AD677KR - 16-Bit 100 kSPS Serial SAR ADC | Analog Devices
MPN: AD677KR ⚠ Last Time BuyAD677KR Overview
A SAR ADC is a successive-approximation analog-to-digital converter. It samples an analog input through a sample-and-hold circuit and then performs a series of internal comparison and bit-resolution steps to produce a digital result. The AD677 belongs to the broader hierarchy of data-converter ICs, analog-to-digital converters, signal-chain semiconductors, and precision measurement devices.
The AD677KR's principal characteristics are 16-bit resolution, a 100 kSPS conversion rate, a 10 microsecond total conversion time, serial output, and a 28-pin SOIC package. Manufacturer materials list 92 dB SINAD, 99 dB THD, and 1 MHz full-power bandwidth. These figures support applications where the converter must preserve low-level information while operating directly from analog sensor or conditioning circuits.
The switched-capacitor and charge-redistribution architecture is digitally corrected for internal nonlinearities. Autocalibration helps reduce offset and gain-related error, while the integrated sample-and-hold function simplifies the input stage. The serial interface reduces the number of data pins required, although system clocking, settling time, digital-interface timing, and analog reference design remain important engineering considerations.
Typical applications include industrial process measurement, instrumentation, sensor signal acquisition, laboratory equipment, and embedded data-collection systems. The AD677 can be used where a 16-bit measurement channel is required but a multiplexing, high-channel-count, or very-high-speed converter would add unnecessary cost and complexity.
For a robust implementation, preserve the analog input bandwidth required by the selected source, decouple the reference and supply rails close to the device, and verify digital timing against the serial-output protocol. Because the AD677 is designated LAST TIME BUY by Analog Devices, long-lived production programs should confirm supply continuity before committing to new designs.
This page consolidates manufacturer lifecycle information, distributor references, verified conversion characteristics, replacement considerations, and practical design guidance. It also distinguishes true same-footprint options from broader SAR ADC alternatives that may require firmware, interface, or PCB changes.
Drop-in alternatives for AD677KR — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD677KR (same form factor and footprint) — differing in Architecture, Total Harmonic Distortion.
AD677JRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD677JR
✅ Drop-InContact for price
View Datasheet →AD677KR Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Sampling Rate | 100 kSPS |
| Total Conversion Time | 10 us |
| Architecture | Switched-capacitor/charge-redistribution SAR |
| Input Count | 1 input |
| Output Type | Serial, 16 bit |
| Sample-and-Hold | On-chip |
| Autocalibration | Supported |
| No Missing Codes | 16 bit, no missing codes |
| Signal-to-Noise and Distortion Ratio | 92 dB |
| Total Harmonic Distortion | 99 dB |
| Full-Power Bandwidth | 1 MHz |
| Package | 28-lead SOIC |
| Mounting Type | Surface mount |
| Analog Input Type | Single-ended/unipolar input |
| Digital Interface | Serial output |
| RoHS Status | unknown |
AD677KR 28-lead soic Pin Configuration Guide
Pin configuration for AD677KR (28-lead soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for AD677KR.
Refer to the datasheet for full pin configuration.
Typical Applications
AD677KR is suitable for 6 applications: Industrial Process Measurement, Precision Sensor Signal Acquisition, Laboratory Instrumentation, Data Acquisition Embedded Systems, Communication and Network Monitoring, Test and Measurement Equipment.
Industrial Process Measurement
The AD677KR fits single-channel industrial process measurement when a sensor conditioner's output must be digitized with 16-bit resolution at up to 100 kSPS. Its 92 dB SINAD, 99 dB THD, and integrated sample-and-hold support accurate capture of process variables such as pressure, temperature, or flow. Place the converter behind a low-noise analog front end, use a stable reference, and decouple supply pins close to the package. The manufacturer's 10 microsecond total conversion time permits 100 kSPS operation, while the 28-lead SOIC simplifies assembly in conventional surface-mount industrial electronics.
Recommended
Precision Sensor Signal Acquisition
The AD677KR is appropriate for acquiring a conditioned precision sensor signal when one analog channel and serial output are sufficient. Its 16-bit no-missing-code characteristic and 92 dB SINAD preserve small signal variations better than a lower-resolution converter, while the on-chip sample-and-hold simplifies acquisition timing. The analog signal path still requires careful reference grounding, input filtering, and protection against transients. At 100 kSPS, use the manufacturer's serial timing data to confirm that the controller clocking and data-capture latency meet the measurement bandwidth.
