AD7478ARTZ-REEL - 8-Bit 1 MSPS SAR ADC SOT-23-6 | Analog Devices
MPN: AD7478ARTZ-REEL ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.92 | $4.92 |
| 10 | $4.43 | $44.30 |
| 100 | $3.94 | $394.00 |
| 500 | $3.54 | $1,770.00 |
| 1,000 | $3.15 | $3,150.00 |
AD7478ARTZ-REEL Overview
An ADC (analog-to-digital converter) is a semiconductor device that converts a continuous-time analog voltage into a discrete digital code. Within the broader taxonomy, the AD7478 belongs to the SAR ADC family, which executes a binary-search conversion in N clock cycles - ideal for applications that need deterministic latency, low latency, and low power consumption. SAR ADCs sit under the data-converter hierarchy (ADC -> data converter -> signal chain IC -> mixed-signal semiconductor) and are commonly paired with op-amps, references, and microcontrollers in embedded systems.
The AD7478ARTZ-REEL features a low-noise, wide-bandwidth track-and-hold front end, low power consumption at 1 MSPS with 3 V and 5 V supplies, and standard SPI-/QSPI-/MICROWIRE-compatible serial I/O. Its tiny SOT-23-6 footprint makes it one of the smallest 1 MSPS SAR ADCs in the industry, ideal for portable, battery-powered, and PCB-area-limited designs. The 8-bit resolution is well matched to sensor digitisation, LED brightness control, and simple process-control loops.
Architecturally, the device integrates a sample-and-hold amplifier, an internal reference input structure, a successive-approximation register, and a serial output engine. Conversion is initiated on the falling edge of CNV and the result is clocked out on the rising edges of SCLK. The wide analog-input bandwidth and clean SNR floor let the ADC capture fast transducer signals without the front-end buffer required by slower ADCs.
Typical applications include portable and battery-powered instrumentation, transducer digitisation, data acquisition modules, LED lighting control loops, process and industrial control, and any SPI-bus-based embedded measurement. Using it with a precision op-amp such as the AD8021 or an ADR01 reference preserves linearity in the first few LSBs.
When designing with this part, follow the manufacturer reference schematic for the SOT-23-6 footprint, keep analog and digital grounds separated, and add 0.1 uF decoupling close to the AVDD pin. The compact package has limited thermal mass, so verify that supply headroom stays within the 2.35 V-5.25 V absolute-maximum envelope during transients.
This page synthesises Analog Devices datasheet parameters, current distributor stock and pricing, and drop-in alternatives not aggregated in any single place elsewhere.
Drop-in alternatives for AD7478ARTZ-REEL — 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 AD7478ARTZ-REEL (same form factor and footprint) — differing in Package, Resolution, Data Interface, Operating Temperature, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7478ARTZ-REEL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7478ARTZ-500RL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7476BRTZ-REEL
✅ Drop-In✓ In Stock
$2.85 / Unit
View Datasheet →AD7477SRTZ-REEL
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →AD7478AAKSZ-REEL
✅ Drop-In✓ In Stock
$1.52 / Unit
View Datasheet →AD7478ARTZ-REEL Maximum Ratings & Electrical Characteristics
| Resolution | 8 bits |
| Number of Channels | 1 single-ended input |
| Converter Type | SAR (Successive Approximation) |
| Sampling Rate | 1 MSPS |
| Supply Voltage | 2.35 V to 5.25 V (single) |
| Input Bandwidth | >6 MHz (wide-bandwidth track-and-hold) |
| SNR | 70 dB at 100 kHz input |
| Digital Interface | SPI, QSPI, MICROWIRE, DSP-compatible serial |
| Package | SOT-23-6 (6-lead) |
| Mounting Type | Surface Mount |
| Throughput Type | 1 MSPS, single conversion per CNV |
| Power Consumption | Low power at 1 MSPS with 3 V / 5 V supplies |
| Packaging Type | Tape & Reel (REEL) |
| RoHS Status | Compliant |
AD7478ARTZ-REEL Pin Configuration
| Pin 1 | AVDD — Analog supply (2.35 V to 5.25 V); place 0.1 uF bypass capacitor close to this pin |
| Pin 2 | SDOUT — Serial data output - conversion result clocked out MSB first |
| Pin 3 | SCLK — Serial clock input for SPI/QSPI/MICROWIRE/DSP-compatible interface |
| Pin 4 | GND — Ground return for analog and digital |
| Pin 5 | CNV — Conversion start input - falling edge initiates conversion |
| Pin 6 | AIN — Analog input - single-ended input to the track-and-hold |
Typical Applications
AD7478ARTZ-REEL is suitable for 6 applications: Portable Battery-Powered Instrumentation, Transducer and Sensor Digitisation, Data Acquisition Modules, LED Lighting Control Loops, Industrial Process Control (8-bit, 1 MSPS), Embedded Measurement Modules.
Portable Battery-Powered Instrumentation
The AD7478ARTZ-REEL is well matched to handheld battery-powered test instruments because it operates from a single 2.35 V to 5.25 V supply and consumes low power at 1 MSPS with both 3 V and 5 V rails. With 70 dB SNR at 100 kHz and a 6 MHz analog-input bandwidth track-and-hold, it captures transducer output without external buffering. Paired with an ADR01 reference and AD8021 op-amp, the ADC preserves 8-bit linearity in a palm-sized PCB area.
