U2391B
TELEFUNKEN Semiconductors
Rev. A1, 30-May-96
1 (7)
Quartz Controlled Pulse Generator
Description
The monolithic integrated bipolar circuit, U2391B, is
designed as a quartz controlled pulse generator. The
tristate input enables the selection of different pulse
period durations. The internal switch-on monitoring
achieves the start up of the IC when the power-on occurs.
The output pulse can supply a drive signal upto 150 mA,
which is short circuit protected.
Features
D Standard quartz f
osc
= 32.768 kHz
D Minimum operating voltage 4.5 V/1.5 mA
D Pulse width, t
p
= 31.25 ms
D Power stage with current limitation:
typical 150 mA
D Tristate period selection: 1/36/60 s
D Reset and disable possibility
D Operation with C y 33 pF, as operational time
counter possible
D Minimum dimensions due to SO-case
Application
Operational time counter
Case: SO8
Block Diagram
Selection
logic
36
60
1
Tristate
Pulse former
Programmable
divider
Switch on
monitoring
Divider 2
7
16 Hz
Divider 2
4
Oscillator
1 Hz
Divider 2
4
V
S
= 4.75 to 14 V
Start with V
S
Reset
Tristate
Interrupt
3
1
4
2
2048 Hz
6
5
32768 Hz
7
To test
+
36 s
60 s
1 s
+
0.22 F
Reset
Interrupt
8
390
R
L
10 x V
S
in Ohm
10 F
96 11740
w
m
m
W
Figure 1. Block diagram with external circuit
U2391B
TELEFUNKEN Semiconductors
Rev. A1, 30-May-96
Preliminary Information
2 (7)
Pin Description
Pin
Symbol
Function
1
Period
Period selection input
2
GND
Ground
3
Output
Output control pulse
4
Contr.
Control input
5, 6
Osc.
Quartz-oscillator input
7
Test
Test logic input/output
8
V
S
Supply voltage
1
2
3
4
8
7
6
5
9611805
Period
GND
Output
Contr.
V
S
Test
Osc.
Osc.
Figure 2. Pinning
Description
Pin 1, Period Selection Logic
Period selection at Pin 1 is as follows:
Pin 1 = open,
t = 36 s
Pin 1 = ground
t = 1 s
Pin 1 = V
S
(Pin 8),
t = 60 s
Pin 2, Ground
Pin 3, Output Stage
Output stage, being short circuit protected is limited to a
current value of typical 150 mA. Apart from it, there is a
voltage limitation which controls the power stage at the
rate of V
3
w 28.8 to 32 V and serves as an active Z-diode.
Output pulse width is 31.25 ms when quartz frequency is
32.768 kHz. It is independent of the selected period.
Pin 4, Control Logic
D Counting delay is typ 1.5 s (maximum 8 s) when Pin 4
is open and V
S
is switched on.
D Programmable residual divider t y1 s is reseated if
Pin 4 is connected to Pin 8. This results in an absolute
tolerance, at the start across "Reset/End" to be
v 1 s.
D Clock input to the 2
7
divider is inhibited, if Pin 4 is
connected to the ground (Pin 2). Absolute tolerance
for every interruption is
v 0.488 ms.
D An interruption is ignored (Pin 4 = ) during the out-
put pulse time.
D When Pin 4 is switched to V
S
during the output pulse
time
* this output pulse will be reseated.
Pin 5, 6 Quartz-Oscillator Input
The propagated period time selection is based on circuit
with a low cost clock quartz of 32.768 kHz.
Pin 7, Test Logic, Figure 2, 3
To test the circuit in a reasonable time, it is possible to
control the divider (f
o
= 16 Hz) at Pin 7 as well as to feed
in a higher frequency to the programmed residual counter
(f
i
v 2 kHz
).
Pin 8, Supply Voltage
An operating voltage of 4.5 V is necessary for the func-
tioning of the circuit, although an internal switch-on
monitoring allows it to operate with a voltage of 3.6 V.
This means that there is sufficient reliability for the per-
formance of the circuit.
The circuit is designed for 12 V
" 10% with internal sup-
ply voltage limitation of typical 15 V. In case of higher
voltages there is a need of a series resistance and buffer
capacitance as shown in figure 1.
U2391B
TELEFUNKEN Semiconductors
Rev. A1, 30-May-96
3 (7)
Absolute Maximum Ratings
Reference point Pin 2, unless otherwise specified
Parameters
Symbol
Value
Unit
Supply current
Pin 8
t
v 10 ms
I
S
i
s
30
150
mA
Supply voltage
Pin 8
without series resistance
V
S
13.2
V
Voltages
Selection logic
Pin 1
Control logic
Pin 4
Output stage, without
protection circuit
Pin 3
V
1
V
4
V
3
0 to V
S
0 to V
S
28.8
V
Currents
Test logic
Pin 7
Oscillator
Pin 5, 6
Output stage
t
v 1 ms
Pin 3
I
7
I
osc
I
3
100
100
300
mA
mA
mA
Power dissipation
T
amb
= 45
C
T
amb
= 85
C
P
tot
270
135
mW
Storage temperature range
T
stg
40 to +125
C
Ambient temperature range
T
amb
20 to +100
C
Junction temperature
T
j
125
C
Electrical Characteristics
V
S
= 5 V, Tamb = 25
C, figure 1, reference point Pin 2, unless otherwise specified
Parameters
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
DC supply currents
V
8
= 5 V
Pin 8
V
8
= 12 V
I
S
1.2
1.5
2
mA
Minimum supply voltage
Pin 8
V
S
4.5
V
Supply voltage limitation
I
8
= 3 mA
Pin 8
I
8
= 30 mA
V
S
13.2
15
16.3
17.2
V
Voltage monitoring
Pin 8
Turn-on threshold
V
TON
3.6
V
Turn-off threshold
V
TOFF
2.4
V
Temperature coefficient
TC
0.33
%/K
Selection logic
Pin 1 =
(1 s)
Pin 1 = + (60 s)
I
1
I
1
6
6
mA
Control logic
Pin 4 = 0 V (Interrupt)
Pin 4 = 5 V (Reset)
Reset current
I
4
I
4
I
4
65
45
135
1500
mA
Oscillator
f
osc
= 32768 Hz, C
osc
w 33 pF
Operating current
Pin 5, 6
Iosc
20
mA
Build-up time
t
on
1.5
8
s
U2391B
TELEFUNKEN Semiconductors
Rev. A1, 30-May-96
5 (7)
Applications
8
7
6
5
1
2
3
4
U2391B
47
W
10 F
96 11815
0.22 F
GND
60 s
1 s
36 s
f
osc
= 32768 Hz
R
L
>860
W
1N4148
V
S
= 4.75...14 V
m
m
Figure 5. Standard circuit for V
S
= 4.75 to 14 V, without reset and interruption
Cycle duration selected by Pin 1
8
7
6
5
1
2
3
4
U2391B
68 k
W
10 F
96 11816
0.22 F
f
osc
= 32768 Hz
Reset
V
S
= 19.2...28.8 V
BZX85
C5V1
R
L
>860
W
Interrupt
Operation
1N4148
2.2 k
W
I
s
< 6.7 mA
GND
m
m
Figure 6. V
S
= 24 V
20% with reset and interrupt switch,
Cycle time
t = 60 sec.
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