TLE7231G Datasheet, PDF (12/30 Pages) Infineon Technologies AG – SPIDER - 4 channel low side driver

SPI Driver for Enhanced Relay Control
SPIDER - TLE7231G
Power Stages
6
Power Stages
The TLE7231G is a four channel low-side relay switch.
The power stages are made of N-channel vertical power MOSFET transistors.
6.1
Input Circuit
The TLE7231G has an input pin, that can be configured to be used for control of the output stages. The INn
parameter of the SPI provide the following operation modes:
• channel is in off mode without diagnosis
(if all channels are programmed to this mode, the device goes into idle mode)
• channel is switched according to signal level at input pin IN
• channel is switched on
• channel is switched off with active diagnosis
Figure 4 shows the input circuit of TLE7231G.
IN
I
IN
0
1
0
IN0
Channel 3
Channel 2
Channel 1
Channel 0
&
D0
Figure 4 Input Multiplexer
InputLogic.emf
The current sink to ground ensures that the channels switch off in case of open input pin. The zener diode protects
the input circuit against ESD pulses. After power-on reset, the device enters idle mode.
6.2
Inductive Output Clamp
When switching off inductive loads, the potential at pin OUT rises to V_DS(CL) potential, because the inductance
intends to continue driving the current. The voltage clamping is necessary to prevent destruction of the device,
see Figure 5 for details. Nevertheless, the maximum allowed load inductance is limited.
Datasheet
12
Rev. 1.0, 2008-02-28