Tr i p ath Technol ogy, I n c. - Techni cal In fo rma t io n

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TK2150 – Rev. 1.0/12.02

The MOSFET drivers in the TP2150 are operated from voltages obtained from VN10 and

LO1COM for the low-side driver, and VBOOT1 and HO1COM for the high-side driver. VN10 must

be a regulated 10V above VNN.

N-Channel MOSFETs are used for both the top and bottom of the half bridge. The gate resistors,

Circuit Board Layout

The TK2150 is a power (high current) amplifier that operates at relatively high switching

frequencies. The output of the amplifier switches between VPP and VNN at high speeds while

driving large currents. This high-frequency digital signal is passed through an LC low-pass filter

to recover the amplified audio signal. Since the amplifier must drive the inductive LC output filter

and speaker loads, the amplifier outputs can be pulled above the supply voltage and below

ground by the energy in the output inductance. To avoid subjecting the TK2150 to potentially

damaging voltage stress, it is critical to have a good printed circuit board layout. It is

recommended that Tripath’s layout and application circuit be used for all applications and only be

deviated from after careful analysis of the effects of any changes. Please refer to the TK2150

evaluation board document, RB-TK2150, available on the Tripath website, at www.tripath.com.

The trace that connects the source of the top side output MOSFET to the drain of the bottom side

output MOSFET is very important. This connection should be as wide as possible and as short

as possible. Also a jumper wire of 16 gauge or more can by used in parallel with the trace to

reduce any trace resistance or inductance. Any resistance or inductance on this trace can cause

the switching output to over/undershoot potentially causing damage to both the TP2150 and the

output MOSFETs.

The following components are important to place near either their associated TK2150 or output

MOSFET pins. The recommendations are ranked in order of layout importance, either for proper

device operation or performance considerations.

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and will serve to reduce spikes across the supply rails. Please note that both mosfet

should be at least 150V as this capacitor is exposed to the full supply range, VPP-VNN.

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lowers the output switching frequency by delaying the feedback signals. In addition,

frequency difference greater than 40kHz. This minimizes in-band audio noise. Locate

these capacitors as close to their respective TC2001 pin as possible.

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output MOSFET from output over/undershoots. The over/undershoots are very high

ineffective.

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TC2001 as possible. Make sure that the routing of the high voltage feedback lines is

kept far away from the input op amps or significant noise coupling may occur. It is best

to shield the high voltage feedback lines by using a ground plane around these traces

as well as the input section. The feedback and feedback ground traces should be

routed together in parallel.

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high currents are present on these supplies.