ADCS7477AIMF - 10-Bit 1MSPS SAR ADC, SOT-23-6 | Texas Instruments
MPN: ADCS7477AIMF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.2 | $4.20 |
| 10 | $3.78 | $37.80 |
| 100 | $3.36 | $336.00 |
| 500 | $2.94 | $1,470.00 |
| 1,000 | $2.52 | $2,520.00 |
ADCS7477AIMF Overview
A SAR ADC (Successive Approximation Register Analog-to-Digital Converter) is a type of data converter that uses a binary-search algorithm against an internal DAC to determine each code, requiring only N conversion cycles for an N-bit sample. SAR ADCs sit between slower integrating converters and high-speed pipelined flash ADCs in the data-converter hierarchy: data converter -> ADC -> successive approximation ADC -> medium-speed monolithic ADC -> power management / signal-chain IC. SAR architectures are prized for deterministic latency, low power, and excellent DC accuracy, which is why they dominate industrial control, instrumentation, and battery-powered sensor applications.
Key features of the ADCS7477AIMF include 1 MSPS throughput, 10-bit resolution with no missing codes, an internal 2.5 V reference option (ADCS7478 / ADCS7476 variants adjust resolution), a true-differential analog input stage, and a hardware-friendly shutdown pin that drops supply current to microamp levels for power-cycled applications. The 6-pin SOT-23 footprint makes the device the smallest member of TI/NSC's ADCS747x monolithic ADC family.
Typical applications include portable instrumentation, optical module monitoring, high-speed data acquisition front-ends, motor-control feedback sampling, and precision sensor signal chains where compact PCB area and deterministic latency are required. The combination of low power consumption, small footprint, and industry-standard SPI-compatible interface makes this part attractive for designers migrating from legacy parallel ADCs that consumed far more board area.
A primary design trade-off is the choice of internal-versus-external voltage reference: the internal reference minimizes external BOM but constrains absolute accuracy, whereas an external reference improves gain error and temperature drift at the cost of an extra component and pin. Adding a 0.1 µF ceramic decoupling capacitor within 5 mm of the AVDD pin and a small RC anti-alias filter at AIN is recommended.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes beyond what is found on DigiKey, Mouser, or TI's product page, giving engineers a single canonical reference for the ADCS7477AIMF.
Drop-in alternatives for ADCS7477AIMF — 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 ADCS7477AIMF (same form factor and footprint) — differing in Operating Temperature Range, Package, Resolution, RoHS Status, Digital Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADCS7477AIMF/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
ADCS7476AIMF/NOPB
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →ADCS7478AIMF
✅ Drop-In✓ In Stock
$2 / Unit
View Datasheet →ADCS7477AIMFX
✅ Drop-In📋 Reference alternative (not in catalog)
ADCS7477AIMFE/NOPB
✅ Drop-In📋 Reference alternative (not in catalog)
AD7477ARTZ
✅ Drop-In📋 Reference alternative (not in catalog)
ADCS7477AIMF Maximum Ratings & Electrical Characteristics
| Resolution | 10 bits |
| Sampling Rate | 1 MSPS |
| Architecture | SAR (Successive Approximation Register) |
| Number of Channels | 1 single-ended input |
| Analog Input Voltage Range | 0 V to AVDD (true single-ended at AINP) |
| Supply Voltage (AVDD/DVDD) | 2.35 V to 5.25 V |
| Digital Interface | SPI / QSPI / MICROWIRE / DSP-compatible serial |
| Resolution (Effective) | 10-bit, no missing codes |
| Package | 6-pin SOT-23-6 |
| Mounting Type | Surface Mount |
| Operating Temperature Range | -40 °C to +85 °C |
| RoHS Status | Compliant (NOPB suffix) / non-compliant (standard IMF) |
ADCS7477AIMF Pin Configuration
| Pin 1 | AVDD — Analog supply voltage (2.35 V to 5.25 V) - decouple with 0.1 µF to GND |
| Pin 2 | AIN — Analog input (single-ended to GND; full-scale 0 V to AVDD) |
| Pin 3 | GND — Ground - both analog and digital grounds tied to a single low-impedance plane |
| Pin 4 | DOUT — Serial data output - SPI-compatible, three-state when CS_n is high |
| Pin 5 | SCLK — Serial clock input - up to 20 MHz, clocks data out MSB-first on DOUT |
| Pin 6 | CS_n — Active-low chip select - frames conversions and three-states DOUT |
Typical Applications
ADCS7477AIMF is suitable for 6 applications: Portable Sensor Data Acquisition, Motor Control Current/Voltage Sensing, Optical Module Monitoring (SFP/QSFP), Industrial Process Control Analog Front-End, Battery-Operated Test & Measurement, Medical Wearable Vital-Sign Monitoring.
