TLE7234EM Datasheet, PDF (15/36 Pages) Infineon Technologies AG – SPI Driver for Enhanced Relay Control

SPI Driver for Enhanced Relay Control
TLE7234EM
Power Stages
6
Power Stages
The TLE7234EM is an eight channel high-side and low-side relay switch. The power stages are built by N-channel
vertical power MOSFET transistors. The gates of the high-side switches are controlled by charge pumps.
6.1
Input Circuit
There are three input pins available at TLE7234EM, which can be configured to be used for control of the output
stages. The INXn parameter of the input configuration register provide following possibilities:
• channel is switched off
• channel is switched according to signal level at input pin IN1
• channel is switched according to signal level at input pin IN2 or IN3
• channel is switched on
Figure 4 shows the input circuit of TLE7234EM.
IN1
I_IN1
IN2
I_IN2
IN3
I_IN3
Channel 6
Channel 4
Channel 2
0
Channel 0
1
INX0
0
Channel 7
Channel 5
Channel 3
Channel 1
1
INX1
Figure 4 Input Multiplexer
I nputLogic3in . 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.
6.2
Channels 4 and 5
The TLE7234EM provides two auto-configuring high-side or low-side switches (channels 4 and 5). They adjust the
diagnostic and protective functions according their potentials at drain and source automatically.
In high-side configuration, the load is connected between ground and source of the power transistors (S4 or S5).
The drain of the power transistors (D4 and D5) can be connected to any potential between GND-pin potential and
VBB-pin potential. When the drain is connected to VBB, the channel behave like the other high side channels. The
drain can also be connected to a 5 V power supply and the source pin will be utilized as switched 5 V supply line.
In low-side configuration, the source of the power transistors are to be connected to GND.
The configuration can be chosen for each of these channels individually, so it is feasible to connect one channel
in low-side and the other in high-side configuration.
Data Sheet
16
Rev. 1.0, 2010-02-18