Philips Semiconductors

Product data

PCK12429

25–400 MHz differential PECL clock generator

2002 Jun 03

4

32-Pin LQFP

24

23

22

21

20

19

18

17

N/C

N[1]

N[0]

M[8]

M[7]

M[6]

M[5]

M[4]

1

2

3

4

5

6

7

8

32-LEAD LQFP

SW01012

S_CLOCK

S_DATA

S_LOAD

N/C

N/C

XTAL1

PIN DESCRIPTION

SYMBOL

FUNCTION

XTAL1, XTAL2

These pins form an oscillator when connected to an external series-resonant crystal.

S_LOAD (Int. pulldown)

This pin loads the configuration latches with the contents of the shift registers. The latches will be

transparent when this signal is HIGH, thus the data must be stable on the HIGH-to-LOW transition

of S_LOAD for proper operation.

S_DATA (Int. pulldown)

This pin acts as the data input to the serial configuration shift registers.

S_CLOCK (Int. pulldown)

This pin serves to clock the serial configuration shift registers. Data from S_DATA is sampled on the

rising edge.

P_LOAD (Int. pullup)

This pin loads the configuration latches with the contents of the parallel inputs. The latches will be

transparent when this signal is LOW, thus the parallel data must be stable on the LOW-to-HIGH

transition of P_LOAD for proper operation.

M[8:0] (Int. pullup)

These pins are used to configure the PLL loop divider. They are sampled on the LOW-to-HIGH

transition of P_LOAD, M[8] is the MSB, M[0] is the LSB.

N[1:0] (Int. pullup)

These pins are used to configure the output divider modulus. They are sampled on the

LOW-to-HIGH transition of P_LOAD.

OE (Int. pullup)

Active HIGH Output Enable. The Enable is synchronous to eliminate possibility of runt pulse

These differential positive-referenced ECL signals (PECL) are the output of the synthesizer.

TEST

The function of this output is determined by the serial configuration bits T[2:0].

This is the positive supply for the internal logic and the output buffer of the chip, and is connected to

This is the positive supply for the PLL, and should be as noise-free as possible for low-jitter

GND

These pins are the negative supply for the chip and are normally all connected to ground.