ADCS7478AIMF - 1MSPS 8-Bit ADC SAR SPI SOT-23-6 | Texas Instruments
Référence : ADCS7478AIMF ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $3.45 | $3,45 |
| 10 | $3.1 | $31,00 |
| 100 | $2.65 | $265,00 |
| 500 | $2.3 | $1 150,00 |
| 1 000 | $2 | $2 000,00 |
ADCS7478AIMF Présentation
An analog-to-digital converter (ADC) is a data conversion device that converts a continuous analog voltage into a discrete digital code. Within the broader data converter hierarchy, an ADC sits inside signal chain ICs -> data converters -> ADCs. SAR ADCs sample the input once per conversion, then perform a binary search through an internal DAC to resolve the bits, offering deterministic latency and excellent DC accuracy with very low power consumption at moderate sample rates. The ADCS7478AIMF targets cost- and size-sensitive embedded designs needing 8 bits of resolution at up to 1 MSPS.
Key features include 1 MSPS throughput, an SPI/QSPI/MICROWIRE-compatible serial interface, an on-chip clock, single 2.7V to 5.25V supply with the supply used as the reference, and an analog input range from 0V to VDD. The part draws only a few mW during active conversion and supports power-down modes for battery-powered or duty-cycled applications. The SOT-23-6 footprint measures roughly 2.9mm x 1.6mm, making the converter one of the smallest 1 MSPS SAR ADCs available.
The ADCS7478AIMF is built on a CMOS process with an internal track-and-hold front end and a charge redistribution SAR core. It uses VDD as its reference voltage, eliminating the need for an external reference. The serial data output is straight binary, and the conversion rate is fixed at the internal oscillator. According to TI's datasheet, the device can also be used with an external reference by injecting a reference voltage through the VDD pin when configured appropriately.
Typical applications include portable data loggers, isolated voltage and current sensing in industrial controls, optical module monitoring, system monitoring and housekeeping on microcontroller cards, and battery management in portable medical devices. The combination of small package, low power, and standard SPI interface lets the ADCS7478AIMF sit directly behind a sensor or shunt, sending readings back to a microcontroller with minimal firmware overhead.
When designing with the ADCS7478AIMF, ensure the SPI clock is provided only during conversion and acquisition. Decouple VDD with a 100nF ceramic capacitor placed as close to pin 6 as possible, and keep the analog input trace short and guarded to ground. Verify that the microcontroller SPI mode matches the ADC's clock polarity and phase (CPOL=0, CPHA=0 by default).
This page combines distributor pricing, drop-in pin-compatible alternatives, application notes, and a parameter comparison table that goes beyond what is printed in the TI datasheet, providing a single reference for engineers evaluating or sourcing the ADCS7478AIMF.
Alternatives de remplacement direct pour ADCS7478AIMF — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec ADCS7478AIMF (même facteur de forme et même empreinte) — différant par Operating Temperature Range, Resolution, RoHS Status, Package, Input Type.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
ADCS7478AIMF/NOPB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADCS7476AIMF/NOPB
✅ Remplacement direct✓ En stock
$1.55 / unité
Voir la fiche technique →ADCS7477AIMF/NOPB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADCS7478AIMFX/NOPB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD7478ARTZ-REEL7
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
ADCS7478AIMF Valeurs maximales et caractéristiques électriques
| Résolution | 8 bits |
| Architecture | SAR (Successive Approximation Register) |
| Number of Inputs | 1 |
| Fréquence d'échantillonnage | 1 MSPS |
| Supply Voltage Range | 2.7 V to 5.25 V |
| Analog Input Range | 0 V to VDD |
| Reference | VDD (supply used as reference) |
| Digital Interface | SPI, QSPI, MICROWIRE compatible (serial) |
| Boîtier | SOT-23-6 |
| Plage de température de fonctionnement | -40 C to +85 C |
| Type de montage | Surface Mount |
| Packaging | Tape & Reel |
| Input Type | Single-ended |
| Statut RoHS | Compliant |
| Lead-Free | Yes |
Configuration des broches de ADCS7478AIMF
| Broche 1 | VIN — Analog input (0V to VDD) |
| Broche 2 | GND — Ground reference |
| Broche 3 | CS — Chip select, active low; held low for conversion and serial output |
| Broche 4 | DOUT — Serial data output (SPI MISO MOSI) |
| Broche 5 | SCLK — Serial clock input from controller |
| Broche 6 | VDD — Supply voltage (2.7V to 5.25V); also serves as ADC reference |
Applications typiques
ADCS7478AIMF convient pour 6 applications: Portable Data Logger Front End, Isolated Voltage and Current Sensing, Optical Module Monitoring, Microcontroller System Housekeeping, Battery Management in Portable Medical Devices, Industrial 4-20 mA Loop Sensing.
Portable Data Logger Front End
The ADCS7478AIMF suits battery-powered data loggers because it samples at 1 MSPS but draws only a few hundred microamps during conversion, dropping to single-digit microamps when CS is held high. The 8-bit resolution is sufficient for environmental, temperature, and battery-cell voltage monitoring, and the SPI/QSPI/MICROWIRE-compatible serial interface connects directly to low-power MCUs such as the MSP430 or STM32. Designers place a 100nF decoupling cap on VDD and use the 0V-to-VDD input range to read a thermistor or shunt voltage with no external reference.
