Tripath Technology, Inc. – Preliminary Technical Information

7

TPS4100 – KL/Rev. 2.5/02.05

Components Description

Supply decoupling for the power supply pins. For optimum performance, these

components should be located close to the TAA4100 and returned to their

respective “ground” as shown in the Application/Test Circuit.

Supply decoupling for the high current full-bridge supply pins. These components

must be located as close to the power supply pins as possible to minimize output

ringing which causes power supply overshoot. By reducing overshoot, these

capacitors maximize the TAA4100 reliability. These capacitors should have good

high frequency performance including low ESR and low ESL.

Supply decoupling for the charge pump (high side gate drive supply) circuitry.

These components must be located as close to the TAA4100 as possible.

Output diode, which is used to minimize output overshoots/undershoots on the

output nodes These devices clamp the output to the low impedance node formed

Circuit. The “high side” diode protects the bottom side device from excessive

BVDSS due to overshoots on the output node. The “bottom side” diode protects the

device must be an ultra fast rectifier capable of sustaining the entire supply range

and high peak currents.

frequencies. Use a high quality film capacitor capable of sustaining the ripple current

caused by the switching outputs.

under both no load conditions or with real world loads, including loudspeakers,

which usually exhibit a rising impedance with increasing frequency. Depending on

be increased.

switching waveform into an audio signal. Forms a second order filter with a cutoff

frequency of

)

C

L

2

(

1

O

TOT

C

f

π

=

and a quality factor of

TOT

TOT

R

Q

C

L

2

O

=

waveform into an audio signal. Use a high quality film capacitor capable of

sustaining the ripple current caused by the switching outputs.

Differential Output Capacitor. Differential noise decoupling for reduction of

conducted emissions. Must be located near chassis exit point for maximum

effectiveness.

Pull-up resistor for the open drain FAULT pin output. Recommended resistor value

is 51k

Ω.

Charge pump diodes. Used to generate floating supply for driving high side

circuitry. Small signal diodes such as 1N4148 are recommended for these

components.