TLE4211 Datasheet, PDF (5/13 Pages) Siemens Semiconductor Group – Intelligent Double Low-Side Switch 2 x 2 A

TLE 4211
Circuit Description
Input Circuits
The control inputs comprise TTL-compatible Schmitt triggers with hysteresis. Driven by
these stages the inverting buffer amplifiers convert the logic signal for driving the NPN
power transistors.
Switching Stages
The output stages comprise 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 Z-diodes.
Monitoring and Protective Functions
The outputs are monitored for open load, overload, and shorted output to ground (see
table below). In addition, large sections of the circuit are de-activated in case of
excessive supply voltages V_S. Linked via OR gate the information regarding these
malfunctions effects the status output (open collector, active low). 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. An integrated reverse diode protects the supply
voltage V_S against reverse 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.
Status Output (L = Error)
Undervoltage
Operating Range
V_I = L
(active)
V_I = H
(passive)
Normal function
H
H
H
Overload
H
L
H
Open load
H
L
H
Shorted output to ground H
L
L
Overvoltage
L
L
L
L
Semiconductor Group
5