OMO ElectronicOMO Electronic
Expand menu
Hello, Sign inMy Account
0 Cart

LT1943EFE#PBF

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20
LT1943
1
1943fa
FEATURES
APPLICATIO S
U
DESCRIPTIO
U
TYPICAL APPLICATIO
U
■
4 Integrated Switches: 2.4A Buck, 2.6A Boost,
0.35A Boost, 0.35A Inverter (Guaranteed Minimum
Current Limit)
■
Fixed Frequency, Low Noise Outputs
■
Soft-Start for all Outputs
■
Externally Programmable V
ON
Delay
■
Integrated Schottky Diode for V
ON
Output
■
PGOOD Pin for AV
DD
Output Disconnect
■
4.5V to 22V Input Voltage Range
■
PanelProtect
TM
Circuitry Disables V
ON
Upon Fault
■
Available in Thermally Enhanced 28-Lead TSSOP
High Current Quad Output
Regulator for TFT LCD Panels
, LTC and LT are registered trademarks of Linear Technology Corporation.
Quad Output TFT-LCD Power Supply
The LT
®
1943 quad output adjustable switching regulator
provides power for large TFT LCD panels. The device,
housed in a low profile 28 pin thermally enhanced TSSOP
package, can generate a 3.3V or 5V logic supply along with
the triple output supply required for the TFT LCD panel.
Operating from an input range of 4.5V to 22V, a step-down
regulator provides a low voltage output V
LOGIC
with up to
2A current. A high-power step-up converter, a lower-
power step-up converter and an inverting converter pro-
vide 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.
All switchers are synchronized to an internal 1.2MHz
clock, allowing the use of low profile inductors and ce-
ramic capacitors throughout. A current mode architecture
provides excellent transient response. For best flexibility,
all outputs are adjustable. Soft-start is included in all four
channels. A PGOOD pin can drive an optional PMOS pass
device to provide output disconnect for the AV
DD
output.
V
C2
V
C3
SW4
NFB4
FB4
BIAS
BOOST
SW1
FB1
V
C1
SW2
FB2
RUN-SS
SS-234
C
T
PGOOD
V
ON
E3
FB3
GND
SGND
LT1943
V
IN
SW3
6.8k
18k
27k
2.2nF2.2nF
680pF
100pF
100pF
100pF
16.2k
10.0k
10.0k
44.2k
274k
10.0k
10pF
10.0k
4.7µH
0.22µF
V
LOGIC
3.3V
2A
10µF
0.47µF
1µF
V
OFF
–5.5V
50mA
10µH
33µH
10µH
10µH
88.7k
10µF
2.2µF
0.47µF
13k
2.2nF
100pF
AV
DD
12.2V
500mA
PGOOD
V
ON
35V
30mA
1943 TA01
2.2µF
V
IN,
8V TO 20V
22µF
0.015µF
0.015µF
0.047µF
V
C4
AV
DD
10V/DIV
RUN-SS
2V/DIV
V
LOGIC
5V/DIV
I
IN(AVG)
1A/DIV
V
OFF
10V/DIV
V
E3
20V/DIV
V
ON
50V/DIV
5ms/DIV
Startup Waveforms
PanelProtect is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
■
Large TFT-LCD Desktop Monitors
■
Flat Panel Televisions
LT1943
2
1943fa
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage ● 4.5 V
Maximum Input Voltage 22 V
Quiescent Current Not Switching 10 14 mA
RUN-SS = SS-234 = 0V 35 45 µA
RUN-SS, SS-234 Pin Current RUN-SS, SS-234 = 0.4V 1.7 µA
RUN-SS, SS-234 Threshold 0.8 V
BIAS Pin Voltage to Begin SS-234 Charge ● 2.4 2.8 3.15 V
BIAS Pin Current BIAS = 3.1V, All Switches Off 10.5 15 mA
FB Threshold Offset to Begin C
T
Charge (Note 3) 90 125 160 mV
C
T
Pin Current Source All FB Pins = 1.5V 16 20 25 µA
C
T
Threshold to Power V
ON
All FB Pins = 1.5V 1.0 1.1 1.2 V
V
ON
Switch Drop V
ON
Current = 30mA 180 240 mV
Maximum V
ON
Current V
E3
= 30V ● 30 60 mA
PGOOD Threshold Offset 90 125 160 mV
PGOOD Sink Current 200 µA
PGOOD Pin Leakage V
PGOOD
= 36V 1 µA
Master Oscillator Frequency 1.1 1.2 1.35 MHz
● 1.0 1.46 MHz
Foldback Switching Frequency All FB Pins = 0V 250 kHz
Frequency Shift Threshold on FB ∆200kHz 0.5 V
V
IN
Voltage .............................................................. 25V
BOOST Voltage ........................................................ 36V
