LM48312TLXSLASHNOPB中文资料德州仪器数据手册PDF规格书

1FEATURES

23• Passes FCC Class B Radiated Emissions with

20 Inches of Cable

• E2S System Reduces EMI While Preserving

Audio Quality and Efficiency

• Output Short Circuit Protection with Auto-

Recovery

• No Output Filter Required

• Improved Audio Quality

• Minimum External Components

• Five Logic Selectable Gain Settings (0, 3, 6, 9,

12dB)

• Low Power Shutdown Mode

• Click and Pop Suppression

• Available in Space-Saving DSBGA Package

APPLICATIONS

• Mobile Phones

• PDAs

• Laptops

KEY SPECIFICATIONS

• Efficiency at 3.6V, 400mW into 8Ω, 84% (Typ)

• Efficiency at 5V, 1W into 8Ω, 88% (Typ)

• Quiescent Power Supply Current at 5V, 3.1mA

• Power Output at VDD = 5V, RL = 4Ω

– THD+N ≤ 10%, 2.6W (Typ)

– THD+N ≤ 1%, 2.1W (Typ)

• Power Output at VDD = 5V, RL = 8Ω

– THD+N ≤ 10%, 1.6W (Typ)

– THD+N ≤ 1%, 1.3W (Typ)

• Shutdown Current, 0.01μA (Typ)

DESCRIPTION

The LM48312 is a single supply, high efficiency,

mono, 2.6W, filterless switching audio amplifier. The

LM48312 features TI’s Enhanced Emissions

Suppression (E2S) system, that features a unique

patented ultra low EMI, spread spectrum, PWM

architecture, that significantly reduces RF emissions

while preserving audio quality and efficiency. The E2S

system improves battery life, reduces external

component count, board area consumption, and

system cost, simplifying design.

The LM48312 is designed to meet the demands of

portable multimedia devices. Operating from a single

5V supply, the device is capable of delivering 2.6W of

continuous output power to a 4Ω load with less than

10% THD+N. Flexible power supply requirements

allow operation from 2.4V to 5.5V. The LM48312

features both a spread spectrum modulation scheme,

and an advanced, patented edge rate control (ERC)

architecture that significantly reduces emissions,

while maintaining high quality audio reproduction (THD+N = 0.03%) and high efficiency (η = 88%).

The LM48312 features high efficiency compared to

conventional Class AB amplifiers, and other low EMI

Class D amplifiers. When driving an 8Ω speaker from

a 5V supply, the device operates with 88% efficiency

at PO = 1W. The LM48312 features five gain settings,

selected through a single logic input, further reducing

solution size. A low power shutdown mode reduces

supply current consumption to 0.01μA.

Advanced output short circuit protection with auto-

recovery prevents the device from being damaged

during fault conditions. Superior click and pop

suppression eliminates audible transients on power-

up/down and during shutdown.