Overview
The TPS3808G12DBVR, produced by Texas Instruments, is a low-quiescent current supervisor with programmable delay and manual reset. This microprocessor supervisory circuit is designed to monitor system voltages from 0.4 V to 5 V and assert an open-drain RESET signal when the SENSE voltage drops below a preset threshold or when the manual reset (MR) pin is driven low. The device features a precision reference that achieves 0.5% threshold accuracy for voltages up to 3.3 V, making it highly accurate and reliable. With a very low typical quiescent current of 2.4 µA, it is well-suited for battery-powered applications. The TPS3808G12DBVR is available in SOT-23 and 2-mm × 2-mm WSON packages and is fully specified over a temperature range of –40°C to 125°C.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Supply Range | 1.7 to 6.5 | V |
| Nominal Supply Voltage (VDD) | 1.2 V | V |
| Threshold Voltage (VIT) | 1.12 V | V |
| Supply Current (IDD) | 2.4 µA (typical) | µA |
| Low-Level Output Voltage (VOL) | 0.4 V (typical at IOL = 1 mA) | V |
| Reset Delay Time | 20 ms to 10 s (user-adjustable) | ms/s |
| Temperature Range | –40°C to 125°C | °C |
| Package Type | SOT-23, 2-mm × 2-mm WSON |
Key Features
- Power-on reset generator with adjustable delay time from 1.25 ms to 10 s.
- Very low quiescent current of 2.4 µA typical, making it suitable for battery-powered applications.
- High threshold accuracy of 0.5% typical for VIT ≤ 3.3 V.
- Fixed threshold voltages for standard voltage rails from 0.9 V to 5 V and adjustable voltage down to 0.4 V.
- Manual reset (MR) input for initiating a reset from external logic.
- Open-drain RESET output.
- Small SOT-23 and 2-mm × 2-mm WSON packages.
Applications
- DSP or microcontroller applications.
- Notebook and desktop computers.
- PDAs and hand-held products.
- Portable and battery-powered products.
- FPGA and ASIC applications.
Q & A
- What is the primary function of the TPS3808G12DBVR?
The primary function is to monitor system voltages and assert a RESET signal when the voltage drops below a preset threshold or when the manual reset pin is driven low.
- What is the typical quiescent current of the TPS3808G12DBVR?
The typical quiescent current is 2.4 µA.
- How can the reset delay time be adjusted?
The reset delay time can be set to 20 ms by disconnecting the CT pin, 300 ms by connecting the CT pin to VDD using a resistor, or user-adjusted between 1.25 ms and 10 s by connecting the CT pin to an external capacitor.
- What is the temperature range for the TPS3808G12DBVR?
The device is fully specified over a temperature range of –40°C to 125°C.
- What are the available package types for the TPS3808G12DBVR?
The device is available in SOT-23 and 2-mm × 2-mm WSON packages.
- How accurate is the threshold voltage for the TPS3808G12DBVR?
The threshold accuracy is 0.5% typical for VIT ≤ 3.3 V.
- What is the purpose of the manual reset (MR) input?
The manual reset input allows a processor or other logic circuits to initiate a reset by driving the MR pin low.
- Can the TPS3808G12DBVR monitor multiple system voltages?
- How does the TPS3808G12DBVR handle short negative transients on the SENSE pin?
The device is relatively immune to short negative transients on the SENSE pin, with sensitivity dependent on threshold overdrive.
- What is the recommended practice for reducing sensitivity to transients on the SENSE input?
It is recommended to use a 1-nF to 10-nF bypass capacitor on the SENSE input to reduce sensitivity to transients and layout parasitics.
