TA0105A Datasheet, PDF (27/29 Pages) Tripath Technology Inc. – STEREO CLASS-T DIGITAL AUDIO AMPLIFIER DRIVER USING DIGITAL POWER PROCESSING (DPPTM ) TECHNOLOGY

Tripath Technology, Inc. - Technical Information
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V5
VNN
3.57M
1.21M
1000pF
TA0105A
38 _VLOW
AGND
V5
VPP
1.33M
1.33M
1000pF
37 _VHIGH
AGND
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Figure 8: Voltage Supply Sensing Structure for TA0104A Emulation
- Add the 1000pF capacitors (C_VB). These capacitors stabilize the sensing circuit resulting in
repeatable voltage trip points. Please note that the return point is to analog ground (pin 1 on
the TA0105A).
- The values of C_FB should be reevaluated. It is likely that the value for channel 2 will need to be
increased as compared to the previous TA0104A design due to slightly different internal
compensation. For best performance make sure that the difference between the two channels
idle switching frequency is greater than 40kHz. In addition, make sure that the idle switching
frequency of both channels is maintained above 575kHz.
- Other components such as output filter values, MOSFET type, gate resistor values, etc. should
remain unchanged from the TA0104A design. Typical output filter components are 11uH,
0.22uF along with appropriate zobel compensation (15ohm/5W and 0.22uF). Typical MOSFET
choice is the STW34NB20 or similar along with 5.6ohm gate resistors. The Application/Test
Circuit provided earlier in this data sheet is intended for +/-185V (maximum), “high impedance”
operation, not for driving low impedance loads like those typically used in TA0104A
applications.
- It is highly recommended that the supply bypassing (C_HBR) and diode (D_O) clamping structure
shown in the Application/Test circuit is utilized for new designs. This structure has been shown
to minimize output node transients during high current events and will result in a more robust
design.
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TA0105A – RW/ Rev. 2.2/05.05