Connection Diagrams

Pin Descriptions

Pin No.

Pin

Name

I/O

Description

24-Pin

CSP

20-Pin

TSSOP

24

1

V

—

Power supply voltage input for RF analog and RF digital circuits. Input may range

from 2.7V to 5.5V. V

close as possible to this pin and be connected directly to the ground plane.

2

2

Vp1

—

Power supply for Main charge pump. Must be

≥ V

33

CP

O

Internal Main charge pump output. For connection to a loop filter for driving the

input of an external VCO.

4

4

GND

—

Ground for Main digital circuitry.

55

f

I

Main prescaler input. Small signal input from the VCO.

66

f

I

Main prescaler complementary input. For single ended operation, a bypass

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

directly to the ground plane.

7

7

GND

—

Ground for Main analog circuitry.

8

8

OSC

in

I

Oscillator input. The input has a V

external CMOS or TTL logic gate.

10

9

GND

—

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

11

10

Fo/LD

O

Multiplexed output of the Main/Aux programmable or reference dividers,

Main/Auxiliary lock detect signals and Fastlock mode. CMOS output

(see

Programmable Modes in the Datasheet).

12

11

Clock

I

High impedance CMOS Clock input. Data for the various counters is clocked in on

the rising edge, into the 22-bit shift register.

14

12

Data

I

Binary serial data input. Data entered MSB first. The last two bits are the control

bits. High impedance CMOS input.

15

13

LE

I

Load enable. High impedance CMOS input. When LE goes HIGH, data stored in

the shift registers is loaded into one of the 4 appropriate latches (control bit

dependent).

TSSOP 20-Pin Package

DS101026-2

Top View

Order Number LMX2370TM, LMX2370TMX,

LMX2371TM, LMX2371TMX,

LMX2372TM or LMX2372TMX

See NS Package Number MTC20

CSP 24-Pin Package

DS101026-3

Top View

Order Number LMX2370SLBX,

LMX2371SLBX or LMX2372SLBX

See NS Package Number SLB24A

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