LM48820 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – Ground-Referenced, Ultra Low Noise, Fixed Gain, 95mW Stereo Headphone Amplifier

LM48820
www.ti.com
SNAS370B – MAY 2007 – REVISED MAY 2013
LM48820
Ground-Referenced, Ultra Low Noise, Fixed
Gain, 95mW Stereo Headphone Amplifier
Check for Samples: LM48820
FEATURES
1
•2 Available in Space Saving 0.4mm Pitch
DSBGA Package
• Fixed Logic Levels
• Ground Referenced Outputs
• High PSRR
• Ultra Low Current Shutdown Mode
• Improved Pop and Click Circuitry Eliminates
Noises During Turn-On and Turn-Off
Transitions
• No Output Coupling Capacitors, Snubber
Networks, Bootstrap Capacitors, or Gain-
Setting Resistors Required
• Shutdown Either Channel Independently
• Soft Start Feature Reduces Start up Transient
Current
APPLICATIONS
• Mobile Phones
• MP3 Players
• PDAs
• Portable electronic devices
• Notebook PCs
KEY SPECIFICATIONS
• Improved PSRR at 217Hz: 80dB (typ)
• Power Output at VDD = 3V, RL = 16Ω, THD+N =
1%: 95mW (typ)
• Shutdown Current: 0.05μA (typ)
• Internal Fixed Gain: 1.5V/V (typ)
• Wide Operating Voltage Range: 1.6V to 4.5V
DESCRIPTION
The LM48820 is a ground referenced, fixed-gain
audio power amplifier capable of delivering 95mW of
continuous average power into a 16Ω single-ended
load, with less than 1% THD+N from a 3V power
supply.
The LM48820 features a new circuit technology that
utilizes a charge pump to generate a negative
reference voltage. This allows the outputs to be
biased about ground, thereby eliminating output-
coupling capacitors typically used with normal single-
ended loads.
Boomer audio power amplifiers were designed
specifically to provide high quality output power with a
minimal number of external components. The
LM48820 does not require output coupling capacitors
or bootstrap capacitors, and therefore is ideally suited
for mobile phone and other portable applications.
The LM48820 features a low-power consumption
shutdown mode selectable for each channel and a
soft start function that reduces start-up current
transients. Additionally, the LM48820 features an
internal thermal shutdown protection mechanism.
The LM48820 contains advanced pop and click
circuitry that eliminates noises which would otherwise
occur during turn-on and turn-off transitions.
The LM48820 has an internal fixed gain of 1.5V/V.
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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