WM8998 Datasheet, PDF (1/307 Pages) Wolfson Microelectronics plc – High Performance Audio Hub CODEC

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WM8998
High Performance Audio Hub CODEC
DESCRIPTION
The WM8998^[1] is a highly-integrated low-power audio hub
CODEC for smartphones, tablets and other portable audio
devices. It is optimised for use in multimedia devices where
the audio processing requirements are implemented on the
host applications processor.
The WM8998 digital core combines fixed-function signal
processing blocks with a fully-flexible, all-digital audio mixing
and routing engine, for extensive use-case flexibility. Signal
processing blocks include filters, EQ, dynamics processors
and sample rate converters.
A SLIMbus interface supports multi-channel audio paths and
host control register access. Multiple sample rates are
supported concurrently via the SLIMbus interface. Three
further digital audio interfaces are provided, each supporting
a wide range of standard audio sample rates and serial
interface formats. Automatic sample rate detection enables
seamless wideband/narrowband voice call handover.
The stereo headphone driver provides ground-referenced
outputs, with noise levels as low as 1μVRMS for hi-fi quality
line or headphone output. The CODEC also features a
stereo line output, stereo 2W Class-D speaker outputs, a
dedicated BTL earpiece output, PDM for external speaker
amplifiers, and an IEC-60958-3 compatible S/PDIF
transmitter. A signal generator for controlling haptics devices
is included; vibe actuators can connect directly to the Class-
D speaker output, or via an external driver on the PDM
output interface. All inputs, outputs and system interfaces
can function concurrently.
The WM8998 supports up to six analogue mic/line inputs,
and up to three PDM digital inputs. The input multiplexers
support up to three signal paths. Microphone activity
detection with interrupt is available. A smart accessory
interface supports most standard 3.5mm accessories.
Impedance sensing and measurement is provided for
external accessory and push-button detection.
The WM8998 power, clocking and output driver
architectures are all designed to maximise battery life in
voice, music and standby modes. Low-power ‘Sleep’ is
supported, with configurable wake-up events. The WM8998
is powered from a 1.8V external supply. A separate supply
is required for the Class D speaker drivers (typically direct
connection to 4.2V battery).
Two integrated FLLs provide support for a wide range of
system clock frequencies. The WM8998 is configured using
the I2C or SLIMbus interfaces. The fully-differential internal
analogue architecture, minimal analogue signal paths and
on-chip RF noise filters ensure a very high degree of noise
immunity.
FEATURES
• Hi-Fi audio hub CODEC for mobile applications
• Digital audio processing core
- Fully flexible digital signal routing and mixing
- Wind noise, sidetone and other programmable filters
- Dynamic Range Control (compressor, limiter)
- Fully parametric EQs
- Low-pass / High-pass filters
• Multi-channel asynchronous sample rate conversion
• Integrated multi-channel 24-bit hi-fi audio hub CODEC
- 3 ADCs, 96dB SNR microphone input (48kHz)
- 7 DACs, 122dB SNR headphone playback (48kHz)
• Audio inputs
- Up to 6 analogue or 3 digital microphone inputs
- Single-ended or differential mic/line inputs
• Stereo headphone output driver
- 28mW into 32Ω load at 0.1% THD+N
- 6.9mW typical headphone playback power consumption
- Pop suppression functions
- 1µVRMS noise floor (A-weighted)
• Ground-referenced line output driver
- Stereo single-ended or Mono differential configuration
• Mono BTL earpiece output driver
- 100mW into 32Ω BTL load at 5% THD+N
• Stereo (2 x 2W) Class D speaker output drivers
- Direct drive of external haptics vibe actuators
• Two-channel digital speaker (PDM) output interface
• IEC-60958-3 compatible S/PDIF transmitter
• SLIMbus audio and control interface
• 3 full digital audio interfaces
- Standard sample rates from 8kHz up to 192kHz
- TDM support on all AIFs
- 6 channel input and output on AIF1 and AIF2
• Flexible clocking, derived from MCLKn, BCLKn or SLIMbus
• 2 low-power FLLs support reference clocks down to 32kHz
• Advanced accessory detection functions
- Low-power standby mode and configurable wake-up
• Configurable functions on 5 GPIO pins
• Integrated LDO regulators and charge pumps
• Support for single 1.8V supply operation
• Small W-CSP package, 0.4mm pitch
APPLICATIONS
• Smartphones and Multimedia handsets
• Tablets and Mobile Internet Devices (MID)
WOLFSON MICROELECTRONICS plc
Production Data, October 2014, Rev 4.0
[1] This product is protected by Patents US 7,622,984, US 7,626,445, US 7,765,019 and GB 2,432,765
Copyright 2014 Wolfson Microelectronics plc