AN279 Datasheet, PDF (1/5 Pages) Silicon Laboratories – ESTIMATING PERIOD JITTER FROM PHASE NOISE

AN279
Application note
Short-circuit protection on the L6201, L6202 and the L6203
By Giuseppe Scrocchi and Thomas Hopkins
With devices like the L6201, L6202 or L6203 driving external loads you can often have
short- circuits.
A short-circuit can occur for many reasons: a short on the load, a mistake during the
connection of the wires between the device and the load (i.e. L6203 driving a motor), an
accidental short between the wires and so on.
The outputs of these devices are not protected against the short-circuit and if a short
occurs, the current flowing through the outputs can destroy the device.
To avoid this risk, additional a circuitry may be added to protect the device. To have a total
protection, we must consider three types of short-circuit:
■ output to output short-circuit
■ output to supply voltage short-circuit
■ output to ground short-circuit
The first step is to sense the short-circuit current. In output to output short-circuit (Figure 1)
or output to supply (Figure 2) short-circuit, the sensing resistor (R_SL) already used to set the
current flowing in the load during the normal operation, may also be used for short-circuit
sensing.
Figure 1. Short-circuit across output
Figure 2. Short-circuit from output to supply
September 2012
Doc ID 1702 Rev 2
1/5
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