LT1943EFE Linear Technology, LT1943EFE Datasheet - Page 4

• Manufacturer Part Number: LT1943EFE
• Description: IC REG SW QUAD TFT LCD 28-TSSOP
• Manufacturer: Linear Technology

Specifications of LT1943EFE

• Applications: Converter, TFT, LCD
• Voltage - Input: 4.5 ~ 22 V
• Number Of Outputs: 4
• Voltage - Output: 1.25 ~ 40 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP Exposed Pad, 28-eTSSOP, 28-HTSSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

LT1943
PARAMETER
SWITCH 4 (350mA INVERTER)
FB4 Voltage
FB4 Voltage Line Regulation
FB4 Pin Bias Current
NFB4 Voltage (V
NFB4 Voltage Line Regulation
NFB4 Pin Bias Current
Error Amplifier 4 Voltage Gain
Error Amplifier 4 Transconductance
Switch 4 Current Limit
Switch 4 V
Switch 4 Leakage Current
BIAS Pin Current due to SW4
Maximum Duty Cycle (SW4)
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1943E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization, and correlation
with statistical process controls.
Note 3: The C
the FB threshold offset.
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at T
4
TYPICAL PERFOR A CE CHARACTERISTICS
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
0
Maximum Output Current
for V
T
A
CESAT
= 25°C
LOGIC
T
pin is held low until FB1, FB2, FB3 and FB4 all ramp above
FB4
5
INPUT VOLTAGE (V)
-V
= 3.3V
L1 = 4.7µH
NFB4
)
10
L1 = 3.3µH
15
W
1943 G01
U
20
5
4
3
2
1
0
A
0
SW1 Current Limit vs Duty Cycle
T
= 25°C. RUN-SS, SS-234 = 2.5V unless otherwise noted.
A
CONDITIONS
4.5V < V
(Note 4)
4.5V < V
(Note 5)
∆I = 5µA
I
FB4 = 1.5V
I
SW4
SW4
= 25°C
20
The
= 0.3A
= 0.3A
IN
IN
●
DUTY CYCLE (%)
MINIMUM
< 22V
< 22V
denotes the specifications which apply over the full operating
40
TYPICAL
Note 4: Current flows into FB1, FB2, FB3 and FB4 pins.
Note 5: Current flows out of NFB4 pin.
Note 6: Current limit is guaranteed by design and/or correlation to static
test. Slope compensation reduces current limit at high duty cycle.
Note 7: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the internal power switch.
60
80
1943 G02
100
4.5
4.0
3.5
3.0
2.5
●
●
●
●
●
–50
SW1 Current Limit
1.215
1.205
1.23
1.22
0.35
MIN
84
83
–25
0
TEMPERATURE (°C)
1.245
1.25
0.01
0.01
TYP
100
100
200
450
260
0.5
0.1
15
88
25
50
1.275
1.275
MAX
1.27
1.27
0.03
0.03
600
600
390
0.7
1
75
100
µmhos
UNITS
1943 G03
1943fa
%/V
%/V
V/V
mV
mA
nA
nA
µA
125
%
%
V
V
V
V
A