Microchip TC54VN3002ECB713 Voltage Detector IC: Features and Application Circuits
The Microchip TC54VN3002ECB713 is a highly precise, low-power voltage detector (also known as a voltage supervisor or reset IC) designed to monitor power supply voltages in a wide array of electronic systems. Its primary function is to assert a reset signal whenever the supply voltage drops below a predefined threshold, ensuring microcontrollers, DSPs, FPGAs, and other critical components operate only within their safe voltage range, thereby preventing erratic behavior and data corruption.
Key Features
The TC54 series is renowned for its performance, and the TC54VN3002ECB713 variant exemplifies this with several standout characteristics:
Precise Detection Voltage: This specific model is factory-programmed for a 2.0V threshold (as denoted by the "3002" in its part number), with a high accuracy of ±1%.
Ultra-Low Power Consumption: It features an exceptionally low supply current, typically just 1.0 µA. This makes it ideal for battery-powered and portable applications where extending battery life is paramount.
Low Temperature Coefficient: The detection threshold remains stable over a wide operating temperature range, ensuring reliable performance regardless of environmental changes.
Small Form Factor: Housed in a SOT-23-3 package, it is incredibly space-efficient, suitable for compact PCB designs.
Open-Drain Output: The output stage is an open-drain NMOS transistor. This provides design flexibility, as it allows the output reset signal to be pulled up to a voltage level different from the monitored Vdd, which is useful in mixed-voltage systems.
Application Circuits
The versatility of the open-drain output allows the TC54VN3002ECB713 to be configured in several fundamental circuits.
1. Basic Microcontroller (MCU) Reset Circuit
This is the most common application. The voltage detector monitors the MCU's Vdd supply. The output is connected to the MCU's active-low reset pin (`/RST`). A pull-up resistor (typically 10kΩ to 100kΩ) is required to bring the output to a high logic level when the voltage is good.
Operation: When Vdd is above the 2.0V threshold, the output transistor is off, and the `/RST` pin is pulled high by the resistor, allowing the MCU to operate normally. When Vdd falls below 2.0V, the internal transistor turns on, pulling the `/RST` pin low to assert a reset and hold the MCU in a safe state.
2. Power-Fail or Early Warning Circuit
By using a resistor divider network on the input voltage (Vin), the detector can be used to monitor a voltage higher than its own detection threshold. This creates an early warning signal for a power failure, giving a host processor enough time to perform critical shut-down procedures (e.g., saving data).
Operation: The resistors R1 and R2 scale the higher Vin down to a level suitable for the TC54's input. The detector's output will assert when the scaled voltage drops below 2.0V, which corresponds to a specific, higher voltage level (e.g., 4.5V) on Vin.
3. Battery Voltage Monitoring Circuit
In portable devices, it is crucial to monitor battery voltage to prevent deep discharge, which can damage the battery. The TC54VN3002ECB713, with its ultra-low 1µA current draw, is perfectly suited for this task without significantly impacting battery runtime.
Operation: The circuit can be configured similarly to the basic reset circuit or the power-fail circuit, directly monitoring the battery voltage. Its output can interrupt the MCU, triggering a "low battery" alert or initiating an automatic shutdown sequence.
The Microchip TC54VN3002ECB713 is an exceptional choice for designers seeking high accuracy and ultra-low power consumption in a voltage monitoring solution. Its simplicity, reliability, and tiny footprint make it an indispensable component for ensuring system stability in everything from consumer electronics to industrial equipment.
Keywords: Voltage Detector, Low-Power, Reset IC, Microcontroller Supervisor, Battery Monitoring
