
U6046B / U6047B
TELEFUNKEN Semiconductors
Rev. A2, 03-Feb-97
3 (11)
Oscillator, Pin 6
Oscillator frequency, f, is determined mainly by the
R
2
C
2
circuit. Resistance, R
2
, determines the charge time,
and the integrated resistance (2 k ) is responsible for dis-
charge time. For the stability of the oscillator frequency,
it is recommended that the selected R
2
value be much
greater than the internal resistance (2 k ) because the
temperature response and the tolerances of the integrated
resistance are considerably greater than the external
resistance value.
Oscillator frequency, f, is calculated as follows:
f
1
t
1
t
2
where
t
1
= charge time =
1
t
2
= discharge time =
2
R
2
C
2
2 k
C
2
1
and
2
are constants as such
1
= 0.833 and
2
= 1.551 when C
2
= 470 pF to 10 nF
1
= 0.746 and
2
= 1.284 when C
2
= 10 nF to 4700 nF
The debounce time, t
3
, and the delay time, t
d
, depend on
the oscillator frequency, f, as follows:
t
3
6
1
f
t
d
73728
1
f
Table 1 shows relationships between t
3
, t
d
, C
2
, R
2
and
frequencies from 1 Hz to 20 kHz.
Relay Control Output
The relay control output is an open collector Darlington
circuit with an 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 saturation voltage is typically 1.1 V @ 200 mA.
Interference Voltages and Load-Dump
The lC supply is protected by R
1
, C
1
, and an integrated
Z-diode, while the inputs are protected by a series resistor,
integrated Z-diode and RF capacitor (refer to Figures 10
and 11).
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
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 output is disabled.
47 F/
16 V
C
1
510
R
2
C
2
V
Batt
1
2
6
5
8
7
3
4
94 8751
20 k
S1
U6046B
R
1
Figure 5.
TOGGLE function U6046B
47 F/
16 V
C
1
R
1
510
R
2
C
2
V
Batt
1
2
6
5
8
7
3
4
94 8752
2 k
S1
U6047B
Figure 6.
TOGGLE function U6047B