irs20955 International Rectifier Corp., irs20955 Datasheet - Page 9

• Manufacturer Part Number: irs20955
• Description: Protected Digital Audio Driver
• Manufacturer: International Rectifier Corp.

Functional Description
Floating PWM Input
The IRS20955S accepts floating inputs, enabling
easy half-bridge implementation. V
refer to V
directly feed into IN while referencing V
typically the midpoint between the positive and
negative
configuration.
The IRS20955S also accepts a non-floating input
when V
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Figure 5. Floating PWM Input Structure
Floating Bias
0V – 200V
SS
SS
is tied to COM.
DC
. As a result, the PWM input signal can
COM
VDD
CSD
VSS
IN
IRS20955
bus
Floating Input Isolation
voltages
LEVEL
Figure 6. Over-Current Protection Timing Chart
SHIFT
HV
in
DD
PROTECTION
a
, CSD and IN
SS
half-bridge
, which is
Over-Current Protection (OCP)
The IRS20955S features over-current protection to
protect the power MOSFETs during abnormal load
conditions. The IRS20955S engages a sequence of
events when it detects the over-current condition
during high-side or low-side turn on.
As soon as either the high-side or low-side current
sensing block detects over-current:
As long as the over-current condition exists, the IC
will repeat the over-current protection sequence.
1. The OC Latch (OCL) flips logic states and
2. The CSD pin starts discharging the external
3. When V
4. The CSD pin starts charging the external
5. When V
shutdowns the outputs LO and HO.
capacitor C
below the lower threshold V
signal from COMP2 resets OCL.
capacitor C
V
resumes operation.
th1
, the logic on COMP1 flips and the IC
CSD
CSD
t
t
.
.
, the voltage across C
goes above the upper threshold
IRS20955(S)PbF
th2
, an output
9
t
, falls