TS4909 Datasheet, PDF (1/32 Pages) STMicroelectronics – Dual mode low power 150mW stereo headphone amplifier with capacitor-less and single-ended outputs

TS4909
Dual mode low power 150mW stereo headphone amplifier
with capacitor-less and single-ended outputs
Features
■ No output coupling capacitors necessary
■ Pop-and-click noise reduction circuitry
■ Operating from V_CC = 2.2V to 5.5V
■ Standby mode active low
■ Output power:
– 158mW @5V, into 16Ω with 1% THD+N
max (1kHz)
– 52mW @3.0V into 16Ω with 1% THD+N
max (1kHz)
■ Ultra low current consumption: 2.0mA typ.@3V
■ Ultra low standby consumption: 10nA typ.
■ High signal-to-noise ratio: 105 dB typ.@5V
■ High crosstalk immunity: 110dB (F=1kHz) for
single-ended outputs
■ PSRR: 72dB (F=1kHz), inputs grounded, for
phantom ground outputs
■ Low t_WU: 50ms in PHG mode, 100ms in SE mode
■ Available in lead-free DFN10 3x3mm
Applications
■ Headphone amplifier
■ Mobile phone
■ PDA, portable audio player
Description
The TS4909 is a stereo audio amplifier designed
to drive headphones in portable applications.
The integrated phantom ground is a circuit
topology that eliminates the heavy output coupling
capacitors. This is of primary importance in
portable applications where space constraints are
very high. A single-ended configuration is also
available, offering even lower power consumption
because the phantom ground can be switched off.
DFN10 (3x3)
Pin connections (top view)
Vin1 1
Stdby 2
SE/PHG ³
Bypass ⁴
Vin2 ⁵
1 0 Vdd
9 Vout1
8 Vout3
7 _Vout2
6 _Gnd
Functional block diagram
Vdd
SE/PHG
Vin1
Stdby
Bypass
BIAS
Vout1
Vout3
Vin2
Vout2
Gnd
Pop-and-click noise during switch-on and switch-
off phases is eliminated by integrated circuitry.
Specially designed for applications requiring low
power supplies, the TS4909 is capable of
delivering 31mW of continuous average power
into a 32Ω load with less than 1% THD+N from a
3V power supply.
Featuring an active low standby mode, the
TS4909 reduces the supply current to only 10nA
(typ.). The TS4909 is unity gain stable and can be
configured by external gain-setting resistors.
September 2007
Rev 8
1/32
www.st.com
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