Analog Devices Inc./Maxim Integrated MAX132CWG

Overview

MAX132CWG from Maxim Integrated is an 18-bit plus sign, multi-slope integrating analog-to-digital converter (ADC) with serial interface, ±512mV input range (2µV/LSB), 16 conv/sec guaranteed throughput, and 15µV_RMS noise. It delivers ±0.006% FSR accuracy at 16 conversions per second and supports 50Hz/60Hz line rejection via programmable integration timing - ideal for precision weigh scales and battery-powered data loggers.

For engineers reviewing the MAX132CWG datasheet, MAX132CWG pinout, MAX132CWG application, or MAX132CWG equivalent, this page provides verified technical context, validated pin functions, real-world use scenarios, confirmed alternatives, and supply-ready sourcing guidance - all grounded in the official MAX132 datasheet Rev 2 (8/95) and Maxim's product documentation.

Technical Context

The MAX132CWG uses multi-slope integration architecture with fixed-integration time followed by reference deintegration, enabling high resolution without sacrificing speed versus traditional dual-slope converters. Its internal oscillator supports crystal (32.768kHz) or external clock input, and integration period is programmable for exact 20ms (50Hz) or 16.67ms (60Hz) rejection.

Digital control is implemented via a 4-wire serial interface (CS, SCLK, DIN, DOUT) with twos-complement output coding and three user-accessible registers: two command input registers (for configuration and P0–P3 control) and one status register (EOC, polarity, sleep, collision). Four programmable digital outputs (P0–P3) support external multiplexer or PGA control.

Key Specifications

Pinout & Package

The MAX132CWG is housed in a 24-pin wide SO (Small Outline) package, RoHS-compliant, with gull-wing leads and 0.300" body width. Pin numbering follows standard SOIC convention, with Pin 1 at top-left corner (notch or dot indicator).

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MAX132CWG, the ADS1258IPWR offers higher resolution but demands more external components and lacks native 50/60Hz timing control, while the LTC2440IGN#PBF matches sleep current and rejection capability but omits the four programmable outputs essential for compact transducer interfaces.

Availability

MAX132CWG is available at Aetrix Electronics and suitable for precision weigh scales, battery-powered data loggers, and industrial process control systems requiring stable component supply, long-lifecycle support, and guaranteed performance across 0°C to +70°C.

Supply support for MAX132CWG 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 industrial, medical, and communications applications.

The MAX132CWG belongs to Maxim's precision data acquisition product line, designed specifically for low-power, high-accuracy DC and low-frequency AC measurement systems where noise, drift, and line interference rejection are critical.

FAQ

What is the guaranteed accuracy specification for the MAX132CWG at its rated conversion rate?

The MAX132CWG is guaranteed to deliver ±0.006% FSR integral nonlinearity accuracy at 16 conversions per second, as specified in the Electrical Characteristics table under "Integral Nonlinearity" with conditions f_CLK = 32.768kHz and 60Hz mode. This applies across the full 0°C to +70°C operating range and is tested per Maxim's production test flow. The MAX132CWG achieves this with multi-slope integration and internal calibration techniques that minimize drift-related errors.

Does the MAX132CWG support both 50Hz and 60Hz line frequency rejection, and how is it configured?

Yes, the MAX132CWG supports both 50Hz and 60Hz line rejection via a dedicated bit (D6) in Command Input Register 0. When cleared (0), integration time is set to 545 clock cycles for 60Hz rejection; when set (1), it becomes 655 cycles for 50Hz rejection - both optimized for use with a 32.768kHz crystal. This eliminates external filtering and ensures >60dB rejection without software intervention. The MAX132CWG's functional diagram and timing figures confirm this hardware-based rejection mechanism.

What are the supply voltage requirements for the MAX132CWG, and what happens if they exceed absolute maximum ratings?

The MAX132CWG requires V+ = +4.5V to +5.5V and V− = −5.5V to −4.5V, with DGND and AGND referenced to 0V. Absolute maximum ratings are V+ to DGND ≤ +6.0V and V− to DGND ≥ −9.0V. Exceeding these - even momentarily - may cause permanent damage due to junction breakdown or metallization failure. The MAX132CWG datasheet explicitly warns that exposure beyond absolute maximums affects reliability, and operation outside recommended ranges voids accuracy guarantees.

How does the MAX132CWG achieve its low 1µA sleep-mode current, and what functionality remains active?

The MAX132CWG achieves 1µA sleep current by shutting down its internal oscillator and analog integrator circuitry while keeping the serial interface fully operational. CS, SCLK, DIN, and DOUT remain functional, allowing register reads and wake-up commands without external reset. The EOC pin stays active, and the status register retains polarity and sleep state. This behavior is confirmed in the "Power Requirements" section and Functional Description, where sleep mode is triggered by setting the sleep bit (D5) in Command Register 0.

Can the MAX132CWG's P0–P3 outputs drive standard logic-level inputs directly, and what are their voltage specifications?

Yes, the MAX132CWG's P0–P3 outputs are CMOS-compatible and can directly drive standard 5V TTL or CMOS inputs. Per the Electrical Characteristics table, VOH is ≥4.0V (min) at I_OH = −100µA, and VOL is ≤0.4V (max) at I_OL = 100µA, with VIH ≥2.4V and VIL ≤0.8V. These specs ensure robust noise margins and compatibility with common microcontrollers and logic families. The MAX132CWG pin description confirms P0–P3 are actively driven outputs, not open-drain.