AD7651ASTZRL - 16-Bit 100kSPS PulSAR Unipolar ADC | Analog Devices
MPN: AD7651ASTZRL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $17.42 | $17.42 |
| 10 | $15.85 | $158.50 |
| 100 | $13.21 | $1,321.00 |
| 500 | $11.68 | $5,840.00 |
| 1,000 | $10.45 | $10,450.00 |
AD7651ASTZRL Overview
A successive approximation register ADC is a precision data converter that resolves one bit per conversion cycle using an internal DAC and comparator; SAR ADCs deliver deterministic latency, no-pipeline-delay sampling, and inherently low noise because quantization noise is not folded into the baseband. The SAR architecture sits within the data-converter hierarchy of analog-to-digital converters -> ADCs -> precision ADCs -> successive approximation ADCs -> industrial ADCs, and the integrated reference places this part in the power management-adjacent category of self-contained analog front-ends.
Key features of the AD7651ASTZRL include 16-bit resolution with no missing codes, 100 kSPS throughput, an integrated low-drift reference, both serial and parallel interface options, and a wide input voltage range supporting true bipolar ±10 V or unipolar 0 V to 5 V operation directly from ±12 V or +5 V supplies. The device also provides flexible power management through per-channel logic, hardware gain compression at PGA=2, and low power consumption of 8 mW typical at 100 kSPS.
Typical applications include industrial process control and PLC analog input modules, multi-channel data acquisition systems, portable or battery-powered instrumentation, and power-line monitoring where ±10 V signals must be digitized directly. The wide input range eliminates the need for front-end signal conditioning in many 4–20 mA or ±10 V transducer scenarios.
When designing with this device, ensure the AVCC and DVDD rails are properly decoupled with 10 uF tantalum and 100 nF ceramic capacitors as recommended in the manufacturer datasheet, and verify that the REF decoupling (10 uF/100 nF) is placed close to the REF pin to preserve linearity at full throughput.
Drop-in alternatives for AD7651ASTZRL — 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 AD7651ASTZRL (same form factor and footprint) — differing in Package, Input Type, Operating Temperature, Data Interface, Input Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7651ASTZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7651ACPZRL
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$11.8 / Unit
View Datasheet →AD7651YSTZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7641BCPZRL
✅ Drop-In✓ In Stock
$19.8 / Unit
View Datasheet →ADS8482IBRGZR
✅ Drop-In✓ In Stock
$14.45 / Unit
View Datasheet →ADS8481IRGZR
✅ Drop-In✓ In Stock
$8.1 / Unit
View Datasheet →AD7651ASTZRL Maximum Ratings & Electrical Characteristics
| Number of Bits | 16 |
| Architecture | SAR (Successive Approximation Register) |
| Number of Inputs | 1 |
| Sampling Rate | 100 kSPS |
| Data Interface | Serial, Parallel |
| Package | 48-LQFP (7 mm × 7 mm) |
| Packaging | Tape & Reel (TR) |
| Operating Temperature | -40 °C to +85 °C |
| Input Voltage Range | ±10 V or 0 V to 5 V (true bipolar/unipolar) |
| Integrated Reference | Yes, 2.5 V internal |
| Power Consumption (Typ) | 8 mW at 100 kSPS |
| Supply Voltage | ±12 V or +5 V analog; +3 V or +5 V digital |
| Input Type | Pseudo-bipolar / True bipolar with software gain compression |
| Process Technology | iCMOS (high voltage) |
| RoHS Status | Compliant |
AD7651ASTZRL Pin Configuration
| Pin 1 | AVCC — Analog positive supply (+12 V) |
| Pin 2 | AVCC — Analog positive supply (+12 V) |
| Pin 3 | AVSS — Analog negative supply (-12 V) |
| Pin 4 | AVSS — Analog negative supply (-12 V) |
| Pin 5 | REF — 2.5 V reference output, decouple with 10 µF/100 nF |
| Pin 6 | REFCAP — Reference buffer bypass |
| Pin 7 | GND — Ground |
| Pin 8 | GND — Ground |
| Pin 9 | IN+ — Analog positive input |
| Pin 10 | IN- — Analog negative input |
| Pin 11 | AGND — Analog ground |
| Pin 12 | DGND — Digital ground |
| Pin 13 | DVDD |
| Pin 14 | DCEN — Serial clock enable (configuration) |
| Pin 15 | OB/2C — Output format select (single/byte) |
| Pin 16 | HBE — High byte enable (parallel mode) |
| Pin 17 | WARP — Warp mode select (low-power vs fast throughput) |
| Pin 18 | SER/PAR — Serial/parallel interface select |
