Features
| • | 18-bit stereo DAC |
| • | Multiple distinct output modes |
| • | Mono speaker amplifier |
| • | Stereo headphone amplifier |
| • | Mono earpiece amplifier |
| • | Differential mono analog input |
| • | Independent loudspeaker, headphone and mono earpiece volume controls |
| • | I
2C/SPI (selectable) compatible interface
|
| • | Ultra low shutdown current |
| • | Click and Pop Suppression circuit |
Description The LM4937 is an integrated audio sub-system designed for mono voice, stereo music cell phones connecting to base band processors
with mono differential analog voice paths. Operating on a 3.3V supply, it combines a mono speaker amplifier delivering 520mW
into an 8Ω load, a stereo headphone amplifier delivering 36mW per channel into a 32Ω load, and a mono earpiece amplifier delivering
55mW into a 32Ω load. It integrates the audio amplifiers, volume control, mixer, and power management control all into a single
package. In addition, the LM4937 routes and mixes the single-ended stereo and differential mono inputs into multiple distinct
output modes. The LM4937 features an I
2S serial interface for full range audio and an I
2C or SPI compatible interface for control. The full range music path features an SNR of 85dB with a 192kHz playback.
Boomer audio power amplifiers are designed specifically to provide high quality output power with a minimal amount of external
components.
Key Specification
| ■
POUT, BTL, 8Ω, 3.3V, 1%
|
520mW (typ)
|
| ■
POUT H/P, 32Ω, 3.3V, 1%
|
36mW (typ)
|
| ■
POUT Mono Earpiece, 32Ω, 1%
|
55mW (typ)
|
| ■
Shutdown current
|
0.6µA (typ)
|
| ■
SNR (DAC + Amplifier)
|
85dB (typ)
|
Applications
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