Analog Devices Inc. AD7895ARZ-2REEL

Overview

AD7895ARZ-2REEL from Analog Devices is a 12-bit successive-approximation analog-to-digital converter (ADC) with integrated track/hold amplifier, on-chip clock, and high-speed serial interface. It operates from a single +5 V supply, delivers 3.8 µs conversion time in Mode 1, supports 0 V to +2.5 V unipolar input range, consumes ≤20 mW, and is housed in an 8-pin SOIC package. It is used in precision data acquisition systems requiring compact size and low power.

For engineers reviewing the AD7895ARZ-2REEL datasheet, AD7895ARZ-2REEL pinout, AD7895ARZ-2REEL application, or AD7895ARZ-2REEL equivalent, key selection criteria include unipolar 0–2.5 V input scaling, straight binary output coding, 12-bit resolution with ±1 LSB relative accuracy, 70 dB SNR at 50 kHz, and compatibility with microcontroller serial interfaces via SCLK/SDATA/BUSY signals.

Technical Context

The AD7895ARZ-2REEL implements a laser-trimmed internal clock driving a 12-bit R-2R ladder SAR core, with on-chip track/hold enabling full-scale sine wave digitization up to >100 kHz input bandwidth. Its analog front-end directly accepts 0 V to +2.5 V inputs with <500 nA input current and no external scaling resistors.

It features two operating modes: Mode 1 (high-speed, 3.8 µs conversion, BUSY active during conversion) and Mode 2 (auto-sleep after conversion, 9.8 µs total cycle including 6 µs wake-up). Serial data output is 16-bit frame (4 leading zeros + 12-bit straight binary result), synchronized to falling edges of SCLK up to 15 MHz.

Key Specifications

Pinout & Package

AD7895ARZ-2REEL is supplied in an 8-pin Small Outline Integrated Circuit (SOIC) package, 3.9 mm × 4.9 mm body, 1.27 mm pitch, RoHS-compliant, tape-and-reel format (REEL suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7894ARZ, AD7895ARZ-2REEL trades 2 bits of resolution for faster conversion and lower power; versus ADS7822U, it offers superior speed and SNR but requires strict +5 V operation and dedicated layout - making it optimal for high-fidelity, battery-conscious 5 V systems.

Availability

AD7895ARZ-2REEL is available at Aetrix Electronics and suitable for portable instrumentation, industrial process monitoring, medical diagnostics, and test equipment requiring stable component supply across multi-year production cycles.

Supply support for AD7895ARZ-2REEL 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The AD7895 belongs to Analog Devices' precision data acquisition ADC family, designed specifically for space-constrained, low-power, high-accuracy measurement systems requiring integrated track/hold and serial interface in minimal footprint.

FAQ

What input voltage range does the AD7895ARZ-2REEL support?

The AD7895ARZ-2REEL supports a unipolar 0 V to +2.5 V analog input range. This is fixed for the "-2" variant and differs from the ±10 V (AD7895-10) and ±2.5 V (AD7895-3) versions. Input is applied directly to the VIN pin with high impedance (>1 GΩ effective), and no external scaling resistors are needed. The part requires a stable +2.5 V reference on the REF IN pin to maintain accuracy across this range.

Does the AD7895ARZ-2REEL require an external clock source?

No, the AD7895ARZ-2REEL contains a laser-trimmed on-chip oscillator that generates the internal conversion clock. An external serial clock (SCLK) is required only for reading data from the SDATA pin - it does not drive the ADC core. SCLK can run up to 15 MHz and controls the timing of serial bit transfers; the part is fully functional with any microcontroller GPIO or SPI peripheral providing this clock.

How does the power-down mode work on the AD7895ARZ-2REEL?

The AD7895ARZ-2REEL enters automatic power-down mode (Mode 2) when the CONVST pin is held low after conversion completes (i.e., after BUSY goes low). In this state, supply current drops to ≤10 µA. The part "wakes up" on the rising edge of the next CONVST pulse, with a 6 µs wake-up delay before track/hold enters hold mode. This feature reduces average power in low-duty-cycle applications such as periodic sensor polling.

What is the output data format of the AD7895ARZ-2REEL?

The AD7895ARZ-2REEL outputs 16-bit serial frames on the SDATA pin: four leading zero bits followed by 12 bits of straight (natural) binary conversion result. This differs from the 2's complement format used by AD7895-10 and AD7895-3 variants. The frame is clocked out on the falling edge of SCLK, and data remains valid for 10 ns after each falling edge, enabling reliable capture by standard microcontroller inputs.

Can the AD7895ARZ-2REEL be used with a 3.3 V microcontroller interface?

Yes - while the AD7895ARZ-2REEL requires a +5 V supply (VDD), its digital outputs (SDATA, BUSY) are CMOS-compatible and swing rail-to-rail (0 V to +5 V). To interface with a 3.3 V microcontroller, use a simple level-shifter or resistor divider on SDATA and BUSY lines; SCLK input accepts 0.8 V / 2.4 V logic thresholds, so a 3.3 V controller can drive it directly. No level translation is needed for CONVST if driven from a 3.3 V GPIO.