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Mio336i PDA Maintenance
Mio336i PDA Maintenance
1.3.2.5 Audio Amplifier : TI TPA0253
The TPA0253 is a 1-W mono bridge-tied-load (BTL) amplifier designed to drive speakers with as low as 8
Ω
impedance. The mono signal is created by summing left and right inputs internally. The amplifier can be
reconfigured on-the-fly to drive two stereo single-ended (SE) signals into head phones. This makes the device ideal
for use in small notebook computers, PDAs, digital personal audio players, anyplace a mono speaker and stereo
head phones are required. From a 5V supply, the TPA0253 can delivery 1W of power into a 8
Ω
speaker.
The gain of the input stage is set by the user-selected input resistor and a 50k
Ω
internal feedback resistor (AC=-
RF/RI). The power stage is internally configured with a gain of –1.25V/V in SE mode, and –2.5V/V in BTL mode.
Thus, the overall gain of the amplifier is 62.5k
Ω
/RI in SE mode and 125k
Ω
/RI in BTL mode. The input terminals
are high-impedance CMOS inputs, and can be used as summing nodes. The TPA0253 is available in the 10-pin
thermally-enhanced MSOP package (DGQ) and operates over an ambient temperature range of -40 ºC to 85 ºC .
Description
Ideal for Notebook Computers, PDA , and Other Small Portable Audio Devices
1 W Into 8 ohm from 5-V Supply
0.3 W Into 8 ohm from 3-V Supply
Stereo Head Phone Drive
Mono (BTL) Signal Created by Summing Left and Right Signals Internally
Features :
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