Analog Devices Inc. AD673JNZ

Overview

AD673JNZ from Analog Devices is a complete 8-bit successive approximation analog-to-digital converter (ADC) with integrated buried Zener reference, on-chip clock, comparator, SAR, and 3-state digital outputs. It delivers ±1/2 LSB relative accuracy, supports unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges, and achieves full conversion in ≤30 µs using +5 V and –12 V to –15 V supplies - ideal for precision data acquisition in industrial instrumentation and test equipment.

For engineers reviewing the AD673JNZ datasheet, AD673JNZ pinout, AD673JNZ application, or AD673JNZ equivalent, key selection considerations include its self-contained architecture (no external DAC/reference required), dual-range input flexibility via Pin 16 control, guaranteed no-missing-codes performance over 0°C to +70°C, and compatibility with 8-bit microprocessor buses without interface logic.

Technical Context

The AD673JNZ implements successive approximation using integrated injection logic (I2L) and a laser-trimmed SiCr thin-film resistor ladder, enabling true 8-bit linearity and stability. Its buried Zener reference provides temperature-compensated voltage reference for the internal 8-bit current-output DAC, ensuring ±1/2 LSB relative accuracy across its operating range.

Conversion is initiated by the trailing edge of a ≥500 ns positive CONVERT pulse; DATA READY (DR) asserts within 1.5 µs after the leading edge to signal reset completion and goes low upon conversion finish. The 5 kΩ trimmed input resistor enables precise full-scale calibration - adjustable to ±2 LSB error using an external 15 Ω or 200 Ω potentiometer.

Key Specifications

Pinout & Package

AD673JNZ is supplied in a 20-pin plastic DIP (N-20) package with 0.3-inch body width and through-hole mounting. Pin 1 identifier is marked with a notch; Pins 1 and 2 are internally connected to test points and must remain unconnected.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit successive approximation ADC applications.

Compared with AD673JNZ, AD7572A offers higher package robustness but sacrifices bipolar input flexibility and requires external clocking, while MAX160 reduces supply complexity and power at the cost of accuracy, input range, and missing-codes guarantee - making AD673JNZ optimal for precision dual-range industrial acquisition where ±1/2 LSB monotonicity is mandatory.

Availability

AD673JNZ is available at Aetrix Electronics and suitable for industrial process monitoring, automated test equipment, medical instrumentation, and legacy avionics data acquisition requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for AD673JNZ 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 AD673JNZ belongs to Analog Devices' precision data acquisition IC family, designed specifically for applications demanding self-contained, high-accuracy ADC functionality without external support components in industrial and instrumentation environments.

FAQ

What is the maximum conversion time specification for the AD673JNZ?

The AD673JNZ has a maximum conversion time of 30 µs across its full operating temperature range of 0°C to +70°C. This value is guaranteed and tested on all production units. The typical conversion time is 20 µs, and the minimum is 10 µs. This timing is measured from the falling edge of the CONVERT pulse to the assertion of DATA READY going low, and it enables sampling rates up to approximately 100 kSPS in burst-mode applications where DR is used for handshaking.

How does the AD673JNZ support both unipolar and bipolar input ranges?

The AD673JNZ supports unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges through hardware configuration of Pin 16 (BIPOLAR OFFSET CONTROL). Grounding Pin 16 to Digital Common selects unipolar mode; leaving Pin 16 open selects bipolar mode. Internally, this controls a switch that injects a precise offset current equal to MSB–½ LSB into the comparator's summing node, shifting the transfer function accordingly - no software or external components are needed.

What supply voltages are required for proper operation of the AD673JNZ?

The AD673JNZ requires two supply rails: +5 V (V+, Pin 19) and –12 V to –15 V (V–, Pin 20), both referenced to Digital Common. The +5 V rail powers logic, reference, and output buffers; the negative rail powers the DAC and comparator. Operation outside these ranges - such as using –5 V or +12 V - is not supported and may cause malfunction or damage. Decoupling capacitors must be placed separately for each rail, returning to their respective common planes.

Does the AD673JNZ require external components to achieve full 8-bit accuracy?

No, the AD673JNZ is a complete 8-bit ADC and requires no external components to achieve full accuracy under nominal conditions. Its integrated buried Zener reference, laser-trimmed 5 kΩ input resistor, on-chip clock, and comparator eliminate the need for external references, clocks, or DACs. However, for fine full-scale calibration, a 200 Ω trimmer potentiometer may be added in series with the analog input - but this is optional, not mandatory, for basic operation.

What is the meaning of "no missing codes" in the AD673JNZ specifications?

"No missing codes" means the AD673JNZ guarantees monotonicity across its entire transfer function: every possible 8-bit output code (0 to 255) appears at least once as the analog input is swept across its full range. This is verified over the full 0°C to +70°C temperature range and ensures reliable operation in closed-loop control, servo positioning, and waveform digitization where code gaps would cause instability or distortion. It is distinct from differential nonlinearity and is a stronger guarantee than linearity alone.