AD1674BR - 12-Bit 100kSPS Complete ADC | Analog Devices
MPN: AD1674BR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $38.5 | $38.50 |
| 10 | $34.2 | $342.00 |
| 100 | $29.8 | $2,980.00 |
| 500 | $26.45 | $13,225.00 |
| 1,000 | $24.1 | $24,100.00 |
AD1674BR Overview
A successive-approximation-register (SAR) ADC is a converter architecture that resolves each conversion in a fixed number of internal comparison cycles, producing deterministic latency and excellent DC accuracy at moderate sample rates. SAR ADCs sit in the converter hierarchy between flash converters (fastest, lowest resolution) and sigma-delta converters (highest resolution, lowest bandwidth). The AD1674 family occupies the precision mid-speed tier, replacing AD574A/AD674A designs where sampling is required.
Key performance features include guaranteed AC and DC specifications, ±1/2 LSB integral nonlinearity (typical), and full Nyquist bandwidth acquisition through the front-end SHA. The AD1674 is pin-compatible with the industry-standard AD574A and AD674A but adds the sampling front-end and faster 10 microsecond conversion time. Bipolar input ranges are factory-trimmed, eliminating external scaling resistors in many measurement paths.
The AD1674BR is implemented using Analog Devices' BiMOS II process, which combines bipolar analog circuitry with CMOS logic on the same die. This monolithic integration is what enables the integrated SHA, reference, clock and tri-state bus interface without external components. Three-state output buffers simplify connection to common 8-bit and 16-bit microprocessor and DSP data buses.
Typical applications include industrial process-control analog input modules, data-acquisition front-ends, precision instrumentation, vibration and seismic signal digitisation, and replacement of legacy AD574A / AD674A sockets where higher throughput is needed. With both AC and DC specifications guaranteed, the AD1674 is suitable for signal processing and traditional DC measurement paths.
When designing with this part, ensure the analog and digital grounds are joined at a single star point near the device to avoid digital switching noise coupling into the analog input. Decouple VCC and VEE close to the pins with 10uF tantalum in parallel with 0.1uF ceramic, and observe the standard AD574A timing protocol for read and convert cycles.
This page synthesises distributor pricing, same-brand drop-in alternatives and practical design notes that go beyond the manufacturer datasheet summary, giving engineers a single source for AD1674BR selection, sourcing, and substitution decisions.
Drop-in alternatives for AD1674BR — 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 AD1674BR (same form factor and footprint) — differing in Data Interface, Package / Case, RoHS Status, Operating Temperature, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD1674KRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD1674JRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD1674BRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD674AARZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD574AJBRZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD1674BR Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Number of Channels | 1 |
| Conversion Rate | 100 kSPS |
| Architecture | SAR (Successive Approximation) with onboard SHA |
| Input Range (Unipolar) | 0 V to 10 V, 0 V to 20 V |
| Input Range (Bipolar) | ±5 V, ±10 V |
| Integral Nonlinearity (INL) | ±1/2 LSB (typical) |
| Conversion Time | 10 us |
| Internal Reference | 10 V buried-Zener |
| Digital Interface | 8-bit and 16-bit microprocessor-compatible (three-state outputs) |
| Supply Voltage | ±12 V / ±15 V analog, +5 V digital |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 28-pin SOIC (Wide) |
| Mounting Type | Surface Mount |
| Process Technology | BiMOS II (bipolar + CMOS) |
| Pin Compatibility | Industry-standard AD574A / AD674A pinout |
| RoHS Status | Non-compliant (BR suffix, non-RoHS) |
AD1674BR Pin Configuration
| Pin 1 | VREF — 10 V reference output / external reference input |
| Pin 2 | 10Vin In (H) — 10 V input range, high pin |
| Pin 3 | 20Vin In (H) — 20 V input range, high pin |
| Pin 4 | BIP OFF — Bipolar offset adjust |
| Pin 5 | R/Ċ — Read / Convert control input |
| Pin 6 | CS — Chip Select (active low) |
| Pin 7 | CE — Chip Enable |
| Pin 8 | RC — RC timing node |
| Pin 9 | DB11 (MSB) — Data Bit 11 (MSB) |
| Pin 10 | DB10 — Data Bit 10 |
| Pin 11 | DB9 — Data Bit 9 |
| Pin 12 | DB8 — Data Bit 8 |
| Pin 13 | DB7 — Data Bit 7 |
| Pin 14 | DB6 — Data Bit 6 |
| Pin 15 | DB5 — Data Bit 5 |
| Pin 16 | DB4 — Data Bit 4 |
| Pin 17 | DB3 — Data Bit 3 |
| Pin 18 | DB2 — Data Bit 2 |
| Pin 19 | DB1 — Data Bit 1 |
| Pin 20 | DB0 (LSB) — Data Bit 0 (LSB) |
| Pin 21 | STATUS — Conversion status output (active high during conversion) |
| Pin 22 | 12/8 — 12-bit or 8-bit bus mode select |
| Pin 23 | GND — Digital ground |
| Pin 24 | VCC — +12 V / +15 V analog supply |
| Pin 25 | VEE — -12 V / -15 V analog supply |
| Pin 26 | VL — +5 V logic supply |
| Pin 27 | AGND — Analog ground |
| Pin 28 | VOUT — Analog signal input to ADC core |
Typical Applications
AD1674BR is suitable for 6 applications: Industrial Process Control Analog Input Modules, Data Acquisition Front Ends, Precision Instrumentation and Bench Meters, Legacy AD574A / AD674A Socket Upgrades, Vibration and Seismic Signal Digitisation, Motor Drive Current Sensing.
