The **ADCMP392** is a high-performance, dual-channel, low-power comparator designed by Analog Devices. It is specifically engineered for systems where power consumption and precision are critical factors. --- ### ## 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Number of Comparators** | 2 (Dual) | | **Supply Voltage Range** | 2.3 V to 5.5 V | | **Supply Current** | 18.6 µA (Typical per comparator) | | **Propagation Delay** | 4 µs | | **Output Type** | Open-drain | | **Operating Temperature** | −40°C to +125°C | | **Package Options** | 8-lead MSOP | --- ### ## 2. Core Electronic Components & Architecture The ADCMP392 consists of several internal functional blocks that define its behavior: 1. **Input Stage:** Features high-impedance inputs with a common-mode range that includes the negative supply rail (Ground). This allows it to sense signals near 0V accurately. 2. **Internal Hysteresis:** The device includes built-in hysteresis (typically 4 mV). This prevents "chatter" or multiple transitions at the output when the input signal is noisy or moving slowly through the threshold. 3. **Open-Drain Output:** Unlike "push-pull" outputs, the open-drain requires an external pull-up resistor. This allows for: * Level shifting (interfacing a 3.3V comparator with a 5V logic circuit). * Wired-OR logic configurations. 4. **Voltage Reference Compatibility:** While it does not have an internal reference, it is designed to work seamlessly with low-power references like the ADR34xx series. --- ### ## 3. Typical Application Circuit To use the ADCMP392, you generally need two external resistors for the output stage and potentially a resistor network for the input threshold. ```cpp // Example of how to calculate the Pull-up Resistor (Rp) // If V_logic = 3.3V and desired sink current is 1mA: // Rp = V_logic / I_sink // Rp = 3.3V / 0.001A = 3.3 kOhms ``` --- ### ## 4. Common Use Cases * **Battery Monitoring:** Due to the ultra-low current draw (sub-20 µA), it is ideal for battery-powered sensors. * **Threshold Detectors:** Used to trigger an interrupt when a sensor voltage exceeds a specific limit. * **Window Comparators:** By using both channels, you can monitor if a signal stays within a specific "safe" voltage range. * **Zero-Crossing Detectors:** Detecting when an AC signal crosses the 0V reference. ---