YDA137
D- 2
STEREO 5W DIGITAL AUDIO POWER AMPLIFIER
■Overview
YDA137 (D-2) is a high efficient digital audio power amplifier IC that operates on a single 5V power supply.
With YDA137 in BTL connection, an audio power amplifier with a maximum output of 5W (RL=2Ω)×2ch can be
configured with one chip.
YDA137 converts an input analog data into a digital pulse by the digital modulation circuit in the IC and outputs a high
current digital pulse from the output buffer circuit. This digital pulse signal is converted into an audio signal by an
external low-pass filter and is output to the speaker.
Low-distortion rate characteristics and high S/N ratio are realized as a digital amplifier among same class, by adopting
Yamaha’s unique modulation system.
In addition, class AB headphone amplifier with output of 20mW (RL=16Ω)×2ch is embedded and switching between
digital amplifier output and headphone amplifier output can be done by the control of terminal termination.
YDA137 has the over-current protection function for speaker terminals, the high-temperature protection function for IC,
and the pop noise rejection function.
IC operation can be restricted by the two control signals of /SLEEP and /MUTE. /SLEEP signal can stop all functions and
decrease the consumption power to a minimum. In addition, /MUTE signal can pull-down the output buffer (hereinafter,
described as WL) and make the output mute.
■Features
・High Output Power
5.0 W ＠ VDD=5.0V, RL=2Ω, THD+N<10%
3.7 W ＠ VDD=5.0V, RL=3Ω, THD+N<10%
3.0 W ＠ VDD=5.0V, RL=4Ω, THD+N<10%
・High Efficient Operation
75 % ＠ VDD=5.0V, RL=2Ω, Po=5W
80 % ＠ VDD=5.0V, RL=3Ω, Po=3W
・Low Distortion Rate (THD+N)
0.03 % ＠ 1kHz, RL=2Ω, Po=2.5W
0.02 % ＠ 1kHz, RL=3Ω, Po=1.5W
・High S/N Ratio
105dB ＠VDD=5.0V, input sensitivity 1.0Vrms,
RL=2Ω, Po=5W
98dB ＠VDD=5.0V, input sensitivity 150mVrms,
RL=2Ω, Po=5W
・IC Low Consumption Current
25 mA ＠ VDD=5.0V, no signal (no filter)
10 mA ＠ VDD=5.0V, at mute
1 µA ＠ VDD=5.0V, at sleep
・CS(Channel Separation)
80dB ＠ 1kHz
・Class AB headphone amp. is embedded.
20mW ＠ VDD=5.0V, RL=16Ω, THD+N<1.0%
・Arbitral gain setting with external resistor is possible.
・Sleep function by /SLEEP terminal
・Output mute function by /MUTE terminal
・Output Over-Current Protection Function
(Ground short-circuit/Load short-circuit)
・Over-Temperature Protection Function
・Auto Resume Function from Over-Current,
High-Temperature Protection.
・Monaural Function by /MONO terminal
・Pop Noise Rejection Function at power-up or
power-cutoff.
・Analog input / BTL(Bridge-Tied Load) output
・28pin plastic TSSOP
pin lead plating with Pd-free (YDA137-AZ)
YDA137 CATALOG
CATALOG No.:LSI-4DA137A30
2005.1