Recommandé
Isolated Voltage and Current Sensing
The ADCS7478AIMF fits isolated sensor modules that digitize a current-shunt or voltage-divider signal at the analog side of a digital isolator. Its 1 MSPS throughput captures fast transients on switching rails, and the 8-bit resolution is adequate for motor-control overcurrent detection or telemetry on power-converter secondary sides. The SOT-23-6 footprint fits small PCBs behind an optocoupler or digital isolator such as the ISO7721, and the VDD-as-reference topology eliminates an external reference that would otherwise consume board area.
Recommandé
Optical Module Monitoring
Optical modules in telecom and datacom hardware require monitoring of laser bias current, TEC temperature, and receive power. The ADCS7478AIMF digitizes these slow-changing analog signals with 1 MSPS to spare, and its SPI-compatible output streams samples directly to the module's microcontroller. The SOT-23-6 package fits inside the tight confines of an SFP or QSFP form factor, and the 2.7V to 5.25V supply range aligns with the 3.3V rail typical of optical modules.
Recommandé
Microcontroller System Housekeeping
Embedded designs benefit from one or more housekeeping ADCs that digitize supply rails, board temperature, and external analog alarms. The ADCS7478AIMF is a small, low-cost housekeeping ADC that reports back to the system MCU through SPI, leaving the MCU's internal ADC for user-facing measurements. With a 0V-to-VDD input range and VDD as reference, the part reads divider-scaled signals with no extra components, and the SOT-23-6 footprint sits on board space adjacent to the supervisor and reset IC.
Recommandé
Battery Management in Portable Medical Devices
Battery-powered medical devices such as glucose meters, pulse oximeters, and infusion pumps need to monitor battery voltage and analog sensor channels with minimum power and PCB area. The ADCS7478AIMF combines a 1 MSPS SAR, an SPI output, and a sub-milliwatt active power budget in a SOT-23-6 footprint, making it a natural fit. Designers duty-cycle the ADC by toggling CS, putting the device into power-down between infrequent conversions to extend battery life. The 8-bit resolution covers fuel-gauge telemetry and strip-read signal paths where absolute precision is less critical than cost and size.
Recommandé
Industrial 4-20 mA Loop Sensing
Sensor-transmitter nodes convert a 4-20 mA current loop into a digital reading. The ADCS7478AIMF digitizes a shunt-resistor voltage with 1 MSPS to track loop current while SPI delivers samples to the node controller. The 2.7V to 5.25V supply range aligns with loop-powered or locally-powered transmitters, and the small SOT-23-6 footprint fits inside a compact field-mount enclosure. The VDD-as-reference topology keeps the BOM small in cost-sensitive industrial nodes.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour ADCS7478AIMF — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | ADCS7478AIMF/NOPB | ADCS7476AIMF/NOPB | ADCS7477AIMF/NOPB | ADCS7478AIMFX/NOPB | AD7478ARTZ-REEL7 |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Package | SOT-23-6 | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same | SOT-23-6 - same |
| Resolution | 8 bits | 8 bits | 12 bits | 10 bits | 8 bits | 8 bits |
| Sampling Rate | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS | 1 MSPS |
| Architecture | SAR | SAR | SAR | SAR | SAR | SAR |
| 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 |
| Digital Interface | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI compatible |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
Principaux différenciateurs
- Direct drop-in replacement for the legacy AD7478 in SOT-23-6 (vs AD7478ARTZ-REEL7)
- Three resolution options on one pinout for cost-precision trade-off (vs ADCS7476AIMF/NOPB)
- Smallest 1 MSPS SAR footprint in TI's SAR portfolio (vs ADS78xx)
Notes de conception
Decouple VDD with a 100nF low-ESR ceramic capacitor placed within 2mm of the VDD pin. Because VDD is used as the reference, switching noise on the supply directly couples into the conversion result. Place a 10uF bulk capacitor on the analog supply rail feeding the ADC and isolate the ADC from digital loads with a ferrite bead or small resistor to keep reference noise low.
Route the analog input trace on a different layer from the SPI bus and the DOUT line, surrounded by a ground guard to minimize coupling. Keep the SCLK trace short and series-terminate if the controller is more than 25mm away. Place a 10k pull-up or pull-down on CS per the datasheet recommendation so that CS defaults to a defined state at power-up and avoids spurious SCLK edges.
The ADCS7478AIMF does not tolerate analog inputs above VDD or below GND; clamp with a low-leakage diode pair or a series resistor if the source can exceed the rail. Designers often forget that VDD also serves as the reference, so a noisy 3.3V rail produces a noisy 8-bit result. Add a pi-filter (10ohm-10uF-10ohm) on VDD when using a shared switching regulator. Also ensure the MCU's SPI mode matches the ADC's CPOL=0, CPHA=0 timing.
Use SCLK frequencies well below the 40 MHz maximum; 10-20 MHz is typical for microcontroller hosts. Add a small RC snubber on SCLK or a series 33ohm resistor if overshoot or ringing is observed on DOUT due to capacitive loading. Keep DOUT trace matched to 50 ohm characteristic impedance when running long traces above 50mm.
Informations de conformité
Lead-free and RoHS-compliant per the /NOPB suffix in the TI datasheet. Not AEC-Q100 qualified - not intended for automotive safety use. Conflict-minerals status compliant per TI declarations.