AD7490BRU-REEL - 12-Bit 1MSPS 16-Ch SAR ADC, 28-TSSOP | ADI
MPN: AD7490BRU-REEL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $11.5 | $11.50 |
| 10 | $10.3 | $103.00 |
| 100 | $8.95 | $895.00 |
| 500 | $7.6 | $3,800.00 |
| 1,000 | $6.4 | $6,400.00 |
AD7490BRU-REEL Overview
What is a SAR ADC? A successive-approximation register analog-to-digital converter is a medium-speed, medium-resolution ADC architecture that uses a binary-search algorithm and an internal capacitive DAC to convert an analog input to a digital code one bit per conversion step. Within the broader taxonomy, SAR ADCs sit between flash converters (highest speed, lowest resolution) and delta-sigma ADCs (highest resolution, lower speed). The AD7490's 12-bit resolution and 1 MSPS throughput place it in the mainstream industrial data-acquisition tier used for multi-channel sensor monitoring.
Key features include 16 single-ended analog input channels with on-chip sequencing, a flexible serial interface compatible with DSP, MICROWIRE, QSPI, and SPI, and low power consumption of 5.4 mW maximum at 870 kSPS with 3 V supplies, rising to 12.5 mW maximum at 1 MSPS. The TSSOP-28 (4.40 mm body width) package provides a compact footprint while exposing the analog and digital domains on opposite sides of the pinout for easier board layout.
The AD7490 uses a charge-redistribution DAC architecture combined with an input track-and-hold that supports input bandwidths exceeding the Nyquist limit of the 1 MSPS sample rate, allowing accurate sampling of AC inputs without an external buffer. The on-chip channel sequencer allows the user to pre-program a sequence of up to 16 channels, reducing host-processor overhead and simplifying multi-channel data-acquisition firmware.
Typical applications include industrial process control, multi-channel data acquisition systems, portable battery-powered instrumentation, motor control feedback, and medical patient monitoring where multiple sensor channels must be digitized with deterministic latency.
When designing with this part, populate the recommended bypass network on AVDD/DVDD rails and respect the analog/digital ground split documented in the datasheet to avoid code-dependent noise coupling. The internal sequencer can be bypassed for software-driven channel selection, but external anti-aliasing RC filtering on each analog input remains essential.
This page synthesizes distributor pricing, drop-in alternative listings, and practical design guidance not aggregated elsewhere, enabling a faster, more confident selection decision for engineers.
Drop-in alternatives for AD7490BRU-REEL — 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:
AD7490BRUZ-REEL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7490BRUZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7490BRU
✅ Drop-In📋 Reference alternative (not in catalog)
AD7490BRUZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD7490BCPZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7490BRU-REEL Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices, Inc. |
| Part Number | AD7490BRU-REEL |
| Function | 12-bit, 16-channel, successive-approximation ADC |
| Number of Bits | 12 |
| Sampling Rate | 1 MSPS |
| Number of Input Channels | 16 single-ended |
| Architecture | SAR with on-chip track-and-hold |
| Input Bandwidth | > 1 MHz (track-and-hold) |
| Supply Voltage (VDD) | 2.7 V to 5.25 V (single supply) |
| Power Dissipation (max) | 5.4 mW @ 870 kSPS / 3 V; 12.5 mW @ 1 MSPS |
| Data Interface | DSP, MICROWIRE, QSPI, Serial, SPI |
| Reference Type | External (per datasheet typical application) |
| Package / Case | 28-TSSOP (4.40 mm body width) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (REEL) |
| RoHS Status | Non-RoHS (SnPb finish implied by 'BRU' suffix per ADI legacy naming) |
| Lead-Free | No (legacy finish) |
| Pin Count | 28 |
AD7490BRU-REEL Pin Configuration
| Pin 1 | VDD — Power supply input, 2.7 V to 5.25 V |
| Pin 2 | AGND — Analog ground |
| Pin 3 | REF — External reference input (per datasheet typical application) |
| Pin 4 | VIN0 — Analog input channel 0 |
| Pin 5 | VIN1 — Analog input channel 1 |
| Pin 6 | VIN2 — Analog input channel 2 |
| Pin 7 | VIN3 — Analog input channel 3 |
| Pin 8 | VIN4 — Analog input channel 4 |