BOOST Voltage Above SW1 ..................................... 25V
BIAS Pin Voltage ..................................................... 18V
SW2, SW4 Pin Voltages .......................................... 40V
SW3 Voltage ............................................................ 40V
FB1, FB2, FB3, FB4 Voltages...................................... 4V
NFB4 Voltage ................................................ +6V, –0.6V
VC1, VC2, VC3, VC4 Pin Voltages .............................. 6V
RUN-SS, SS-234 Pin Voltages................................... 6V
PGOOD Pin Voltage ................................................. 36V
E3 Pin Voltage ......................................................... 38V
V
ON
Voltage ............................................................. 38V
C
T
Pin Voltage ........................................................... 6V
Junction Temperature........................................... 125°C
Operating Temperature Range (Note 2) ...–40°C to 85°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
T
JMAX
= 125°C, θ
JA
= 25°C/W, θ
JC
= 7.5°C/W
LT1943EFE
ABSOLUTE AXI U RATI GS
W
WW
U
PACKAGE/ORDER I FOR ATIO
UUW
(Note 1)
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN-SS, SS-234 = 2.5V unless otherwise noted.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
GND
VC1
VC2
FB1
FB2
FB3
NFB4
FB4
VC3
VC4
SGND
BOOST
SW1
SW1
SW2
SW2
V
ON
C
T
E3
PGOOD
BIAS
SW3
GND
SW4
RUN-SS
SS-234
V
IN
V
IN
FE PACKAGE
28-LEAD PLASTIC TSSOP
EXPOSED PAD (PIN 29) IS GROUND
(MUST BE SOLDERED TO PCB)
29
FE PART MARKING
1943E
LT1943
3
1943fa
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN-SS, SS-234 = 2.5V unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
SWITCH 1 (2.4A BUCK)
FB1 Voltage 1.23 1.25 1.27 V
● 1.22 1.27 V
FB1 Voltage Line Regulation 4.5V < V
IN
< 22V 0.01 0.03 %/V
FB1 Pin Bias Current (Note 4) ● 100 600 nA
Error Amplifier 1 Voltage Gain 200 V/V
Error Amplifier 1 Transconductance ∆I = 5µA 450 µmhos
Switch 1 Current Limit Duty Cycle = 35% (Note 6) ● 2.4 3.2 4.3 A
Switch 1 V
CESAT
I
SW
= 2A 310 470 mV
Switch 1 Leakage Current FB1 = 1.5V 0.1 10 µA
Minimum BOOST Voltage Above SW1 Pin I
SW
= 1.5A (Note 7) 1.8 2.5 V
BOOST Pin Current I
SW
= 1.5A 30 50 mA
Maximum Duty Cycle (SW1) ● 82 92 %
SWITCH 2 (2.6A BOOST)
FB2 Voltage 1.23 1.25 1.27 V
● 1.22 1.27 V
FB2 Voltage Line Regulation 4.5V < V
IN
< 22V 0.01 0.03 %/V
FB2 Pin Bias Current (Note 4) ● 220 1000 nA
Error Amplifier 2 Voltage Gain 200 V/V
Error Amplifier 2 Transconductance ∆I = 5µA 450 µmhos
Switch 2 Current Limit ● 2.6 3.8 4.9 A
Switch 2 V
CESAT
I
SW2
= 2A 360 540 mV
Switch 2 Leakage Current FB2 = 1.5V 0.1 1 µA
BIAS Pin Current I
SW2
= 2A 45 mA
Maximum Duty Cycle (SW2) ● 85 92 %
SWITCH 3 (350mA BOOST)
FB3 Voltage 1.23 1.25 1.27 V
● 1.22 1.27 V
FB3 Voltage Line Regulation 4.5V < V
IN
< 22V 0.01 0.03 %/V
FB3 Pin Bias Current (Note 4) ● 100 600 nA
Error Amplifier 3 Voltage Gain 200 V/V
Error Amplifier 3 Transconductance ∆I = 5µA 450 µmhos
Switch 3 Current Limit ● 0.35 0.5 0.7 A
Switch 3 V
CESAT
I
SW3
= 0.2A 180 280 mV
Switch 3 Leakage Current FB3 = 1.5V 0.1 1 µA
BIAS Pin Current I
SW3
= 0.2A 14 mA
Maximum Duty Cycle (SW3) 84 88 %
● 83 %
Schottky Diode Drop I = 170mA 700 mV
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P20

LT1943EFE#PBF

Mfr. #:
Buy LT1943EFE#PBF
Manufacturer:
Analog Devices / Linear Technology
Description:
Switching Voltage Regulators Hi C 4x Out Reg for TFT LCD Panels
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet