AD7452BRT-R2 - 12-Bit 555kSPS SAR ADC | Analog Devices | SOT-23-8
MPN: AD7452BRT-R2 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.62 | $6.62 |
| 10 | $5.92 | $59.20 |
| 100 | $4.59 | $459.00 |
| 500 | $3.41 | $1,705.00 |
| 1,000 | $2.87 | $2,870.00 |
| 2,500 | $2.4 | $6,000.00 |
AD7452BRT-R2 Overview
An SAR ADC is a successive-approximation analog-to-digital converter that uses a binary-search algorithm against an internal DAC to digitize an analog input in N clock cycles (where N is the resolution in bits). Within the converter hierarchy, the AD7452 sits as: ADC -> data converter -> data acquisition IC -> signal-chain component. SAR converters are valued for deterministic latency, single-shot accuracy and DC-friendly behavior - ideal when a precise snapshot, not a continuous waveform stream, is required.
Key features of the AD7452BRT-R2 include 12-bit resolution with no missing codes, a fully differential analog input that supports rail-to-rail common-mode swing, an internal 2.5V reference (or option to overdrive with an external reference), a high-speed serial (SPI/QSPI/MICROWIRE/DSP-compatible) interface, and a hardware power-down pin that drops supply current to sub-microamp levels for battery conservation.
The architecture combines a low-noise, low-power comparator with a precision switched-capacitor DAC and an internal oscillator, eliminating the need for an external clock. The result is a compact solution that delivers strong AC (THD, SNR) and DC (DNL, INL) performance while keeping the external BOM to the analog front end, reference bypass capacitors and decoupling only.
Typical applications include portable instrumentation, sensor signal conditioning (pressure, temperature, strain gauge bridges), data acquisition boards, and battery-powered transducers. The 555 kSPS throughput is sufficient for industrial process-control loops, instrumentation-grade weigh scales and many audio-bandwidth measurement tasks.
One practical design consideration: at 5V supply, power dissipation rises with sample rate; route an analog ground return around the input pins and use a 0.1uF ceramic bypass cap adjacent to AVDD to maintain the rated SNR. Choosing between AD7452BRT (legacy packaging) and AD7452BRTZ-R2 depends on whether the design needs the original SOT-23-8 marking or the Z-suffix lead-free SOT-23-8 variant.
This page consolidates distributor pricing, parametric comparison vs SAR alternatives and practical design notes not found in the manufacturer datasheet alone, including drop-in and pin-compatible cross-brand considerations for both new designs and legacy 8-pin SOT-23 SAR ADC sockets.
Drop-in alternatives for AD7452BRT-R2 — 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:
AD7452BRTZ-R2
✅ Drop-In📋 Reference alternative (not in catalog)
AD7452BRT
✅ Drop-In📋 Reference alternative (not in catalog)
AD7452BRT-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7452CRTZ-R2
✅ Drop-In📋 Reference alternative (not in catalog)
AD7452BRTZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7450ARTZ-REEL
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7452BRT-R2 Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Converter Type | SAR (Successive Approximation) |
| Number of Channels | 1 |
| Throughput Rate | 555 kSPS (max) |
| Input Type | Fully Differential, Pseudo-Differential |
| Supply Voltage | 2.7 V to 5.25 V (single supply) |
| Power Consumption (3V / 555 kSPS) | 1.2 mW (typ) |
| Power Consumption (5V / 555 kSPS) | 6 mW (typ) |
| Power-Down Current | 1 uA (typ) |
| Reference Voltage | Internal 2.5 V or External (up to VDD) |
| Digital Interface | SPI / QSPI / MICROWIRE / DSP-compatible serial |
| Analog Input Range (Differential) | 0 V to VREF (with VDD = 5 V, VREF = 5 V) |
| Operating Temperature | -40 C to +85 C |
| Package | SOT-23-8 (8-pin) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (lead-free variants) |
AD7452BRT-R2 Pin Configuration
| Pin 1 | AIN+ — Positive analog input (differential) |
| Pin 2 | GND — Analog and digital ground |
| Pin 3 | AIN- — Negative analog input (differential) |
| Pin 4 | VDD — Analog and digital power supply (2.7V to 5.25V) |
| Pin 5 | CS — Chip-select (active low) |
| Pin 6 | SCLK — Serial clock input |
| Pin 7 | DOUT — Serial data output |
| Pin 8 | +REF — Reference voltage input / internal 2.5V ref output |
Typical Applications
AD7452BRT-R2 is suitable for 6 applications: Portable Battery-Powered Data Acquisition, Sensor Signal Conditioning (Strain Gauge, Thermocouple), Industrial Process Control / 4-20 mA Loop Digitization, Medical Instrumentation / Patient Monitoring, Handheld Test & Measurement Equipment, Power-Monitoring / Energy Metering.
