Analog Devices Inc. AD7575KPZ

Overview

AD7575KPZ from Analog Devices is an 8-bit successive approximation ADC with integrated track-and-hold, single +5 V supply operation, ±1/2 LSB total unadjusted error (max), 5 µs conversion time (with 4 MHz external clock), and 50 kHz full-power signal bandwidth. It digitizes 0–2.46 V analog inputs for microprocessor-based data acquisition in industrial control and test instrumentation.

For engineers reviewing the AD7575KPZ datasheet, AD7575KPZ pinout, AD7575KPZ application, or AD7575KPZ equivalent, key selection considerations include its unipolar/bipolar configurability, LC2MOS process low power (15 mW typ), 100 ns data access time, and compatibility with Z80H, 8085A-2, 6502B, 68B09, and TMS32010 microprocessors via memory-mapped or ROM-style interfaces.

Technical Context

The AD7575KPZ implements a SAR architecture with on-chip track-and-hold that captures input signals on the third falling edge of CLK after CS and RD assertion. Its internal clock oscillator (RCLK/CCLK-based) or external 4 MHz clock drives a 20-cycle conversion sequence (10 internal cycles), enabling deterministic sampling timing.

It uses standard microprocessor control logic (CS/RD) to initiate conversion and latch 8-bit parallel output (DB0–DB7) onto a three-state bus. The TP pin must be hard-wired HIGH; BUSY provides conversion status for WAIT-state or interrupt-driven readout coordination.

Key Specifications

Pinout & Package

AD7575KPZ is packaged in a 20-terminal plastic leaded chip carrier (PLCC), designated P-20A per Analog Devices' ordering guide. Pin 1 identifier is marked on top surface; NC pins are not internally connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7575KPZ, AD7574KN lacks integrated track-and-hold and delivers slower conversion, while MAX160BCNG+ requires dual supplies and offers looser accuracy-making AD7575KPZ optimal for compact, single-rail, high-fidelity 8-bit data acquisition.

Availability

AD7575KPZ is available at Aetrix Electronics and suitable for industrial data acquisition, automated test equipment, embedded instrumentation, and audio signal conditioning requiring stable component supply and long-term obsolescence management.

Supply support for AD7575KPZ 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 AD7575 series belongs to Analog Devices' precision data acquisition product line, designed specifically for cost-sensitive, microprocessor-coupled 8-bit ADC applications demanding low power, small footprint, and minimal external components.

FAQ

What is the maximum input signal frequency the AD7575KPZ can accurately digitize?

The AD7575KPZ supports a full-power signal bandwidth of 50 kHz, meaning it can accurately digitize 2.46 V_PP sine waves up to that frequency without slew-induced distortion. This corresponds to a maximum input slew rate of 386 mV/µs. For signals exceeding this bandwidth, amplitude accuracy degrades due to track-and-hold limitations-not sampling theorem constraints-so the AD7575KPZ remains valid for anti-alias filtering upstream of the converter.

Does the AD7575KPZ require external calibration for typical use?

No, the AD7575KPZ does not require external calibration in most applications because its total unadjusted error is specified at ±1/2 LSB maximum across temperature, eliminating the need for offset or gain trimming. The device achieves this through precision laser-trimmed DAC elements and matched transistor arrays in its LC2MOS process. Only high-accuracy metrology systems demanding <0.1% absolute error should consider optional full-scale and offset adjustments using the procedures in the datasheet.

Can the AD7575KPZ operate in bipolar mode, and how is it configured?

Yes, the AD7575KPZ supports bipolar operation via an external resistor network (Figure 17 in the datasheet) that maps ±5 V input to the internal 0–2.46 V unipolar range. The output code is offset binary (00000000 = –FS, 10000000 = 0 V, 11111111 = +FS – 1 LSB). Calibration resistors R2–R5 must be 0.1% tolerance; R4 and R5 may be replaced by a single 3.3 kΩ resistor, and R2 and R3 by a single 2.5 kΩ resistor to maintain specified performance without adjustment.

What are the critical layout guidelines for minimizing noise in AD7575KPZ circuits?

Key layout practices for the AD7575KPZ include: (1) keeping AIN and AGND traces short and adjacent as a controlled-impedance pair; (2) separating analog (AGND) and digital (DGND) ground planes, joined only at a single point near the AD7575KPZ; (3) placing 0.1 µF ceramic + 47 µF tantalum decoupling capacitors within 5 mm of VDD and VREF pins; and (4) routing CLK, CS, and RD away from analog traces to prevent coupling. Source impedance should remain below 2 kΩ to avoid settling errors.

How does the AD7575KPZ interface with the TMS32010 DSP processor?

The AD7575KPZ interfaces directly with the TMS32010 using its ROM-style interface: conversion starts on the first IN A, PA instruction (asserting CS/RD), and result data is read on the second IN A, PA instruction. The AD7575KPZ's 100 ns data access time and BUSY status output ensure reliable handshaking at TMS32010 clock frequencies up to 18 MHz. No wait-state generation is needed-the DSP reads prior conversion data while the AD7575KPZ performs the next conversion in background.