Philips Semiconductors
4-digit static LCD car clock
LCD voltage (see Fig.5)
The adjustable voltage regulator controls the supply
voltage (see Section “LCD voltage programming”) in
relation to temperature for good contrast, for example
when VDD = 4.5 V at +25 °C, then:
VDD = 3 to 4 V at +85 °C.
VDD = 5 to 6 V at −40 °C.
Product specification
PCF1174C
−8
V SS
(V)
−6
(3)
(2)
−4
(1)
MSA995
−2
0
40
0
40
80 T ( o C) 120
(1) Programmed to 4.0 V at 25 °C (value within the specified operating range).
(2) Programmed to 4.5 V at 25 °C (value within the specified operating range).
(3) Programmed to 5.0 V at 25 °C (value within the specified operating range).
Fig.5 Regulated voltage as a function of temperature (typical).
1997 Apr 16
5