| Pin 9 | VIN5 — Analog input channel 5 |
| Pin 10 | VIN6 — Analog input channel 6 |
| Pin 11 | VIN7 — Analog input channel 7 |
| Pin 12 | VIN8 — Analog input channel 8 |
| Pin 13 | VIN9 — Analog input channel 9 |
| Pin 14 | VIN10 — Analog input channel 10 |
| Pin 15 | VIN11 — Analog input channel 11 |
| Pin 16 | VIN12 — Analog input channel 12 |
| Pin 17 | VIN13 — Analog input channel 13 |
| Pin 18 | VIN14 — Analog input channel 14 |
| Pin 19 | VIN15 — Analog input channel 15 |
| Pin 20 | GND — Digital ground |
| Pin 21 | DOUT — Serial data output (SPI/MICROWIRE/QSPI/DSP) |
| Pin 22 | DIN — Serial data input (configuration words) |
| Pin 23 | SCLK — Serial clock input |
| Pin 24 | CS — Chip select, active low |
| Pin 25 | WR — Write / conversion start |
| Pin 26 | BUSY — Conversion in progress, active high |
| Pin 27 | DGND — Digital ground |
| Pin 28 | VDD — Power supply input, 2.7 V to 5.25 V |
Typical Applications
AD7490BRU-REEL is suitable for 6 applications: Multi-Channel Industrial Data Acquisition, Portable Battery-Powered Instrumentation, Motor Control Feedback Loops, Medical Patient Monitoring, Programmable Logic Controller (PLC) Analog Input Modules, Audio / Vibration Spectrum Analysis Front End.
Multi-Channel Industrial Data Acquisition
The AD7490BRU-REEL's 16 single-ended analog inputs with on-chip channel sequencing make it ideal for industrial data-acquisition systems that monitor multiple sensors (RTDs, thermocouples via front-end amps, 4-20 mA loops via shunt resistors). The 1 MSPS aggregate throughput comfortably handles scans of all 16 channels at 62.5 kSPS per channel, while the wide-bandwidth track-and-hold (>1 MHz) preserves signal integrity for AC-coupled transducers. Designers should place the recommended 10 nF + 100 nF decoupling network close to AVDD and DVDD pins and route analog/digital grounds as a star from a single point to avoid code-dependent noise.
Recommended
Portable Battery-Powered Instrumentation
Drawing only 5.4 mW at 870 kSPS from a 3 V supply (per the AD7490 datasheet), the AD7490BRU-REEL is well suited to handheld, battery-powered instruments such as multimeters and portable loggers. Its single 2.7 V to 5.25 V supply rail can be powered directly from a Li-ion cell plus LDO, and the SPI interface minimizes GPIO consumption on small microcontrollers. To extend battery life, designers can gate the conversion clock and duty-cycle the ADC; the wide supply tolerance also tolerates the sagging voltage of a discharging Li-ion pack.
Recommended
Motor Control Feedback Loops
Brushless DC and stepper motor controllers require deterministic, multi-channel sampling of phase currents, back-EMF, and position sensors. The AD7490BRU-REEL's 1 MSPS throughput lets a motor controller sample three phase currents plus DC-bus voltage and temperature inside a single PWM cycle, while the on-chip sequencer reads the programmed channel order automatically without MCU intervention. The wide-bandwidth track-and-hold (>1 MHz per datasheet) preserves fidelity on PWM-edge transients, so the digital current loop runs with minimal aliasing.
Recommended
Medical Patient Monitoring
Patient monitors digitize multiple biopotential signals (ECG, SpO2, respiration, NIBP) at modest per-channel rates. The AD7490BRU-REEL's 16 single-ended inputs handle these sensor channels through appropriate analog front ends, and its low power dissipation (5.4 mW at 3 V) keeps total monitor thermal budget within IEC 60601-1 limits. The serial SPI-compatible interface simplifies isolation with a digital isolator to meet patient-leakage requirements; ADI's ADuM1411 isolator pairs cleanly with this ADC.
Recommended
Programmable Logic Controller (PLC) Analog Input Modules
PLC analog input modules typically service 8 or 16 channels at 12-16 bit resolution. The AD7490BRU-REEL fits this slot exactly with 16 single-ended inputs, on-chip sequencing, and the 1 MSPS speed needed to refresh all channels within the PLC scan cycle. Its 28-TSSOP package is industrial-standard and the wide 2.7-5.25 V supply rails accept 24 V-bus-derived 5 V or 3.3 V rails directly. Use the SPI interface to a backplane isolator; the on-chip sequencer dramatically simplifies ladder-logic channel addressing.
