEIVER

INPUT

INVALID

REGION

VOLTAGE

(V)

INVALID

OUTPUT

(V)

INVH

INVL

V+

When using the minimum required capacitor values,

make sure the capacitor value does not degrade

excessively with temperature. If in doubt, use capaci-

tors with a larger nominal value. The capacitor’s equiva-

lent series resistance (ESR) usually rises at

low temperatures and influences the amount of ripple

on V+ and V-.

V-

(b)

Figure 5. AutoShutdown Trip Levels

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

5V/div

2V/div

OUT

= 3.0V

OUT

-1

-2

-3

-4

-5

-6

OUT

50µs/div

= +3.3V

LOAD CURRENT PER TRANSMITTER (mA)

C1–C4 = 0.1µF

Figure 7a. MAX3243 Transmitter Output Voltage vs. Load

Current per Transmitter

Figure 6. Transmitter Outputs when Exiting Shutdown or

Powering Up

Microsoft. The MAX3243 successfully drove all serial

mice and met their respective current and voltage

requirements. Figure 7a shows the transmitter outputs

under increasing load current. The MAX3243’s switching

regulator ensures the transmitters will supply at least 5V

during worst-case conditions. The AutoShutdown feature

does not work with a mouse, so FORCEOFF and

Power-Supply Decoupling

In most circumstances a 0.1µF bypass capacitor is

adequate. In applications that are sensitive to power-

supply noise, decouple V

to ground with a capacitor

of the same value as the charge-pump capacitor C1.

Connect bypass capacitors as close to the IC as possible.

Transmitter Outputs

when Exiting Shutdown

FORCEON should be connected to V

High Data Rates

The MAX3221/MAX3223/MAX3243 maintain the RS-232

5.0V minimum transmitter output voltage even at high

data rates. Figure 8 shows a transmitter loopback test

circuit. Figure 9 shows a loopback test result at

120kbps, and Figure 10 shows the same test at

235kbps. For Figure 9, all three transmitters were driv-

en simultaneously at 120kbps into RS-232 loads in par-

allel with 1000pF. For Figure 10, a single transmitter

was driven at 235kbps, but all three transmitters were

loaded with an RS-232 receiver in parallel with 1000pF.

Figure 6 shows two transmitter outputs when exiting

shutdown mode. As they become active, the two trans-

mitter outputs are shown going to opposite RS-232

levels. Each transmitter is loaded with 3kΩ in parallel

with 2500pF. The transmitter outputs display no ringing

or undesirable transients as they come out of shut-

down. Note that the transmitters are enabled only when

the magnitude of V- exceeds approximately 3V. Figure

7a shows the MAX3243’s transmitter output voltage

vs. current per transmitter. Figure 7b is a mouse driver

test circuit.

Interconnection with 3V and 5V Logic

The MAX3221/MAX3223/MAX3243 can directly inter-

face with various 5V logic families, including ACT and

HCT CMOS. See Table 4 for more information on possi-

ble combinations of interconnections.

Mouse Driveability (MAX3243)

The MAX3243 has been specifically designed to power

serial mice while operating from low-voltage power sup-

plies. It has been tested with samples of ten major mouse

models from six manufacturers including the leading

three: Logitech (5 models), Mouse Systems, and

_______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

+3.3V

0.1µF

C1+

V+

0.1µF

C1-

C2+

COMPUTER SERIAL PORT

MAX3243

V-

0.1µF

C2-

-V

T1IN

T1OUT

T2IN

T3IN

LOGIC

INPUTS

T2OUT 10

T3OUT

GND

R2OUTB

R1OUT

R2OUT

R1IN

R2IN

LOGIC

OUTPUTS

R3OUT

R4OUT

R3IN

R4IN

R5IN

RS-232

INPUTS

SERIAL

MOUSE

R5OUT

FORCEON

FORCEOFF

INVALID

TO POWER

MANAGEMENT

UNIT

GND

Figure 7b. Mouse Driver Test Circuit

10 ______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

Table 3. Required Capacitor Values

(V)