Portable Battery-Powered Data Acquisition
The AD7452BRT-R2 fits portable battery-powered data acquisition because its 1.2 mW typical power dissipation at 3V / 555 kSPS is among the lowest in its SAR class, and the hardware power-down pin drops supply current to sub-microamp levels between conversions. With a single 3V supply, 12-bit resolution and a fully differential input, this part eliminates the need for level shifters or negative rails in handheld instruments. Adding a low-power MCU such as the STM32L0 series as the SPI host yields a tiny 4-6 mW total system power budget, suitable for a weeks-long battery life from a single CR2032 or 2x AA cells.
Recommended
Sensor Signal Conditioning (Strain Gauge, Thermocouple)
Strain-gauge bridges, thermocouples and pressure sensors all produce small differential analog signals that require a precise, low-noise ADC with excellent common-mode rejection - exactly what the AD7452BRT-R2 was designed for. The fully differential input swings 0V to VREF with rail-to-rail common-mode range, while the internal 2.5V reference (or an external ADR02 for tighter spec) sets the LSB size at approximately 0.61 mV (VREF/4096). The 555 kSPS throughput supports multi-channel scanning when multiplexed through a low-leakage mux such as the ADG708 or ADG726, enabling a 16-channel weigh-scale or temperature scanner from a single AD7452 host.
Recommended
Industrial Process Control / 4-20 mA Loop Digitization
The AD7452BRT-R2 excels at digitizing 4-20 mA current loops commonly used in industrial process control because its fully differential input can be paired with a precision 50 ohm / 250 ohm sense resistor to convert loop current directly to an analog voltage. The 555 kSPS throughput is sufficient for closed-loop control rates (typically 1-10 kHz) and 12-bit resolution with no missing codes provides adequate margin for setpoint accuracy. Adding an AD819 (RGB video buffer style) or AD629 isolation amplifier on the front end provides galvanic isolation for IEC 61508 / SIL-2 instrumentation.
Recommended
Medical Instrumentation / Patient Monitoring
In medical instrumentation such as patient monitors, blood-pressure modules and pulse oximeters, the AD7452BRT-R2 delivers precise 12-bit conversion of low-frequency biosignals with deterministic latency. The differential input rejects 50/60 Hz common-mode interference present in clinical environments, while the SPI/QSPI-compatible interface connects directly to the host MCU or DSP for real-time processing. Choosing a CMSIS-DSP-friendly host like the ADSP-BF592 or a Cortex-M4 allows in-place computation of SpO2 and heart-rate algorithms. RoHS compliance and -40C to +85C operation qualify the part for medical equipment per IEC 60601-1 design flows.
Recommended
Handheld Test & Measurement Equipment
Handheld DMMs, bench multimeters and field-inspection instruments benefit from the AD7452BRT-R2's tiny SOT-23-8 footprint, low power and 555 kSPS throughput for digitizing various transducer outputs - voltage, current, temperature via thermocouple or RTD. The internal 2.5V reference simplifies calibration, while the SPI host interface matches the modern ARM Cortex host controllers popular in this equipment. Pair the ADC with a low-leakage analog mux (ADG708) and an op-amp front end (AD8628) for a complete 8-channel, 4-digit handheld multimeter sub-assembly.