Recommended
Transducer and Sensor Digitisation
Factory sensor signals (strain gauges, thermocouples after amplification, photodiodes, accelerometers) settle fast enough for the AD7478ARTZ-REEL's 1 MSPS conversion rate. The wide-bandwidth track-and-hold accepts >6 MHz analog inputs, simplifying the front-end filter design. SPI/QSPI/MICROWIRE-compatible serial output streams results directly to an MCU/DSP for closed-loop control. SOT-23-6 footprint fits even the smallest sensor-module PCBs.
Recommended
Data Acquisition Modules
As the digital interface (SPI/QSPI/MICROWIRE/DSP-compatible) is shared by the whole AD7476/AD7477/AD7478 family, an 8-bit AD7478ARTZ-REEL module can stay in the BOM alongside higher-resolution channels. The same CNV, SCLK, SDOUT wiring reduces firmware complexity. The 1 MSPS throughput supports multiplexing many channels per second via an external analog MUX, while the wide input bandwidth catches transient events the S&H preserves without aliasing.
Recommended
LED Lighting Control Loops
The AD7478ARTZ-REEL reads photodiode or thermistor analogue signals to drive LED brightness or colour-mixing loops. At 8-bit resolution, the device produces 256 PWM-grade steps which is adequate for many lighting dimming curves. Its single 2.35-5.25 V supply lets it share the LED driver's 3.3 V or 5 V rail, eliminating a separate ADC supply. SOT-23-6 minimises footprint inside smart-lamp PCBs.
Recommended
Industrial Process Control (8-bit, 1 MSPS)
For 8-bit process-control loops - valve position, motor speed feedback, simple temperature readouts - the AD7478ARTZ-REEL gives a deterministic, low-latency conversion without the complexity of delta-sigma ADCs. The SAR architecture completes every conversion in fixed clock cycles, making control-loop timing predictable. The 2.35-5.25 V supply tolerance matches 3.3 V PLC backplanes and 5 V analogue I/O cards alike.
Recommended
Embedded Measurement Modules
When an MCU/DSP lacks an internal ADC with the required speed, the AD7478ARTZ-REEL drops into SPI and adds 8-bit 1 MSPS capture capability. It avoids the MCU's internal ADC multiplexer and timing conflicts, freeing the CPU for measurement processing. The SOT-23-6 keeps board footprint under 10 mm squared, ideal for wearable fitness bands, environmental sensors, and IoT edge nodes. Pin-compatible upgrade path to AD7476 (12-bit) preserves layout silicon-de-risk.
Recommended
Recommended Products Summary
Engineering reference data for AD7478ARTZ-REEL — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7478ARTZ-REEL7 | AD7478ARTZ-500RL7 | AD7476BRTZ-REEL | AD7477SRTZ-REEL | AD7478AAKSZ-REEL |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | SOT-23-6 | SOT-23-6 (identical) | SOT-23-6 (identical) | SOT-23-6 (identical) | SOT-23-6 (identical) | SOT-23-6 (or alternate 6-lead) |
| Resolution | 8 bits | 8 bits | 8 bits | 12 bits | 10 bits | 8 bits (A-generation) |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Supply Voltage | 2.35 V to 5.25 V | 2.35 V to 5.25 V | 2.35 V to 5.25 V | 2.35 V to 5.25 V | 2.35 V to 5.25 V | 2.35 V to 5.25 V |
| Digital Interface | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP | SPI/QSPI/MICROWIRE/DSP |
| Input Bandwidth | >6 MHz | >6 MHz | >6 MHz | >6 MHz | >6 MHz | Improved TR/HF input |
| Reel Quantity | 10,000 (REEL) | 3,000 (REEL7) | 500 (500RL7) | 10,000 (REEL) | 10,000 (REEL) | 10,000 (REEL) |
| RoHS Compliance | Compliant | Compliant | Compliant | Compliant | Compliant | Compliant |
Key Differentiators
- Pin-compatible resolution upgrade path within same family (vs AD7476BRTZ-REEL (12-bit) / AD7477SRTZ-REEL (10-bit))
- Industrial-defining SOT-23-6 miniature footprint for 1 MSPS (vs AD7478AAKSZ-REEL)
- Multiple reel-packaging options within same SKU family (vs AD7478ARTZ-REEL7 / AD7478ARTZ-500RL7)
Design Notes
Place 0.1 uF X7R decoupling ceramic within 2 mm of the AVDD pin (pin 1). Separate analog and digital ground returns - tie them together only at a single point under the IC's GND pin. Keep the analog input trace to pin 6 short and routed away from digital signals (SCLK, CNV, SDOUT) to preserve the 70 dB SNR floor at 100 kHz.
Drive CNV and SCLK with clean CMOS-level signals (rise/fall times < 10 ns) to avoid spurious conversion starts. Place a small RC filter (10 ohm + 22 pF) on SCLK if the bus is longer than 50 mm. The wide-bandwidth track-and-hold (>6 MHz) keeps input bandwidth high but does not replace a proper front-end antialias filter.
Do not exceed the 7 V absolute maximum on AVDD, even during transient hot-plug events. Ensure reference decoupling (0.1 uF) is present if the internal reference path is used. Do not assume the ADC is a 'pure digital' device - the analog input pin AIN must be driven by a low-impedance op-amp output to keep below 0.5 LSB settling at full 1 MSPS throughput.
Compliance Information
The 'Z' suffix in AD7478ARTZ indicates lead-free, RoHS-compliant packaging per Analog Devices part number convention. AEC-Q100 not qualified - this part targets industrial and consumer, not automotive. Halogen-free status not explicitly listed in the verified data.
