irs20954s International Rectifier Corp., irs20954s Datasheet - Page 13

• Manufacturer Part Number: irs20954s
• Description: Protected Digital Audio Driver
• Manufacturer: International Rectifier Corp.

For the negative load current, low side over-current sensing monitors over load condition and shutdown the switching operation
if the load current exceeds the preset trip level.
The low side current sensing is based on measurement of V
current value due to overshoot , V
OCSET pin is to program the threshold for low side over-current sensing. The threshold voltage at V
protection is the same as the voltage applied to the OCSET pin to COM. It is recommended to use V
voltage to a resistive divider, R4 and R5, generating a voltage to OCSET for better immunity against V
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Low Side Over-Current Sensing
LEVEL
SHIFT
HV
FLOATING HIGH SIDE
5V REG
DEAD TIME
SD
HIGH
SIDE
CS
REF
OC
S
DETECT
sensing ignores the first 200 ns signal after LO turned on.
DETECT
UV
Figure 12: Bi-Directional Over-Current Protection
UV
UV
OCREF
COM
LEVEL
5.1V
SHIFT
Figure 13: Low-Side Over-Current Sensing
HV
Q
R4
R5
LOW SIDE CS
0.5mA
OCSET
OC Comparator
+
-
IRS20954
DS
VCC
LO
CSH
VB
HO
VS
LO
COM
OCSET
OC
VREF
during the low side MOFET on state. In order to avoid incorrect
R3
VS
LO
Cbs
R2
R5
R4
R1
Dbs
Q2
Q1
D1
+B
-B
OUT
Q2
Q1
+B
Vcc
-B
CC
REF
S
fluctuations.
pin turning on the OC
to supply a reference
IRS20954S
OUT
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