TECHNICAL DATA
IW4541B
Programmable Timer
High-Performance Silicon-Gate CMOS
The IW4541 programmable timer consists of a 16-stage binary
counter, an oscillator that is controlled by external R-C components (2
resistors and a capacitor), an automatic power-on reset circuit, and
output control logic. The counter increments on positive-edge clock
transitons and can also be reset via the MASTER RESET input.
The output from this timer is the Q or not Q output from the 8th,
10th, 13th, or 16th counter stage. The desired stage is chosen using
time-select inputs A and B. The output is available in either of two
modes selectable via the MODE input, pin 10. When this MODE input
is a logic “1”,the output will be a continuous square wave having a
ORDERING INFORMATION
frequency equal to the oscillator frequency divided by 2
N
. With the
IW4541BN Plastic
MODE input set to logic ”0” and after a MASTER RESET is initiated,
IW4541BD SOIC
the output (assuming Q output has been selected) changes from a low
N-1
to a high state after 2 counts and remains in that state until another
T
A
= -55° to 125° C for all packages
MASTER RESET pulse is applied or the MODE input is set to a logic
“1”.
Timing is initialized by setting the AUTO RESET input (pin 5) to logic “0”and turning power on. If pin 5 is
set to logic “1”, the AUTO RESET circuit is disabled and counting will not start untill after a positive MASTER
RESET pulse is applied and returns to a low level. The AUTO RESET consumes an appreciable amount of
power and should not be used if low-power operation is desired. For reliable automatic power-on reset, V
CC
should be greater than 5V.
•
Operating Voltage Range: 3.0 to 18 V
•
Maximum input current of 1
µA
at 18 V over full package-temperature range; 100 nA at 18 V and 25°C
•
Noise margin (over full package temperature range):
1.0 V min @ 5.0 V supply
2.0 V min @ 10.0 V supply
2.5 V min @ 15.0 V supply
LOGIC DIAGRAM
PIN ASSIGNMENT
NC = NO CONNECTION
PIN 14 =V
CC
PIN 7 = GND
PINS 4,11 = NO CONNECTION
173
IW4541B
MAXIMUM RATINGS
*
Symbol
V
CC
V
IN
V
OUT
I
IN
P
D
P
D
Tstg
T
L
*
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage (Referenced to GND)
DC Output Voltage (Referenced to GND)
DC Input Current, per Pin
Power Dissipation in Still Air, Plastic DIP+
SOIC Package+
Power Dissipation per Output Transistor
Storage Temperature
Lead Temperature, 1 mm from Case for 10 Seconds
(Plastic DIP or SOIC Package)
Value
-0.5 to +20
-0.5 to V
CC
+0.5
-0.5 to V
CC
+0.5
±10
750
500
100
-65 to +150
260
Unit
V
V
V
mA
mW
mW
°C
°C
Maximum Ratings are those values beyond which damage to the device may occur.
Functional operation should be restricted to the Recommended Operating Conditions.
+Derating - Plastic DIP: - 10 mW/°C from 65° to 125°C
SOIC Package: : - 7 mW/°C from 65° to 125°C
RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
IN
, V
OUT
T
A
Parameter
DC Supply Voltage (Referenced to GND)
DC Input Voltage, Output Voltage (Referenced to GND)
Operating Temperature, All Package Types
Min
3.0
0
-55
Max
18
V
CC
+125
Unit
V
V
°C
This device contains protection circuitry to guard against damage due to high static voltages or electric
fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated
voltages to this high-impedance circuit. For proper operation, V
IN
and V
OUT
should be constrained to the range
GND≤(V
IN
or V
OUT
)≤V
CC
.
Unused inputs must always be tied to an appropriate logic voltage level (e.g., either GND or V
CC
).
Unused outputs must be left open.
