Analog Devices Inc. AD7895AN-10

Overview

AD7895AN-10 from Analog Devices is a 12-bit successive-approximation analog-to-digital converter (ADC) with ±10 V bipolar input range, 3.8 µs conversion time, single +5 V supply operation, and high-speed serial interface - used in precision data acquisition systems requiring fast sampling of industrial sensor signals.

For engineers reviewing the AD7895AN-10 datasheet, AD7895AN-10 pinout, AD7895AN-10 application, or AD7895AN-10 equivalent, key selection criteria include bipolar ±10 V input scaling, on-chip track/hold acquisition time of 0.5 µs, 2s complement output coding, 70 dB SNR at 50 kHz, and compatibility with microcontroller serial interfaces via SCLK/SDATA/BUSY signaling.

Technical Context

The AD7895AN-10 implements a laser-trimmed internal clock driving a 12-bit R-2R ladder SAR core, with integrated track/hold amplifier optimized for full-scale sine wave inputs up to 100 kHz. Its analog front-end uses resistor scaling (R1=30 kΩ, R2=7.5 kΩ, R3=10 kΩ) to support ±10 V input while operating from +5 V only.

It operates in two modes: Mode 1 (high-speed, 3.8 µs conversion, BUSY active during conversion) and Mode 2 (auto power-down after conversion, 9.8 µs total cycle including 6 µs wake-up). Serial data output is 16-bit wide (4 leading zeros + 12-bit result), clocked on SCLK falling edge with 10 ns hold time.

Key Specifications

Pinout & Package

AD7895AN-10 is housed in an 8-pin plastic DIP (N-8 package), 0.3" wide, with 0.1" lead pitch. Pin 1 is marked with a notch or dot; pins are numbered counterclockwise from top-left in top view.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit serial ADC applications.

Compared with AD7895AN-10, AD7895AR-10 offers identical performance in a smaller SOIC package but with reduced thermal margin, while AD7894AR-10 delivers 2 additional bits of resolution with no change to interface or timing - making it a direct upgrade path for higher-accuracy designs.

Availability

AD7895AN-10 is available at Aetrix Electronics and suitable for industrial process monitoring, portable data loggers, test equipment, and motor control feedback systems requiring stable component supply across extended production lifecycles.

Supply support for AD7895AN-10 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7895 belongs to Analog Devices' precision data acquisition ADC family, designed specifically for industrial and instrumentation applications demanding fast, accurate, low-power digitization of ±10 V sensor signals in compact 8-pin packages.

FAQ

What is the maximum recommended serial clock frequency for AD7895AN-10?

The AD7895AN-10 supports up to 15 MHz SCLK, but system-level timing must respect t4 (603 ns max data access time) and t5 (10 ns min hold time). At 15 MHz, the 16-bit read takes ~1.1 µs. To maintain 192 kHz throughput, ensure the read completes ≥300 ns before the next CONVST falling edge. Lower frequencies are acceptable but reduce sampling rate.

Does AD7895AN-10 require an external reference, and what are the specifications?

Yes, AD7895AN-10 requires an external +2.5 V reference applied to the REF IN pin. The reference must be stable within ±5% (2.375 V to 2.625 V), deliver ≤1 µA, and exhibit ≤10 pF capacitance. Gain error and full-scale accuracy scale directly with reference tolerance; precision references like AD780 or AD680 are recommended for optimal performance.

How does the auto power-down mode work in AD7895AN-10?

In Mode 2, AD7895AN-10 enters power-down automatically when CONVST remains low after conversion completes (BUSY goes low). It draws ≤10 µA. The rising edge of the next CONVST "wakes up" the device, initiating a 6 µs wake-up period before conversion begins. Total cycle time becomes 9.8 µs (6 µs wake-up + 3.8 µs conversion), ideal for low-duty-cycle sampling.

What is the input impedance of AD7895AN-10, and how does it affect signal source design?

The AD7895AN-10 exhibits ≥24 kΩ input resistance at VIN under dc conditions. Its front-end uses passive resistor scaling followed by a high-impedance track/hold input, so dynamic loading is negligible. Signal sources should drive ≤24 kΩ to avoid gain error; for high-impedance sensors, a unity-gain buffer (e.g., AD8605) is recommended to preserve linearity and settling.

Is AD7895AN-10 pin-compatible with other variants in the AD7895 family?

Yes, all AD7895 variants (AD7895AN-2, AD7895AN-3, AD7895AN-10, and their SOIC counterparts) share identical 8-pin DIP/SOIC pinouts and serial interface timing. Only the analog input range (±10 V, ±2.5 V, or 0–2.5 V) and output coding (2s complement vs. straight binary) differ - allowing hardware reuse across variants with firmware configuration changes.