PCF1179 View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

PCF1179

4-digit duplex LCD car clock

Philips Electronics 

Philips Semiconductors

4-digit duplex LCD car clock

Product specification

PCF1179C

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

1. Set SEL to VSS and a level of VDD − 5 V to VPP

2. The quartz-frequency deviation ∆f/f is measured and (n) is calculated (see Table 1)

3. A first pulse tE is applied to the DATA input clears the EEPROM to give the highest backplane frequency

4. The calculated pulses (n) are entered in (tH, tL). If the maximum backplane period is reached and an additional pulse

is applied the period will return to the lowest value.

5. The backplane period is controlled and when correct fixed by applying the store pulse tW

6. Release SEL and VPP.

Table 1 Time calibration (∆t = 7.63 µs; SEL at VSS)

OSCILLATOR-FREQUENCY DEVIATION

∆f/f

(× 10−6)

0

+3.8

+7.6

+11.4

.

.

.

+117.8

NUMBER OF PULSES

(n)

0

1

2

3

.

.

.

31

BACKPLANE PERIOD

(ms)

15.625

15.633

15.641

15.648

.

.

.

15.861

1997 Apr 16

7

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