LT3513
2MHz High Current
5-Output Regulator
for TFT-LCD Panels
FEATURES
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DESCRIPTION
The LT
®
3513 5-output adjustable switching regulator
provides power for large TFT-LCD panels. The 38-pin
5mm
×
7mm QFN device can generate a 3.3V or 5V logic
supply along with the triple output supply required for the
TFT-LCD panel. A lower voltage secondary logic supply
may also be generated with the addition of an external
NPN driven by the internal linear regulator. A step-down
regulator provides a low voltage output, V
LOGIC
, with up
to 1.2A of current while capable of operating from a wide
input range of 4.5V to 30V. A high power step-up con-
verter, a lower power step-up converter and an inverting
converter provide the three independent output voltages:
AV
DD
, V
ON
and V
OFF
required by the LCD panel. A high-side
PNP provides delayed turn-on of the V
ON
signal and can
handle up to 30mA. Protection circuitry ensures that V
ON
is disabled if any of the four outputs are more than 10%
below the programmed voltage.
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
PanelProtect is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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4.5V to 30V Input Voltage Range
Four Integrated Switches: 2.2A Buck, 1.5A Boost,
0.25A Boost, 0.25A Inverter (Guaranteed Minimum
Current Limit)
External NPN LDO Driver
Fixed Frequency, Low Noise Outputs
Inductor Current Sense for Buck
Soft-Start for All Outputs
Externally Programmable V
ON
Delay
Three Integrated Schottky Diodes
PGOOD
Pin for AV
DD
Output Disconnect
PanelProtect
TM
Circuitry Disables V
ON
Upon Fault
Thermally Enhanced 38-Lead 5mm
×
7mm QFN
Package
APPLICATIONS
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Automotive TFT-LCD Displays
Large TFT-LCD Desktop Monitors
Flat Panel Televisions
TYPICAL APPLICATION
V
IN
8V TO 16V
V
OFF
–10V
20mA
2.2μF
69.8k
0.47μF
60.4k
10μH
UVLO LDOPWR V
IN
SW4
D4
NFB4
10k
4.7μH
V
LOGIC
5V
0.5A
0.22μF
SW1
SENSE
+
SENSE
–
FB1
LT3513
V
ON_CLK
V
ON
V
ONSINK
E3
6.8μH
V
LDO
3.3V
0.5A
10μF
10k
BD
FB5
42.2k
V
C1
7.5k
2.7nF
V
C2
4.7k
GND
V
C3
30k
SW3
FB3
V
C4
13k
2.2nF
165k
V
LOGIC
5V
10k
2.2μF
V
ON_CLK
232k
V
ON
22V
20mA
BIAS
BOOST
SW2
FB2
PGOOD
RUN-SS1
RUN-SS2
RUN-SS3/4
C
T
47nF
15nF
15nF
15nF
RUN/SS 2V/DIV
V
LOGIC
5V/DIV
AV
DD
10V/DIV
V
OFF
10V/DIV
10k
10μF
AV
DD
8V
80mA
10μF 178k
V
LOGIC
5V
10μH
53.6k
100k
Start-Up Waveforms
30.1k
22μF
10k
V
E3
20V/DIV
V
ON
20V/DIV
I
IN(AVG)
1A/DIV
0.47μF
5ms/DIV
3513 TA01b
4.7nF 1.5nF
3513fa
1
LINER [ LINEAR TECHNOLOGY ]
