Datasheet

OUTPUT VOLTAGE
PROGRAMMING GUIDE
OUTPUT
VOLTAGE
R1 R2
1.8 V
2.8 V
5.0 V
392 kW
1.07 MW
2.55 MW
806 kW
806 kW
806 kW
V
OUT
V
IN
FB
R1
R2
GND
IN
TPS715A01
0.1 mF
0.47 mF
OUT
R1 +
ǒ
V
OUT
V
REF
* 1
Ǔ
R2
V
OUT
+ V
REF
ǒ
1 )
R1
R2
Ǔ
TPS715Axx
SBVS047F –MAY 2004–REVISED OCTOBER 2012 www.ti.com
Programming the TPS715A01 Adjustable LDO Regulator
The output voltage of the TPS715A01 adjustable regulator is programmed using an external resistor divider as
shown in Figure 15. The output voltage is calculated using Equation 3:
(3)
where:
V
REF
= 1.205V typ (the internal reference voltage)
Resistors R1 and R2 should be chosen for approximately 1.5μA divider current. Lower value resistors can be
used for improved noise performance, but the solution consumes more power. Higher resistor values should be
avoided as leakage current into/out of FB across R1/R2 creates an offset voltage that artificially
increases/decreases the feedback voltage and thus erroneously decreases/increases V
O
. The recommended
design procedure is to choose R2 = 1MΩ to set the divider current at 1.5μA, and then calculate R1 using
Equation 4:
(4)
Figure 15. TPS715A01 Adjustable LDO Regulator Programming
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