Analog Devices Inc. AD7872JNZ

Overview

AD7872JNZ from Analog Devices is a complete monolithic 14-bit successive approximation analog-to-digital converter (ADC) with integrated track-and-hold amplifier, 3 V buried Zener reference, and serial-only digital interface. It operates from ±5 V supplies, accepts ±3 V bipolar analog inputs, achieves 80 dB SNR at 10 kHz, delivers 57 ns data access time, and supports 83 kSPS throughput. It is used in high-speed DSP servo control and spectrum analysis systems requiring precise timing and low-noise conversion.

For engineers reviewing the AD7872JNZ datasheet, AD7872JNZ pinout, AD7872JNZ application, or AD7872JNZ equivalent, this page provides verified technical context, real-world interface constraints, confirmed dynamic and DC specifications, package-validated terminal functions, and two rigorously cross-checked alternative parts for serial-output 14-bit sampling ADCs in industrial temperature range designs.

Technical Context

The AD7872JNZ implements a self-contained LC2MOS SAR architecture with laser-trimmed internal 2 MHz clock-no external timing components required-and uses twos-complement coding for bipolar input representation. Its track-and-hold acquires to 14-bit accuracy in ≤2 μs, enabling full-scale signal conversion up to 41.5 kHz while maintaining 80 dB SNR.

All digital outputs (SSTRB, SCLK, SDATA) are three-state, open-drain (SCLK/SDATA) or active-low (SSTRB), requiring external pull-up resistors (4.7 kΩ on SSTRB/SDATA, 2 kΩ on SCLK). The internal 3 V reference is accessible at REFOUT with ±40 ppm/°C tempco and 500 μA load capability, decoupled via 10 nF capacitor at CREF to AGND.

Key Specifications

Pinout & Package

AD7872JNZ is housed in a 16-pin plastic DIP (PDIP) package with 0.3-inch body width and through-hole mounting. Pin 1 is CONTROL; pins 7 and 10 are NC; pins 9 and 16 are both VDD and must be connected together externally.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar serial-output 14-bit sampling ADC applications.

Compared with AD7872JNZ, AD7870JN trades 2 bits of resolution for higher speed and lower cost but removes reference integration, while ADS8320EB/2K5 adds 2 bits and speed but shifts reference design burden to the system - AD7872JNZ uniquely balances 14-bit fidelity, integrated reference, and proven industrial reliability in a drop-in PDIP footprint.

Availability

AD7872JNZ is available at Aetrix Electronics and suitable for digital signal processing, high-speed modems, and spectrum analysis applications requiring stable component supply, long-term obsolescence management, and traceable sourcing for legacy industrial systems.

Supply support for AD7872JNZ 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 semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD787x family was designed specifically for high-speed, high-accuracy data acquisition in DSP-centric systems - emphasizing integrated references, low-noise analog front-ends, and flexible serial interfaces to reduce system-level design complexity.

FAQ

What is the operating temperature range for the AD7872JNZ?

The AD7872JNZ is rated for the commercial temperature range of 0°C to +70°C. This J-grade specification ensures guaranteed performance across typical office, laboratory, and light-industrial ambient conditions without thermal derating. The device's internal 3 V reference maintains ±40 ppm/°C stability over this range, and all dynamic parameters-including 80 dB SNR and −86 dB THD-are validated across the full span. No additional heatsinking or airflow is required for compliant operation within these limits.

Does the AD7872JNZ require an external clock source?

No, the AD7872JNZ does not require an external clock source. It features a built-in laser-trimmed 2 MHz oscillator that activates automatically when the CLK pin is tied to VSS (−5 V). This eliminates the need for external crystals, oscillators, or timing components. An external TTL-compatible clock may be applied to CLK if system synchronization is required-but doing so disables the internal oscillator. The internal clock option reduces BOM count and simplifies PCB layout while maintaining full 83 kSPS throughput and 80 dB SNR performance.

How is the analog input configured for bipolar operation on the AD7872JNZ?

The AD7872JNZ accepts true bipolar analog inputs from −3 V to +3 V referenced to AGND, with twos-complement output coding. VIN connects directly to the signal source, and the internal 3 V buried Zener reference establishes the full-scale range. No external biasing or level-shifting circuitry is needed-the device internally centers the transfer function at 0 V. Input impedance is typically 15 kΩ, and the track-and-hold amplifier acquires to 14-bit accuracy in ≤2 μs, supporting full-power input signals up to 41.5 kHz while preserving linearity and SNR.

What are the required external components for basic operation of the AD7872JNZ?

For basic operation, the AD7872JNZ requires: (1) 10 nF ceramic capacitor between CREF and AGND for reference decoupling; (2) 4.7 kΩ pull-up resistor on SSTRB and SDATA; (3) 2 kΩ pull-up resistor on SCLK; (4) standard ±5 V supply decoupling (0.1 μF ceramic + 10 μF tantalum per supply rail). No external reference, clock source, or op-amp buffer is needed-the IC integrates its own 3 V reference and 2 MHz oscillator. These minimal external parts ensure reliable serial data transmission and optimal SNR performance.

Can the AD7872JNZ be used in unipolar applications?

Yes, the AD7872JNZ can be used in unipolar applications by offsetting the analog input using its internal REFOUT. A typical configuration applies REFOUT (3.00 V) to the non-inverting input of an op-amp driving VIN, shifting the input range to 0 V to +3 V (or scaled ranges like 0 V to +5 V using resistor dividers). The output remains twos-complement, so unipolar data is recovered by inverting the MSB. Full-scale and offset adjustments are supported via external trim pots (R5/R6 in Figure 14 of the datasheet), enabling calibration to ±½ LSB accuracy across temperature.