Philips Semiconductors
24-stage frequency divider and oscillator
Product specification
HEF4521B
MSI
Fig.7 RC oscillator circuit;
f ≈ 2----,--3-----×-----R-1---T---C-----×-----C--- ; RS ≥ 2 RTC, in which:
f in Hz, R in Ω, C in F.
RS
+
RTC
<
V-----I-L----m----a---x
ILI
(maximum input voltage LOW)
(input leakage current)
January 1995
RTC; C = 1 nF; RS ≈ 2 RTC
C; RTC = 56 kΩ; RS = 120 kΩ
Fig.8
Oscillator frequency as a
function of RTC and C;
VDD = 10 V; test circuit is
Fig.7.
9