The MAX1421 is a 3.3V, 12-bit analog-to-digital converter (ADC) with a fully-differential input, pipelined, 12-stage ADC architecture. It features wideband track-and-hold (T/H) and digital error correction with a fully-differential signal path. The MAX1421 is designed for low-power, high-dynamic performance applications in imaging and digital communications. It operates from a single 3.3V supply, consuming only 188mW of power while delivering a typical signal-to-noise ratio (SNR) of 66dB at an input frequency of 15MHz and a sampling frequency of 40Msps. The fully-differential input stage has a small signal -3dB bandwidth of 400MHz and can be operated with single-ended inputs. It uses an internal 2.048V precision bandgap reference to set the full-scale range of the ADC. The reference structure is flexible and can accommodate an internal or externally applied buffered or unbuffered reference for applications requiring increased accuracy or a different input voltage range. In addition to low operating power, the MAX1421 offers two power-down modes: reference power-down and shutdown mode. In reference power-down mode, the internal bandgap reference is deactivated, resulting in a typical 2mA supply current reduction. For idle periods, a full shutdown mode is available to maximize power savings. The MAX1421 provides parallel, offset binary, CMOS-compatible three-state outputs. It is available in a 7mm x 7mm, 48-pin TQFP package.
The MAX1421 is a 12‑bit, 40 Msps analog‑to‑digital converter optimized for low‑power, high‑dynamic‑range applications such as imaging and digital communications. It operates from a single 3.3 V supply, consumes only 188 mW, and provides a fully‑differential input path with a 400 MHz small‑signal bandwidth.
The datasheet lists electrical characteristics, absolute maximum ratings, timing parameters, and typical operating curves. It also includes ordering information, a 48‑pin TQFP package outline, pin configuration, and power‑down modes (reference shutdown and full shutdown).
| Resolution | 12 bits |
|---|---|
| Sampling Rate | 40 Msps |
| Supply Voltage | 3.3 V |
| Power Dissipation (typical) | 188 mW |
| Internal Reference | 2.048 V precision bandgap |
| SNR at 5 MHz | 67 dB |
| SNR at 15 MHz | 66 dB |
| Package | 48‑pin TQFP |
| Input Bandwidth | 400 MHz (-3 dB) |
| Power‑Down Modes | Reference shutdown 180 mW, full shutdown 10 pW |
The MAX1421 operates from a single 3.3 V supply.
It offers a reference shutdown mode (180 mW) and a full shutdown mode (10 pW).
The device includes an internal 2.048 V precision bandgap reference.
The typical signal‑to‑noise ratio is 66 dB at 15 MHz.