R2A20101BM/NP

REJ03D0790-0300 Rev.3.00 May 14, 2008

Page 3 of 9

Pin Arrangement

A5

A1

A3

E5

E1

E3

C5

C1

B2

B4

51

32

4

D2

D4

F2

F4

A

E

C

B

D

F

C3

R2A20101BM

(CSP-15)

(Bottom view)

8

9

10

11

19

R2A20101NP

(QFN-24)

(Bottom view)

5432

24

23

22

21

20

1

6

14

15

16

17

18

13

12

7

Pin Description

Pin No.

R2A20101BM

(CSP-15)

R2A20101NP

(QFN-24)

Pin Name

Pin Function

A1, A3, A5

15, 16, 17

PGND

Power ground

B2, B4

11, 20

LX

Inductor connection node

C1, C3, C5

10, 21

VIN

Power supply voltage input

D4

22

ON/

OFF

Output on/off control input

D2

9

CRFB

CR feedback input

E5

23

PWGD

Power good monitor output

E1

8

VFB

Feedback voltage input

F4

2

EAO

Error amplifier output (for current share)

E3

5

VREF

Vout control voltage input

F2

4

AGND

Analog ground (IC chip ground voltage)

Note:

Please apply solder to pins 1, 3, 6, 7, 12, 13, 14, 18, 19, and 24 even though they are NC pins.

Solder on the underside pads improves heat-radiation characteristics.