BTM7700G

Data Sheet

1

Rev. 1.0, 2007-06-12

4

Circuit Description

4.1

Input Circuit

The control inputs IH1,2 consist of TTL/CMOS compatible Schmitt-Triggers with hysteresis. Buffer amplifiers are

driven by these stages and convert the logic signal into the necessary form for driving the power output stages.

The inputs are protected by ESD clamp-diodes. The inputs IL1 and IL2 are connected to the gates of the standard

N-channel vertical power-MOS-FETs.

4.2

Output Stages

The output stages consist of an low

R

diodes can be used for freewheeling when communicating inductive loads. If the high-side switches are used as

single switches, positive and negative voltage spikes which occur when driving inductive loads are limited by

integrated power clamp diodes.

4.3

Short Circuit Protection

The outputs are protected against short circuit to ground and short circuit over load

An internal OP-Amp controls the Drain-Source-Voltage by comparing the DS-Voltage-Drop with an internal

reference voltage. Above this trip point the OP-Amp reduces the output current depending on the junction

temperature and the drop voltage.

4.4

Overtemperature Protection

The high-side switches also incorporate an over temperature protection circuit with hysteresis which switches off

the output transistors and sets the status output to low.

4.5

Undervoltage Lockout

When

V

transistors are switched off if the supply voltage

V

4.6

Status Flag

The status flag output is an open drain output with zener-diode which requires a pull-up resistor, as shown in the

application circuit in Figure 4 “Application Example BTM7700G” on Page 15. Various errors as listed in the

table “Diagnosis” are reported by switching the open drain output ST to low.