The LM4990 is an 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 an 8? BTL load and 2 watts of continuous average power (NGZ and DGQ only) to a 4? BTL load with less than 1% distortion (THD+N+N) from a 5VDC power supply.

Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. The LM4990 does not require output coupling capacitors or bootstrap capacitors, and therefore is ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement.

The LM4990 features a low-power consumption shutdown mode. To facilitate this, Shutdown may be enabled by either logic high or low depending on mode selection. Driving the shutdown mode pin either high or low enables the shutdown pin to be driven in a likewise manner to enable shutdown.

The LM4990 contains advanced pop & click circuitry which eliminates noise which would otherwise occur during turn-on and turn-off transitions.

The LM4990 is unity-gain stable and can be configured by external gain-setting resistors.

• Available in Space-Saving Packages: WSON, Exposed-DAP MSOP-PowerPAD, VSSOP, and DSBGA
• Ultra Low Current Shutdown Mode
• Improved Click and Pop Circuitry Eliminates Noise During Turn-On and Turn-Off Transitions
• 2.2 - 5.5V Operation
• No Output Coupling Capacitors, Snubber Networks or Bootstrap Capacitors Required
• Unity-Gain Stable
• External Gain Configuration Capability
• User Selectable Shutdown High or Low Logic Level

Key Specifications

• Improved PSRR at 217Hz & 1KHz: 62dB
• Power Output at 5.0V, 1% THD+N,
  • 4? (NGZ and DGQ only): 2W (Typ)
• Power Output at 5.0V, 1% THD+N, 8?: 1.25W (Typ)
• Power Output at 3.0V, 1% THD+N, 4?: 600mW (Typ)
• Power Output at 3.0V, 1% THD+N, 8?: 425mW (Typ)
• Shutdown Current: 0.1µA (Typ)