I/O interface description
GVI Product Manual: Frames C, D & E
30
192-300300N1 GVI Frames C, D & E 2019-9
8.3
Key_Input
8.3.1. Function
The KEY_INPUT supplies battery voltage to the motor controller for its logic circuitry. The vehicle start Key
Switch often controls power to the KEY_INPUT, as shown in Figure 10. The KEY_INPUT voltage is
monitored.
8.3.2. Protection
CAUTION
Inrush current – risk of damage to equipment
The Key Switch connected to the KEY_INPUT must handle the short inrush current spike to the
ESD protection capacitors. The current peak is depending on the external circuit and wire.
NOTE
It is recommended that the cable length between KEY_INPUT and battery is less than 10 m.
The KEY_INPUT is protected against reverse polarity with a diode and has a capacitance to B- for ESD
protection and other filtering. This capacitance may give a high current spike at KEY_INPUT depending on
the external circuit.
An internal resistor reduces the inrush current to the DC/DC main capacitor at KEY_INPUT. During the
DC/DC startup, ripple current is drawn from the Key Switch line.
For fuse F2, shown in Figure 10, see chapter 7.8.
8.4
Digital input
8.4.1. Function
The digital inputs are intended for connection to B+ via a switch, as seen in the example in Figure 10.
NOTE
For critical functions where good diagnostic coverage is necessary, it is recommended to use
two digital inputs for plausibility check, for example, use of both normally open and normally
closed switches.
8.4.2. Protection
The Digital Inputs have a capacitor to B- for ESD protection.
