PCF2120_1

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 01 — 5 February 2008

3 of 14

NXP Semiconductors

PCF2120

Quartz oscillator

7.2 Pin description

8.

Functional description

The 32 kHz quartz oscillator is optimized for directly connecting to a 32 kHz tuning fork

quartz crystal. No additional tuning capacitors are required. Laser tuning of the quartz or

quartz selection for matching is used to tune the oscillator if required.

A digital 32 kHz signal is available on pin CLKOUT. The signal on pin CLKOE is used to

gate and synchronize the 32 kHz CLKOUT signal. Pin CLKOUT is a CMOS push-pull

output. If disabled, it goes to LOW level.

Table 3.

Pin description

Symbol

Pin

Pad

Description

HVSON10

Wire bond die

n.c.

1

-

not connected

OSCI

2

1

oscillator input

OSCO

3

2

oscillator output

n.c.

4

-

not connected

5

3

ground

n.c.

6

-

not connected

TEST

7

4

test pin

CLKOUT

8

5

clock output (push-pull)

9

6

supply voltage

CLKOE

10

7

clock output enable input

(1) OSCO-internal 32 kHz signal: internal signal after the Schmitt trigger connected to pin OSCO.

Fig 4.

CLKOUT output signal

OSCO-

internal

32 kHz

001aaf633

(1)

CLKOE

CLKOUT