PCF1172CT PHILIPS [NXP Semiconductors], PCF1172CT Datasheet - Page 4

• Manufacturer Part Number: PCF1172CT
• Description: 31/2-digit LCD car clock
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
OPERATIONAL INPUTS
Operational inputs S1, S2 and S3 have an internal pull-up
resistor to facilitate use of external single-pole,
single-throw switches. A specific debounce circuit is
integrated as protection against contact debounce and
parasitic voltages.
In the description below, an arrangement as shown in
Fig.5 is assumed and S1, S2 and S3 refer to the external
switches rather than the corresponding inputs.
Set hours, switch S1
Closure of S1 increments the hours according to the
correction mode selected by S6 (see Chapter “Input
options”).
1997 Apr 16
3
1
/
2
-digit LCD car clock
AM
PM
TIME
Fig.3 Display mode (12-hour with AM/PM annunciator).
AM
C1
B1
Fig.2 Segment designation of LCD.
F2
E2
G2
D2
A2
C2
B2
4
Set minutes/reset seconds, switch S2
When S2 is closed, the minute setting is corrected
according to the correction mode determined by S6 (see
Chapter “Input options”).
The seconds counter is reset to zero each time S2 is
closed, and begins running each time S2 is opened.
Segment test/reset, switches S1 and S2
If S1 and S2 are closed simultaneously all LCD segments
are switched on. When the switches are released, the
clock starts at 1 : 00.
P1 (P3)
P2 (P4)
E3
F3
A3
G3
D3
C3
B3
F4
E4
MSA990
G4
D4
A4
Product specification
MSA989
PCF1172C
C4
B4