AD678JD - 12-Bit 200 kSPS Sampling ADC | Analog Devices
MPN: AD678JD ✓ ActiveAD678JD Overview
An ADC is a data-conversion IC that transforms a continuous analog voltage into a numeric code for processing, measurement, or control. The AD678 belongs to the monolithic sampling ADC hierarchy, combining analog input conditioning, conversion, reference generation, clocking, and digital output in one device. This integration simplifies PCB design and reduces the number of external functional blocks required by microprocessor-based or embedded control systems.
The AD678 provides one analog input, 12-bit output resolution, and a maximum conversion rate of 200 kSPS. Its flash-conversion architecture is intended for high-speed signal acquisition and supports dynamic-performance measurements including signal-to-noise-plus-distortion ratio, total harmonic distortion, and intermodulation distortion. According to the Analog Devices AD678 product page, the AD678 also provides an upgrade path to the 14-bit, 128 kSPS AD679 while retaining the same pinout.
The converter is designed for signal-processing applications where dynamic accuracy matters. A complete sampling ADC architecture places the sample-and-hold function before the internal quantizer, helping the device acquire rapidly changing analog inputs while the conversion and digital interface operate. Its microprocessor-compatible output interface supports integration with embedded processors, while the internal voltage reference and clock circuitry reduce the external component count.
Typical uses include industrial process measurement, instrumentation, industrial control, embedded data acquisition, and general-purpose signal processing. The 200 kSPS rate is suitable for sampled measurement systems that do not require video-rate conversion, while the 28-pin SBCDIP package supports through-hole assembly and maintenance-friendly legacy instrument upgrades.
When designing a replacement or new circuit, verify the complete data-sheet pinout, input range, reference behavior, timing, and acquisition requirements rather than relying only on the 12-bit and 200 kSPS headline specifications. The manufacturer states that versions compliant with MIL-STD-883 are available and directs users to the current AD678/883B data for detailed specifications.
This page consolidates manufacturer information, distributor listings, family upgrade guidance, verified drop-in candidates, and practical selection guidance. It distinguishes documented facts from values that require confirmation from the current Analog Devices data sheet, supporting faster sourcing and more reliable engineering evaluation.
Drop-in alternatives for AD678JD — 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 AD678JD (same form factor and footprint) — differing in Package, Mounting Type, Conversion Architecture, Converter Type.
AD678KD
✅ Drop-InContact for price
View Datasheet →AD678TD
✅ Drop-In📋 Reference alternative (not in catalog)
AD678TD/883B
✅ Drop-In📋 Reference alternative (not in catalog)
AD678BD
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →AD678KD/883B
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD678JD Maximum Ratings & Electrical Characteristics
| Resolution | 12 bit |
| Sampling Rate | 200 kSPS |
| Number of Analog Inputs | 1 input |
| Conversion Architecture | Flash ADC |
| Converter Type | Monolithic complete sampling ADC |
| Integrated Sample-and-Hold Amplifier | Yes |
| Digital Interface | Microprocessor-compatible bus |
| Internal Voltage Reference | Yes |
| Internal Clock Generation | Yes |
| Package | 28-pin SBCDIP |
| Mounting Type | Through-hole |
| Dynamic Performance Metrics | S/N+D ratio, THD, and IMD |
| Military Availability | Versions compliant with MIL-STD-883 |
| Upgrade Path | AD679, 14-bit, 128 kSPS, same pinout |
AD678JD 28-pin sbcdip Pin Configuration Guide
Pin configuration for AD678JD (28-pin sbcdip 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 AD678JD.
Refer to the datasheet for full pin configuration.
Typical Applications
AD678JD is suitable for 6 applications: Industrial Process Measurement, Embedded Data Acquisition, Precision Instrumentation, Industrial Control Systems, Signal Processing Systems, Legacy Test Equipment Upgrade.
Industrial Process Measurement
The AD678JD fits industrial process-measurement loops that require a complete 12-bit, 200 kSPS sampling ADC rather than separate conditioning and conversion stages. Its integrated sample-and-hold amplifier, voltage reference, clock circuitry, and microprocessor-compatible bus reduce the number of external functional blocks needed to acquire sensor signals. A 200 kSPS conversion rate provides useful temporal resolution for pressure, temperature, level, and flow monitoring. The principal design trade-off is that the 28-pin SBCDIP package occupies more board area than a modern surface-mount ADC, so it is most attractive for legacy instruments, controller slots, and service-compatible equipment.
Recommended
Embedded Data Acquisition
The AD678JD is suitable for embedded acquisition systems that need direct parallel digital data from a sampled analog input. Its 12-bit resolution provides 4096 nominal code levels, while the 200 kSPS rate supports signal sampling substantially faster than many slow industrial-control tasks. The integrated sample-and-hold amplifier and internal reference simplify the acquisition path, and the microprocessor-compatible bus can connect to a compatible processor or bus interface. Designers must still confirm input range, acquisition time, output timing, and logic levels in the current data sheet before treating the device as a drop-in logic solution.
