LM4667 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – Filterless High Efficiency 1.3W Switching Audio Amplifier

LM4667, LM4667MMBD
www.ti.com
SNAS165C – SEPTEMBER 2003 – REVISED MAY 2013
LM4667
Filterless High Efficiency 1.3W Switching Audio
Amplifier
Check for Samples: LM4667, LM4667MMBD
FEATURES
1
•2 No Output Filter Required for Inductive
Transducers
• Selectable Gain of 6dB or 12dB
• Very Fast Turn on Time: 5ms (typ)
• Minimum External Components
• "Click and Pop" Suppression Circuitry
• Micro-Power Shutdown Mode
• Short Circuit Protection
• Space-Saving DSBGA and VSSOP Packages
KEY SPECIFICATIONS
• Efficiency at 3V, 100mW into 8Ω Transducer
74% (typ)
• Efficiency at 3V, 450mW into 8Ω Transducer
84% (typ)
• Efficiency at 5V, 1W into 8Ω Transducer 86%
(typ)
• Total Quiescent Power Supply Current: 3.5mA
(typ)
• Total Shutdown Power Supply Current: 0.01μA
(typ)
• Single Supply Range: 2.7V to 5.5V
APPLICATIONS
• Mobile Phones
• PDAs
• Portable Electronic Devices
DESCRIPTION
The LM4667 is a fully integrated single-supply high
efficiency switching audio amplifier. It features an
innovative modulator that eliminates the LC output
filter used with typical switching amplifiers.
Eliminating the output filter reduces parts count,
simplifies circuit design, and reduces board area. The
LM4667 processes analog inputs with a delta-sigma
modulation technique that lowers output noise and
THD when compared to conventional pulse width
modulators.
The LM4667 is designed to meet the demands of
mobile phones and other portable communication
devices. Operating on a single 3V supply, it is
capable of driving 8Ω transducer loads at a
continuous average output of 450mW with less than
1%THD+N. Its flexible power supply requirements
allow operation from 2.7V to 5.5V.
The LM4667 has high efficiency with an 8Ω
transducer load compared to a typical Class AB
amplifier. With a 3V supply, the IC's efficiency for a
100mW power level is 74%, reaching 84% at 450mW
output power.
The LM4667 features a low-power consumption
shutdown mode. Shutdown may be enabled by
driving the Shutdown pin to a logic low (GND).
The LM4667 has fixed selectable gain of either 6dB
or 12dB. The LM4667 has short circuit protection
against a short from the outputs to V_DD, GND, or
across the outputs.
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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