Pin No.

Pin

Name

I/O

Description

24-Pin

CSP

20-Pin

TSSOP

16

14

Vµc

—

Power supply for MICROWIRE circuitry. Must be

≤ V

same supply level as µprocessor or baseband controller to enable programming at

low voltages.

17

15

GND

—

Ground for Aux analog circuitry.

18

16

f

I

Auxiliary prescaler input. Small signal input from the VCO.

19

17

GND

—

Ground for Aux digital, MICROWIRE, FoLD, and oscillator.

20

18

CP

O

Aux internal charge pump output. For connection to a loop filter for driving the

input of an external VCO.

22

19

Vp2

—

Power supply for Aux charge pump. Must be

≥ V

23

20

V

—

Power supply voltage input for Aux analog, Aux digital, FoLD, and oscillator

circuits. Input may range from 2.7V to 5.5V. V

capacitors should be placed as close as possible to this pin and be connected

directly to the ground plane.

1, 9,

13, 21

—

NC

—

No Connect

Block Diagram

DS101026-4

www.national.com

3