IRS20954STRPBF International Rectifier, IRS20954STRPBF Datasheet - Page 17

• Manufacturer Part Number: IRS20954STRPBF
• Description: IC DVR DGTL AUDIO PROT 16-SOIC
• Manufacturer: International Rectifier
• Type: MOSFET Driverr

Specifications of IRS20954STRPBF

• Applications: Amplifiers, Receivers
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A longer dead time period is required for a MOSFET with a larger gate charge value because of the longer t
effective deadtime setting is always beneficial to achieve better linearity in the Class D switching stage. However, the likelihood
of shoot-through current increases with narrower deadtime settings in mass production. Negative values of effective deadtime
may cause excessive heat dissipation in the MOSFETs, potentially leading to serious damage. To calculate the optimal
deadtime in a given application, the fall time tf for both output voltages, HO and LO, in the actual circuit needs to be measured.
In addition, the effective deadtime can also vary with temperature and device parameter variations. Therefore, a minimum
effective deadtime of 10 ns is recommended to avoid shoot-through current over the range of operating temperatures and
supply voltages.
Programming Deadtime
DT pin provides a function setting deadtime. The IRS20954 determines its deadtime based on the voltage applied to the DT pin.
An internal comparator translates which pre-determined deadtime is being used by comparing internal reference voltages.
Threshold voltages for each mode are set internally by a resistive voltage divider off V
absolute voltage to set the mode. The relationship between the operation mode and the voltage at DT pin is illustrated in the
Fig. 16 below.
www.irf.com
.
Not recommended for new designs.
15nS
25nS
35nS
45nS
Dead- time
Please use IRS20957SPBF.
Figure 16: Deadtime Settings vs. V
HO (or LO)
LO (or HO)
0.23 xVcc
Figure 15: Effective Deadtime
90%
10%
0.36 xVcc
tf
Dead-
time
Effective dead-time
0.57 xVcc
DT
10%
Voltage
CC
, negating the need of using a precise
Vcc
IRS20954SPBF
V
DT
f
. A shorter
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