TCA2002 Datasheet, PDF (12/18 Pages) Tripath Technology Inc. – STEREO CLASS-T™ AUDIO CONTROLLER USING DIGITAL POWER PROCESSING (DPP™) TECHNOLOGY

Tripath Technology, Inc. - Technical Information
It should be noted that only one channel of the modulator is required to create a bridged amplifier.
This is done by reversing the Y1 and Y1B connections to the second FET driver. This creates an out
of phase signal at HB OUTN with respect to HB OUTP.
A bridged amplifier has the advantage of potentially 4 times the output power for a given supply rail.
But the disadvantage is that the required number of FET drivers and MOSFETs per channel
increases by a factor of two.
The modulator feedback resistors are:
RFBA = User specified, typically 1K Ω
R FBB = ^{R FBA * VPP}
(VPP - 2)
R FBC = ^{R FBA * VPP}
2
AV - MODULATOR ≈ ^{R FBC * (R FBA + R FBB )} + 1
R FBA * R FBB
The above equations assume that VPP=|VNN|.
For example, in a system with a SPLIT-SUPPLY, BRIDGED OUTPUT amplifier of VPP_MAX=60V and
VNN_MAX=-60V,
R_FBA = 1kΩ, 1%
R_FBB = 1.071kΩ, use 1.07kΩ, 1%
R_FBC = 15.0kΩ, use 15.0kΩ, 1%
The resultant modulator gain is:
AV - MODULATOR ≈ ^{15.0k Ω * (1.0k Ω + 1.07k Ω )} + 1 = 30.02V/V
1.0k Ω * 1.07k Ω
For SINGLE-SUPPLY, BRIDGED OUTPUT operation:
TCA2002
Y1
Y1B
FET Driver
HIN1
LIN1
HS OUT1
LS OUT1
HIN2
LIN2
HS OUT2
LS OUT2
FBKP1 FBKN1
V5
R _{FBA RFBC}
V5
R _FBB
R _{FBA RFBC}
R _FBB
VPP
MOSFETS
HS GATE1 ^{HB OUTP}
LS GATE1
HS GATE2
LS GATE2 ^{HB OUTN}
Figure 5: Single Supply, Bridged Output (One Channel)
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TCA2002 – KLi/0.95/04.06