Analog Devices Inc. AD7878SE/883B

Overview

AD7878SE/883B from Analog Devices is a military-grade, LC2MOS 12-bit analog-to-digital converter with integrated track/hold, 3 V Zener reference, and 8-word FIFO-designed for high-speed DSP interfacing. It delivers 100 kHz sampling rate, 70 dB SNR at 10 kHz input, 41 ns data access time, and operates across –55°C to +125°C. Used in radar front-ends and avionics signal acquisition where wide temperature range and deterministic timing are critical.

For engineers reviewing the AD7878SE/883B datasheet, AD7878SE/883B pinout, AD7878SE/883B application, or AD7878SE/883B equivalent, key selection considerations include its MIL-STD-883B Class B qualification, bipolar ±3 V analog input, FIFO programmable almost-full threshold, BUSY-synchronized read/write control, and compatibility with ADSP-2100/TMS320x0 DSP buses.

Technical Context

The AD7878SE/883B implements a successive approximation ADC core synchronized to an external 8 MHz TTL clock, with internal clock division enabling precise 500 ns bit trial timing. Its FIFO architecture supports pipelined acquisition: up to eight 12-bit twos-complement samples (plus OOR flag) can be stored before host intervention.

Control logic includes a status/control register accessible via ADD0-high reads/writes, supporting ALFL interrupt generation, FIFO overrun detection (FOVR), output disable during BUSY (DISO), and real-time word count monitoring. All digital timing parameters-including t9 (41 ns data access) and t14 (41 ns data access after BUSY)-are 100% production tested over full temperature range.

Key Specifications

Pinout & Package

AD7878SE/883B is supplied in a 28-lead leadless ceramic chip carrier (LCCC), hermetically sealed and qualified to MIL-STD-883B Class B. Package outline conforms to E-28A specification with 0.050" lead pitch and glass-sealed ceramic body.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit high-speed ADC applications.

Compared with AD7878SQ/883B, AD7878SE/883B offers faster 41 ns access and LCCC mechanical robustness; versus ADS8320UB, it provides military qualification, FIFO buffering, and deterministic DSP bus timing-but at lower resolution and fixed ±3 V input range.

Availability

AD7878SE/883B is available at Aetrix Electronics and suitable for radar signal acquisition, avionics sensor interfacing, electronic warfare receivers, and secure voice terminals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7878SE/883B 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 precision instrumentation, aerospace, and defense markets since 1965.

The AD7878 product line was engineered specifically for military and aerospace signal acquisition systems requiring deterministic timing, wide-temperature operation, and direct DSP bus compatibility-prioritizing FIFO efficiency, MIL qualification, and spectral purity over generic ADC metrics.

FAQ

What is the guaranteed data access time for AD7878SE/883B over its full operating temperature range?

The AD7878SE/883B guarantees 41 ns maximum data access time (t9 parameter) from DMRD assertion to valid data on DB11–DB0, fully tested across –55°C to +125°C per MIL-STD-883B. This specification ensures compatibility with ADSP-2100 and TMS32020 DSPs without wait-state insertion, even under extreme thermal stress.

Does AD7878SE/883B require an external reference voltage, or is the 3 V reference internally generated?

The AD7878SE/883B integrates a precision 3.0 V Zener reference output at the REF OUT pin, specified to ±15 mV over –55°C to +125°C. No external reference is required; however, capacitive loads exceeding 50 pF demand a series resistor to maintain stability, as detailed in the Internal Reference section of the datasheet.

How does the FIFO almost-full (ALFL) function work in AD7878SE/883B, and how is it configured?

The ALFL output in AD7878SE/883B asserts low when the FIFO word count reaches a user-programmed threshold (1–8 words) stored in bits DB10–DB8 of the status/control register. Configuration occurs via a write to the status register with ADD0 high; ALFL updates at end-of-conversion and resets upon FIFO read-enabling programmable interrupt-driven buffer management in DSP firmware.

Can AD7878SE/883B perform conversions while the host processor reads data from the FIFO?

Yes-AD7878SE/883B supports concurrent conversion and read operations via its decision-point slippage mechanism. If DMRD or DMWR is asserted during a critical tLOW window before internal comparator strobing, the bit decision is deferred by one CLK IN cycle, preventing bus-induced errors while maintaining FIFO throughput and conversion integrity.

What package type and qualification standard applies to AD7878SE/883B?

AD7878SE/883B is packaged in a 28-lead leadless ceramic chip carrier (E-28A) and is fully qualified to MIL-STD-883B Class B, including temperature cycling, burn-in, and hermeticity testing. This qualification confirms suitability for high-reliability defense and aerospace applications with stringent environmental and lifetime requirements.