Overview
The UCC2946PWTRG4, produced by Texas Instruments, is a microprocessor supervisor with integrated watchdog timer functions. This device is designed to provide accurate supervision of microprocessors, ensuring reliable operation during power-up, power-down, and normal operation. It features programmable reset thresholds and periods, as well as a watchdog timer to monitor microprocessor activity. The UCC2946PWTRG4 is available in an 8-pin TSSOP package, making it suitable for a variety of microprocessor-based systems where robust supervision is critical.
Key Specifications
| Parameter | Min | |||
|---|---|---|---|---|
| Operating Voltage (VDD) | 2.1 | 5.5 | V | |
| Supply Current (IDD) | 12 | 18 | µA | |
| Reset Threshold Voltage | 1.170 | 1.235 | 1.260 | V |
| Reset Period | 140 | 200 | 320 | ms (CRP = 64 nF) |
| Watchdog Period | 0.96 | 1.60 | 2.56 | s (CRP = 64 nF) |
| Input Leakage Current | 5 | nA | ||
| High-Level Output Voltage | VDD - 0.3 | V (ISOURCE = 2 mA) | ||
| Low-Level Output Voltage | 0.1 | V (ISINK = 2 mA) |
Key Features
- Fully Programmable Reset Threshold and Period: The reset trip voltage and reset period can be programmed using external resistors and capacitors, respectively.
- Fully Programmable Watchdog Period: The watchdog period can be adjusted using an external capacitor.
- Accurate Reset Threshold: The reset threshold voltage is accurate to within 2% of the nominal value.
- Low Input Current: The device has a maximum input current of 18 µA.
- Glitch Immunity: The device is resistant to voltage glitches on the VDD line.
- Separate Outputs for Reset and Watchdog: The reset (RES) and watchdog (WDO) outputs are independent, allowing for flexible design configurations.
- Compact Packaging: Available in 8-pin SOIC, PDIP, and TSSOP packages to optimize board space.
Applications
The UCC2946PWTRG4 is suitable for a variety of microprocessor-based systems where reliable supervision is essential. These include:
- Embedded systems requiring robust power-up and power-down supervision.
- Industrial control systems where microprocessor activity needs to be monitored.
- Automotive systems that demand high reliability and fault tolerance.
- Medical devices and other critical systems that require accurate and reliable supervision.
Q & A
- What is the primary function of the UCC2946PWTRG4?
The primary function is to provide accurate microprocessor supervision, including reset and watchdog functions.
- How is the reset threshold voltage programmed?
The reset threshold voltage can be programmed using two external resistors connected to the RTH pin.
- What is the purpose of the watchdog timer?
The watchdog timer monitors the microprocessor’s activity and asserts the WDO pin if the microprocessor does not toggle the WDI pin within the set watchdog period.
- What are the available package types for the UCC2946PWTRG4?
The device is available in 8-pin SOIC, PDIP, and TSSOP packages.
- How does the device handle voltage glitches on the VDD line?
The device is designed to ignore voltage glitches whose amplitude and duration are less than specified values, ensuring glitch immunity.
- What is the minimum operating voltage for the UCC2946PWTRG4?
The minimum operating voltage is 2.1 V for the UCC2946 and 2.0 V for the UCC3946.
- Can the reset and watchdog outputs be connected together?
- What type of capacitor should be used for the reset period programming?
A high-quality, low-leakage capacitor such as an NPO ceramic capacitor should be used to maintain timing tolerances.
- Is the UCC2946PWTRG4 suitable for automotive applications?
- What is the recommended decoupling capacitor for the VDD supply rail?
A 0.1-µF capacitor is recommended to decouple the UCCx946 from switching transients on the VDD supply rail.
