Analog Devices Inc./Maxim Integrated MAX6225ACPA+

Overview

MAX6225ACPA+ from Maxim Integrated is a precision 2.500V buried-zener voltage reference IC with ±0.02% initial accuracy, 2.0ppm/°C max temperature coefficient (0°C to +70°C), 1.5µV_P-P (0.1Hz–10Hz) output noise, and ±15mA source/sink capability in an 8-pin plastic DIP package. It serves as the primary reference in high-resolution ADC/DAC signal chains requiring laboratory-grade stability.

For engineers reviewing the MAX6225ACPA+ datasheet, MAX6225ACPA+ pinout, MAX6225ACPA+ application, or MAX6225ACPA+ equivalent, key selection criteria include its low-noise performance, trimmable output, noise-reduction pin (NR), and guaranteed load regulation up to ±15mA - critical for metrology-grade instrumentation and 16-bit data acquisition systems.

Technical Context

The MAX6225ACPA+ employs buried-zener technology for ultra-low noise and long-term stability (20ppm/1000h), with internal temperature compensation delivering near-zero curvature over 0°C to +70°C. Its output is buffered to maintain low impedance (<1Ω at 1kHz) and stable performance across capacitive loads (0–100µF).

It features dedicated TRIM and NR pins enabling ±15mV external adjustment and optional 1µF noise-reduction capacitance, respectively. Input voltage range is 8V to 36V, with supply current of 2.7mA typical and 3.0mA max at +25°C.

Key Specifications

Pinout & Package

MAX6225ACPA+ is housed in an 8-pin plastic DIP (dual in-line package) with 0.3-inch body width and through-hole mounting. Pin 1 is top-left corner when notch faces up; pins 1–4 on left side, 5–8 on right.

Key Features

Applications

Equivalent & Alternatives

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

Compared with REF5025IDR and ADR441BRZ, the MAX6225ACPA+ offers superior temperature stability (2.0ppm/°C vs. ≥3ppm/°C), unique TRIM/NR flexibility, and through-hole DIP packaging - making it optimal for lab-grade calibration hardware and legacy-compatible test fixtures where manual adjustment and noise tailoring are required.

Availability

MAX6225ACPA+ is available at Aetrix Electronics and suitable for digital voltmeters, high-resolution data acquisition systems, and automated test equipment requiring stable component supply, long-lifecycle support, and RoHS-compliant through-hole packaging.

Supply support for MAX6225ACPA+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for precision, industrial, and communications applications.

The MAX6225 series belongs to Maxim's precision voltage reference product line, engineered specifically for metrology, calibration, and high-bit-depth data conversion systems demanding sub-ppm stability and ultra-low noise.

FAQ

What is the maximum operating temperature range for the MAX6225ACPA+?

The MAX6225ACPA+ is rated for operation from 0°C to +70°C. This commercial temperature grade is defined by the "C" suffix in the part number and confirmed in the Ordering Information table. Its 2.0ppm/°C max temperature coefficient is guaranteed across this full range, ensuring predictable performance in benchtop instruments and non-extended-environment industrial controllers. The MAX6225ACPA+ does not support extended or military temperature ranges.

Can the MAX6225ACPA+ be used with capacitive loads, and what is the recommended output capacitor value?

Yes, the MAX6225ACPA+ is stable with output capacitance from 0µF to 100µF across all load currents - a key design feature verified in the Electrical Characteristics and Applications Information sections. No minimum output capacitor is required; however, a 2.2µF ceramic capacitor placed directly at the OUT pin improves transient response and reduces glitching during load steps. Larger values do not degrade stability but offer diminishing noise-reduction returns beyond 10µF.

Does the MAX6225ACPA+ require an external noise-reduction capacitor, and how does it affect performance?

The NR pin on the MAX6225ACPA+ is optional: leaving it open yields baseline 1.5µV_P-P (0.1Hz–10Hz) noise, while connecting a 1µF capacitor to GND reduces wideband noise by >20dB above 10Hz, per Figure 2 and Typical Operating Characteristics. This capacitor has no effect on DC accuracy, tempco, or long-term stability. Values larger than 1µF provide negligible additional benefit, and the NR pin must never be shorted or driven externally.

What is the purpose of the TRIM pin on the MAX6225ACPA+, and what is its adjustment range?

The TRIM pin on the MAX6225ACPA+ enables external fine-tuning of the output voltage using a 10kΩ potentiometer between OUT and GND, with the wiper connected to TRIM. This provides a ±15mV adjustment range (±0.6% of 2.5V), allowing correction of system-level errors such as PCB trace resistance or ADC input offset. Crucially, external trimming does not degrade the device's specified temperature coefficient or long-term stability, as stated in the Detailed Description section.

Is the MAX6225ACPA+ pin-compatible with other members of the MAX6225/MAX6241/MAX6250 family?

Yes, the MAX6225ACPA+ shares identical pinout and package (8-pin plastic DIP) with all MAX6225, MAX6241, and MAX6250 variants - including MAX6241ACPA+ (4.096V) and MAX6250ACPA+ (5.000V). This allows drop-in replacement across output voltages within the same grade (e.g., "A" grade, "C" temp range), provided the application can accommodate the different nominal output. Pin functions (IN, NR, GND, TRIM, OUT) and absolute maximum ratings remain consistent across the family.