AD779KD - 14-Bit 128 kSPS Sampling ADC | Analog Devices
MPN: AD779KD ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $38.5 | $38.50 |
| 10 | $34.2 | $342.00 |
| 100 | $28.75 | $2,875.00 |
| 500 | $24.1 | $12,050.00 |
| 1,000 | $20.45 | $20,450.00 |
AD779KD Overview
A sampling ADC is a type of analog-to-digital converter that captures an instantaneous analog input through a front-end sample-and-hold stage before quantization, eliminating the need for an external track-and-hold and ensuring well-defined aperture timing at high input frequencies. Within the broader component hierarchy, the AD779KD belongs to successive-approximation register (SAR) ADCs > data converters > signal chain ICs > analog/mixed-signal semiconductors. Sampling ADCs bridge the analog sensor world and the digital processor, and are widely deployed wherever a clean, repeatable snapshot of a fast-moving analog waveform must be digitized into a 14-bit codeword.
Key features include 14-bit resolution with no missing codes, an integrated 5 V reference, a throughput rate of 128 k samples per second, and monolithic BiMOS construction. The AD779 is available in AC- and DC-characterized K, B, and T grades, providing designers with parametric options for different accuracy budgets. MIL-STD-883-compliant versions are available for aerospace and defense designs.
The architecture combines a fast input SHA that holds the analog signal during conversion with a SAR core, achieving low aperture uncertainty and consistent conversion timing. The internal reference removes one external component and improves overall gain temperature coefficient.
Typical applications include precision industrial data acquisition, signal processing front ends, audio and vibration analysis, medical instrumentation, and military/aerospace digital signal processing subsystems. The CDIP-28 ceramic package supports extended-temperature and high-reliability environments.
When designing with the AD779, observe the datasheet's analog and digital supply decoupling recommendations and respect the 128 kSPS throughput limit to avoid pipeline timing violations. Bypass both AVCC and DVCC pins with 0.1 microfarad ceramic capacitors placed as close to the package as possible.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for AD779KD — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD779KN
✅ Drop-In📋 Reference alternative (not in catalog)
AD779JD
✅ Drop-In📋 Reference alternative (not in catalog)
AD779BD
✅ Drop-In📋 Reference alternative (not in catalog)
AD779TD
✅ Drop-In📋 Reference alternative (not in catalog)
AD779JN
✅ Drop-In📋 Reference alternative (not in catalog)
AD779KD Maximum Ratings & Electrical Characteristics
| Resolution | 14 bit |
| Sample Rate | 128 kSPS |
| Number of Input Channels | 1 |
| Architecture | SAR with integrated SHA |
| Input Type | Single-ended |
| Conversion Type | Successive Approximation with Sample/Hold |
| Integral Reference | 5 V on-chip voltage reference |
| Data Interface | Parallel, microprocessor-compatible |
| Package | 28-CDIP (Ceramic DIP) |
| Mounting Type | Through-hole |
| Pin Count | 28 |
| Technology | BiMOS monolithic |
| RoHS Status | non_compliant (ceramic DIP, contains lead-bearing terminations on legacy variants) |
| Military/Hi-Rel | MIL-STD-883 versions available |
AD779KD Pin Configuration
| Pin 1 | VCC — Positive analog/digital supply |
| Pin 2 | GND — Ground (analog) |
| Pin 3 | DGND — Digital ground |
| Pin 4 | AVCC — Analog positive supply |
| Pin 5 | REF OUT — +5 V reference output |
| Pin 6 | REF IN — Reference input |
| Pin 7 | AIN — Analog input |
| Pin 8 | NC — Not connected (per datasheet) |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | AGND — Analog ground |
| Pin 11 | V- — Negative analog supply or GND |
| Pin 12 | BUF — Buffer / SHA output |
| Pin 13 | DGND — Digital ground |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | DB0 — Data bit 0 (LSB) |
| Pin 16 | DB1 — Data bit 1 |
| Pin 17 | DB2 — Data bit 2 |
| Pin 18 | DB3 — Data bit 3 |
| Pin 19 | DB4 — Data bit 4 |
| Pin 20 | DB5 — Data bit 5 |
| Pin 21 | DB6 — Data bit 6 |
| Pin 22 | DB7 — Data bit 7 |
| Pin 23 | DB8 — Data bit 8 |
| Pin 24 | DB9 — Data bit 9 |
| Pin 25 | DB10 — Data bit 10 |
| Pin 26 | DB11 — Data bit 11 |
| Pin 27 | DB12 — Data bit 12 |
| Pin 28 | DB13 (MSB) — Data bit 13 (MSB) |
Typical Applications
AD779KD is suitable for 6 applications: Precision Industrial Data Acquisition, Signal Processing Front End, Medical Instrumentation, Military and Aerospace Digital Signal Processing, Audio and Vibration Analysis, Process Control and Automation.
Precision Industrial Data Acquisition
The AD779KD's 14-bit resolution with 128 kSPS throughput and integrated sample-hold amplifier makes it well suited for precision industrial data-acquisition front ends digitizing sensor signals from strain gauges, pressure transducers, and thermocouples. Its integrated 5 V reference removes a common source of gain drift, and its monolithic BiMOS construction provides long-term reliability compared with multi-chip hybrid ADC designs. Placed between the analog front end and a microprocessor via the parallel bus interface, the part delivers consistent conversions even under the noisy electrical conditions typical of industrial environments.
Recommended
Signal Processing Front End
The K-grade characterization for AC parameters such as S/N+D ratio, THD, and intermodulation distortion makes the AD779KD a strong choice for signal-processing front ends where dynamic performance matters as much as DC accuracy. Used to digitize audio-band or vibration signals at up to 128 kSPS, the part provides a clean codeword stream for downstream DSP. The internal SHA eliminates the need for an external track-and-hold and reduces aperture uncertainty, which directly improves SNR in wideband signal acquisition.
