## KA393D Dual Differential Comparator The **KA393D** is a precision dual differential comparator designed to operate from a single power supply over a wide range of voltages. It is the Fairchild (now ON Semiconductor) version of the industry-standard **LM393**. --- ### 1. Key Technical Specifications The following table highlights the primary electrical characteristics of the KA393D: | Parameter | Specification | | :--- | :--- | | **Supply Voltage (Single)** | +2.0V to +36V | | **Supply Voltage (Dual)** | ±1.0V to ±18V | | **Number of Channels** | 2 (Dual) | | **Output Type** | Open Collector | | **Response Time** | 1.3 μs (typical) | | **Input Offset Voltage** | ±1.0 mV to ±5.0 mV | | **Operating Temperature** | 0°C to +70°C | | **Package Type** | 8-SOP (Surface Mount) | --- ### 2. Functional Features * **Wide Input Common-Mode Voltage Range:** The input common-mode voltage range includes ground, even though operated from a single power supply voltage. * **Low Current Drain:** It consumes very low supply current (typically 0.8 mA), which is independent of the supply voltage. * **Open Collector Output:** The output stage is an uncommitted collector of a grounded-emitter NPN transistor. This allows for: * Easy interfacing with different logic families (TTL, DTL, CMOS). * "Wired-OR" connections where multiple outputs are tied together. * **Differential Input Range:** The differential input voltage range is equal to the power supply voltage. --- ### 3. Pin Configuration (8-SOP) The KA393D is typically housed in an 8-pin Small Outline Package (SOP). | Pin Number | Symbol | Description | | :--- | :--- | :--- | | 1 | OUTPUT A | Output of first comparator | | 2 | INPUT A (-) | Inverting input of first comparator | | 3 | INPUT A (+) | Non-inverting input of first comparator | | 4 | GND | Ground (or negative supply) | | 5 | INPUT B (+) | Non-inverting input of second comparator | | 6 | INPUT B (-) | Inverting input of second comparator | | 7 | OUTPUT B | Output of second comparator | | 8 | Vcc | Positive power supply | --- ### 4. Typical Applications The KA393D is highly versatile and found in many consumer and industrial circuits: 1. **Limit Comparators:** Checking if a voltage is within a specific range. 2. **Simple ADC:** Basic 1-bit analog-to-digital conversion. 3. **Pulse/Square Wave Generators:** Creating timing signals. 4. **Zero-Crossing Detectors:** Identifying when an AC signal crosses 0V. 5. **Voltage Level Detectors:** Used in battery monitoring or over-voltage protection. --- ### 5. Circuit Implementation Example Because it has an **Open Collector** output, a **Pull-up Resistor** is mandatory to get a high voltage signal at the output. ```python # Conceptual logic for a KA393D operation # If Vin(+) > Vin(-): # Output Transistor = OFF # Output Pin = Pull-up Voltage (Logic HIGH) # If Vin(+) < Vin(-): # Output Transistor = ON # Output Pin = Ground (Logic LOW) ```