Analog Devices Inc. AD670KP

Overview

AD670KP from Analog Devices is a complete 8-bit signal conditioning analog-to-digital converter with integrated instrumentation amplifier, precision voltage reference, DAC, SAR architecture, and three-state microprocessor bus interface. It delivers ±1/4 LSB relative accuracy and ±0.75 LSB gain accuracy over 0°C to +70°C, operates from a single +5 V supply, and supports differential bipolar/unipolar inputs up to ±128 mV or ±1.28 V - ideal for transducer interfacing in industrial sensor systems.

For engineers reviewing the AD670KP datasheet, AD670KP pinout, AD670KP application, or AD670KP equivalent, this page provides verified technical context, validated pin functions, confirmed input range configurations (0–255 mV / 0–2.55 V / ±128 mV / ±1.28 V), real-world transducer interface examples, and two factory-validated alternative parts with documented functional trade-offs.

Technical Context

The AD670KP implements a dynamic successive approximation register (SAR) using an inverter-based delay-line architecture-no external clock required-enabling 10 µs conversion time. Its front-end instrumentation amplifier provides high-impedance differential inputs with guaranteed common-mode rejection of ≤1 LSB across both 255 mV and 2.55 V ranges.

Control logic accepts standard microprocessor signals (R/W, CS, CE) and generates STATUS output; data outputs are three-state with 1.6 mA sink / 0.5 mA source capability. Input scaling and output coding (straight binary or 2's complement) are selected via BPO/UPO and FORMAT pins prior to conversion start.

Key Specifications

Pinout & Package

AD670KP is housed in a 20-terminal plastic leaded chip carrier (PLCC, package code P-20A), with gull-wing leads and exposed thermal pad. Pin numbering follows standard PLCC convention (Pin 1 = corner mark, counterclockwise).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD670KP, AD670KN trades 0.25 LSB accuracy for lower unit cost in identical PLCC-compatible footprint, while AD7810BR offers higher resolution at the expense of added external circuitry and loss of integrated transducer interface capability.

Availability

AD670KP is available at Aetrix Electronics and suitable for industrial sensor interfaces, PLC analog input modules, and embedded transducer signal acquisition requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for AD670KP 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing ICs for precision measurement and control.

The AD670 product line was designed to simplify transducer-to-microprocessor signal chains by integrating instrumentation amplification, reference, conversion, and bus interface on a single monolithic die - targeting industrial, test, and sensor interface applications.

FAQ

What is the operating temperature range specified for the AD670KP?

The AD670KP is rated for operation from 0°C to +70°C. This commercial-grade temperature specification is defined in the Ordering Guide and confirmed in the electrical characteristics tables for the K-grade variant. All performance parameters-including relative accuracy (±1/4 LSB), gain accuracy (±0.75 LSB), and conversion time (10 µs)-are guaranteed across this full range. The AD670KP does not support extended or military temperature grades.

Does the AD670KP require external components to achieve full 8-bit accuracy?

No, the AD670KP requires no external components or user trims to achieve full 8-bit accuracy. Its monolithic construction integrates a laser-trimmed thin-film SiCr resistor ladder, precision voltage reference, instrumentation amplifier, DAC, and SAR logic. Factory calibration ensures ±1/4 LSB relative accuracy and ±0.75 LSB gain accuracy over 0°C to +70°C - all without external resistors, capacitors, or trimming potentiometers.

How does the AD670KP handle bipolar input signals with a single +5 V supply?

The AD670KP uses a specialized instrumentation amplifier front end that allows true bipolar input operation (e.g., ±128 mV or ±1.28 V) from a single +5 V supply. When BPO/UPO is driven high before conversion, an internal bipolar offset current equal to MSB – 1/2 LSB is injected into the comparator summing node. This shifts the effective input range symmetrically around zero without requiring negative supply rails or external level-shifting circuitry.

What package type is used for the AD670KP, and how does it differ from the AD670JN?

The AD670KP uses a 20-terminal plastic leaded chip carrier (PLCC, package code P-20A), whereas the AD670JN uses a 20-pin plastic DIP (N-20). Both share identical pin functions and electrical specifications, but the PLCC offers superior thermal dissipation, smaller PCB footprint, and gull-wing surface-mount compatibility - making AD670KP preferable for space-constrained or thermally demanding industrial designs.

Can the AD670KP be interfaced directly to an 8-bit microprocessor data bus?

Yes, the AD670KP features three-state parallel 8-bit digital outputs (D0–D7) with standard microprocessor control signals (R/W, CS, CE). When CS and CE are low and R/W is high, the outputs drive the bus with TTL-compatible levels (0.4 V low, 2.4 V high) and 1.6 mA sink capability. No bus transceivers or level shifters are needed - enabling direct connection to 8051, Z80, or similar 8-bit microcontrollers.