ES9218PC datasheet(17/101 Pages) ESS

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ES9218P Datasheet

CONFIDENTIAL ADVANCE INFORMATION 1.8

December 6, 2018

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

THD Compensation

THD Compensation minimizes the non-linearity of the DAC output resistors and to a lesser degree the non-linearity of passive components in the

output stage.

Non-linearity of the DAC output resistors can lead to output distortion in two ways:

1. Amplitude modulation of the output current from the DAC

2. Gain modulation of the output stage as the output impedance of the DAC swings with the audio signal

The ES9218P includes models for its output resistors and can compensate for their characteristic curve by finely adjusting the DAC codes for large

and small signal amplitudes.

THD compensation can be enabled via bypass_thd in Register 13: THD Compensation Bypass & Mono Mode (0x0D)

The coefficient for manipulating second harmonic distortion is stored in Register 22-23: THD Compensation C2 (0x16 - 0x17)

The coefficient for manipulating third harmonic distortion is stored in Register 24-25: THD Compensation C3 (0x18 - 0x19)

Left and right channels use the same compensation coefficients unless

enable_seperate_thd_comp in Register 48: Analog Control (0x30) is

used.

ES9218PC Datasheet(PDF) 17 Page - ESS Technology,Inc