Recommended
Medical Instrumentation
Medical instrumentation such as patient monitors, ECG front ends, and blood-analyzer digitizers benefit from the AD779KD's 14-bit resolution, integrated sample-hold, and ceramic-package reliability. The CDIP-28 package supports the extended-temperature operation required for clinical and laboratory-grade instruments, while the device's monolithic integration reduces bill-of-material complexity. Positioned between the analog signal-conditioning block and a microcontroller or DSP, the AD779KD delivers the deterministic 128 kSPS throughput needed for time-stamped bio-signal recordings.
Recommended
Military and Aerospace Digital Signal Processing
The AD779KD is available with MIL-STD-883 screening (883B suffix variants), making it qualified for military and aerospace DSP subsystems. The ceramic CDIP-28 package tolerates the extended temperature ranges and mechanical stresses typical of avionics and defense platforms. At 14 bits and 128 kSPS, it can digitize IF or audio-bandwidth signals in tactical radios, sonar, and vibration-monitoring systems, with the reliability pedigree that legacy military programs require for long-life cycle deployment.
Recommended
Audio and Vibration Analysis
Vibration-analysis systems and high-fidelity audio analyzers rely on consistent 14-bit conversions at high sampling rates to capture waveform detail. The AD779KD's integrated SHA and SAR core deliver 128 kSPS with well-defined aperture, ensuring that broadband vibration signatures or audio-band signals are sampled without the timing errors that degrade FFT-based analysis. The internal 5 V reference improves the temperature coefficient of full-scale accuracy, which is critical when measuring small accelerations or acoustic amplitudes over long test campaigns.
Recommended
Process Control and Automation
Industrial process-control loops require a rugged ADC front end to digitize 4-20 mA current loops, RTD outputs, and process-variable sensor signals. The AD779KD's monolithic design and ceramic-package reliability translate the analog process variable into a 14-bit codeword that the controller's microprocessor reads over the parallel bus. The integration of reference and clock reduces part count, simplifying the bill of materials for long-life, field-deployed PLC and DCS modules.
Recommended
Recommended Products Summary
Engineering reference data for AD779KD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD779KN | AD779JD | AD779BD | AD779TD | AD779JN |
|---|---|---|---|---|---|---|
| Package | 28-CDIP (Ceramic DIP) | 28-PDIP (Plastic DIP) | 28-CDIP (Ceramic DIP) - same | 28-CDIP (Ceramic DIP) - same | 28-CDIP (Ceramic DIP) - same | 28-PDIP (Plastic DIP) |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 14 bit | 14 bit | 14 bit | 14 bit | 14 bit | 14 bit |
| Sample Rate | 128 kSPS | 128 kSPS | 128 kSPS | 128 kSPS | 128 kSPS | 128 kSPS |
| Temperature Grade | Industrial (K-grade) | Industrial (K-grade) | Commercial (J-grade) | Industrial (B-grade) | Extended/MIL (T-grade) | Commercial (J-grade) |
| Package Type | Ceramic DIP (lead-bearing) | Plastic DIP (lead-free) | Ceramic DIP (lead-bearing) | Ceramic DIP (lead-bearing) | Ceramic DIP (lead-bearing) | Plastic DIP (lead-free) |
| MIL-STD-883 Screening | Optional (883B variant) | Optional | Optional | Optional | Yes (T-grade screened) | No |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
| Input Channels | 1 | 1 | 1 | 1 | 1 | 1 |
| Architecture | SAR + integrated SHA | SAR + integrated SHA | SAR + integrated SHA | SAR + integrated SHA | SAR + integrated SHA | SAR + integrated SHA |
Key Differentiators
- Monolithic BiMOS integration with on-chip reference (vs AD779KN (plastic DIP K-grade))
- K-grade AC + DC characterization (vs AD779JD (J-grade))
- MIL-STD-883 screening available on T-grade ceramic DIP (vs AD779TD (T-grade CDIP))
Design Notes
Power the AD779KD from a clean analog supply; AVCC and DVCC should be decoupled with 10 microfarad tantalum in parallel with 0.1 microfarad ceramic capacitors placed within 5 mm of the supply pins per the datasheet reference design. Sharing the analog and digital grounds through a single star-point ground at the ADC prevents digital switching noise from corrupting the sample-and-hold acquisition window. Estimated: assuming 100 mA peak AVCC current during SAR bit-cycles, supply-trace impedance should be < 0.1 ohm to limit cross-supply noise pickup.
Place the AD779KD close to the analog input and the parallel bus connector to keep analog traces short and matched; route the 14 data lines in a controlled-impedance group and avoid crossing noisy digital return currents. Keep the analog input trace (AIN) over a continuous ground plane with no splits beneath it. Estimated: 50 ohm characteristic impedance traces require 0.5-0.8 mm spacing on a 4-layer FR-4 stackup; verify with field-solver for your exact board stack.
Do not exceed the maximum analog input voltage to AIN or the absolute-maximum rating on any digital I/O pin — the part lacks internal ESD clamps robust enough to survive handling transients. Ensure that conversions are initiated only after the internal reference has settled (typically several hundred microseconds after power-up). Pulling CONVST or reading data during a conversion can cause metastability; gate read accesses with the BUSY pin falling edge per the datasheet timing diagram.
Compliance Information
Legacy ceramic DIP package includes lead-bearing terminations on original AD779KD parts. RoHS-compliant lead-free equivalents (AD779KNZ, AD779JNZ) are available from the same family. MIL-STD-883B screening is available on T-grade variants per the AD779 datasheet family.
