Analog Devices Inc./Maxim Integrated MAX1242BESA

Overview

MAX1242BESA from Maxim Integrated is a low-power, 10-bit successive-approximation analog-to-digital converter (SAR ADC) with internal 2.5V reference, 73ksps throughput, 7.5µs conversion time, and SPI/QSPI/MICROWIRE-compatible 3-wire serial interface - designed for space-constrained remote sensor nodes requiring precision analog measurement under single +2.7V to +5.25V supply.

For engineers reviewing the MAX1242BESA datasheet, MAX1242BESA pinout, MAX1242BESA application, or MAX1242BESA equivalent, this page delivers verified electrical specs, SO-8 package mapping, real-world timing behavior, functional alternatives, and design-critical interface constraints - all confirmed against Maxim's Rev 3 (Jan 2012) official datasheet.

Technical Context

The MAX1242BESA integrates a track/hold amplifier with 1.5µs acquisition time, a 10-bit SAR core, and on-chip 2.5V reference trimmed to ±0.25% initial accuracy (±30ppm/°C drift). Its serial interface operates at up to 2.1MHz SCLK with no duty-cycle restriction beyond 200ns minimum high/low phase width.

Conversion is initiated by CS falling edge; DOUT signals end-of-conversion (EOC) with rising edge, then outputs 10 data bits (MSB-first), two sub-bits, and one leading EOC bit - requiring ≥13 SCLK falling edges for full readout. Shutdown mode reduces supply current to ≤15µA (VDD ≤3.6V).

Key Specifications

Pinout & Package

MAX1242BESA is housed in an 8-pin SO (Small Outline) package (S8+5, outline 21-0041), RoHS-compliant, with gull-wing leads and 1.27mm pitch. Thermal resistance θ_JA = 170°C/W; derating 5.88mW/°C above +70°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with MAX1242BESA, MAX1240BCSA+ offers higher resolution in identical form factor with drop-in compatibility, while ADS7822U trades internal reference and shutdown for higher speed - making MAX1242BESA optimal for low-power, self-contained 10-bit measurement where board space and BOM count are constrained.

Availability

MAX1242BESA is available at Aetrix Electronics and suitable for portable data logging, process control monitoring, and isolated data acquisition requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX1242BESA 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) designs precision analog, mixed-signal, and power management ICs for industrial, medical, and communications applications.

The MAX1242 family targets low-power, space-constrained data acquisition systems requiring integrated reference, simple 3-wire interface, and guaranteed performance from –40°C to +85°C.

FAQ

What is the operating temperature range for MAX1242BESA?

The MAX1242BESA is rated for –40°C to +85°C operation, as confirmed by its ordering code suffix "E" (industrial grade) and the Electrical Characteristics table in Maxim's Rev 3 datasheet. This range is validated across all DC and dynamic parameters including INL, gain error, and reference stability - making MAX1242BESA suitable for factory-floor and outdoor instrumentation deployments where ambient extremes are expected.

Does MAX1242BESA require an external reference capacitor?

Yes, MAX1242BESA requires a 4.7µF capacitor at the REF pin when using the internal 2.5V reference - as specified in the "Capacitive Bypass at REF" row of the Electrical Characteristics table and Figure 3. This capacitor stabilizes the reference during conversion and limits wake-up delay after shutdown. Omitting it causes reference droop and conversion inaccuracy, especially at high throughput rates.

How does the SHDN pin function on MAX1242BESA?

On MAX1242BESA, the SHDN pin is three-level: pulled low → shutdown mode (≤15µA supply current); pulled high → internal reference enabled; left open → internal reference disabled (allowing external reference use). This behavior is explicitly documented in the Pin Description section and differs from MAX1243 variants - confirming MAX1242BESA's flexible reference configuration without additional control logic.

What is the maximum SCLK frequency supported by MAX1242BESA?

MAX1242BESA supports SCLK frequencies up to 2.1MHz, as stated in the Timing Characteristics table under "fSCLK". The datasheet further specifies no duty-cycle restriction beyond minimum 200ns high and low times - enabling robust interface timing with diverse microcontrollers. Exceeding 2.1MHz risks setup/hold violations and invalid data reads, per Figure 9 timing diagram constraints.

Is MAX1242BESA pin-compatible with other devices in the MAX124x family?

Yes, MAX1242BESA shares identical 8-pin SO package pinout with MAX1240/MAX1241 (12-bit) and MAX1243 variants, as confirmed by the unified Pin Configuration diagram and "Pin-Compatible 12-Bit Upgrades" feature bullet. This allows hardware reuse across resolution tiers - though firmware must accommodate differing bit widths and reference configurations when substituting MAX1242BESA with MAX1240BCSA+ or MAX1243BESA.