LT1431C Linear Technology, LT1431C Datasheet - Page 9

• Manufacturer Part Number: LT1431C
• Description: Programmable Reference
• Manufacturer: Linear Technology

TYPICAL APPLICATIO S
GND-S
V
RTN
+
V IN
OFF
LT1431
NOTES: UNLESS OTHERWISE SPECIFIED
1
1
2
GND-F
COLL
1. ALL RESISTANCES ARE IN , 0.25W, 5%
2. ALL CAPACITANCES ARE IN F, 50V, 10%
3. SHUTDOWN LOGIC STATE MUST BE DEFINED BY A LOGIC GATE OR BY TYING TO GND
+
10 **
1k
REF
C1
220 F
35V
RUN = 0
SHUTDOWN 3V
5V Power Supply Monitor with 500mV
+
6k*
5k
R3
10k
1N4148
Window and 50mV Hysteresis
D1
BAT85
C2
4.7 F 35V
TANTALUM
470k
R1
GND-S
V
+
LT1431
U
GND-F
D4
BAT85
COLL
High Efficiency Buck Converter E = 85% to 89%
1k
10 **
REF
GND
LT1170
3
V
IN
**SETS HYSTERESIS
5
*DETERMINES WINDOW SIZE
Q1
VN2222LL
R4
100
V = (R – 5)(0.5mA)
V
C
V
1
R2
1k
SW
FB
4k*
5k
2N3904
C3
0.1 F
4
2
“HIGH” FOR
OVER VOLTAGE OR
UNDER VOLTAGE
Q2
0.047 F
R5
680
0.033 F
C5
D2
BAT85
2N3904
C4
LT1431 • TA13
Q3
R8*
24.9k
D3
MBR330
3
4
V +
R
TOP
GND-S
COMP
50 H 3A
5
BOLD LINE INDICATES HIGH CURRENT PATHS
C3, C4, C5 = WIMA-MKS-2
LT1431CN8
L1
2
D3 = MOTORALA-MBR330
6
5
4
3
2
1
0
D1, D2 = PHILIPS-BAT85
VR2
0
C1 = NICHICON-UPL1V221MPH
C6 = NICHICON-UPL1C471MPH6
L1 = COILTRONICS CTX50-3-MP
0.12m
* = 1% FILM RESISTORS
GND-F
COLL
6
ESR
1
1
R
REF
MID
Transfer Function
2
+
8
7
C6
470 F
16V
V
3
IN
4
LT1431
LT1431 • TA14
LT1431 • TA15
5
R6*
23.7k
R7*
24.9k
5V
2.5A
6
9