(µF)

C2, C3, C4

(µF)

0.1µF

3.0 to 3.6

4.5 to 5.5

3.0 to 5.5

0.1

0.047

0.1

0.33

0.47

C1+

V+

V-

C1-

C2+

Table 4. Logic Family Compatibility with

Various Supply Voltages

MAX3221

MAX3223

MAX3243

C2-

SYSTEM

POWER-

SUPPLY

VOLTAGE

(V)

SUPPLY

VOLTAGE

(V)

T_ OUT

T_ IN

COMPATIBILITY

R_ IN

R_ OUT

Compatible with all CMOS

families.

3.3

EN (MAX3221/3)

FORCEOFF

1000pF

Compatible with all TTL and

CMOS-logic families.

GND

Compatible with ACT and

HCT CMOS, and with TTL.

Incompatible with AC, HC,

or CD4000 CMOS.

3.3

Figure 8. Loopback Test Circuit

5V/div

T1IN

5V/div

T1IN

5V/div

T1OUT

R1OUT

5V/div

T1OUT

R1OUT

5µs/div

2µs/div

= +3.3V, 120kbps

= +3.3V, 235kbps

C1–C4 = 0.1µF

Figure 9. Loopback Test Result at 120kbps

Figure 10. Loopback Test Result at 235kbps

______________________________________________________________________________________ 11

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

__________________________________________________Typical Operating Circuits

+3.3V

0.1µF

C1+

V+

V-

0.1µF

C1-

C2+

+3.3V

0.1µF

MAX3221

0.1µF

C1+

C2-

V+

0.1µF

T1IN

0.1µF

T1OUT 13

C1-

C2+

MAX3243

V-

0.1µF

R1OUT

R1IN

C2-

T1IN

T1OUT

TO POWER

MANAGEMENT

UNIT

RS-232

T2IN

T3IN

LOGIC

T2OUT 10

INVALID 10

OUTPUTS

INPUTS

T3OUT

FORCEOFF

FORCEON

GND

R2OUTB

R1OUT

R1IN

+3.3V

0.1µF

R2OUT

R3OUT

R4OUT

R2IN

R3IN

R4IN

R5IN

C1+

V+

V-

0.1µF

C1-

C2+

LOGIC

OUTPUTS

MAX3223

RS-232

INPUTS

0.1µF

C2-

T1IN

T1OUT 17

TTL/CMOS

INPUTS

RS-232

OUTPUTS

T2IN

T2OUT

R5OUT

15 R1OUT

R1IN

FORCEON

FORCEOFF

INVALID

TTL/CMOS

OUTPUTS

RS-232

INPUTS

R2IN

10 R2OUT

TO POWER

MANAGEMENT UNIT

GND

TO POWER

MANAGEMENT

UNIT

INVALID 11

FORCEOFF

FORCEON

GND

12 ______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

______3V-Powered EIA/TIA-232 and EIA/TIA-562 Transceivers from Maxim

GUAR-

ANTEED

DATA

RATE

(kbps)

POWER-

SUPPLY

VOLTAGE

(V)

