AN2621 Datasheet, PDF (1/5 Pages) STMicroelectronics – TS488/9 low power stereo headphone amplifier

AN2621
Application note
TS488/9 low power stereo headphone amplifier
evaluation board user guidelines
Introduction
This application note concerns the evaluation board DEMOTS488/9, designed to evaluate
the TS488 or TS489 pop-free 120mW stereo headphone amplifier.
In this document, you will find:
■ a brief description of the TS488/9 low power stereo audio amplifier
■ a description of the evaluation board and all of its components
■ the layout of the evaluation board
About the TS488, TS489
The TS488/9 is an enhancement of TS486/487 that eliminates pop & click noise. It is a dual
audio power amplifier capable of driving, in single-ended mode, either a 16Ω or a 32Ω stereo
headset.
It delivers up to 31mW per channel (into 16Ω loads) of continuous average power with 0.1%
THD+N in the audio bandwidth from a 2.5V power supply.
An externally-controlled standby mode reduces the supply current to 10nA (typical). The
TS488/9 is unity gain stable and is configured by external gain-setting resistors.
Key features of the TS488/9 include:
■ Pop & click noise protection circuitry
■ Operating range from V_CC = 2.2V to 5.5V
■ Standby mode active low (TS488) or high (TS489)
■ Output power:
– 120mW @5V, into 16Ω with 0.1% THD+N max (1kHz)
– 55mW @3.3V, into 16Ω with 0.1% THD+N max (1kHz)
■ Low current consumption: 2.7mA max @5V
■ Ultra low standby current consumption: 10nA typical
■ High signal-to-noise ratio
■ High crosstalk immunity: 102dB (F = 1kHz)
■ PSRR: 70dB typ. (F = 1kHz), inputs grounded @5V
■ Unity-gain stable
■ Short-circuit protection circuitry
■ Available in lead-free MiniSO-8 and DFN8 2mm x 2mm
For complete information about the TS488/9, refer to the datasheet.
September 2007
Rev 1
1/5
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