AK4708EQ

Overview

The AK4708EQ is an I2C-controlled audio and video switch matrix designed for digital TV and set-top-box applications. It integrates analog switches, video filters, and routing capabilities to support dual SCART connections. The device features stereo analog volume control with pop-noise-free circuits, ranging from +6dB to -60dB. Video sections include integrated low-pass filters (-40dB@27MHz), 75Ω drivers, and 6dB gain outputs. It operates on 5V and 12V supplies, consuming minimal current in standby mode (typ. 10μA). The component is housed in a compact 48-pin LQFP package.

Feature Summary

• Supports dual SCART connections with independent TV and VCR routing paths.
• Includes pop-noise-free circuitry for smooth power-on/off transitions.
• Features integrated video low-pass filtering and 75Ω output drivers.
• Offers auto-startup mode for power saving by detecting video signals.

Applications

• Digital television systems
• Set-top box designs
• AV switch matrices requiring dual SCART interfaces

Procurement Notes

Verify the specific ordering suffix matches the required temperature range and package variant. Confirm that the I2C bus voltage levels are compatible with the system logic. Ensure proper decoupling capacitors are used for the multiple power supply pins as specified in the datasheet. Check for RoHS compliance status if required by local regulations.

Selection Notes

Select this component when a single IC solution is needed for both audio and video switching in SCART-based systems. Consider the 48-pin LQFP package size constraints against available PCB space. Evaluate the need for integrated volume control and pop-noise reduction features versus external components. Verify that the operating temperature range meets the environmental requirements of the target application.

Part Context

The AK4708EQ belongs to the AK4708 family of AV switch matrices manufactured by Asahi Kasei Microdevices. It is specifically engineered for consumer electronics requiring high-performance signal routing between TV and VCR sources. The 'EQ' suffix typically denotes the commercial temperature grade and LQFP packaging variant within the product line.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult the manufacturer's official replacement guide or contact technical support for qualified alternatives.

FAQ

How does the AK4708 handle pop noise during volume changes?

The device includes a pop-noise-free circuit that controls the transition time of volume changes. By setting the MOD bit to '1', the gain changes smoothly over a selectable transition period (5.3ms to 42.7ms), preventing audible clicks.

What is the function of the Auto Startup Mode?

In Auto Startup Mode, most blocks are powered down until a video signal is detected at the TVVIN or VCRVIN pin. Upon detection, the device automatically enters standby mode and sends an interrupt pulse via the INT pin, optimizing power consumption.

Can the AK4708 support YPbPr video signals?

Yes, the device supports YPbPr signals through its encoder inputs. The DC-restore circuits can be configured to handle the specific clamp voltages required for RGB or YPbPr formats using the CLAMP bits.