ST AN1766 APPLICATION NOTE

Application note

TS4990 low voltage audio power amplifier

Evaluation board user guidelines

TS4990 features

■ TS4990 low voltage audio power amplifier with active low standby mode

■ Operating from V

■ 1.2W output power @ V

■ Ultra low power consumption in standby mode (10nA)

■ 62dB PSRR @ 217Hz in grounded mode (Av=2V/V)

■ Near zero pop & click

■ Ultra low distortion (0.1%)

■ Module gain set at 2V/V

■ Thermal and short circuit protection

Description

=2.2V to 5.5V

CC

CC

=5V, THD=1%, F=1kHz, with 8Ω load

AN1766

The DEMO TS4990 is an evaluation board designed for the TS4990 low power audio
amplifier. The micropackage DFN8 (dual flat non leaded 8 pins) allows space saving and
good thermal dissipation.

The BTL gain is set at 2V/V and can be ad apted if necessary with a modificati on of R1 or R2
values.

On the board, R3 and C3 component locations are empty to allow you to modify the input
configuration from single ended to differential. For differential mode, R4 must be modified.

The C1 component location is also empty so that you can add a low pass filter if required.
More information about component calculations is available in the TS4990 datasheet.

November 2006 Rev 3 1/5

www.st.com

Connector configuration AN1766

Connector configuration

Caution: When you apply power supply through Cn1, DO NOT invert the polarity because it would

destroy the amplifier U1.

Connector Description

Cn1 Pow er connector (V

and GND). Power supply voltage from 2.2V to 5.5V.

CC

Cn2 and Cn3 Input signal connector (GND and active input signal).
Cn4 Output signal connector (V

Standby control connector (V

Cn5

and standby puts U1 in operation mode. A short-circuit between GND and

and V

out1

, standby, GND). A short-circuit between VCC

CC

out2

).

Standby puts U1 in standby mode.

Figure 1. Schematic diagram

2/5