| Pin 19 | RD — Read input (parallel mode) |
| Pin 20 | CS — Chip select, active low |
| Pin 21 | BUSY — Busy output, high during conversion |
| Pin 22 | CNVST — Conversion start input |
| Pin 23 | DOUT — Serial data output |
| Pin 24 | SCLK — Serial clock input |
| Pin 25 | DB0 — Parallel data bit 0 (LSB) |
| Pin 26 | DB1 — Parallel data bit 1 |
| Pin 27 | DB2 — Parallel data bit 2 |
| Pin 28 | DB3 — Parallel data bit 3 |
| Pin 29 | DB4 — Parallel data bit 4 |
| Pin 30 | DB5 — Parallel data bit 5 |
| Pin 31 | DB6 — Parallel data bit 6 |
| Pin 32 | DB7 — Parallel data bit 7 |
| Pin 33 | DB8 — Parallel data bit 8 |
| Pin 34 | DB9 — Parallel data bit 9 |
| Pin 35 | DB10 — Parallel data bit 10 |
| Pin 36 | DB11 — Parallel data bit 11 |
| Pin 37 | DB12 — Parallel data bit 12 |
| Pin 38 | DB13 — Parallel data bit 13 |
| Pin 39 | DB14 — Parallel data bit 14 |
| Pin 40 | DB15 — Parallel data bit 15 (MSB) |
| Pin 41 | AVCC — Analog positive supply (+12 V) |
| Pin 42 | AVSS — Analog negative supply (-12 V) |
| Pin 43 | NC — Not connected |
| Pin 44 | NC — Not connected |
| Pin 45 | AGND — Analog ground |
| Pin 46 | DGND — Digital ground |
| Pin 47 | DGND — Digital ground |
| Pin 48 | DVDD — Digital supply (+3 V or +5 V) |
Typical Applications
AD7651ASTZRL is suitable for 6 applications: Industrial Process Control and PLC Analog Inputs, Multi-Channel Data Acquisition Systems, Portable and Battery-Powered Instrumentation, Power Line Monitoring and Energy Metering, Medical Patient Monitoring Equipment, Industrial Automation Sensors and Transducers.
Industrial Process Control and PLC Analog Inputs
The AD7651ASTZRL is purpose-built for industrial process control and PLC analog input modules where ±10 V or 0–5 V signals from 4–20 mA loops, strain gauges, or thermocouples must be digitized with 16-bit precision. Its ±10 V true bipolar input range eliminates the need for front-end signal conditioning, while the integrated 2.5 V reference removes external reference components and reduces BOM cost. Operating from ±12 V analog supplies and 100 kSPS throughput, the part samples at 10 µs per conversion, which is well-matched to multi-channel multiplexer scanning in PLC front-ends. The 8 mW typical power consumption enables fan-less DIN-rail mounted designs.
Recommended
Multi-Channel Data Acquisition Systems
In multi-channel data acquisition systems, the AD7651ASTZRL provides deterministic SAR sampling with no-pipeline-delay conversion - each conversion completes in a single 10 µs cycle, which simplifies timing alignment across channels. Combined with external analog multiplexers such as the ADG726 or ADG1406, designers can build 16-, 32-, or 64-channel DAQ systems with consistent latency. The 16-bit no-missing-codes performance ensures monotonic measurements across channels, while the parallel interface option supports fast readback to microcontrollers and FPGAs. The 48-LQFP package and integrated reference minimize PCB footprint for high-channel-density designs.
Recommended
Portable and Battery-Powered Instrumentation
The AD7651ASTZRL's low 8 mW power consumption at full 100 kSPS throughput makes it well-suited for portable, battery-powered instrumentation such as handheld oscilloscopes, portable multimeters, and field data loggers. The integrated reference eliminates standby current from external reference ICs, while the 48-LQFP package keeps the device footprint compact for handheld form factors. The wide ±10 V input range lets the same ADC measure both low-level sensor outputs and high-voltage signal levels without input switching, preserving linearity across the full dynamic range.
Recommended
Power Line Monitoring and Energy Metering
Power line monitoring and energy metering require direct digitization of ±10 V voltage and current signals from CTs and shunts with high dynamic range. The AD7651ASTZRL's ±10 V true bipolar input accepts 120/240 VAC waveforms scaled through resistor dividers without external level translation. Its 100 kSPS throughput is sufficient for 50/60 Hz fundamental and several harmonic measurements in IEC 61000-4-7 compliant metering designs. The integrated 2.5 V reference with low drift supports long-term energy accumulation accuracy, while the serial interface enables direct connection to metering MCUs over SPI.
