u6044b ETC-unknow, u6044b Datasheet - Page 3

• Manufacturer Part Number: u6044b
• Description: Radiator Controlled Timer
• Manufacturer: ETC-unknow

Oscillator, Pin 6
Oscillator frequency, f, is determined mainly by
R
whereas the integrated resistance (2 k
discharge time. For the stability of the oscillator frequency,
it is recommended to select R
resistance (2 k
the tolerances of the integrated resistance are considerably
greater than the external resistance value.
Oscillator frequency, f, is calculated as follows:
where
t
t
a 1
a 1
a 1
Debounce time, t
oscillator frequency, f, as follows:
Table 1 shows relationships between t
frequencies from 1 Hz to 20 kHz.
Output, Pin 2
Output Pin 2 is an open collector Darlington circuit with
integrated 23-V Z-diode for limitation of the inductive
cut–off pulse of the relay coil. The maximum static
collector current must not exceed 300 mA and the
saturation voltage is typically 1.1 V @ 200 mA.
The output stage can be activated
D
D
Interference voltages and load dump
The IC supply is protected by R
Z-diode, while the inputs are protected by a series resistor,
integrated Z-diode and RF-capacitor (refer to Figure 3).
The relay control output is protected via the integrated
23-V Z-diode in the case of short interference peaks. It is
switched to conductive condition for a battery voltage of
greater than approx. 40 V in the case of load dump. The
TELEFUNKEN Semiconductors
1
2
Rev. A1: 12.12.1994
2
= charge time =
= discharge time =
C
= 0.746 and
and
= 0.833 and
directly with the AC input independent of the ignition
input and S
during the delay time which is started by the ignition
input with the S
2
-circuit. Resistance, R
t
t
a 2
3
d
+
+
f
are constants and has
+
6
73728
t
@
th
W
1
a 2
a 2
)
1
f
), because the temperature response and
1
input
3
= 1.284 when C
a 1
= 1.551 when C
, and the delay time, t
th
t
@
2
@
1
a 2
input
f
R
@
2
@
2 k
C
2
2
W
, determines the charge time,
2
@
C
much greater than internal
2
1
2
2
, C
= 10 nF to 4700 nF
= 470 pF to 10 nF
W
1
, and an integrated
) is responsible for
3
, t
d
, depend on the
d
, C
2
, R
2
and
output transistor is dimensioned so that it can withstand the
current produced.
Power-on reset
When the operating voltage is switched on, an internal
power-on reset pulse (POR) is generated which sets the
logic of the circuits to a defined initial condition. The relay
control output is disabled.
Input stages
Figure 3a shows the internal input circuit of ignition
(Pin 3). It has an integrated pull-down resistor (20 k
RF-capacitor (15 pF) and 7-V Z-diode. It reacts to voltages
greater than 2 V.
The thermal switch input, S
only needs an external protection resistor. The air
conditioning input, AC, and the signal input, ignition, are
not debounced and external R/C filters are recommended
to prevent the integrated circuit from unintentional
activation by transients.
The ignition input is switched to V
inputs are switched to GND and need pull up resistors
externally (figure 3b).
The detection threshold voltage of all three input stages is
typically 2 V.
Ignition input (terminal 15) is not debounced. Debouncing
can be achieved by external circuit (R
Pin 3 (see figures 1 and 5).
Ignition
Terminal 15
Pin 4, 5
Figure 3a Input circuit for ignition (Pin 3)
Figure 3b Input circuit Pin 4 and Pin 5
20 k
100 nF
W
Pin 3
V
th,
7 V
S
is internally debounced and
(Pin 8)
U 6044 B
15 pF
Batt
3
15 pF
,C
, the S
+
–
3
) connected to
94 8815
2 V
20 k
th
and AC
+
–
94 8813
W
W),
3