Recommended
Audio / Vibration Spectrum Analysis Front End
For condition-monitoring and audio spectrum analysis front ends, the AD7490BRU-REEL's >1 MHz track-and-hold bandwidth comfortably exceeds the bandwidth needed to capture acoustic and vibration content up to the 1 MSPS Nyquist band. Multiple piezo sensors or MEMS microphones can be time-multiplexed into the 16 single-ended inputs, then handed off to an FFT DSP via the SPI port. The 12-bit dynamic range suits vibration-impact alarms, and the low 12.5 mW dissipation at full speed keeps dense multi-channel front ends thermally manageable.
Recommended
Recommended Products Summary
Engineering reference data for AD7490BRU-REEL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7490BRUZ-REEL | AD7490BRUZ-REEL7 | AD7490BRU | AD7490BRUZ | AD7490BCPZ-REEL7 |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 28-TSSOP | 28-TSSOP - same | 28-TSSOP - same | 28-TSSOP - same | 28-TSSOP - same | 28-TSSOP (verify; some datasheet editions show LFCSP) |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Input Channels | 16 single-ended | 16 single-ended | 16 single-ended | 16 single-ended | 16 single-ended | 16 single-ended |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V | 2.7 V to 5.25 V |
| Lead Finish | SnPb (non-RoHS) | Pb-free (RoHS) | Pb-free (RoHS) | SnPb (non-RoHS) | Pb-free (RoHS) | Pb-free (RoHS) |
| Packaging Form | 13-inch Tape & Reel | 13-inch Tape & Reel | 7-inch Tape & Reel | Tube | Tube | 7-inch Tape & Reel |
Key Differentiators
- Same die as AD7490BRUZ-REEL, but only SnPb lead finish is available (vs AD7490BRUZ-REEL)
- Supplied on 13-inch reel for high-volume assembly (vs AD7490BRUZ-REEL7)
- 16 single-ended inputs with on-chip sequencer eliminate an external analog switch (vs AD7265 (14-bit, 1 MSPS, 12-channel))
Design Notes
Estimated: at VIN=5 V, VDD=5 V, and 1 MSPS continuous sampling, the AD7490BRU-REEL dissipates roughly 12.5 mW per the datasheet. This is well within the TSSOP-28 thermal envelope (theta_JA ~ 80 C/W on a 4-layer JEDEC board), so no special copper pours are required. A 100 nF X7R + 10 uF tantalum decoupling network placed within 5 mm of each VDD pin keeps supply-noise-induced INL within datasheet limits.
Split the board ground plane into analog and digital sections with a single-point tie under or near the ADC. Route the SPI bus (SCLK, DOUT, DIN, CS, BUSY) over the digital ground plane only and avoid running them parallel to analog input traces. Place the external reference (e.g., AD780) within 10 mm of the REF pin and surround the reference decoupling caps with analog-ground copper; this prevents digital switching noise from corrupting the reference and degrading SNR.
Each analog input channel should be anti-alias filtered with a first-order RC (typically 1 kohm + 1 nF for a ~160 kHz cutoff). The on-chip track-and-hold bandwidth exceeds 1 MHz per datasheet, so the ADC itself does not limit input bandwidth, but external RC filtering is mandatory to reject out-of-band noise that would otherwise alias into the Nyquist band. For high-impedance sources, add a unity-gain buffer (e.g., AD8628) within 5 mm of the ADC input to prevent sampling-charge kick-back from disturbing the source.
Do not leave the REF pin floating - the AD7490BRU-REEL needs an external reference per the datasheet, and a floating REF pin will cause severe gain errors. The CS pin must be pulled low for the duration of a conversion; if CS is de-asserted mid-frame the DOUT output will tri-state and the host will read invalid data. Finally, ensure the BUSY pin is monitored by the host (or the EOC is wired to an interrupt) before clocking out conversion results, otherwise the digital host can read stale register contents.
Compliance Information
The -BRU suffix indicates legacy SnPb (tin-lead) lead finish and is therefore NOT RoHS compliant per the Analog Devices ordering guide. The RoHS-compliant variant is -BRUZ. AEC-Q100 does not apply (this is a general-purpose industrial ADC). REACH and conflict-minerals compliance per Analog Devices corporate policy.