174
IW4541B
DC ELECTRICAL CHARACTERISTICS
Digital Section
V
CC
Symbol
V
IH
Parameter
Minimum High-Level
Input Voltage
Maximum Low -Level
Input Voltage
Minimum High-Level
Output Voltage
Maximum Low-Level
Output Voltage
Maximum Input
Leakage Current
Maximum Quiescent
Supply Current
(per Package)
Minimum Output Low
(Sink) Current
Test Conditions
V
OUT
=0.5V or V
CC
-0.5V
V
OUT
=1.0V or V
CC
-1.0V
V
OUT
=1.5V or V
CC
-1.5V
V
OUT
=0.5V or V
CC
-0.5V
V
OUT
=1.0V or V
CC
-1.0V
V
OUT
=1.5V or V
CC
-1.5V
V
IN
=GND or V
CC
V
5
10
15
5
10
15
5.0
10
15
5.0
10
15
18
5.0
10
15
20
5.0
10
15
5.0
5.0
10
15
Guaranteed Limit
≥
-55
°C
3.5
7
11
1.5
3
4
4.95
9.95
14.95
0.05
0.05
0.05
±0.1
5
10
20
100
1.9
5
12.6
-6.2
-1.9
-5
-12.6
≤
25
°C
3.5
7
11
1.5
3
4
4.95
9.95
14.95
0.05
0.05
0.05
±0.1
5
10
20
100
1.55
4
10
-5
-1.55
-4
-10
≤
125
°C
3.5
7
11
1.5
3
4
4.95
9.95
14.95
0.05
0.05
0.05
±1.0
150
300
600
3000
1.08
2.8
7.2
mA
-3
-1.08
-2.8
-7.2
Unit
V
V
IL
V
V
OH
V
V
OL
V
IN
=GND or V
CC
V
I
IN
I
CC
V
IN
= GND or V
CC
V
IN
= GND or V
CC
µA
µA
I
OL
V
IN
= GND or V
CC
U
OL
=0.4 V
U
OL
=0.5 V
U
OL
=1.5 V
V
IN
= GND or V
CC
U
OH
=2.5 V
U
OH
=4.6 V
U
OH
=9.5 V
U
OH
=13.5 V
mA
I
OH
Minimum Output High
(Source) Current
175
IW4541B
AC ELECTRICAL CHARACTERISTICS
(C
L
=50pF, R
L
=200kΩ, Input t
r
=t
f
=20 ns)
V
CC
Symbol
f
max
Parameter
Maximum Clock Frequency (Figure 1)
V
5.0
10
15
5.0
10
15
5.0
10
15
5.0
10
15
5.0
10
15
-
1.5
4
6
10.5
3.8
2.9
18
10
7.5
200
100
80
360
180
130
Guaranteed Limit
≥-55°C
25°C
1.5
4
6
10.5
3.8
2.9
18
10
7.5
200
100
80
360
180
130
7.5
≤125°C
0.75
2
3
21
7.6
5.8
36
20
15
400
200
160
720
360
260
pF
ns
Unit
MHz
t
PLH
, t
PHL
Maximum Propagation Delay,
Clock to Q (Figure 1)
(2
8
)
(2 )
t
THL
Maximum Output Transition Time, Any Output
(Figure 1)
Maximum Output Transition Time, Any Output
(Figure 1)
Maximum Input Capacitance
16
ns
t
TLH
C
IN
TIMING REQUIREMENTS
(C
L
=50pF, R
L
=200kΩ, Input t
r
=t
f
=20 ns)
V
CC
Symbol
t
w
Parameter
Minimum Pulse Width, Master Reset or Clock
(Figure 1)
Maximum Rise and Fall Time, Clock
(Figure 1)
5
10
15
5
10
15
Guaranteed Limit
+25° C
900
300
225
Unlimited
-40° C
to +85° C
1800
600
450
Unit
ns
t
r
,t
f
µs
176
IW4541B
Figure 1. Switching Weveforms
FREQUENCY SELECTION TABLE
INPUTS
A
B
L
L
L
H
H
L
H
H
No. of Stages
N
13
10
8
16
Count
2
N
8192
1024
256
65536
PIN
5
6
9
FUNCTION TABLE
STATE
0
Auto Reset On
Master Reset Off
Output Initially
Low After Reset
(Q)
Single Transition
Mode
1
Auto Reset Disable
Master Reset On
Output Initially High
After Reset (not Q)
Recycle Mode
10
EXPANDED LOGIC DIAGRAM
177
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