April 6, 2015

CONFIDENTIAL ADVANCE INFORMATION Rev. 0.71

ES9023 Datasheet

5

ESS TECHNOLOGY, INC. 237 South Hillview Drive, Milpitas, CA 95035, USA Tel (408) 643-8800 • Fax (408) 643-8801

MUTE_B Pin (Active Low)

This input pin provides the ability to slowly ramp down the audio volume, and then enter low power standby. Release of mute

will cause the ES9023 to emerge from low power mode and then slowly ramp the audio to provide a pop free startup.

MUTE_B

(Internal)

Attenuation

0dB

-



25600 / fs

AOUT

49512 / fs

(Internal)

Power Down

Power up delay

32768 / MCLK

Activation/release of the MUTE_B input pin initiates a sequence of internal events detailed below:



On assertion of the MUTE_B pin:

o

The output signal will ramp to the -

 level. The ramping takes 25600 / fs seconds, where fs = sampling rate in Hz.

o

After the output signal reaches the -

 level, analog section is turned off and the ES9023 enters a low power standby

state.



On release of the MUTE_B pin:

o

The ES9023 emerges from low power standby, starts an internal counter and activates the analog section

o

During the delay counter time, the internal charge pump and Vref stabilize.

o

When the counter reaches 32768 MCLK cycles, the audio signal is applied and the volume is ramped over 49512 / fs

seconds to maximum, where fs = sampling rate in Hz.

p.10) after the power supply and MCLK are stabilized.



This can be realized using a reset IC, an MCU GPIO pin (default to low at power-up and changed to high by software

later), or an RC time delay on this pin.



If MUTE_B pin is released too early, pop noise may occur due to the ramp-up of internal voltage.

AVCC

MCLK

MUTE_B

Assert MUTE_B until t

the power supply and MCLK are

stabilized

Same time as AVCC or later

t

DMUTE