Analog Devices Inc./Maxim Integrated MAX6350EPA

Overview

MAX6350EPA from Maxim Integrated is a precision 5V voltage reference IC using buried-zener technology, delivering ±0.02% initial accuracy, 0.75ppm/°C typical temperature coefficient (1.5ppm/°C max), and 3.0µV_p-p (0.1Hz–10Hz) output noise. It supports ±15mA source/sink current and operates from 8V to 36V input, targeting high-resolution ADC/DAC biasing in industrial instrumentation.

For engineers reviewing the MAX6350EPA datasheet, MAX6350EPA pinout, MAX6350EPA application, or MAX6350EPA equivalent, key selection criteria include its 5V output stability over –40°C to +85°C, optional external trim capability, noise-reduction pin support, and compatibility with capacitive loads up to 100µF without oscillation.

Technical Context

The MAX6350EPA employs a temperature-compensated buried-zener core with low-power curvature correction, achieving near-zero thermal hysteresis (7ppm) and 30ppm/1000hr long-term stability. Its output impedance remains below 1Ω up to 10kHz, enabling stable operation with fast load transients.

It features dedicated NR (noise reduction) and TRIM pins for external 1µF capacitor attachment and ±30mV (±0.6%) output adjustment respectively, both decoupled from temperature drift performance. The device maintains ±0.01% turn-on settling in 10µs and exhibits <5ppm/mA load regulation across full ±15mA range.

Key Specifications

Pinout & Package

MAX6350EPA is housed in an 8-pin plastic DIP package (0.300" wide), rated for –40°C to +85°C operation. Pin 1, 7, and 8 are internally connected and must remain unconnected on PCB.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision voltage reference applications.

Compared with ADR445BRZ and REF5050AIDR, the MAX6350EPA uniquely combines 5V precision, ±15mA bidirectional drive, dedicated NR/TRIM pins, and DIP packaging for prototyping-making it optimal for industrial calibration hardware requiring field serviceability and robust load handling.

Availability

MAX6350EPA is available at Aetrix Electronics and suitable for high-accuracy industrial process controllers, portable digital multimeters, and automated test equipment requiring stable component supply across extended temperature ranges.

Supply support for MAX6350EPA 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 high-performance analog and mixed-signal ICs for industrial, automotive, and communications markets.

The MAX63xx family targets precision instrumentation applications demanding laboratory-grade voltage stability, low noise, and long-term reliability-specifically engineered for metrology, calibration, and high-resolution data conversion systems.

FAQ

What is the maximum operating temperature range for the MAX6350EPA?

The MAX6350EPA is specified for operation from –40°C to +85°C, as indicated by the "E" grade suffix in its part number. This extended temperature range makes it suitable for industrial control cabinets and outdoor instrumentation where ambient conditions exceed commercial-grade limits. The device maintains its full electrical specifications-including ±0.02% initial accuracy and 1.5ppm/°C max tempco-across this entire range. Thermal hysteresis is characterized at 7ppm, ensuring repeatable performance after thermal cycling. MAX6350EPA's plastic DIP package is qualified to meet these environmental requirements without derating.

Does the MAX6350EPA require an external capacitor on the NR pin?

No, the NR (Noise Reduction) pin on the MAX6350EPA is optional: it should be left open if wideband noise reduction is not required. When used, a 1µF capacitor connected between NR and GND reduces integrated output noise by approximately 40% in the 0.1Hz–10Hz band-critical for high-resolution measurements. Larger capacitors provide diminishing returns, and values below 0.1µF yield negligible improvement. The MAX6350EPA remains fully functional and stable without any NR capacitor, maintaining its specified 3.0µV_p-p noise floor. This design flexibility allows users to optimize for noise performance versus board space.

Can the MAX6350EPA drive a 10µF output capacitor without instability?

Yes, the MAX6350EPA is explicitly characterized and guaranteed stable with output capacitive loads ranging from 0µF to 100µF across its full operating range and load current (±15mA). This eliminates the need for series isolation resistors or complex compensation networks commonly required with other voltage references. The internal architecture provides sufficient phase margin even under worst-case conditions-such as cold temperature and maximum load-ensuring monotonic startup and absence of ringing during load transients. This feature simplifies layout in noise-sensitive applications like portable DVMs and medical sensors where large bulk capacitance is used for EMI suppression.

What is the purpose of the TRIM pin on the MAX6350EPA?

The TRIM pin on the MAX6350EPA enables ±30mV (±0.6%) adjustment of the nominal 5.000V output using an external 10kΩ potentiometer connected between OUT and GND, with the wiper tied to TRIM. This allows system-level calibration to correct for PCB trace resistance, solder joint offsets, or sensor nonlinearity-without affecting temperature coefficient or long-term stability. The trim function operates independently of the buried-zener core's thermal compensation, preserving the device's 0.75ppm/°C typical tempco. MAX6350EPA's TRIM pin is inactive when left open, making it safe for use in fixed-reference applications without risk of accidental adjustment.

How does the MAX6350EPA compare to the MAX6325 and MAX6341 variants?

The MAX6350EPA shares identical architecture, pinout, tempco (1.5ppm/°C max), noise performance (3.0µV_p-p), and load capability (±15mA) with the MAX6325EPA (2.5V) and MAX6341EPA (4.096V), differing only in nominal output voltage. All three support NR and TRIM functions, operate from 8V–36V, and are offered in the same E-grade temperature range (–40°C to +85°C) and 8-pin DIP package. Designers can migrate between them without layout changes-only adjusting feedback networks or load expectations. The MAX6350EPA's 5V output specifically targets legacy systems, microcontroller AVCC rails, and 5V-based DACs where 4.096V or 2.5V would require level-shifting or gain correction.