General Description

The MAX121 is a complete, BiCMOS, serial-output, sampling 14-bit analog-to-digital converter (ADC) that combines an on-chip track/hold and a low-drift, low noise, buried-zener voltage reference with fast conversion speed and low power consumption. The throughput rate is as high as 308k samples per second (ksps). The full scale analog input range is ±5V.

The MAX121 utilizes the successive-approximation architecture with a high-speed DAC to achieve both fast conversion speeds and low-power operation. Operating with +5V and -12V or -15V power supplies, power consumption is only 210mW.

The MAX121 can be directly interfaced to the serial port of most popular digital-signal processors, and comes in space-saving 16-pin DIP and SO and smaller 20-pin SSOP packages. The MAX121 operates with TTL- and CMOS-compatible clocks in the frequency range from 1.1MHz to 5.5MHz. All logic inputs and outputs are TTL and CMOS-compatible. This data sheet includes application notes for easy interface to TMS320, µPD77230, and ADSP2101 digital-signal processors, as well as µPs using the Motorola SPI and QSPI interface standards.

Benefts and Features

● 14-Bit Resolution

● 2.9µs Conversion Time/308ksps Throughput

● 400ns Acquisition Time

● Low Noise and Distortion

• 78d8 SINAD

• -85dB THD

● ±5V Bipolar Input Range, Overvoltage Tolerant to ±15V

● 210mW Power Dissipation

● Continuous-Conversion Mode Available

● 30ppm/°C, -5V Internal Reference

● Interfaces to DSP Processors

● 16-Pin DIP and SO Packages,

20-Pin SSOP Package

Applications

● Digital Signal Processing

● Audio and Telecom Processing

● Speech Recognition and Synthesis

● DSP Servo Control

● Spectrum Analysis