Analog Devices Inc. AD7824KN

Overview

AD7824KN from Analog Devices is a 4-channel, 8-bit LC2MOS successive-approximation analog-to-digital converter with built-in track-and-hold, single 5 V supply operation, ±1 LSB total unadjusted error, and 2.5 µs per-channel conversion time. It digitizes 0 V to 5 V analog inputs across four multiplexed channels and is used in real-time data acquisition systems requiring multichannel sampling without external sample-and-hold circuitry.

For engineers reviewing the AD7824KN datasheet, AD7824KN pinout, AD7824KN application, or AD7824KN equivalent, this page delivers verified technical context, package mapping, functional timing behavior, microprocessor interface compatibility (Z80, MC68000), and validated alternative options for industrial sensor monitoring, speech analysis, and multi-channel instrumentation.

Technical Context

The AD7824KN employs a half-flash architecture-two 4-bit flash ADCs plus an internal 4-bit DAC-to generate full 8-bit results without external clocking. Its analog input structure inherently performs track-and-hold over ~1 µs, enabling accurate digitization of 10 kHz signals (157 mV/µs slew rate) on all four channels.

Digital control uses Chip Select (CS) and Read (RD) to initiate conversions and read data from three-state DB0–DB7 outputs. Mode 0 supports WAIT-state microprocessors (e.g., Z80, MC68000); Mode 1 enables non-WAIT operation (e.g., TMS32010) with pipelined reads and INT-driven status signaling.

Key Specifications

Pinout & Package

AD7824KN is packaged in a 24-lead plastic DIP (N-24), 0.3" wide, with 0.1" lead pitch and JEDEC MO-095AG compliance. Pin 1 identifier located at top-left corner when viewed from top with notch or dot oriented left.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-channel, 8-bit ADC applications.

Compared with AD7824LN, AD7824KN trades 0.5 LSB accuracy for lower cost and broader commercial-grade availability; compared with MAX112, it offers superior analog input handling at 10 kHz without added components but lacks serial interface flexibility and channel count.

Availability

AD7824KN is available at Aetrix Electronics and suitable for industrial sensor monitoring, speech analysis systems, and multi-channel instrumentation requiring stable component supply, long-term obsolescence management, and traceable sourcing for legacy embedded designs.

Supply support for AD7824KN 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, communications, automotive, and consumer markets since 1965.

The AD7824KN belongs to Analog Devices' legacy LC2MOS precision ADC family, designed specifically for cost-sensitive, multichannel data acquisition in microprocessor-based systems where simplicity, low power, and integrated track-and-hold are critical.

FAQ

What is the maximum input signal frequency the AD7824KN can digitize without external sample-and-hold?

The AD7824KN supports full-specification digitization of analog inputs up to 10 kHz (157 mV/µs slew rate) across all four channels due to its inherent track-and-hold function. This capability is confirmed in the AD7824/AD7828 datasheet Rev. F, Figure 3 and "INHERENT SAMPLE-HOLD" section, and applies directly to the AD7824KN variant at its rated 0°C to 70°C temperature range.

Does the AD7824KN require an external clock signal to operate?

No, the AD7824KN does not require an external clock. Its half-flash conversion architecture generates internal timing, allowing operation solely from CS and RD control signals. This is explicitly stated in the "GENERAL DESCRIPTION" and "PRODUCT HIGHLIGHTS" sections of the AD7824/AD7828 datasheet Rev. F, and applies identically to the AD7824KN.

What are the logic voltage thresholds for CS and RD inputs on the AD7824KN?

The AD7824KN logic inputs (CS, RD, A0, A1) have guaranteed thresholds of VINH ≥ 2.4 V (minimum) and VINL ≤ 0.8 V (maximum), compliant with standard 5 V TTL levels. These values are specified in the "LOGIC INPUTS" table of the AD7824/AD7828 datasheet Rev. F and apply to all versions including AD7824KN.

Can the AD7824KN be used in bipolar input configurations?

Yes, the AD7824KN supports bipolar operation via its fully differential VREF(+) and VREF(–) inputs. Using external op-amp conditioning (e.g., AD544 as shown in Figure 12), it achieves ±4 V input range with complementary offset binary output. This capability is documented in the "BIPOLAR OPERATION" section of the AD7824/AD7828 datasheet Rev. F and applies to AD7824KN.

What package type is used for the AD7824KN and what are its key mechanical dimensions?

The AD7824KN uses a 24-lead plastic DIP (N-24) package, 0.3" wide, with 0.1" lead pitch and JEDEC MO-095AG compliance. Key dimensions include body width 0.300–0.325", height 0.110–0.180", and lead length 0.120–0.150". These are defined in the "OUTLINE DIMENSIONS" section of the AD7824/AD7828 datasheet Rev. F.