LM4941SDX/NOPB.A中文资料德州仪器数据手册PDF规格书

1FEATURES

2• Improved RF Suppression, By Up to 20dB

Over Previous Designs in Selected

Applications

• Fully Differential Amplification

• Available in Space-Saving DSBGA Package

• Ultra Low Current Shutdown Mode

• Can Drive Capacitive Loads up to 100pF

• Improved Pop & Click Circuitry Eliminates

Noises During Turn-On and Turn-Off

Transitions

• 2.4 - 5.5V Operation

• No Output Coupling Capacitors, Snubber

Networks or Bootstrap Capacitors Required

APPLICATIONS

• Mobile Phones

• PDAs

• Portable Electronic Devices

KEY SPECIFICATIONS

• Improved PSRR at 217Hz 95dB (typ)

• Power Output, VDD = 5.0V, RL = 8Ω, 1% THD+N

1.25W (typ)

• Power Output, VDD = 3.0V, RL = 8Ω, 1% THD+N

430mW (typ)

• Shutdown Current 0.1μA (typ)

DESCRIPTION

The LM4941 is a fully differential audio power

amplifier primarily designed for demanding

applications in mobile phones and other portable

communication device applications. It is capable of

delivering 1.25 watts of continuous average power to

a 8Ω load with less than 1% distortion (THD+N) from

a 5VDC power supply. The LM4941 does not require

output coupling capacitors or bootstrap capacitors,

and therefore is ideally suited for mobile phone and

other small form factor applications where minimal

PCB space is a primary requirement.

The LM4941 also features proprietary internal

circuitry that suppresses the coupling of RF signals

into the chip. This is important because certain types

of RF signals (such as GSM) can couple into audio

amplifiers in such a way that part of the signal is

heard through the speaker. The RF suppression circuitry in the LM4941 makes it well-suited for

portable applications in which strong RF signals

generated by an antenna from or a cellular phone or

other portable electronic device may couple audibly

into the amplifier.

Other features include a low-power consumption

shutdown mode, internal thermal shutdown

protection, and advanced pop & click circuitry.