No. OF

TRANSMITTERS/

RECEIVERS

EIA/TIA-

232

RECEIVERS

ACTIVE IN

SHUTDOWN

PART

FEATURES

OR 562

MAX212

MAX218

3.0 to 3.6

3/5

2/2

120

232

Drives mice

Operates directly from batteries

without a voltage regulator

1.8 to 4.25

MAX562

MAX563

2.7 to 5.25

3.0 to 3.6

3/5

2/2

230

120

562

230kbps guaranteed data rate

0.1µF capacitors

AutoShutdown, complementary

receiver, drives mice, transient

detection

MAX3212

2.7 to 3.6

3/5

235

232

MAX3221

MAX3222

MAX3223

MAX3232

3.0 to 5.5

1/1

2/2

120

232

0.1µF capacitors, 16-pin SSOP

0.1µF capacitors, MAX242 pinout

0.1µF capacitors, AutoShutdown

0.1µF capacitors, MAX232 pinout

N/A

0.1µF capacitors, 2 complemen-

tary receivers, drives mice

MAX3241

3.0 to 5.5

3/5

120

232

0.1µF capacitors, AutoShutdown

complementary receiver,

drives mice

MAX3243

3.0 to 5.5

3/5

120

232

______________________________________________________________________________________ 13

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

__________________________________________________________Pin Configurations

TOP VIEW

C1+

V+

FORCEOFF

16 FORCEOFF

C1+

V+

GND

C1-

T1OUT

R1IN

C1-

C2+

C2-

V-

13 T1OUT

MAX3221

MAX3223

C2+

C2-

FORCEON

R1OUT

FORCEON

T1IN

11 T1IN

10 INVALID

V-

T2OUT

R1IN

R1OUT

R2IN

T2IN

R2OUT

INVALID

SSOP/TSSOP

DIP/SSOP/TSSOP

C2+

C2-

C1+

V+

V-

R1IN

R2IN

R3IN

R4IN

R5IN

T1OUT

T2OUT

T3OUT

T3IN

T2IN

T1IN

GND

C1-

MAX3243

FORCEON

FORCEOFF

INVALID

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

SO/SSOP/TSSOP

___________________Chip Information

MAX3221

TRANSISTOR COUNT: 269

MAX3223

TRANSISTOR COUNT: 339

MAX3243

TRANSISTOR COUNT: 476

14 ______________________________________________________________________________________

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

________________________________________________________Package Information

______________________________________________________________________________________ 15

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

___________________________________________Package Information (continued)

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

Printed USA

is a registered trademark of Maxim Integrated Products.

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MAX3243CAI产品参数

型号:	MAX3243CAI
是否无铅：	含铅
是否Rohs认证：	不符合
生命周期：	Obsolete
零件包装代码：	SSOP
包装说明：	SSOP, SSOP28,.3
针数：	28
Reach Compliance Code：	not_compliant
ECCN代码：	EAR99
HTS代码：	8542.39.00.01
Factory Lead Time：	1 week
风险等级：	5.02
Is Samacsys：	N
其他特性：	5 RECEIVERS ACTIVE UNDER SHUTDOWN; EXTERNAL CHARGE PUMP; AUTO SHUTDOWN
差分输出：	NO
驱动器位数：	3
输入特性：	SCHMITT TRIGGER
接口集成电路类型：	LINE TRANSCEIVER
接口标准：	EIA-232; TIA-232; V.24; V.28
JESD-30 代码：	R-PDSO-G28
JESD-609代码：	e0
长度：	10.2 mm
湿度敏感等级：	1
功能数量：	3
端子数量：	28
最高工作温度：	70 °C
最低工作温度：
最小输出摆幅：	5 V
输出特性：	3-STATE
最大输出低电流：	0.0016 A
输出极性：	INVERTED
封装主体材料：	PLASTIC/EPOXY
封装代码：	SSOP
封装等效代码：	SSOP28,.3
封装形状：	RECTANGULAR
封装形式：	SMALL OUTLINE, SHRINK PITCH
峰值回流温度（摄氏度）：	240
电源：	3.3/5 V
认证状态：	Not Qualified
最大接收延迟：
接收器位数：	5
座面最大高度：	1.99 mm
子类别：	Line Driver or Receivers
最大压摆率：	1 mA
最大供电电压：	5.5 V
最小供电电压：	3 V
标称供电电压：	3.3 V
表面贴装：	YES
技术：	CMOS
温度等级：	COMMERCIAL
端子面层：	Tin/Lead (Sn85Pb15)
端子形式：	GULL WING
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：	20
宽度：	5.29 mm
Base Number Matches：	1

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