LPA8302 Datasheet, PDF (1/14 Pages) Lowpower Semiconductor inc – Unique Modulation Scheme Reduces EMI Emissions

Preliminary Datasheet LPA8302
3-Walts Mono Filter-free Class-D Audio Power Amplifier
General Description
The LPA8302 is a high efficiency, 3W mono class-D
audio power amplifier. A low noise, filterless PWM
architecture eliminates the output filter, reducing
external component count, system cost, and simplifying
design.
Operating in a single 5V supply, LPA8302 is capable of
driving 4Ω speaker load at a continuous average output
of 3W/10% THD+N or 2W/1% THD+N. The LPA8302
has high efficiency with speaker load compared to a
typical class D amplifier. With a 3.6V supply driving an
8Ω speaker, the efficiency for a 400mW power level is
88%.In cellular handsets, the earpiece, speaker phone,
and melody ringer can each be driven by the LPA8302.
The gain of LPA8302 is externally configurable which
allows independent gain control from multiple sources
by summing signals from seperated sources.
The LPA8302 is available in space-saving MSOP-8
packages.
Order Information
LPA8302 □ □ □
F: Pb-Free
Package Type
MS: MSOP-8
Applications
 PMP,PSP, Game, Data-Bank
 Cellular and Smart mobile phone
 PDA/DSC
Features
 Unique Modulation Scheme Reduces EMI
Emissions
 Efficiency at 3.6V With an 8-Ω Speaker:
 − 88% at 400 mW
 − 80% at 100 mW
 Low 2.4-mA Quiescent Current
 0.5-µA Shutdown Current
 2.5V to 5.5V Wide Supply Voltage
 Shutdown Pin has 1.8V Compatible Thresholds
 Optimized PWM Output Stage Eliminates LC
Output Filter
 Improved PSRR (−72 dB) Eliminates Need for a
Voltage Regulator
 Fully Differential Design Reduces RF Rectification
 and Eliminates Bypass Capacitor
 Improved CMRR Eliminates Two Input Coupling
Capacitors
 Internally Generated 250-kHz Switching
Frequency
 Integrated Pop and Click Suppression Circuitry
 MSOP-8 package
 RoHS compliant and 100% lead(Pb)-free
Typical Application Circuit
C1 _R1
IN-
DIFFERENTIAL
INPUT
C1 _R1
IN+
INTERNAL
OSCILLATOR
VDD
TO BATTERY
CS
-
PWM
H-
BRIDGE
VO+
+
VO-
SHUTDOWN
BIAS
CIRCUITRY
GND
FILTER-FREE CLASS D
Marking Information
Please see website.
LPA8302–02 May.-2010
Email: [e-mail]
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