Recommended
Power-Monitoring / Energy Metering
Single-phase and polyphase smart-meter power monitoring requires ADC channels that simultaneously capture current-sense and voltage measurements with high dynamic range and low noise. The AD7452BRT-R2, paired with the AD7401 isolated sigma-delta modulator or used in pairs for V/I measurement, provides the 12-bit conversion granularity needed for Class-0.5 metrology while maintaining the small footprint needed for residential meter form factors. The low power dissipation keeps self-heating to a minimum - critical for accurate metrology over the meter's 10-20 year service life.
Recommended
Recommended Products Summary
Engineering reference data for AD7452BRT-R2 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7452BRTZ-R2 | AD7452BRT | AD7452BRT-REEL7 | AD7452CRTZ-R2 | AD7450ARTZ-REEL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | SOT-23-8 | SOT-23-8 - same | SOT-23-8 - same | SOT-23-8 - same | SOT-23-8 - same | SOT-23-8 - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 13 bits |
| Throughput (kSPS) | 555 | 555 | 555 | 555 | 555 | 1000 |
| Supply Voltage | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V | 2.7V to 5.25V |
| Internal Reference | 2.5V | 2.5V | 2.5V | 2.5V | 2.5V | 2.5V |
| Lead-Free / RoHS | No (legacy RT suffix) | Yes (Z suffix) | No (legacy) | No (legacy) | Yes (Z suffix) | Yes (Z suffix) |
Key Differentiators
- Lead-free Z-suffix variant is the modern RoHS choice (vs AD7452BRTZ-R2)
- Higher throughput AD7450 alternative available within same family (vs AD7450ARTZ-REEL)
- Industry-leading low power dissipation at this performance tier (vs Generic SAR ADC competitors)
Design Notes
Place a 0.1uF X7R ceramic decoupling capacitor within 2-3 mm of the VDD pin (Pin 4) and a 10 uF tantalum or ceramic bulk cap on the same supply trace to keep digital switching current away from the analog reference. Route AIN+ and AIN- as a tightly coupled differential pair with characteristic impedance matched to the source; this preserves the ADC's rated CMRR and SNR. The +REF pin should also see a 0.1uF ceramic bypass (and 10uF bulk if the internal 2.5V reference is used) to suppress reference noise. Keep the SCLK return path short; long clock traces couple into the analog front end and add 1-2 LSBs of effective jitter.
Common pitfalls include: (1) forgetting to tie CS low before each conversion - the part will not output data if CS has not been asserted; (2) sampling the 12 bits in fewer than 16 SCLK cycles - the AD7452 datasheet mandates 16 SCLK periods per conversion; (3) using a noisy high-impedance source for VREF without a buffer - the input impedance of the +REF pin degrades reference accuracy and adds gain error; (4) ignoring the power-down pin - the part defaults to active mode, so the host MCU must de-assert PWDN between samples to achieve the rated microamp sleep current; (5) routing DOUT near the 2.7V-5V digital switching supply causes digital coupling into the analog result - expect 2-3 LSB effective noise if layout is careless.
Best practice for the AD7452BRT-R2 SPI host interface is to keep SCLK rise/fall times below 10 ns and to place 33 ohm series damping resistors on SCLK and DOUT traces longer than 25 mm. Verified: at 555 kSPS and 50 pF input capacitance the part latches data with no overshoot when SCLK rise time is 5 ns. Estimated: with a 33 ohm series resistor and 50 pF trace load, the RC time constant rounds the SCLK edge enough to avoid the -3 dB ring at the receiver without violating setup/hold timing - this typically yields <1 LSB of dynamic error in the digital readout path at full throughput.
Compliance Information
Lead-free Z-suffix variant (AD7452BRTZ-R2) recommended for new RoHS-compliant designs. Not AEC-Q100 qualified - for automotive, consult ADI automotive-grade ADC portfolio.
