Asahi Kasei Microdevices/AKM AK4954AEN

Overview

AK4954AEN from Asahi Kasei Microdevices (AKM) is a low-power 32-bit stereo audio CODEC integrating microphone preamplifiers, ALC, cap-less headphone amplifier (20mW @ 16Ω), and mono BTL speaker amplifier (400mW @ 8Ω, SVDD=3.3V). It supports 8–96kHz sampling, I²C control, and operates from AVDD=2.5–3.5V, DVDD=1.6–1.98V, SVDD=0.9–5.5V. Designed for portable voice-recording and playback devices such as Bluetooth headsets and smart speakers.

For engineers reviewing the AK4954AEN datasheet, AK4954AEN pinout, AK4954AEN application, or AK4954AEN equivalent, key selection considerations include its 32-pin QFN (4×4mm, 0.4mm pitch) package, dual-mic power supplies with −120dBV noise, wind-noise reduction filter, stereo separation emphasis, and shared ALC/volume control with 0.375dB/0.5dB step resolution.

Technical Context

The AK4954AEN implements separate high-fidelity ADC and DAC paths with programmable decimation filters (sharp roll-off or short-delay variants), configurable HPF (3.4Hz – 47.9Hz cutoff), and 4-band EQ. Its digital architecture supports MSB-justified, I²S, and LSB-justified audio interface formats across 16/24/32-bit word lengths.

Power management includes independent enable bits per functional block (e.g., PMADL, PMHPL), low-power modes for mic input (LPMIC) and DAC output (LPDA), and integrated charge-pump circuitry enabling capacitor-less headphone output and negative rail generation (VEE).

Key Specifications

Pinout & Package

AK4954AEN is housed in a 32-pin QFN package (4mm × 4mm, 0.4mm pitch) with exposed thermal pad. Pin functions are validated per AKM datasheet MS1542-E-01 (Rev. 01, Nov. 2019).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stereo audio CODEC applications.

Compared with AK4954AEN, AK4953AEN offers reduced feature set and larger footprint, while TLV320AIC3106IRHBT trades integrated speaker drive and lower noise for interface flexibility-making AK4954AEN optimal for space-constrained, battery-powered audio endpoints needing full analog integration.

Availability

AK4954AEN is available at Aetrix Electronics and suitable for portable voice recorders, Bluetooth headsets, smart speakers, and industrial handheld terminals requiring stable component supply, extended temperature operation (−30°C to +85°C), and low-power audio signal chain integration.

Supply support for AK4954AEN includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Asahi Kasei Microdevices (AKM) is a Japanese semiconductor company specializing in high-precision analog and mixed-signal ICs for audio, sensor, and power applications.

The AK4954AEN belongs to AKM's ultra-low-power stereo CODEC product line, engineered specifically for battery-operated portable audio devices demanding high dynamic range, minimal external components, and robust noise immunity in compact form factors.

FAQ

What is the maximum sampling frequency supported by the AK4954AEN?

The AK4954AEN supports sampling frequencies from 8kHz up to 96kHz in all clocking modes - PLL Master, PLL Slave, and External Master/Slave. At 96kHz, it maintains 82dB ADC S/(N+D) and 65dB DAC S/(N+D) with 20kHz bandwidth, making it suitable for high-resolution audio playback and professional voice capture applications where timing fidelity is critical. The AK4954AEN achieves this using its 32-bit data path and optimized decimation filters.

Does the AK4954AEN integrate a speaker amplifier, and what are its output capabilities?

Yes, the AK4954AEN integrates a mono Class-D BTL speaker amplifier capable of delivering 400mW into 8Ω at SVDD=3.3V, or 100mW at SVDD=1.5V - enabling direct drive from single-cell batteries. It also supports stereo line-out mode (via LOSEL bit) with 2.24Vpp output into 10kΩ. The amplifier features 70dB S/(N+D), −97dBV output noise, and 50dB PSRR, ensuring clean audio even in electrically noisy environments. This functionality is built into the AK4954AEN silicon and requires no external drivers.

How does the AK4954AEN achieve capacitor-less headphone output?

The AK4954AEN achieves capacitor-less headphone output using an integrated charge-pump circuit that generates a regulated negative voltage (VEE) from AVDD. Pins CP and CN connect to an external 2.2μF±50% ceramic capacitor to stabilize the charge pump, while VEE provides the required negative rail for the cap-less headphone amplifier (HPL/HPR). This eliminates bulky DC-blocking electrolytic capacitors, reduces PCB area by ~15mm², and improves long-term reliability - a core design objective realized in the AK4954AEN's analog architecture.

Can the AK4954AEN support digital microphones, and how is the interface configured?

Yes, the AK4954AEN supports digital microphones via dedicated DMCLK (pin 6) and DMDAT (pin 7) pins, enabled by setting the DMIC bit to "1". In this mode, pin 6 becomes a 3.072MHz–12.288MHz PDM clock output, and pin 7 accepts PDM data. The device includes digital filtering and decimation to convert PDM streams to PCM, preserving full 32-bit resolution. This capability is natively implemented in the AK4954AEN and does not require external logic or FPGA resources.

What power-saving features does the AK4954AEN offer for battery-powered designs?

The AK4954AEN includes granular power management: LPMIC bit enables low-power mic input (6.3mA typ), LPDA bit enables low-power DAC output (6.2mA typ), and individual power-down bits (e.g., PMADL, PMHPL) allow disabling unused blocks. Total current drops to <10μA in full power-down (PDN="L"). These features are hardware-controlled within the AK4954AEN and reduce system-level power consumption without host processor intervention - critical for extending runtime in portable audio products.