Analog Devices Inc./Maxim Integrated MAX19538ETL+

Overview

The MAX19538ETL+ from Maxim Integrated is a 12-bit, 95Msps analog-to-digital converter optimized for intermediate frequency (IF) sampling in communication receivers. It features a fully differential track-and-hold input, 68.4dB SNR at 175MHz input frequency, 492mW power consumption with 3.3V supply, and CMOS-compatible parallel output with pin-selectable two's complement or Gray code format.

For engineers reviewing the MAX19538ETL+ datasheet, MAX19538ETL+ pinout, MAX19538ETL+ application, or MAX19538ETL+ equivalent, key selection considerations include its 175MHz analog input bandwidth, ±0.35V to ±1.10V adjustable full-scale range, internal 2.048V bandgap reference, data-valid indicator (DAV), and out-of-range flag (DOR) - all critical for high-dynamic-range IF digitization in compact, low-power systems.

Technical Context

The MAX19538ETL+ employs a 10-stage fully differential pipelined ADC architecture with digital error correction to ensure no missing codes and compensate for comparator offsets across stages. Its switched-capacitor track-and-hold operates synchronously with the sampling clock, achieving 8.5 clock-cycle latency and <0.2psRMS aperture jitter.

It supports three reference configurations: internal (REFOUT → REFIN), buffered external (2.048V applied to REFIN), or unbuffered external (REFP/REFN/COM driven externally). Clock interface flexibility includes single-ended or differential inputs with an on-chip duty-cycle equalizer (DCE) accepting wide input duty cycles.

Key Specifications

Pinout & Package

The MAX19538ETL+ is housed in a 6mm × 6mm × 0.8mm, 40-pin thin QFN package with exposed paddle (EP), specified for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed ADC applications.

Compared with MAX1211ETL+, the MAX19538ETL+ delivers 30Msps higher throughput and 3.7dB better SFDR at 175MHz, justifying its higher power draw in infrastructure-grade receivers; versus MAX19537ETL+, it trades LVDS noise immunity for simpler CMOS interfacing and lower FPGA I/O bank utilization.

Availability

The MAX19538ETL+ is available at Aetrix Electronics and suitable for cellular base station IF receivers, point-to-point microwave radios, and medical PET detector front-ends requiring stable component supply across extended industrial temperature ranges.

Supply support for MAX19538ETL+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for communications, industrial, and medical applications.

The MAX19538ETL+ belongs to Maxim's high-speed pipeline ADC product line, designed specifically for direct IF sampling in wireless infrastructure and precision instrumentation where dynamic range, low latency, and power efficiency are co-optimized.

FAQ

What is the maximum analog input frequency supported by the MAX19538ETL+?

The MAX19538ETL+ maintains excellent dynamic performance up to 175MHz input frequency, with documented SNR of 68.4dB and SFDR of 76.2dBc at that frequency. Its architecture supports direct IF sampling up to 400MHz, though dynamic specifications degrade beyond 175MHz and must be verified per application layout and signal conditions. The device's 10-stage pipelined design and low-aperture-jitter track-and-hold enable this high-frequency capability.

Does the MAX19538ETL+ require an external reference voltage?

No, the MAX19538ETL+ includes an internal 2.048V bandgap reference (available at REFOUT) that can be used directly by connecting REFOUT to REFIN. Alternatively, it supports buffered external reference (2.048V applied to REFIN) or unbuffered external reference modes. This flexibility eliminates the need for external reference ICs in most designs, reducing component count and board space while maintaining accuracy across temperature.

How does the DAV (Data-Valid) output function in the MAX19538ETL+?

The DAV output of the MAX19538ETL+ is a single-ended, duty-cycle-compensated replica of the input clock, synchronized to valid data transitions. It eliminates the need for external clock conditioning circuits when latching output data into FPGAs or ASICs. DAV accounts for internal clock path delays and duty-cycle variations, ensuring reliable setup/hold timing margins without requiring custom delay-matched PCB traces or external PLLs.

Can the MAX19538ETL+ operate with a single-ended clock input?

Yes, the MAX19538ETL+ supports both differential and single-ended clock inputs. When CLKTYP is tied to GND, the device operates in single-ended mode: CLKP accepts the clock signal and CLKN is connected to GND. The internal duty-cycle equalizer (DCE) remains functional, allowing robust operation even with non-50% duty-cycle clocks - a key advantage over many competing ADCs that require strict clock symmetry.

What is the purpose of the DOR (Data Out-of-Range) pin on the MAX19538ETL+?

The DOR pin on the MAX19538ETL+ is an active-high digital flag indicating when the analog input voltage exceeds the full-scale range (±0.35V to ±1.10V). It provides real-time overrange detection without requiring post-acquisition software analysis. This enables immediate corrective action - such as AGC adjustment or gain switching - in closed-loop receiver systems, improving dynamic range utilization and preventing saturation-induced distortion in downstream processing.