DS2452 - 2.1 December 1992

SP5024

3-Wire Bus Controlled Synthesiser

The SP5024 is a programming variant of the SP5510

bus format depending on which device is inserted.

The

SP5024, when used with a TV varicap tuner, forms a complete

phase locked loop tuning system. The circuit consists of a

divide-by-8 prescaler with its own preamplifier and a 15 bit

programmable divider controlled by a serially - loaded data

register.

Four open-collector outputs, each independently

programmable, are included. The device has two modes of

operation selected by the 'mode selected input'. In mode 1 the

comparison frequency is 7.8125kHz and the programmable

divider MSB is bypassed; mode 2 comparison frequency is

6.25kHz. The comparison frequencies are both obtained from

a 4MHz crystal controlled on-chip oscillator. The comparator

has a charge pump output with an output amplifier stage

around which feedback may be applied. Only one external

transistor is required for varicap line driving.

FEATURES

TD6381

*

† Normal ESD handling procedures should be observed

APPLICATIONS

Prescaler

Fig. 1 Pin connections – top view

CHARGE PUMP

CRYSTAL

MODE SELECT

DATA

CLOCK

PORT P4

PORT P3

PORT P2

PORT P1

DRIVE OUTPUT

RF INPUT

RF INPUT

NC

NC

LOCK

ENABLE

1

2

3

4

5

6

7

8

9

18

17

16

15

14

13

12

11

10

1

8

CHARGE PUMP

CRYSTAL

MODE SELECT

DATA

CLOCK

PORT P4

PORT P3

PORT P2

MP16

16

9

DRIVE OUTPUT

RF INPUT

RF INPUT

LOCK

ENABLE

PORT P1

DP18

ORDERING INFORMATION

SP5024 DP

-

(18-lead plastic package)

SP5024S MP

-

(16-lead miniature plastic package)