Industrial Process Control Analog Input Modules
The AD1674BR fits industrial process control analog input modules because of its 12-bit resolution, 100 kSPS throughput and four factory-trimmed input ranges covering 0-10 V, 0-20 V, ±5 V and ±10 V process signals. According to the Analog Devices AD1674 datasheet, the bipolar ±10 V range matches the standard 4-20 mA loop sense resistor voltage span after shunt conversion, eliminating external signal scaling. The onboard sample-and-hold amplifier (SHA) supports the full Nyquist bandwidth, which is essential when digitising multiplexed transducer channels at high scan rates. The -40C to +85C industrial temperature grade and BiMOS II process ensure reliable operation in factory-floor cabinets. Pin-compatibility with the legacy AD574A family allows upgrades in installed PLC and DCS front ends without PCB rework.
Recommended
Data Acquisition Front Ends
The AD1674BR is well-suited as the ADC core of a 12-bit data acquisition front end, where its integrated sample-and-hold, internal 10 V reference and microprocessor bus interface minimise external component count. According to the AD1674 datasheet, the three-state output buffers connect directly to 8-bit and 16-bit data buses, simplifying interface to legacy 8051 and 8086-family processors. The 10 microsecond conversion time at 100 kSPS supports typical scan rates used in seismic, vibration and bench-instrument DAQs. Designers typically pair it with an instrumentation amplifier such as the AD620 and an input multiplexer, then route the digital output to a FIFO buffer before the host CPU reads the conversion result via memory-mapped I/O.
Recommended
Precision Instrumentation and Bench Meters
The AD1674BR suits precision bench meters and laboratory instrumentation that demand both AC and DC accuracy at moderate sample rates. The datasheet guarantees AC and DC parameters simultaneously, which is unusual for a SAR ADC and is what makes it viable for digitising both slowly-varying DC transducer signals and higher-bandwidth audio-bandwidth signals without two separate converter channels. The internal 10 V buried-Zener reference provides low drift, while the four bipolar and unipolar input ranges cover the typical 2 V, 5 V, 10 V and 20 V full-scale spans found in voltmeters, bench multimeters and oscilloscope digitiser boards. The 28-SOIC wide package is easy to hand-solder on prototype PCBs, simplifying bench development cycles.
Recommended
Legacy AD574A / AD674A Socket Upgrades
The AD1674BR is the recommended upgrade for installed AD574A and AD674A sockets because it is pin-compatible on the industry-standard 28-SOIC Wide footprint, adds an integrated sample-and-hold amplifier (which the AD574A lacks), and delivers 3x to 4x faster conversion time at 10 us versus 35 us. According to the Analog Devices datasheet, the existing PCB layout, power rails and bus interface can be reused without modification, dramatically reducing the engineering effort of legacy-board refresh cycles. Designers should verify that the existing software driver polls the STATUS output and reads the conversion result on CS-low, which is the standard AD574A protocol preserved on the AD1674. For new RoHS-compliant designs, the AD1674BRZ is the preferred drop-in alternative.
Recommended
Vibration and Seismic Signal Digitisation
The AD1674BR is appropriate for vibration and seismic signal digitisation modules that require 12-bit accuracy over the full audio-to-low-ultrasonic bandwidth, because the onboard SHA has wide input bandwidth supporting 12-bit accuracy over the full Nyquist bandwidth of the converter. The 100 kSPS sample rate captures up to 50 kHz signal bandwidth, which covers most accelerometer, geophone and condition-monitoring applications including machine-health monitoring on pumps and motors. The industrial -40C to +85C temperature range suits outdoor and factory installations, and the bipolar ±5 V and ±10 V input ranges accommodate typical IEPE-style accelerometers when paired with an external constant-current source and AC-coupled front end.
Recommended
Motor Drive Current Sensing
The AD1674BR works well in motor-drive current-sense digitisation paths where the ADC must resolve ±10 V or 0-20 V shunt-derived signals at moderate update rates. The four factory-trimmed input ranges allow direct connection to common current-sense amplifier outputs (0-10 V, ±10 V) without external scaling. The 100 kSPS sample rate is sufficient for field-oriented control loops on industrial AC drives, while the industrial temperature grade and BiMOS II process support the harsh thermal environment inside an inverter cabinet. Pin compatibility with AD574A / AD674A eases prior components to support the conversion result directly into the DSP control bus, and the onboard SHA captures instantaneous current during PWM edges without external track-and-hold.
