PCF1175CT Philips Semiconductors, PCF1175CT Datasheet - Page 4

• Manufacturer Part Number: PCF1175CT
• Description: 4-digit duplex LCD car clock
• Manufacturer: Philips Semiconductors

Philips Semiconductors
FUNCTIONAL DESCRIPTION AND TESTING
Outputs
The circuit outputs 1 : 2 multiplexed data (duplex) to the
LCD. Generation of BP1 and BP2 (three-level backplane
signals) and the output signals are shown in Fig.4.
1997 Apr 16
4-digit duplex LCD car clock
TIME
TIME
AM
PM
Fig.3 Typical displays.
PM
a. 12-hour mode.
b. 24-hour mode.
E1
(b)
(a)
G1
A1
D1
B1
C1
Fig.2 Segment designation of LCD.
MSA994
F2
E2
MSA993
G2
A2
D2
4
B2
C2
The average voltages across the segments are:
1. V
2. V
SEGMENT
P1 (P3)
P2 (P4)
OFF
OFF
ON(RMS)
OFF(RMS)
ON
ON
1
Fig.4 Backplane and output signals.
F3
E3
MSB226
= 0.79 V
= 0.35 V
SEGMENT
BP1
BP2
OFF
OFF
ON
ON
2
G3
D3
A3
DD
DD
V DD /2
V DD /2
.
V DD
V DD
V DD
V DD
V DD
V DD
B3
C3
0
0
0
0
0
0
F4
E4
G4
Product specification
A4
D4
15.625 ms
PCF1175C
MSA992
B4
C4