Q67000-A9094 SIEMENS [Siemens Semiconductor Group], Q67000-A9094 Datasheet - Page 5

• Manufacturer Part Number: Q67000-A9094
• Description: Intelligent Double Low-Side Switch 2 x 0.5 A
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

TLE 4214 G
Circuit Description
Input Circuits
The control inputs and the enable input consist of TTL-compatible Schmitt triggers with
hysteresis. Controlled by these stages the buffer amplifiers drive the NPN power
transistors.
Switching Stages
The output stages consist of NPN power transistors with open collectors. Since the
protective circuit allocated to each stage limits the power dissipation, the outputs are
shorted-load protected to the supply voltage throughout the entire operating range.
Positive voltage peaks, which occur during the switching of inductive loads, are limited
by the integrated clamp diodes.
Monitoring and Protective Functions
During the activated status the outputs are monitored for open load, overload, and
shorted load to ground (see table below). In addition, large sections of the circuit are shut
V
down in case of excessive supply voltages
. Linked via OR gate the information
S
regarding these malfunctions effects the status output (open collector, active high). An
internally determined delay time applied to all malfunctions but overvoltage prevents the
output of messages in case of short-term malfunctions. Furthermore, a temperature
protection circuit prevents thermal overload. If overload occurs, the outputs are
protected according to the safe operating area (SOA) mode (see diagram). If voltage
and current are outside the SOA, the outputs oscillate to reduce the power dissipation.
The switching frequency depends on the internal delay time and the external load
(inductances and capacitances). If the frequency is low, the status output may follow the
oscillation. An integrated reverse diode protects the supply voltage
V
against reverse
S
polarities. Similarly the load circuit is protected against reverse polarities within the limits
established by the maximum ratings (no shorted load at the same time!). At supply
voltages below the operating range an undervoltage detector ensures that neither the
status nor the outputs are activated. At supply voltages below the operating range the
output stages are de-activated.
Semiconductor Group
298