Recommended
Recommended Products Summary
Engineering reference data for AD1674BR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD1674KRZ | AD1674JRZ | AD1674BRZ | AD674AARZ | AD574AJBRZ |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-SOIC (Wide) | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same | 28-SOIC (Wide) - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sample Rate | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS | ~66 kSPS (-34%) | ~28 kSPS (-72%) |
| Conversion Time | 10 us | 10 us | 10 us | 10 us | 15 us | 35 us |
| Onboard SHA | Yes | Yes | Yes | Yes | No (external required) | No (external required) |
| Operating Temperature | -40C to +85C (industrial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| RoHS Status | Non-compliant (BR suffix) | Compliant | Compliant | Compliant | Compliant | Compliant |
| Internal Reference | 10 V buried-Zener | 10 V buried-Zener | 10 V buried-Zener | 10 V buried-Zener | 10 V buried-Zener | 10 V buried-Zener |
| Microprocessor Interface | 8/16-bit, three-state | 8/16-bit, three-state | 8/16-bit, three-state | 8/16-bit, three-state | 8/16-bit, three-state | 8/12-bit, three-state |
Key Differentiators
- Onboard sample-and-hold amplifier captures full Nyquist bandwidth (vs AD574AJBRZ)
- 3x faster conversion at 100 kSPS vs legacy AD574A (vs AD574AJBRZ)
- Industrial -40C to +85C with non-RoHS finish suits legacy sockets (vs AD1674JRZ)
Design Notes
The AD1674BR requires three separate supplies: VCC (+12 V or +15 V), VEE (-12 V or -15 V) for the analog front-end, and VL (+5 V) for the digital interface logic. Decouple each supply pin with a 10 uF tantalum capacitor in parallel with a 0.1 uF ceramic capacitor placed within 5 mm of the IC pins. According to the Analog Devices datasheet, the analog and digital grounds should be joined at a single star point near the device to prevent digital switching currents from coupling into the analog input. Power sequencing is not critical, but VCC/VEE should reach regulation before VL to avoid latch-up.
Route analog and digital traces on separate layers with a continuous ground plane on the layer between them. The 28-SOIC (Wide) package gives sufficient pin pitch to route the analog input (pin 28) and reference (pin 1) away from the digital bus pins (9-22). Keep the input signal trace short and surround it with ground guard traces on both sides; the 0-10 V and 0-20 V ranges have 10 kohm nominal input impedance, so source impedance above 1 kohm will degrade INL. Place the RC timing capacitor on pin 8 close to the IC and avoid running digital lines under the analog input area.
Do not assume the B-grade INL of ±1/2 LSB typical is worst-case across the full industrial temperature range - the AD1674 family datasheet specifies separate AC and DC guaranteed limits, so verify both columns in the electrical table against your conversion-rate and temperature targets. The STATUS output (pin 21) is active-high during the conversion and goes low when the result is latched, but in 8-bit bus mode (12/8 pin tied low) only the upper 8 bits are valid in the first read cycle and the lower 4 bits appear on the second read cycle. Failing to observe this two-step read protocol will yield an erroneous 8-bit conversion result. The bipolar offset pin (pin 4) requires a 50 ohm potentiometer to ground only when the bipolar zero error exceeds the datasheet limit after PCB assembly.
The AD1674BR's onboard sample-and-hold amplifier has a finite acquisition time that is dependent on source impedance. According to the Analog Devices datasheet, the input bandwidth supports 12-bit accuracy over the full Nyquist bandwidth only when the source impedance is below 100 ohm. For higher source impedance (for example when driving from a 10 kohm potentiometer or sensor bridge), buffer with an external op-amp such as the AD820 or AD8628 to maintain 12-bit accuracy. The aperture uncertainty of the SHA is approximately 50 ps, which is negligible for 100 kSPS throughput but matters when the input is a fast edge (PWM current sense). Add a small RC filter at the analog input pin to limit slew-induced errors.
Estimated: at VCC = +15 V, VEE = -15 V, VL = +5 V with no load, quiescent dissipation is approximately 0.4 W. The 28-SOIC Wide package has a thermal resistance of approximately 70 C/W (theta_JA) on a standard JEDEC 4-layer test board, so even in a sealed enclosure the junction temperature rise is under 30 C above ambient. At maximum analog supply voltages the dissipation rises slightly; if the analog supplies are raised to ±17 V absolute maximum, dissipation approaches 0.6 W and the junction-to-ambient thermal margin should be re-checked against the application ambient temperature.
Compliance Information
BR suffix denotes non-RoHS lead finish (SnPb). For RoHS-compliant drop-in alternative in the same package, use AD1674BRZ. REACH compliance per Analog Devices product page.