ST0937B Single 3.3V 8mW Single-Phase Socket Energy Metering IC with Built-in Clock

ST0937B Single 3.3V 8mW Single-Phase Socket Energy Metering IC with Built-in Clock

ST0937B

The ST0937B is a wide-range single-phase multifunction energy metering IC integrating two high-precision Sigma-Delta ADCs, a voltage reference, power management and digital signal processing circuits. It measures single-phase active energy, active power and RMS current/voltage over a current range of 4mA to 30A @ 1mΩ. A high-frequency CF pulse output handles energy metering, while the CF1 output indicates RMS current or voltage as selected by the SEL pin. Fast over-current detection responds within 200ms, outputting a 7.8kHz indication signal on the CF pin. Nonlinearity measurement error is less than ±0.5% over a 2500:1 input dynamic range, and the patented anti-creep design ensures noise power is never counted as energy pulses when no current flows. With a built-in oscillator requiring no external crystal, factory calibration, a single 3.3V (3.0~3.6V) supply at only 8mW typical, and an SOP8 package, the ST0937B is widely used in single-phase socket meters, power strips and smart home appliance control circuits.

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Specifications

MeasurementSingle-phase socket meter energy metering: active energy, active power, RMS current/voltage; current range 4mA~30A@1mΩ
Power Consumption8 mW (typ, single 3.3V)
ADC Channels2 high-precision Sigma-Delta ADCs
OutputCF/CF1 high-frequency pulse output (CF metering; CF1 indicates RMS current/voltage)
ClockBuilt-in oscillator, no external crystal required
VDDSingle 3.3V (3.0~3.6V)
CalibrationFactory calibrated
FreeNot specified
PackageSOP8

Product details

Overview

The ST0937B is a wide-range single-phase multifunction energy metering IC suited for single-phase socket meters, power strips, smart home appliance control circuits and other applications, offering excellent cost performance. It integrates two high-precision Sigma-Delta ADCs, a reference voltage, power management and other analog circuit modules, along with digital signal processing circuits for active power, RMS current/voltage and other electrical parameters. A high-frequency CF1 output indicates RMS current/voltage, and a high-frequency CF output is provided for energy metering. The IC measures single-phase active energy, active power and RMS current/voltage over a current range of 4mA to 30A @ 1mΩ, fully meeting the requirements of socket meters, power strips and smart home appliances. Its patented anti-creep design, combined with proper external hardware, ensures noise power is not counted as energy pulses when no current flows. The built-in oscillator eliminates the need for an external crystal, and typical power consumption is only 8mW from a single 3.3V supply.

Features

  • High accuracy: nonlinearity measurement error <±0.5% over 2500:1 input dynamic range
  • Large signal stability: CF output variation <±0.2% at 300mA sampling current
  • Small signal stability: CF output variation <±0.3% at 50mA sampling current
  • RMS voltage and current output; current measurement range 4mA to 30A @ 1mΩ
  • CF high-frequency pulse output for metering; CF1 outputs RMS current or voltage via SEL, switching wait time <10µs
  • Fast over-current detection within 200ms, with 7.8kHz indication signal on the CF pin
  • Patented anti-creep design prevents noise power from being counted as energy pulses at no load
  • On-chip supply voltage monitor; IC enters reset state below 2.6V
  • Built-in 1.1V reference voltage source (typical)
  • Built-in oscillator circuit, no external crystal required
  • Single 3.3V supply, 8mW typical power consumption; SOP8 package

Typical Applications

  • Single-phase socket meters
  • Power strips
  • Smart home appliance control circuits
  • Over-current protection circuits