Datasheet


  
    
SLVS323B − FEBRUARY 2001 − REVISED JANUARY 2007
8
APPLICATION INFORMATION
output voltage programming
The output voltage of the TPS76201 adjustable regulator is programmed using an external resistor divider as
shown in Figure 18. The output voltage is calculated using:
V
O
+ V
ref
ǒ
1 )
R1
R2
Ǔ
(
1)
Where:
V
ref
= 0.6663 V typ (the internal reference voltage)
Resistors R1 and R2 should be chosen for approximately 10-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 = 66.5 kΩ to set the divider current at 10 µA and then calculate R1 using:
R1 +
ǒ
V
O
V
ref
* 1Ǔ R2
(2)
V
O
V
I
OUT
FB
R2
GND
EN
IN
≤0.9 V
≥1.7 V
TPS76201
1 µF
OUTPUT
VOLTAGE
(V)
R1 R2
0.7
0.9
1.2
1.5
1.8
2.5
3.3
3.6
4
5
3.36
23.2
53.6
83.5
113
182
246
294
332
432
66.5
66.5
66.5
66.5
66.5
66.5
66.5
66.5
66.5
66.5
OUTPUT VOLTAGE
PROGRAMMING GUIDE
DIVIDER RESISTANCE
(kΩ)
‡
‡
1% values shown.
3
1
4
2
R1
5
ESR = 0.5 Ω
4.7 µF
Figure 18. TPS76201 Adjustable LDO Regulator Programming
www.ti.com