AKM 公司的AK4203是立體聲無電容線路放大器和視頻放大器,具有內置的電荷泵電路,采用單個3.3V電源,可得到2Vrms輸出,并具有極好的線性度.音頻放大器的THD+N為 -90dB, S/N為102dB,視頻放大器的S/N為75dB(typ),放大器增益為+6dB.本文介紹了AK4203主要特性,方框圖,典型連接圖,評估板AKD4203-A功能和方框圖,以及電路圖和元件布局圖.

Stereo Cap-less LINE-Amp and Video-Amp
The AK4203 is an audio stereo cap-less line driver with 1-channel video driver. It eliminates the need for large DC-blocking capacitors with a built-in Charge-pump circuit. The AK4203 achieves 2Vrms outputs with excellent linearity 2Vrms output by single 3.3V power supply. The AK4203 is available in small 16-pin TSSOP, saving the system space and cost.

AK4203主要特性:
Audio Line-Amp
􀂆 Differential Input
􀂆 Stereo Cap-less Amplifier (No DC-blocking capacitors required)
􀂆 Line-Out level: 2.0Vrms
􀂆 THD+N: -90dB
􀂆 S/N: 102dB
􀂆 Output gain: 6dB
􀂆 Low-pass Filter: fc= 130kHz
􀂆 Pop Noise Free Ground-referenced Output Video Amp
􀂆 1ch Stereo Cap-less Amplifier (No DC-blocking capacitors required)
􀂆 Integrated Video Amplifier (+6dB)
􀂆 Input Level: 1.5Vpp (max)
􀂆 SN: 75dB(typ), Bandwidth: 100kHz ∼ 6MHz
􀂆 LPF: -0.5dB@ 6.75MHz (typ), -43dB@27MHz (typ)
􀂆 Video Mute Function
􀂆 Power Supply: 3.0V ~ 3.6V
􀂆 Ta: -20 ~ 85℃
􀂆 Package: 16TSSOP

圖1.AK4203 方框圖

圖2.AK4203 典型連接框圖

AK4203評估板AKD4203-A
The AKD4203-A is an evaluation board for a fast evaluation of the AK4203,
Evaluation requires audio/video analog analyzers/generators and a power supply.

評估板AKD4203-A功能:
• RCA jacks for analog audio input/output
• XLR jacks for analog audio input
• RCA jacks for video input/output

圖3.評估板AKD4203-A方框圖

圖4.評估板AKD4203-A電路圖(1)

圖5.評估板AKD4203-A電路圖(2)

圖6.評估板AKD4203-A電路圖(3)

圖7.評估板AKD4203-A電路圖(4)

圖8.評估板AKD4203-A元件布局圖