CD4541BM CD4541BC Programmable Timer
February 1988
CD4541BM CD4541BC Programmable Timer
General Description
The CD4541B Programmable Timer is designed with a
16-stage binary counter an integrated oscillator for use with
an external capacitor and two resistors output control logic
and a special power-on reset circuit The special features of
the power-on reset circuit are first no additional static pow-
er consumption and second the part functions across the
full voltage range (3V–15V) whether power-on reset is en-
abled or disabled
Timing and the counter are initialized by turning on power if
the power-on reset is enabled When the power is already
on an external reset pulse will also initialize the timing and
counter After either reset is accomplished the oscillator
frequency is determined by the external RC network The
16-stage counter divides the oscillator frequency by any of 4
digitally controlled division ratios
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Features
Y
Y
Y
Y
Y
Available division ratios 2
8
2
10
2
13
or 2
16
Increments on positive edge clock transitions
Built-in low power RC oscillator (
g
2% accuracy over
temperature range and
g
10% supply and
g
3% over
k
10 kHz)
processing
Y
Oscillator frequency range
DC to 100 kHz
Oscillator may be bypassed if external clock is available
(apply external clock to pin 3)
Automatic reset initializes all counters when power
turns on
External master reset totally independent of automatic
reset operation
Operates at 2
n
frequency divider or single transition
timer
Q Q select provides output logic level flexibility
Reset (auto or master) disables oscillator during reset-
ting to provide no active power dissipation
Clock conditioning circuit permits operation with very
slow clock rise and fall times
Wide supply voltage range 3 0V to 15V
High noise immunity 0 45 V
DD
(typ )
5V– 10V– 15V parameter ratings
Symmetrical output characteristics
Maximum input leakage 1
mA
at 15V over full tempera-
ture range
High output drive (pin 8) min one TTL load
Logic Diagram
V
DD
e
Pin 14
V
SS
e
Pin 7
TL F 6001 – 1
Connection Diagram
Dual-In-Line Package
Order Number CD4541B
NC
Not connected
Top View
C
1995 National Semiconductor Corporation
TL F 6001
TL F 6001 – 2
RRD-B30M105 Printed in U S A
NSC [ NATIONAL SEMICONDUCTOR ]
