U6032B_05 Datasheet, PDF (6/12 Pages) ATMEL Corporation – Automotive Toggle Switch IC

4.8 ON, OFF Inputs, Pins 3 and 4
To avoid simultaneous operation of both inputs, pin 3 (ON) and pin 4 (OFF), the use of a
two-way contact with centre-off position with spring returns (also known as rocker-actuated
switch) is recommended.
Pressing the push-button switch (pin 3 ON) leads to an activation of the relay after the debounce
time, t₃, has ellapsed whereas the switching of pin 4 switch correspondingly leads to the
de-energization of the relay. If the relay is not de-energized by the push-button switch, the out-
put remains active.
Combined operation “TOGGLE” and “ON/OFF” is not possible due to the fact that there is only
one debouncing circuit. Debouncing is possible in both modes, i.e., whenever S₁ is ON or OFF.
Figure 4-4 shows the input circuit of U6032B. It has an integrated pull-down resistor (20 kΩ), RF
capacitor (15 pF) and Z-diode (7 V). It reacts to voltages greater than 2 V. The external protec-
tive resistor has a value of 20 kΩ and the push-button switch, S, is connected to the battery as
shown in the diagram.
The contact current, I, is calculated as follows:
I
=
---^V----^B---^a---^t-^t---–----^V----^Z----
R(= 20 kΩ)
where V_Batt = 12 V, V_Z = 7 V
I
=
(_---1_---2_------_----7_---)_----V_--
20 kΩ
≈
0.25 mA
It can be increased by connecting a 5.6 kΩ resistor from the push-button switch to ground as
shown in Figure 4-6 on page 7.
Figure 4-4. Input Circuit
V_Batt
S R ^{Pin 3, 4, 5}
20 kΩ
7V
2V
-
+
20 kΩ
15 pF
Figure 4-5. ON/OFF Function
V_Batt
R_{1 510 Ω}
C₁
R₂
C₂
20 kΩ
S₃
20 kΩ
47 µF/
16 V ₈
7
6
5
U6032B
1
2
3
4
6 U6032B
4771B–AUTO–11/05