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IRAUDAMP10 REV
1.1
Over-Current Protection (OCP)
Low-Side Current Sensing
The low-side current sensing feature protects the low side DirectFET from an overload condition
from negative load current by measuring drain-to-source voltage across R
DS(ON)
during its on state.
OCP shuts down the switching operation if the drain-to-source voltage exceeds a preset trip level.
The voltage setting on the OCSET pin programs the threshold for low-side over-current sensing.
When the VS voltage becomes higher than the OCSET voltage during low-side conduction, the
IRS2052 turns the outputs off and pulls CSD down to -VSS.
High-Side Current Sensing
The high-side current sensing protects the high side DirectFET from an overload condition from
positive load current by measuring drain-to-source voltage across R
DS(ON)
during its on state. OCP
shuts down the switching operation if the drain-to-source voltage exceeds a preset trip level.
High-side over-current sensing monitors drain-to-source voltage of the high-side DirectFET during
the on state through the CSH and VS pins. The CSH pin detects the drain voltage with reference
to the VS pin, which is the source of the high-side DirectFET. In contrast to the low-side current
sensing, the threshold of the CSH pin to trigger OC protection is internally fixed at 1.2V. An
external resistive divider R15, R16 and R17 are used to program a threshold as shown in Fig 20.
An external reverse blocking diode D1 is required to block high voltage feeding into the CSH pin
during low-side conduction. By subtracting a forward voltage drop of 0.6V at D1, the minimum
threshold which can be set for the high-side is 0.6V across the drain-to-source.
Over-Voltage Protection (OVP)
OVP is provided externally to the IRS2052M. OVP shuts down the amplifier if the bus voltage
between GND and -B exceeds 51V. The threshold is determined by a Zener diode Z3. OVP
protects the board from harmful excessive supply voltages, such as due to bus pumping at very
low frequency-continuous output in stereo mode.
Under-Voltage Protection (UVP)
UVP is provided externally to the IRS2052M. UVP prevents unwanted audible noise output from
unstable PWM operation during power up and down. UVP shuts down the amplifier if the bus
voltage between GND and -B falls below a voltage set by Zener diode Z4.
Offset Null (DC Offset) Adjustment
The IRAUDAMP10 requires no output-offset adjustment. DC offsets are tested to be less than ±20
mV.
