U6032B Datasheet, PDF (6/12 Pages) ATMEL Corporation – AUTOMOTIVE TOGGLE SWITCH IC

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-actu-
ated 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-but-
ton switch, the output 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 6 shows the input circuit of U6032B. It has an integrated pull-down resistor
(20 kW), RF capacitor (15 pF) and Z-diode (7 V). It reacts to voltages greater than 2 V.
The external protective resistor has a value of 20 kW 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 kW )
where V_Batt = 12 V, V_Z = 7 V
I = -⁽--¹--₂-²--₀---^---_k--⁷--_W-⁾----^V-- » 0.25 mA
It can be increased by connecting a 5.6 kW resistor from the push-button switch to
ground as shown in Figure 8 on page 7.
Figure 6. Input Circuit
V_Batt
S R ^{Pin 3, 4, 5}
20 kΩ
7V
2V
-
+
20 kΩ
15 pF
Figure 7. 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
4771A–AUTO–11/03