TL1963A-XX Datasheet, PDF (15/26 Pages) Texas Instruments – 1.5-A LOW-NOISE FAST-TRANSIENT-RESPONSE LOW-DROPOUT REGULATOR

TL1963A-xx
www.ti.com ........................................................................................................................................................ SLVS719A – JUNE 2008 – REVISED AUGUST 2008
V_IN > 3.7 V
C1
10 µF
R1
0.01k
R2
0.01k
SHDN
IN
OUT
TL1963A-3.3
SHDN SENSE
GND
IN
OUT
TL1963A
SHDN SENSE
GND
3.3 V at 3 A
C2
22 µF
R6
6.65k
R7
4.12k
R3
R4
R5
2.2k 2.2k
1k
+
–
C3
0.01 µF
NOTE: All capacitors are ceramic.
Figure 31. Paralleling Regulators for Higher Output Current
R_P
IN
OUT
TL1963A
V_IN
SHDN SENSE
Load
GND
R_P
Figure 32. Kelvin Sense Connection
Adjustable Operation
The adjustable version of the TL1963A has an output voltage range of 1.21 V to 20 V. The output voltage is set
by the ratio of two external resistors as shown in Figure 33. The device maintains the voltage at the ADJ pin at
1.21 V referenced to ground. The current in R1 is then equal to 1.21 V / R1, and the current in R2 is the current
in R1 plus the ADJ pin bias current. The ADJ pin bias current, 3 µA at 25°C, flows through R2 into the ADJ pin.
The output voltage can be calculated using the formula shown in Figure 33. The value of R1 should be less than
4.17 kΩ to minimize errors in the output voltage caused by the ADJ pin bias current. Note that in shutdown the
output is turned off, and the divider current is zero.
Copyright © 2008, Texas Instruments Incorporated
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