Portable Sensor Data Acquisition
The ADCS7477AIMF fits portable sensor front-ends because it operates from 2.35 V to 5.25 V and samples at 1 MSPS while drawing only milliwatts at full rate. Paired with a low-power MCU such as the MSP430 or STM32L4 over an SPI bus, it digitizes temperature, pressure, or strain-gauge signals through a small anti-alias RC filter at AIN. Its 10-bit resolution (1024 codes) keeps quantisation noise below 1 mV at a 2.5 V full-scale, suitable for sensor digitisation, and the shutdown pin lets duty-cycling firmware extend battery life on wireless IoT nodes. The SOT-23-6 footprint keeps the analog section under 10 mm² - critical for wearable and remote-monitoring designs.
Recommended
Motor Control Current/Voltage Sensing
The ADCS7477AIMF digitizes phase-current and DC-bus-voltage signals in BLDC and stepper motor drives, where its deterministic SAR latency avoids the variable-delay artefacts that complicate zero-crossing detection. With 10-bit resolution and 1 MSPS sampling, motor-control firmware can resolve 1 A phase-current steps at full PWM duty when paired with a 5 mΩ shunt and OPA365 buffer. The SOT-23-6 footprint fits alongside the gate-driver and Hall-effect sensors on compact inverter boards. Designers should ground the analog supply through a ferrite bead from the digital rail to keep switching noise out of the conversion result.
Recommended
Optical Module Monitoring (SFP/QSFP)
The ADCS7477AIMF is well-suited to optical transceiver modules like SFP, QSFP, and CFP where PCB area is at a premium and supply rails are 3.3 V. The 1 MSPS throughput is more than enough to oversample receive-power (RSSI) and laser-bias monitoring channels at 10 kHz while leaving headroom for diagnostic loops, and the 10-bit resolution satisfies the ±3 dB accuracy requirement typical of SFF-8472. The SOT-23-6 footprint sits inside the module cage without competing with the TOSA/ROSA footprint, and the SPI interface connects directly to the module's monitoring MCU.
Recommended
Industrial Process Control Analog Front-End
The ADCS7477AIMF operates across the industrial -40 °C to +85 °C temperature range and tolerates supply transients typical of 24 V PLC backplanes regulated down to 5 V. Its 1 MSPS throughput means a single ADC can service 8-16 multiplexed analog channels at the typical 4-10 kHz loop-control rate needed for PID loops. The SOT-23-6 footprint helps shrink module form-factors, and the SPI/QSPI interface connects directly to industrial MCUs and DSPs over opto-isolated links without additional glue logic. Designers should add a TVS diode at AIN to meet IEC 61000-4-2 surge requirements on field-mounted inputs.
Recommended
Battery-Operated Test & Measurement
Handheld DMMs, oscilloscope probes, and field-test instruments benefit from the ADCS7477AIMF's low power, SOT-23-6 footprint, and 1 MSPS throughput. The 10-bit resolution is sufficient for trend logging and AC/DC measurement displays, while the SAR architecture's no-missing-codes guarantee keeps the display image stable when the unit is battery-powered. Combined with a lithium-ion cell and buck-boost regulator, the ADC shares the 3.3 V rail with an OLED display and BLE SoC, eliminating the need for separate analog and digital power domains.
Recommended
Medical Wearable Vital-Sign Monitoring
The ADCS7477AIMF's 1 MSPS sampling and 10-bit resolution make it suitable for low-power photoplethysmography (PPG) and single-lead ECG frontend applications, where its SOT-23-6 footprint is small enough for wrist-worn designs. Operating from a 2.35 V to 5.25 V supply, it shares the same lithium-polymer battery rail with the BLE SoC that streams data to a phone. The SAR ADC's deterministic latency avoids switching-induced noise artefacts in pulse-oximetry, and the shutdown pin supports duty-cycling firmware that extends the device's wear time to several days on a single charge.
