WM8998 datasheet(39/307 Pages) WOLFSON

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Production Data

WM8998

PD, October 2014, Rev 4.0

OTHER FEATURES

The WM8998 incorporates two 1kHz tone generators which can be used for ‘beep’ functions through

any of the audio signal paths. The phase relationship between the two generators is configurable,

providing flexibility in creating differential signals, or for test scenarios.

Two Pulse Width Modulation (PWM) signal generators are incorporated. The duty cycle of each PWM

signal can be modulated by an audio source, or can be set to a fixed value using a control register

setting. The PWM signal generators can be output directly on a GPIO pin.

The WM8998 provides 5 GPIO pins, supporting selectable input/output functions for interfacing,

detection of external hardware, and to provide logic outputs to other devices. Comprehensive Interrupt

(IRQ) functionality is also provided for monitoring internal and external event conditions.

A signal generator for controlling haptics devices is included, compatible with both Eccentric Rotating

Mass (ERM) and Linear Resonant Actuator (LRA) haptic devices. The haptics signal generator is

highly configurable, and can execute programmable drive event profiles, including reverse drive

control. An external vibe actuator can be driven directly by the Class D speaker output.

The WM8998 can be powered from a 1.8V external supply. A separate supply (4.2V) is typically

required for the Class D speaker driver. Integrated Charge Pump and LDO Regulators circuits are

used to generate supply rails for internal functions and to support powering or biasing of external

microphones.

A smart accessory interface is included, supporting most standard 3.5mm accessories. Jack

detection, accessory sensing and impedance measurement is provided, for external accessory and

push-button detection. Accessory detection can be used as a ‘Wake-Up’ trigger from low-power

standby. Microphone activity detection with interrupt is also available.

System clocking can be derived from the MCLK1 or MCLK2 input pins. Alternatively, the SLIMbus

interface, or the audio interfaces (configured in Slave mode), can be used to provide a clock

reference. Two integrated Frequency Locked Loop (FLL) circuits provide support for a wide range of

clocking configurations, including the use of a 32kHz input clock reference.

WM8998 датащи(PDF) 39 Page - Wolfson Microelectronics plc