IRS20954STRPBF International Rectifier, IRS20954STRPBF Datasheet - Page 16

• 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

Low-side Over-current Setting
Designing with the same MOSFET as in high-side with R
trip level is given by:
V
Choose R4+R5=10 kΩ for proper loading of VREF pin, thus
Choose R5 = 5.6 kΩ and R4 = 3.9 kΩ from E-12 series.
In general, R
Although this characteristic is preferable from a device protection point of view, these variation needs to be considered as well
as variations of external or internal component values.
Deadtime Generator
The deadtime generator block provides a blanking time between the high-side on and low-side on to avoid a simultaneous on
state causing shoot-through. The IRS20954 has an internal deadtime generation block to reduce the number of external
components in the output stage of a Class D audio amplifier. Selectable deadtime programmed through the DT/SD pin voltage
is an easy and reliable function, which requires only two external resistors. This selectable deadtime way of setting prevents
outside noise from modulating the switching timing, which is critical to the audio performances.
How to Determine Optimal Deadtime
The effective deadtime in an actual application differs from the deadtime specified in this datasheet due to finite switching fall
time, t
switching stage to the starting point of turn-on on the other side as shown in Fig. 15. The fall time of MOSFET gate voltage
must be subtracted from the deadtime value in the datasheet to determine the effective dead time of a Class D audio amplifier.
(Effective deadtime) = (Deadtime in datasheet) – (fall time, t
www.irf.com
=
=
R
OCSET
5
5
3
5
=
8 .
0 .
1 .
V
V
V
k
V
f
OCSET
. The deadtime value in this datasheet is defined as the time period from the starting point of turn-off on one side of the
Ω
REF
⋅
= I
10
Where V
TRIP+
k
⋅
10
Ω
DS(ON)
k
x R
Ω
REF
has a positive temperature coefficient that needs to be considered when the threshold level is being set.
DS(ON)
is the output voltage of VREF pin, 5.1 V typical.
= 30 A x 100 m
Not recommended for new designs.
Please use IRS20957SPBF.
Ω
= 3.0 V
f
)
DS(ON)
of 100 m
Ω
, the OCSET voltage, V
IRS20954SPBF
OCSET
, to set 30 A
16