Recommended
Recommended Products Summary
Engineering reference data for ADCS7477AIMF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADCS7477AIMF/NOPB | ADCS7476AIMF | ADCS7478AIMF | ADCS7477AIMFX | ADCS7477AIMFE/NOPB | AD7477ARTZ |
|---|---|---|---|---|---|---|---|
| Package | SOT-23-6 | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Resolution | 10 bits | 10 bits | 8 bits | 12 bits | 10 bits | 10 bits | 10 bits |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Supply Voltage Range | 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 | 2.35 V to 5.25 V |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR | SAR |
| Digital Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| RoHS Compliance | Non-RoHS (IMF only) / RoHS via NOPB suffix | RoHS compliant | Non-RoHS (NOPB available) | Non-RoHS (NOPB available) | Non-RoHS (NOPB available) | RoHS compliant | RoHS compliant |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Smallest SAR ADC footprint in TI/NSC's ADCS747x family (vs ADCS7478AIMF)
- 2-bit finer resolution than ADCS7476AIMF (vs ADCS7476AIMF)
- Direct register-level compatibility with original AD7477 (vs AD7477ARTZ)
- Industrial temperature range guaranteed (vs [DATA_NEEDED: industrial temp parts competitor list])
Design Notes
Place a 0.1 µF X7R ceramic decoupling capacitor within 5 mm of the AVDD pin (pin 1) to bypass switching current to GND. Star-route the AGND (pin 3) to the system ground plane with a short, low-inductance trace to keep ADC reference noise from coupling into the analog input. For best 10-bit performance in noisy digital environments, add a ferrite bead between the AVDD pin and the digital 3.3 V rail fed from the LDO.
Route the SCLK (pin 5) signal on an inner PCB layer or short top-layer trace, keeping it perpendicular to any analog traces running underneath. Use 1 kΩ series resistors at DOUT (pin 4) and SCLK (pin 5) if the trace to the host MCU exceeds 25 mm, to damp reflections and reduce radiated emissions. Keep the analog input trace from AIN (pin 2) routed symmetrically with the input reference to maintain CMRR; add a small RC anti-alias filter (10 Ω + 10 pF typical) directly at the pin.
When designing with the ADCS7477AIMF, choose a low-noise LDO (such as TPS7A4533 or similar) with at least 50 mA headroom to supply the ADC plus its analog front-end buffer. The ADC's internal reference does not require external decoupling, but adding a 4.7 µF bulk capacitor near AVDD improves full-rate sampling noise. Estimated: at 5 V AVDD and 1 MSPS, the ADC itself draws roughly 3 mA at full rate; verify with the datasheet figure before committing layout.
Do not drive AIN (pin 2) with source impedances > 1 kΩ without an input buffer, or the ADC's internal track-and-hold will introduce gain error. Ensure CS_n (pin 6) returns high between conversions to three-state DOUT (pin 4) and avoid bus contention. Do not exceed the absolute maximum AVDD of 5.25 V. The ADCS7477AIMF does not include a dedicated shutdown pin in the standard IMF package - designs targeting sub-µA standby should switch the LDO instead, or migrate to the ADCS7477AIMFE/NOPB variant if a hardware-shutdown pin is required.
CS_n is the conversion-start trigger: hold CS_n low during SCLK to clock conversion data out. Cycle CS_n high-low-high at the desired sample rate, and avoid jitter > 10 ns on CS_n at 1 MSPS because it appears directly as aperture jitter in the captured sample. For sampling clocks recovered from an MCU timer, use the MCU's hardware SPI peripheral rather than bit-banging to keep jitter and gap times within datasheet limits.
Compliance Information
Standard ADCS7477AIMF (no /NOPB suffix) is not RoHS compliant - it ships with lead-based finish. The /NOPB suffix variant is RoHS compliant and lead-free and is the recommended choice for new designs. AEC-Q100 qualification is not applicable because this part is targeted at industrial / general-purpose markets, not automotive.
