TPS77601EP, TPS77615EP, TPS77618EP, TPS77625EP

TPS77628EP, TPS77633EP WITH PG OUTPUT

FAST TRANSIENT RESPONSE 500mA LOW DROPOUT VOLTAGE REGULATORS

SGLS176A − AUGUST 2003 − REVISED MARCH 2007

15

POST OFFICE BOX 655303

APPLICATION INFORMATION

external capacitor requirements (continued)

PG

OUT

OUT

7

6

5

IN

IN

EN

GND

3

16

14

13

VI

C1

0.1

µF

PG

VO

10

µF

+

Co

250 k

Ω

Figure 25. Typical Application Circuit (Fixed Versions)

programming the TPS77601 adjustable LDO regulator

The output voltage of the TPS77601 adjustable regulator is programmed using an external resistor divider as shown

in Figure 26. The output voltage is calculated using:

V

O +

V

ref

1

) R1

R2

(1)

Where:

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 = 110 k

Ω to set the divider current at approximately 10 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

4.75 V

UNIT

121

196

226

332

110

110

110

110

k

Ω

k

Ω

k

Ω

k

Ω

OUTPUT VOLTAGE

PROGRAMMING GUIDE

VO

VI

PG

OUT

FB / NC

R1

R2

GND

EN

IN

≤ 0.9 V

≥ 1.7 V

TPS77601

PG Output

0.1

µF

250 k

Ω

Co

Figure 26. TPS77601 Adjustable LDO Regulator Programming