Datasheet

TPS76515, TPS76518, TPS76525, TPS76527
TPS76528, TPS76530, TPS76533, TPS76550, TPS76501
ULTRA-LOW QUIESCIENT CURRENT 150-mA LOW-DROPOUT VOLTAGE REGULATORS
SLVS236 – AUGUST 1999
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
external capacitor requirements (continued)
PG
OUT
OUT
6
5
4
IN
IN
EN
GND
3
2
7
8
V
I
0.1 µF
PG
V
O
4.7 µF
+
TPS765xx
C
O
1
NC/FB
300 mΩ
250 kΩ
Figure 28. Typical Application Circuit (Fixed Versions)
programming the TPS76501 adjustable LDO regulator
The output voltage of the TPS76501 adjustable regulator is programmed using an external resistor divider as
shown in Figure 29. The output voltage is calculated using:
V
O
V
ref
1
R1
R2
(1)
Where
V
ref
= 1.224 V typ (the internal reference voltage)
Resistors R1 and R2 should be chosen for approximately 7-µA divider current. Lower value resistors can be
used but offer no inherent advantage and waste more power. Higher values should be avoided as leakage
currents at FB increase the output voltage error. The recommended design procedure is to choose
R2 = 169 kΩ to set the divider current at 7 µA and then calculate R1 using:
R1
V
O
V
ref
1 R2
(2)
OUTPUT
VOLTAGE
R1 R2
2.5 V
3.3 V
3.6 V
4.0 V
5.0 V
UNIT
174
287
324
383
523
169
169
169
169
169
kΩ
kΩ
kΩ
kΩ
kΩ
OUTPUT VOLTAGE
PROGRAMMING GUIDE
V
O
V
I
PG
OUT
FB / NC
R1
R2
GND
EN
IN
≤ 0.8 V
≥ 2.0 V
TPS76501
PG
0.1 µF
250 kΩ
300 mΩ
C
O
Figure 29. TPS76501 Adjustable LDO Regulator Programming