IRAUDAMP5 Datasheet, PDF (12/49 Pages) International Rectifier – 120W x 2 Channel Class D Audio Power Amplifier Using the IRS2092S and IRF6645

.
+B
VAA CSH
GND
VB
IN-
HO
. _{AUDIO_INPUT}
COMP VS
.
CSD VCC
CH1
VSS
LO
R19
VREF COM
CSLO DT
+VCC
R5
IRS2092S
-B
.
System-level View of Class D Controller and Gate Driver IRS2092S
Fig 11
Selectable Dead-Time
The dead time of the IRS2092S is based on the voltage applied to the DT pin. (Fig 12) An
internal comparator determines the programmed dead time by comparing the voltage at the DT
pin with internal reference voltages. An internal resistive voltage divider based on different ratios
of VCC negates the need for a precise reference voltage and sets threshold voltages for each of
the four programmable settings. Shown in the table below are component values for
programmable dead times between 15 and 45 ns. To avoid drift from the input bias current of the
DT pin, a bias current of greater than 0.5mA is suggested for the external resistor divider circuit.
Resistors with up to 5% tolerance can be used.
Selectable Dead-Time
Dead-time mode
Dead time
R5
DT1
~15ns
3.3k
DT2
~25ns
5.6k
DT3
~35ns
8.2k
DT4
~45ns
open
R13
8.2k
4.7k
3.3k
<10k
DT voltage
0.71 x Vcc
0.46 x Vcc
0.29 x Vcc
0 x Vcc
Default
Operational Mode
15nS
Default
25nS
Dead-time
35nS
45nS
Shutdown
0.23xVcc 0.36xVcc 0.57xVcc 0.89xVcc Vcc
VDT
Fig 12 Dead-time Settings vs. V_DT Voltage
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IRAUDAMP5 REV 3.0
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