TLE7238GS

Power Stages

Data Sheet

16

Rev. 1.0, 2008-10-30

6

Power Stages

The TLE7238GS 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 two input pins available at TLE7238GS, 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

•

channel is switched on

Figure 4 shows the input circuit of TLE7238GS.

Figure 4

Input Multiplexer

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 TLE7238GS 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.

Channel 7

Channel 6

Channel 5

Channel 4

Channel 3

Channel 2

Channel 1

IN1

IN2

Channel 0

1

0

INX0

InputLogic.emf