Recommended
Laboratory Instrumentation
The AD677KR can serve as the measurement converter in laboratory instrumentation requiring a precise single-ended input and moderate acquisition speed. Its 100 kSPS rate and 16-bit resolution balance resolution with system complexity, and the serial interface limits the number of connections required between the ADC and control electronics. For bench equipment, focus on reference stability, low-noise supply design, and avoiding digital return currents beneath the analog input and reference pins. The LAST TIME BUY status should be considered before designing additional instrument models around this converter.
Recommended
Data Acquisition Embedded Systems
AD677KR is suitable for an embedded data-acquisition channel that must output 16-bit measurement data to a microcontroller, DSP, or FPGA through a serial interface. The 100 kSPS maximum rate is ample for many slow or medium-bandwidth sensors and avoids the cost of a high-speed parallel ADC. Firmware must handle the specified clock and conversion timing, while the hardware must accommodate the device's supply and reference requirements. Because the verified information does not include exact interface logic levels, verify them against the current datasheet rather than inferring compatibility from the serial-output description.
Recommended
Communication and Network Monitoring
The AD677KR can monitor a slow-changing analog control, supply, or sensor node within communications equipment when 100 kSPS resolution is adequate. Its 16-bit conversion resolution supports calibration and diagnostic measurements, while the serial output leaves more board area available than a parallel interface. Design the input network to prevent RF pickup and keep the reference away from switching regulators. For network equipment with long product lifetimes, verify supply continuity because the AD677 family is LAST TIME BUY and may not be appropriate for a newly created platform with an extended production forecast.
Recommended
Test and Measurement Equipment
The AD677KR is a practical choice for bench and production test equipment requiring a dedicated 16-bit measurement input rather than a high-channel-count converter. Its 92 dB SINAD, 99 dB THD, and 1 MHz full-power bandwidth provide useful dynamic range for calibrated stimulus-response measurements. A well-controlled reference and quiet analog layout are essential if the full resolution is to be realized. The 100 kSPS sampling rate supports many general-purpose measurements, while specialized high-frequency test systems should use a converter with a substantially higher sample rate.
Recommended
Recommended Products Summary
Engineering reference data for AD677KR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD677JRZ | AD677JR |
|---|---|---|---|
| Package | 28-lead SOIC | 28-lead SOIC | 28-lead SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 16 bit | 16 bit | 16 bit |
| Sampling Rate | 100 kSPS | 100 kSPS | 100 kSPS |
| Conversion Time | 10 us | 10 us | 10 us |
| Architecture | Switched-capacitor/charge-redistribution SAR | Switched-capacitor/charge-redistribution SAR | Switched-capacitor/charge-redistribution SAR |
| Output Interface | 16-bit serial | 16-bit serial | 16-bit serial |
| SINAD | 92 dB | 92 dB | 92 dB |
| THD | 99 dB | 99 dB | 99 dB |
| Full-Power Bandwidth | 1 MHz | 1 MHz | 1 MHz |
| Operating Temperature Grade | K commercial grade; exact limits unavailable | J grade; exact limits unavailable | J grade; exact limits unavailable |
| Lifecycle Status | LAST TIME BUY | AD677 family LAST TIME BUY | AD677 family LAST TIME BUY |
Key Differentiators
- Verified same-family replacement path (vs AD677JRZ)
- Single-channel precision with integrated sampling (vs AD676 parallel-output family)
- Documented low-distortion performance (vs AD677JR)
Design Notes
Route the analog input, reference, and analog ground paths away from digital clock and serial-data return currents. Place the input network, reference bypass components, and supply decoupling in the order required by the current Analog Devices datasheet. A compact, quiet analog section is especially important because the converter provides 16-bit resolution; excessive trace resistance, via inductance, or shared return paths can degrade effective accuracy even when the nominal ADC specifications are met.
Use the supply voltages and bypass-capacitor values stated in the manufacturer datasheet rather than generic values. The supplied verified excerpts do not provide the exact rails, reference voltage, or recommended capacitance, so these items remain data-needed. Check startup sequencing, supply tolerances, reference settling, and power-supply noise at the pins. If the ADC shares a board with switching converters, isolate its reference and provide local high-frequency bypassing rather than relying on bulk capacitance alone.
Do not substitute a generic 16-bit SAR ADC solely by resolution and sample rate. The AD677's 28-lead SOIC pin functions, serial timing, reference arrangement, supply requirements, and conversion latency must match the existing PCB and firmware. The verified cross-reference results identify AD677 family temperature-grade options, but broader parts such as AD7606, AD7608, and AD7124 can require different packages, channel counts, and interfaces. Verify the manufacturer pinout and timing diagrams before approving any substitution.
Compliance Information
The supplied verified excerpts do not explicitly state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive-qualification status. No compliance claim should be inferred solely from the manufacturer or distributor listing.