Asahi Kasei Microdevices/AKM AK4621EF

Overview

AK4621EF from Asahi Kasei Microdevices (AKM) is a 24-bit stereo audio CODEC IC supporting up to 192kHz sampling, featuring dual 2-channel 24-bit ADCs with differential inputs and dual 2-channel 24-bit DACs with differential outputs. It delivers S/(N+D) of 102dB (ADC) and 100dB (DAC), 115dB A-weighted SNR, and operates across 32–216kHz sampling rates. It is used in professional audio sound cards and digital audio workstations requiring high-fidelity analog-to-digital and digital-to-analog conversion.

For engineers reviewing the AK4621EF datasheet, AK4621EF pinout, AK4621EF application, or AK4621EF equivalent, this page provides verified technical context, package mapping, real-world use scenarios, and validated alternative parts for Pro Audio, DAW, and high-resolution recording systems - all derived from AKM's official MS1258-E-02 datasheet.

Technical Context

The AK4621EF integrates two independent signal paths: an Enhanced Dual-Bit ADC architecture enabling high dynamic range and low noise, and an Advanced Multi-Bit DAC architecture with Switched Capacitor Filter (SCF) technology for low out-of-band noise and high jitter tolerance. Its digital filters support three selectable roll-off profiles per channel (Sharp, Short Delay Sharp, Slow), each with defined passband ripple, stopband attenuation, and group delay (e.g., GD = 39/fs for ADC Sharp filter at 48kHz).

It supports serial and parallel control interfaces, configurable master clock ratios (128fs–1024fs), and flexible audio data formats including I²S, MSB-justified, and LSB-justified. The device includes on-chip HPF for DC offset cancellation, zero-detection flags, overflow monitoring, and programmable digital attenuation (0 dB to –72 dB in 256 + 16 linear steps).

Key Specifications

Pinout & Package

AK4621EF is housed in a 30-pin Very Small Outline Package (VSOP) with 0.65mm pitch, optimized for compact audio PCB layouts while maintaining thermal and EMI performance under continuous 192kHz operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AK4621EF, AK4620B trades 2dB ADC dynamic range and key diagnostics (zero/overflow flags) for lower cost, while CS4272-CQZ offers superior DAC SNR but requires external differential receivers and lacks integrated HPF - making AK4621EF optimal for balanced, low-noise, feature-rich studio I/O.

Availability

AK4621EF is available at Aetrix Electronics and suitable for professional audio interfaces, digital audio workstations, and high-resolution optical disc recording systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AK4621EF 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, particularly audio codecs, Hall-effect sensors, and power management devices.

The AK4621EF belongs to AKM's professional audio CODEC product line, engineered for studio-grade fidelity, low-latency operation, and robust noise immunity in demanding recording and playback environments.

FAQ

What is the maximum sampling rate supported by the AK4621EF?

The AK4621EF supports sampling rates from 32kHz up to 216kHz, with verified operation at 192kHz for both ADC and DAC paths. At 192kHz, it maintains 101dB S/(N+D) for ADC and 97dB for DAC (–1dBFS, 40kHz BW), meeting high-resolution audio standards for mastering and archival applications. The device uses quad-speed mode (DFS1=1, DFS0=0) and accepts MCLK frequencies up to 55.296MHz.

Does the AK4621EF support differential analog inputs and outputs?

Yes, the AK4621EF supports fully differential analog I/O: AINL+/AINL– and AINR+/AINR– for ADC inputs, and AOUTL+/AOUTL– and AOUTR+/AOUTR– for DAC outputs. Each differential pair operates with ±2.82Vpp full-scale swing referenced to VCOM (AVDD/2). This architecture rejects common-mode noise and eliminates the need for external baluns or op-amp level-shifting in pro-audio front-end designs.

How does the AK4621EF handle clock stability and jitter tolerance?

The AK4621EF achieves high jitter tolerance through its Advanced Multi-Bit DAC architecture and integrated Switched Capacitor Filter (SCF), which suppresses out-of-band noise and relaxes upstream clock requirements. Its ADC employs Enhanced Dual-Bit modulation to minimize sensitivity to master clock jitter. The device also includes automatic phase-detect circuitry that resets the internal state if LRCK/MCLK synchronization drifts - ensuring reliable lock under variable clock conditions typical in USB-audio or networked audio systems.

Can the AK4621EF operate in both serial and parallel control modes?

Yes, the AK4621EF supports two hardware-selectable control interface modes: serial (P/S = L) using a 3-wire SPI-like bus (CSN, CCLK, CDTI), and parallel (P/S = H) using dedicated pins (CKS0/CKS1, DFS0, DIF). Mode selection must be fixed before power-up or during PDN = L reset. Serial mode offers greater flexibility with register-based configuration; parallel mode simplifies timing-critical implementations where pin count permits.

What digital audio interface formats does the AK4621EF support?

The AK4621EF supports five PCM audio formats in serial mode (selected via DIF2–DIF0 bits): 24-bit MSB-justified, 16/20-bit LSB-justified, and 24-bit I²S. In parallel mode, it supports only 24-bit MSB-justified (DIF = L) and 24-bit I²S (DIF = H). All formats use MSB-first, two's complement data; SDTO is clocked on BICK falling edge, SDTI latched on rising edge - ensuring compatibility with standard DSPs, FPGAs, and microcontrollers.