ACS37800
Digital power monitoring IC with isolated current sensing and voltage measurement for AC/DC power monitoring applicat...
Product Overview
Description
The ACS37800 is a fully integrated power monitoring IC that combines isolated current sensing, voltage measurement, and power calculation in a single device. The integrated Hall-effect current sensor provides galvanic isolation up to 4.8kV, while the internal voltage sensing enables direct connection to high-voltage rails.
The device features a digital I2C/SPI interface that provides instantaneous current, voltage, and power readings. Integrated diagnostics detect fault conditions including overcurrent, overvoltage, and undervoltage conditions. The ACS37800 eliminates the need for external shunt resistors, isolation amplifiers, and voltage dividers, significantly reducing BOM cost and PCB area.
With a current range of ±30A to ±90A and voltage measurement up to 600V, the ACS37800 is ideal for AC/DC power supplies, solar inverters, and industrial motor drives. The 1.2MHz bandwidth enables accurate measurement of high-frequency switching waveforms.
Product Series
ACS
Primary Application
AC/DC power supply monitoring
Key Features
- Integrated current and voltage sensing
- 4.8kV galvanic isolation
- Digital I2C/SPI interface
- Real-time power calculation
- Integrated fault diagnostics
- 1.2MHz bandwidth
- Overcurrent/overvoltage protection
- Compact SOIC-16 package
Specifications
| Current Range | ±30A to ±90A |
|---|---|
| Voltage Range | Up to 600V |
| Bandwidth | 1.2MHz |
| Isolation Voltage | 4.8kV RMS |
| Current Accuracy | ±1.5% at 25°C |
| Voltage Accuracy | ±1% at 25°C |
| Interface | I2C/SPI digital |
| Supply Voltage | 3.3V or 5V |
| Package | SOIC-16 |
| Temperature Range | -40°C to +125°C |
Applications
AC/DC power supply monitoring
Power conversion and supply
Solar inverter power measurement
Renewable energy systems
Industrial motor drive monitoring
Motor drive and control systems
UPS and battery systems
Battery and charging management
Smart home energy monitoring
Renewable energy systems
Electric vehicle charging
Battery and charging management
FAE Expert Insights
"The ACS37800 is a game-changer for power monitoring applications. The integration of current and voltage sensing with digital output eliminates multiple discrete components - no shunt resistors, no isolation amplifiers, no voltage dividers. This reduces BOM cost by 30-40% and PCB area by 50%. The 1.2MHz bandwidth is excellent for switching power supply monitoring - I've used it to measure PFC stage efficiency with great results. The integrated diagnostics are valuable for detecting fault conditions without microcontroller intervention. The I2C interface makes it easy to integrate with modern microcontrollers. One consideration is the fixed current range - you'll need to select the appropriate variant for your application. Also, the digital interface requires more software development than analog sensors. But for power monitoring applications, the ACS37800 offers unmatched integration and performance."
30-40% BOM cost reduction; 50% PCB area savings; integrated diagnostics; excellent for PFC monitoring
— Jennifer Liu, BeiLuo
Frequently Asked Questions
How does ACS37800 calculate power?
The ACS37800 integrates current and voltage measurement to calculate real-time power: Current measurement - Hall-effect sensor measures load current with 4.8kV isolation; Voltage measurement - high-impedance resistive divider measures bus voltage; Power calculation - internal multiplier computes P = V × I; Energy accumulation - integrated energy counter tracks total energy consumption. The device provides instantaneous current, voltage, power, and energy readings via I2C/SPI interface. Power measurement accuracy is ±2-3% when combining current and voltage errors. The 1.2MHz bandwidth captures high-frequency power variations in switching supplies. For AC applications, the device can measure instantaneous power and calculate RMS values. The digital interface eliminates ADC errors present in analog sensor systems.
ACS37800 provides integrated power calculation; accuracy ±2-3%; digital interface eliminates ADC errors.
What is the I2C interface speed of ACS37800?
The ACS37800 supports I2C interface up to 1MHz (Fast Mode Plus): Standard Mode - up to 100kHz; Fast Mode - up to 400kHz; Fast Mode Plus - up to 1MHz. The device supports clock stretching and has internal registers for configuration and data reading. Register map includes: Current reading (16-bit signed); Voltage reading (16-bit); Power reading (16-bit); Energy counter (32-bit); Configuration registers; Status and fault registers. Reading all parameters takes approximately 100μs at 400kHz. The device also supports SPI interface up to 8MHz for faster data transfer. For power monitoring applications, 400kHz I2C is typically sufficient for 1-10kHz update rates. The digital interface includes CRC protection for data integrity.
Supports up to 1MHz I2C; 100μs read time at 400kHz; SPI available up to 8MHz for faster transfer.
How do I use ACS37800 for AC power monitoring?
AC power monitoring with ACS37800: Connection - connect current sensor in series with AC line or neutral; connect voltage sense to AC line with appropriate safety considerations; ensure 4.8kV isolation between high-voltage and low-voltage sides. Measurement - the device measures instantaneous current and voltage; power is calculated as P = V × I for each sample; positive power indicates power consumption, negative indicates generation. RMS calculation - for AC measurements, calculate RMS by sampling over multiple cycles; I_rms = sqrt(sum(I²)/N); V_rms = sqrt(sum(V²)/N); P_avg = sum(P)/N. Power factor - calculate as PF = P_avg / (V_rms × I_rms). Update rate - sample at > 2× AC frequency (e.g., > 100Hz for 50Hz line); average multiple cycles for stable readings. The 1.2MHz bandwidth captures AC waveform details accurately.
Sample at > 2× AC frequency; calculate RMS over multiple cycles; use for power factor measurement.
What diagnostics does ACS37800 provide?
The ACS37800 includes comprehensive diagnostic features: Overcurrent detection - programmable threshold with fast response; Overvoltage detection - monitors bus voltage for overvoltage conditions; Undervoltage detection - detects low voltage conditions; Fault flags - status register indicates fault conditions; Overtemperature detection - monitors die temperature. Diagnostic configuration: Program thresholds via configuration registers; Enable/disable individual diagnostics; Configure fault response (flag only or automatic actions); Read fault status via I2C/SPI. Use cases: Overcurrent protection - fast shutdown of power stage; Overvoltage protection - prevent damage to downstream circuits; System monitoring - track operating conditions for predictive maintenance. The diagnostics operate independently of the main measurement path, providing redundant protection. Fault outputs can be connected to microcontroller interrupts or directly to system shutdown circuits.
Programmable thresholds for overcurrent, overvoltage, undervoltage; independent fault flags; use for protection and monitoring.
How does ACS37800 compare to discrete solutions?
ACS37800 vs discrete power monitoring solutions: Discrete solution components - shunt resistor (1-5mΩ); isolation amplifier (e.g., AMC1300); voltage divider (high-resistance); ADC (microcontroller or external); total BOM: 8-12 components. ACS37800 solution - single IC with all functions integrated; total BOM: 1 IC + bypass caps. Comparison: PCB area - ACS37800 uses 50% less board space; Cost - ACS37800 reduces BOM cost by 30-40%; Accuracy - comparable when using high-quality discretes; Isolation - both provide galvanic isolation; Bandwidth - ACS37800 1.2MHz vs typical 100-200kHz for isolation amps; Development time - ACS37800 reduces design time significantly. Trade-offs: Current range - discrete solution can be customized; Flexibility - discrete allows component optimization; Availability - single IC vs multiple components. For most power monitoring applications, the ACS37800 offers compelling integration benefits.
ACS37800 reduces BOM cost 30-40%, PCB area 50%; comparable accuracy; faster development vs discrete solutions.