Low-Cost ADCs Record Low Noise Spec

The AD1870 16-bit and AD1871 24-bit A/D converters are said to offer both low-noise and low-cost solutions for audio applications. Based on sigma-delta technology, the AD1870 provides a SNR of 92 dB and a -90 dB THD and THD+N. Capable of interfacing with DSP chips, the new ADC also features a power-down mode that dissipates less than 100 µW typical. Also employing sigma-delta technology, the AD1871 96 kHz a/d converter provides two 24-bit conversion channels, each with a programmable gain amplifier, multi-bit modulator, and decimation filters. In terms of audio performance, the device offers a dynamic range of 105 dB and a -94 dB THD+N. Each channel can be used as either single-ended or differential inputs. Available in 28-pin SSOPs, the AD1870 and AD1871 are priced at $4.52 and $5.09, respectively, each/1,000. ANALOG DEVICES, INC., Wilmington, MA. (800) 262-5643.