Analog Devices Inc. AD573KNZ

Overview

AD573KNZ from Analog Devices is a complete 10-bit successive approximation analog-to-digital converter (ADC) with integrated buried Zener reference, internal clock, comparator, and SAR logic. It delivers ±1 LSB relative accuracy, 20 µs typical conversion time, and supports both unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges. It is used in precision data acquisition systems requiring stable on-chip reference and microprocessor-compatible digital interface.

For engineers reviewing the AD573KNZ datasheet, AD573KNZ pinout, AD573KNZ application, or AD573KNZ equivalent, key selection considerations include its dual-range analog input flexibility, 8-/10-bit bus interface capability via HBE/LBE control, guaranteed no-missing-codes performance over 0°C to +70°C, and compatibility with +5 V / –12 V to –15 V dual-supply operation.

Technical Context

The AD573KNZ implements successive approximation using integrated injection logic (I2L) SAR architecture, with a laser-trimmed SiCr thin-film resistor ladder and temperature-compensated subsurface Zener reference ensuring stability. Its 10-bit current-output DAC compares input current through a 5 kΩ trimmed input resistor against weighted bit currents to generate the final code.

Conversion is initiated by a 500 ns minimum positive CONVERT pulse; DATA READY (DR) signals completion within 1.5 µs after reset and goes low after 10–30 µs. Output data is left-justified: DB9–DB2 (8 MSBs) enabled by HBE, DB1–DB0 (2 LSBs) enabled by LBE - supporting both 8-bit bus interfacing and full 10-bit readout.

Key Specifications

Pinout & Package

AD573KNZ is housed in a 20-pin plastic dual in-line package (PDIP), narrow body (N-20), with 0.300-inch width and standard DIP lead spacing. The package is RoHS-compliant and rated for 0°C to +70°C industrial operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit ADC applications.

Compared with AD573KNZ, AD7819BRUZ offers faster conversion and lower supply voltage but sacrifices bipolar range and dual-supply robustness; MAX1113EPA+ simplifies power design and reduces footprint but removes the analog range configurability and ±1 LSB guarantee over temperature that define AD573KNZ's industrial suitability.

Availability

AD573KNZ is available at Aetrix Electronics and suitable for industrial process monitoring, legacy microprocessor interfacing, and embedded data acquisition requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for AD573KNZ 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD573KNZ belongs to Analog Devices' legacy precision ADC product line, designed specifically for industrial and instrumentation applications demanding guaranteed monotonicity, integrated reference stability, and direct microprocessor bus compatibility without external support components.

FAQ

What is the operating temperature range for the AD573KNZ?

The AD573KNZ is specified for operation from 0°C to +70°C. This industrial-grade temperature range is validated across all electrical parameters including relative accuracy (±1 LSB), conversion time (10–30 µs), and input range fidelity. The "K" grade designation explicitly denotes this temperature rating, and the "NZ" suffix confirms the 20-pin plastic DIP (N-20) package. Unlike the AD573S (–55°C to +125°C), the AD573KNZ is optimized for cost-sensitive commercial and industrial applications where extended temperature coverage is not required.

Does the AD573KNZ require external components to achieve full 10-bit accuracy?

No, the AD573KNZ requires no external components to perform a full-accuracy 10-bit conversion. Its monolithic construction integrates a 10-bit current-output DAC, temperature-compensated buried Zener reference, internal clock generator, comparator, successive approximation register (SAR), and three-state output buffers. The only mandatory external connections are the +5 V and –12 V to –15 V power supplies, analog input signal, and CONVERT trigger. Optional external resistors (e.g., 15 Ω or 50 Ω trimmers) may be used for fine full-scale calibration but are not needed for baseline ±1 LSB performance.

How does the AD573KNZ support both unipolar and bipolar input ranges?

The AD573KNZ selects between unipolar (0 V to +10 V) and bipolar (–5 V to +5 V) input ranges using Pin 16 (BIPOLAR OFFSET CONTROL). When Pin 16 is grounded to DIGITAL COMMON (Pin 14), the device operates in unipolar mode. When Pin 16 is left open, it enters bipolar mode - injecting a precise offset current equal to the MSB minus ½ LSB into the comparator summing node. This hardware-level configuration requires no software change or register write, making it ideal for field-reconfigurable systems. The output coding also switches automatically: unipolar uses true binary; bipolar uses offset binary.

What are the power supply requirements for the AD573KNZ?

The AD573KNZ requires two independent supplies: +5 V applied to Pin 20 (V+) and –12 V to –15 V applied to Pin 11 (V–). The +5 V rail powers digital logic, output buffers, and reference biasing; the negative rail powers the DAC core, comparator, and analog front-end. Absolute maximum ratings allow V+ from +4.5 V to +7 V and V– from –11.4 V to –16.5 V. Operation outside the specified ranges risks degraded linearity, increased offset error, or failure to meet the guaranteed ±1 LSB relative accuracy. Decoupling capacitors (e.g., 0.1 µF ceramic + 10 µF tantalum) are recommended at each supply pin near the package.

Can the AD573KNZ interface directly to an 8-bit microprocessor bus?

Yes, the AD573KNZ is designed for direct interface to 8-bit microprocessor buses such as those found in 8085, Z80, and 6502 systems. Its HBE (Pin 19) and LBE (Pin 18) controls enable the upper 8 bits (DB9–DB2) and lower 2 bits (DB1–DB0) independently, allowing the 10-bit result to be read as two consecutive 8-bit bytes - with DB9–DB2 occupying the high byte and DB1–DB0 aligned to the two most significant bits of the low byte. No external latches, buffers, or address decoders are required for basic memory-mapped or isolated I/O operation, as confirmed in the AD573KNZ functional description and timing diagrams.