RT9187

2

DS9187-09 April 2008

www.richtek.com

Typical Application Circuit

Function Pin Description

Figure 2. Adjustable Operation

Figure 1. Fixed Operation

Note: The value of R2 should be less than 80k to

maintain regulation.

Pin No.

Fixed Output

Voltage

Adjustable

Output Voltage

Pin

Name

Pin Function

1

1

VIN

Supply Input.

2

2

VIN

Supply Input.

3

3

VOUT

Regulator Output.

4

4

VOUT

Regulator Output.

5

--

BP

Noise Reduction. Connecting a 10nF capacitor to GND to reduce

output noise.

--

5

ADJ

If external feedback resistors are applied, the output voltage will be:

) Volts

6

6

GND

Ground

7

7

NC

No Internal Connection.

8

8

EN

Enable Input Logic, Active High. W hen the EN goes to a logic low, the

device is in shutdown mode.

Exposed Pad (9)

NC

No Internal Connection. The exposed pad must be soldered to a

large PCB and connected to GND for maximum power dissipation.

2

1

R

R

2

1

R

R

1

+

V

) Volts

VIN

GND

VOUT

RT9187

C

OUT

2.2uF

2.2uF

BP

10nF

EN

C

IN

C

BP

V

IN

V

OUT

Chip Enable

VIN

GND

VOUT

RT9187

C

OUT

2.2uF

2.2uF

ADJ

EN

C

IN

V

IN

V

OUT

R1

R2

Chip Enable