CS47L15 datasheet(29/279 Pages) CIRRUS

29 / 279 page

DS1137F2

CS47L15

4.2 Input Signal Path

The CS47L15 supports up to 15 GPIO pins, offering a range of input/output functions for interfacing, for detection of

external hardware, and for providing logic outputs to other devices. The GPIOs are multiplexed with other functions.

Comprehensive interrupt 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) haptics 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.

A smart accessory interface is included, supporting most standard 3.5-mm 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 audio interfaces (configured in

Slave Mode), can be used to provide a clock reference. The CS47L15 also provides two integrated FLL circuits for clock

frequency conversion and stability. The flexible clocking architecture supports low-power always-on operation, with

reference frequencies down to 32 kHz. Seamless switching between clock sources is supported; free-running FLL modes

are also available.

The CS47L15 can be powered from 1.8- and 1.2-V external supplies. Separate MICVDD input can be supported (up to

3.6 V), for microphone operation above 1.8 V. A separate supply (4.2 V) is typically required for the Class D speaker

driver.

4.2 Input Signal Path

The CS47L15 provides flexible input channels, supporting up to five analog inputs or up to four digital inputs. Selectable

combinations of analog (mic or line) and digital inputs are multiplexed into two stereo input signal paths.

The IN1 signal paths support high performance analog and digital input modes. The analog paths support single-ended

and differential input, programmable gain control, and are digitized using a high performance sigma-delta ADCs. The IN1

analog input paths can be configured for low-power operation, ideal for always-on applications. The digital paths connect

directly to external digital microphones; the two-wire digital interface incorporates a dedicated clock source and supports

stereo microphone operation.

The IN2 signal paths can be configured for analog or digital input modes. Mono analog (differential) input is supported; the

analog configuration is optimized for low power operation and is ideally suited as an input path for speaker-protection

applications. Stereo digital input can also be supported on the SPKRXDAT pin; the respective data input is synchronized

with the digital speaker (PDM) output interface—these signal paths provide a bidirectional interface to an external speaker

driver.

The microphone bias (MICBIAS) generator provides a low-noise reference for biasing electret condenser microphones

(ECMs) or for use as a low-noise supply for MEMS microphones and digital microphones. Switchable outputs from the

MICBIAS generator allows three separate reference/supply outputs to be independently controlled.

Digital volume control is available on all inputs (analog and digital), with programmable ramp control for smooth, glitch-free

operation. A configurable signal-detect function is available on each input signal path.

The IN1 and IN2 signal paths and control fields are shown in Fig. 4-2.

CS47L15 Datasheet(PDF) 29 Page - Cirrus Logic