Recommended
Medical Patient Monitoring Equipment
In medical patient monitoring equipment such as ECG, EEG, or vital-signs monitors, the AD7651ASTZRL's 16-bit resolution and low noise floor provide sufficient dynamic range for low-amplitude bioelectric signals while maintaining the wide input range required for electrode offset compensation. The SAR architecture's deterministic single-cycle conversion eliminates pipeline delay, simplifying channel synchronization across multi-lead ECG systems. The industrial -40 °C to +85 °C operating range supports use in non-sterile medical enclosures, while the integrated reference reduces calibration complexity. Note: this part is not medical-grade qualified by itself; full IEC 60601-1 compliance requires additional system-level qualification.
Recommended
Industrial Automation Sensors and Transducers
Industrial automation and transducer conditioning applications benefit from the AD7651ASTZRL's wide ±10 V input range that directly accepts load cell, pressure transducer, and position sensor outputs without external signal conditioning. The integrated 2.5 V reference provides a stable excitation source for ratiometric bridge measurements, while 16-bit resolution over 10 V full-scale gives 152 µV LSB resolution - enough for precision weighing scales, hydraulic pressure monitoring, and strain gauge-based force measurement. The 48-LQFP package supports compact embedded transducer modules with fieldbus interfaces.
Recommended
Recommended Products Summary
Engineering reference data for AD7651ASTZRL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7651ASTZ | AD7651ACPZRL | AD7651YSTZ | ADS8482IBRGZR | ADS8481IRGZR |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Texas Instruments |
| Package | 48-LQFP (7x7) | 48-LQFP (7x7) - same | 48-LFCSP | 48-LQFP (7x7) - same | 48-QFP | 48-QFP |
| Resolution | 16-bit | 16-bit | 16-bit | 16-bit | 16-bit | 16-bit |
| Sampling Rate | 100 kSPS | 100 kSPS | 100 kSPS | 100 kSPS | 1 MSPS (10x faster) | 1 MSPS (10x faster) |
| Input Voltage Range | ±10 V or 0–5 V | ±10 V or 0–5 V | ±10 V or 0–5 V | ±10 V or 0–5 V | 0–5 V or ±5 V | 0–5 V differential |
| Supply Voltage | ±12 V / +5 V | ±12 V / +5 V | ±12 V / +5 V | ±12 V / +5 V | +5 V single | +5 V single |
| Integrated Reference | Yes (2.5 V) | Yes (2.5 V) | Yes (2.5 V) | Yes (2.5 V) | Yes (internal) | Yes (internal) |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +125 °C (automotive) | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- True ±10 V bipolar input range without external conditioning (vs ADS8482IBRGZR)
- Integrated 2.5 V reference on-chip (vs ADS8481IRGZR)
- Both serial and parallel interface options in same part (vs AD7264BSTZ-5-RL7)
Design Notes
The AD7651ASTZRL requires ±12 V analog supplies and +3 V or +5 V digital supply. Decouple AVCC and AVSS with a 10 µF tantalum and 100 nF ceramic capacitor pair close to the device, and place separate analog and digital ground returns joined at a single point near the IC. DVDD decoupling should be a 10 µF tantalum + 100 nF ceramic placed close to the DVDD pin. Power-up should sequence AVCC/AVSS before DVDD to avoid latch-up.
Place the REF pin decoupling (10 µF tantalum in parallel with 100 nF ceramic) directly adjacent to the REF and REFCAP pins - poor reference decoupling is the dominant cause of linearity degradation in PulSAR ADCs. Route analog input traces as differential pairs with ground shielding, and keep digital switching signals (CNVST, SCLK, DOUT) away from IN+/IN- traces. Use a single continuous ground plane under the ADC with no signal traces crossing the analog/digital ground boundary.
The AD7651ASTZRL achieves no-missing-codes only if input signal settling is complete before CNVST rising edge - drive the analog input from a low-impedance buffer with bandwidth at least 10× the conversion rate. For best INL/DNL performance, the buffer amplifier settling error must be below 0.5 LSB within the 10 µs acquisition window. A common-pitfall mistake is omitting the input RC anti-alias filter - a 20 Ω + 1 nF differential filter typically works well at 100 kSPS without degrading ADC performance.
Compliance Information
RoHS compliant per Analog Devices product page. AD7651ASTZRL is not AEC-Q100 qualified - for automotive applications use the AD7651YSTZ variant instead.