Recommended
Precision Instrumentation
The AD678JD's combination of 12-bit resolution, 200 kSPS conversion speed, and specified dynamic-performance characteristics makes it suitable for instrumentation that evaluates signal quality as well as static measurement accuracy. Analog Devices identifies S/N+D ratio, total harmonic distortion, and intermodulation distortion as important AD678 specifications, allowing designers to assess behavior beyond simple resolution. The internal sample-and-hold amplifier supports repeatable acquisition of changing inputs, while the internal reference and clock blocks simplify instrument architecture. For laboratory or service equipment, the 28-pin SBCDIP format also provides convenient through-hole replacement and unambiguous physical orientation.
Recommended
Industrial Control Systems
The AD678JD can serve as the acquisition element in a control subsystem that compares a rapidly sampled analog feedback value with a command setpoint. Its 200 kSPS rate offers substantially more update opportunities than a slow controller loop, while 12-bit resolution provides 4096 nominal quantization levels for representing the measured quantity. Integration of the sample-and-hold amplifier, reference, clock, and digital interface reduces component count compared with a discrete converter design. Because no verified input range, supply voltage, or acquisition timing was supplied, an engineer must confirm those electrical limits before defining sensor ranges, loop timing, isolation, and protection.
Recommended
Signal Processing Systems
The AD678JD is appropriate for general signal-processing systems that convert analog waveforms into digital codes for filtering, analysis, or feedback. Its flash ADC architecture and 200 kSPS sampling rate align with the supplied description of a complete 12-bit monolithic sampling ADC. The included sample-and-hold amplifier is important because it captures the analog input before conversion, while the integrated reference and clock-generation circuitry establish a more self-contained signal chain. Designers should verify bandwidth, input impedance, settling behavior, and digital timing from the manufacturer data sheet because those values were not included in the verified search extract.
Recommended
Legacy Test Equipment Upgrade
The AD678JD is a practical candidate for repairing or upgrading legacy test and measurement equipment that uses a 28-pin SBCDIP ADC interface. The through-hole package supports replacement with conventional socketed or soldered assembly, while the AD678 family's integrated converter functions simplify restoration of the acquisition path. The manufacturer specifically notes versions compliant with MIL-STD-883 and directs users to the current AD678/883B data sheet for detailed specifications. Before replacing an installed device, engineers should verify pin names, logic levels, timing, input range, supply requirements, and whether the original assembly used a screened grade.
Recommended
Recommended Products Summary
Engineering reference data for AD678JD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD678KD | AD678TD | AD678TD/883B | AD678BD | AD678KD/883B |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-pin SBCDIP | 28-pin SBCDIP | 28-pin SBCDIP | 28-pin SBCDIP | 28-pin SBCDIP | 28-pin SBCDIP |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 200 kSPS | 200 kSPS | 200 kSPS | 200 kSPS | 200 kSPS | 200 kSPS |
| Analog Input Count | 1 input | 1 input | 1 input | 1 input | 1 input | 1 input |
| Conversion Architecture | Flash ADC | Flash ADC | Flash ADC | Flash ADC | Flash ADC | Flash ADC |
| Integrated Sample-and-Hold Amplifier | Yes | Yes | Yes | Yes | Yes | Yes |
| Internal Voltage Reference | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Documented same-family replacement path (vs AD678KD)
- Manufacturer-backed higher-resolution upgrade (vs AD679)
- Complete monolithic converter integration (vs Discrete flash converter and external interface approach)
Design Notes
Do not treat the AD679's same-pinout statement as proof that every electrical behavior is identical. Analog Devices identifies the AD679 as a 14-bit, 128 kSPS device, whereas the AD678 is a 12-bit, 200 kSPS converter. Before substituting it for an AD678JD, review conversion timing, acquisition time, input range, digital output coding, clock requirements, and software scaling.
The AD678 includes a sample-and-hold amplifier, but the source impedance and settling time of the external signal path still affect acquisition accuracy. Keep the analog input route short, place input conditioning close to pin 1, and isolate it from digital switching paths. Verify the current data sheet's input capacitance, acquisition timing, and allowable source impedance before choosing resistor values or amplifier drive levels.
The AD678JD uses a 28-pin SBCDIP through-hole package. Preserve adequate clearance around adjacent pins and provide clean ground returns for the reference, digital interface, and power connections. Because the 28-pin SBCDIP is a legacy ceramic-DIP format, confirm whether its lead spacing and inserted height match the original PCB footprint; do not assume compatibility with a standard 0.1-inch plastic DIP without dimensional verification.
The verified records do not state the AD678JD supply voltage, quiescent current, or power dissipation. Do not infer these values from the 12-bit or 200 kSPS specifications. Consult the current Analog Devices AD678 or AD678/883B data sheet for supply limits, sequencing requirements, reference behavior, and decoupling recommendations, then validate local power-supply headroom at the required conversion rate.
Compliance Information
The verified manufacturer information states that AD678 versions compliant with MIL-STD-883 are available, but no explicit RoHS, REACH, lead-free, halogen-free, or conflict-minerals statement was provided for AD678JD. AEC-Q100 is not applicable because this is not an automotive-qualified part.
