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ES9219 Datasheet

CONFIDENTIAL ADVANCE INFORMATION 1.0.4

February 27, 2020

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

Functional Description – Analog Features

Charge Pump

The ES9219 includes two charge pumps.

The main low noise charge pump uses a 500kHz switching frequency, which is outside the audio band and therefore does not interfere with audio

signals. The chargepump switches are sequence controlled to minimize pops and clicks. This supply requires a 2.2

F (minimum) ceramic flying

capacitor between pins C1 and C2 and a 22

F (recommended) ceramic hold capacitor from PNEG to AGND_CP. See ES9219C Reference

Schematic.

The auxiliary charge pump uses the same switching frequency as the main chargepump, so no intermodulation frequencies are generated. It

requires a 1

F (recommended) ceramic flying capacitor across pins C1_VC and C2_VC and a 1F (recommended) ceramic hold capacitor from

PNEG_VC to AGND_CP. See ES9219C Reference Schematic.

Use capacitors with an Equivalent Series Resistance (ESR) of less than 100mΩ for optimum performance. Low-ESR ceramic capacitors minimize

the output resistance of the main charge pump. For best performance over the extended temperature range select capacitors with a minimum X5R

dielectric, the X7R dielectric is preferred.

Analog Volume Control

ES9219

Analog volume control (AVC) provides improved noise performance as the gain is reduced. The hardware default programmable analog

gain is -24dB with 1dB steps up to 0dB. See Register 3: ANALOG VOLUME CONTROL.

The AVC is forced to minimum gain until the transition to HiFi mode is complete. The ES9219 follows a programmed timing sequence to

enter HiFi mode. Enabling the AVC is one of the last steps in that sequence. This procedure will not change the value of the analog

volume control register.

See Register 32: AMPLIFIER CONFIGURATION.

Compensation Components

For optimum performance, matched feedback capacitors should be installed between OUT_L and INB_L, IN_L and GSN_L, OUT_R and INB_R,

IN_R and GSN_R. These components set the bandwidth of the headphone amplifier. These capacitors should have a low temperature coefficient,

NP0/C0G type are recommended. See ES9219C Reference Schematic

The ES9219 includes internal feedback resistors for reduced part-count. 2.2nF NP0/C0G feedback capacitors are recommended to filter out-of-band

noise. (2.2nF equals 70KHz bandwidth @ 0dB analog gain, 2.0nF equals 80KHz bandwidth, and 1.5nF equals 100KHz bandwidth).

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