1997 Apr 16

7

Philips Semiconductors

Product specification

4-digit duplex LCD car clock

PCF1178C

The number (n) is stored in a non-volatile memory which is achieved by the following steps (see Fig.6):

2. The quartz-frequency deviation

∆f/f is measured and (n) is calculated (see Table 1)

is applied the period will return to the lowest value.

6. Release SEL and VPP.

Table 1

Time calibration (

OSCILLATOR-FREQUENCY DEVIATION

∆f/f

(

NUMBER OF PULSES

(n)

BACKPLANE PERIOD

(ms)

0

0

15.625

+3.8

1

15.633

+7.6

2

15.641

+11.4

3

15.648

..

.

..

.

..

.

+117.8

31

15.861