Signal Processing with Low Latency. The 4-channel A/D converter (ADC) from Asahi Kasei Microdevices is targeting automotive applications. The AK5734 is a complementary solution for microphones, aiming at active noise control systems (ANC) and road noise control systems (RNC), which are increasingly being installed in vehicles.
By combining with the previously released 6-channel ADC the AK5736, the system can accommodate various microphone channels. Besides ANC and RNC the solution is ideal for the microphone input of a wide variety of in-vehicle systems.
The new AK5734 integrates a "Diagnostics function" and monitoring for microphone connections. With this feature, even during operation, connection abnormalities are notified in real time. In addition to the simple diagnostic mode with 100mV accuracy, a high-precision diagnostic mode with 12-bit accuracy has been implemented. It is also possible to read the DC level (12-bit accuracy) of the connection pins through registers and use it for user-specific diagnostic algorithms.
Optimized for signal processing with 4.3 [1/fs] low latency signal processing, the AK5734 ADC supports line and microphone inputs with an SAR ADC for error detection. The error detection function monitors connection status of line and microphone inputs. The AK5734VN also has Pre-Gain Amplifiers (PGA) for microphone and Microphone bias (MIC bias) voltage sources. These functions make it ideal for microphone array applications such as in automotive Active Noise Cancellation systems (ANC) or Road Noise Control system (RNC), while the TDM audio format makes it easy to connect with a DSP. The low latency also contributes to improving accuracy of noise cancellation where real time processing is required.
Finally, the AK5734 supports a high input impedance of 1.48MΩ (typical). External filters and attenuators required for microphone input and line input can be easily designed. Accelerometers with high output impedance can also be connected without a buffer amplifier.
The 4-channel A/D converter (ADC) from Asahi Kasei Microdevices is available now at Atlantik Elektronik.