1. Overview & Family Identification

️· What these are: These are *voltage detectors*. Their primary purpose is to monitor a power supply voltage and signal an out-of-range condition. Think of them as voltage monitors.
️· Family: The CAT853, CAT859, CAT863, and CAT869 are a family of devices, sharing similar functionality but with varying voltage thresholds and configurations.
️· Key Feature: They are designed for simple, robust voltage monitoring in a variety of applications.

2. Key Features (summarized from throughout the datasheet)

️· Adjustable Voltage Thresholds: A key aspect is the ability to select specific voltage detection thresholds. These come in a range (see Ordering Information – multiple options for each part number).
️· Fixed Hysteresis: They have a fixed hysteresis value. This prevents oscillation or false triggers when the input voltage is near the threshold.
️· Open-Drain Output: The output is open-drain, meaning it can drive a load to ground. Requires an external pull-up resistor.
️· Small Package Size: The SOT-23 package provides a compact solution.
️· Under-voltage and Over-voltage Detection: Able to monitor voltage levels both below *and* above a set threshold.
️· Power-Up Reset Timing: (Implied by functionality; not explicitly detailed in this datasheet, but typical for this type of device). Would ensure system stability when the power first comes on.
️· Low Quiescent Current: Low current consumption in normal operation, important for battery-powered systems.

3. Ordering Information

️· Part Number Structure: This is critical for selecting the correct part. A typical example is: `CAT853LTBI-GT3`.
- `CAT853`: Family identifier
- `L`: Voltage threshold level
- `TBI`: Package style (SOT-23)
- `GT3`: Suffix indicating Tape & Reel packaging.
️· Voltage Thresholds: The datasheet lists several voltage thresholds (e.g., 4.63V, 4.38V, 4.20V, etc.). This is the most important selection criterion.
️· Package Options: Primarily SOT-23.
️· Tape and Reel Packaging: "GT3" indicates tape and reel. Important for automated assembly.

4. Electrical Characteristics

️· Threshold Voltages (V_TH): The critical parameters. These define the voltage at which the output changes state.
️· Hysteresis: A fixed value to prevent bouncing around the threshold.
️· Output Drive Capability: Defines how much current the output can source or sink.
️· Input Voltage Range: The range of voltages the device can tolerate.
️· Supply Voltage: The required supply voltage to operate.

5. Timing Diagrams & Functional Description (Implied)

️· Not directly shown: The datasheet doesn't contain detailed timing diagrams, but the description implies a simple logic: Input voltage crosses the threshold, output changes state. The hysteresis prevents unwanted switching near the threshold.
️· Functional Description: The part compares the input voltage to a programmed voltage threshold. If the input is too high or too low, the output becomes active.

6. Physical Characteristics

️· Package Dimensions: Detailed dimensions of the SOT-23 package.

7. Publication Ordering Information

️· Contact Information: How to order documentation.

8. ON Semiconductor Website
️· Links to order literature and more.



In essence, you have a comprehensive guide to selecting and using these voltage detector ICs. To use this information effectively, you need to identify the voltage range you need to monitor, select a threshold voltage that is appropriate, and understand the implications of the open-drain output.