AK4121VF Overview
Moreover, the book has an appendix that contains a case study. There is only one mounting type recommended for the product, which is Surface Mount. There is a 24-LSSOP (0.220, 5.60mm Width) case embedded in it. Packaged by 24-VSOP, the device is available for purchase.
AK4121VF Features
With 24-LSSOP (0.220, 5.60mm Width) channels

AK4121VF Applications
There are a lot of AKM Semiconductor Inc.
AK4121VF Audio Special Purpose applications.

High-End Audio/Sound Card for PC
Replacement of DIR1703
Other Applications Requiring S/PDIF Receiver
Audio Differential Line Drivers
Audio Mix Consoles
Distribution Amplifiers
Graphic and P arametric Equalizers
Dynamic Range Processors
Digital Effects Processors
Telecom Systems

Mounting Type	Surface Mount
Package / Case	24-LSSOP (0.220, 5.60mm Width)
Supplier Device Package	24-VSOP
Packaging	Tape & Reel (TR)
Part Status	Obsolete
Moisture Sensitivity Level (MSL)	2 (1 Year)