Datasheet TLE6280GP

8

2007-07-19

shut down of the driver. This allows continued operation of the motor in case of undervoltage

shut-down for a short period of time.

As soon as the bootstrap voltage recovers, the output stage condition will be aligned to the

input patterns by the next changing input signal at the corresponding input pin.

Diagnosis

The ERR pin is an open collector output and has to be pulled up with external pull-up resis-

tors to 5V. In normal conditions the ERR signal is high. In case of an error the ERR pin is

pulled down. There are 3 different causes for an error signal:

1) Short circuit of an external Mosfet – all external Mosfets are switched off. The driver has

to be reset to start again.

2) Undervoltage warning: at least one of the external capacitors connected to Bxx pins has

a voltage below the warning level.

3) Over-temperature warning: The device works normally but is out of the maximum ratings.

Immediate actions have to be taken to reduce the thermal load. The error flag will be re-

moved when the driver reached temperatures below the over temperature warning level.

dI/dt control

In all high current PWM applications, transient overvoltages and electro-magnetic emmisions

are critical items. The dI/dt regulation of the TLE6280GP helps to reduce transient overvolt-

age as well as electro-magnetic emissions.

Each real bridge configuration has stray inductance in each half-bridge. When the Mosfets in

the bridge are switching and load current is flowing, the stray inductance together with the

dI/dt in the halfbridge causies transient overvoltages. These transient overvoltages can be

feed to the DIDT pin of the gate driver by a high pass filter. Voltages exceeding 2 to 5V or –2

to –5V at this pin will strongly reduce the gate current of the actually switched Mosfet, result-

ing in an increased switching time in the Miller plateau of the Mosfet, and reducing the

switching speed exactly and only in the critical area of the switching process. Through this

regulation over-voltages are reduced and a smoother dI/dt in the bridge is obtained.

For more detailed information please refer to application note.

Fig. 5: Block diagram of ERR functionality

OR

ERR

Iscp (VMFP)

3.3µA

0.3µA

10pF

Temperature

Sensor

I undervoltage

τ approx. 1µs