HCT5815

The HCT5812/HCT5815/HCT5821 series are low-power, high-accuracy metering ICs with UART/SPI interfaces. Each device integrates dual high-performance ADCs, along with a programmable gain amplifier, high-precision voltage reference, and DSP circuitry. The primary communication interface is UART, with an additional simple checksum-based interface provided for reading real-time waveform data from both ADC channels. The ICs also integrate a DC-DC converter, which significantly reduces power supply requirements in battery-powered applications, enabling the use of smaller and more cost-effective battery components.

Key features

• Single power supply; supply voltage input range: 2.6V~3.6V for HCT5812/HCT5821; 10V~15V for HCT5815.
• Under-voltage detection function.
• Low-power design; operating current approximately 1.5mA during normal operation.
• Dual independent high-precision Sigma-Delta ADCs for voltage and current sampling.
• Voltage ADC channel supports temperature sensor measurement.
• High metering accuracy: active energy error <0.1% over 8000:1 dynamic current range; reactive energy error <0.1% over 5000:1 dynamic current range; RMS current error <0.1% over 5000:1 dynamic current range.
• Supports 3.2kHz data output rate for up to 31st harmonic measurement; configurable to 1.6kHz for up to 15th harmonic measurement.
• Rich data output: raw waveform data and DC components of voltage/current signals; instantaneous and average full-wave active/reactive power (instantaneous refresh period 10ms, average refresh period 320ms); instantaneous and average voltage/current RMS (instantaneous refresh period 10ms, average refresh period 1280ms); fundamental voltage/current RMS and fundamental reactive power; line voltage frequency (measured via fundamental voltage signal).
• Software calibration support: phase correction (step size 0.011°, range ±1.4°, correction accuracy ±0.02%); RMS gain correction and offset compensation; active/reactive power offset compensation.
• Interrupt detection: fast over-current and over-voltage detection; supply under-voltage detection; register configuration self-check; voltage zero-crossing interrupt. Abnormal events trigger interrupt pin output; interrupt source readable via register.
• Integrated 3.2768MHz crystal oscillator circuit with built-in startup capacitors and crystal detection (automatically switches to internal RC clock if crystal is absent or damaged).
• Integrated 3.2MHz internal RC clock for crystal-less applications; clock frequency deviation <±1% over -40℃~85℃. Supports Turbo mode with overall operating frequency ×1.2.
• Half-duplex UART communication; supports 2400, 4800, 9600, and 19200 baud rates.