Overview
The TPS3808G33DBVT, produced by Texas Instruments, is a microprocessor supervisory circuit designed to monitor system voltages and assert a reset signal when the voltage drops below a preset threshold or when a manual reset is triggered. This device is part of the TPS3808 family and is specifically configured for a 3.3V threshold voltage. It features a very low quiescent current of 2.4 μA, making it suitable for battery-powered applications. The TPS3808G33DBVT is available in small SOT-23 and 2-mm × 2-mm WSON packages and operates over a temperature range of –40°C to 125°C.
Key Specifications
| Parameter | Test Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| VDD Input Supply Range | –40°C < TJ < 125°C | 1.7 | 6.5 | V | |
| Supply Current (IDD) | VDD = 3.3 V, RESET not asserted, MR, RESET, CT open | 2.4 | 5 | μA | |
| Low-Level Output Voltage (VOL) | 1.8 V ≤ VDD ≤ 6.5 V, IOL = 1 mA | 0.4 | V | ||
| Threshold Voltage (VIT) | For TPS3808G33 | 3.07 | V | ||
| Threshold Accuracy | VIT ≤ 3.3 V | –1.5% | ±0.5% | 1.5% | % |
| Reset Delay Time | Adjustable between 1.25 ms and 10 s | s | |||
| Temperature Range | –40 | 125 | °C |
Key Features
- Power-on reset generator with adjustable delay time: 1.25 ms to 10 s
- Very low quiescent current: 2.4 μA typical
- High threshold accuracy: 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
- Open-drain RESET output
- Small SOT-23 and 2-mm × 2-mm WSON packages
- Temperature range: –40°C to 125°C
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 TPS3808G33DBVT?
The primary function is to monitor system voltages and assert a reset signal when the voltage drops below a preset threshold or when a manual reset is triggered.
- What is the typical quiescent current of the TPS3808G33DBVT?
The typical quiescent current is 2.4 μA.
- What is the threshold voltage for the TPS3808G33DBVT?
The threshold voltage for the TPS3808G33DBVT is 3.07 V.
- How can the reset delay time be adjusted?
The reset delay time can be adjusted by connecting the CT pin to VDD for a 300-ms delay, leaving the CT pin open for a 20-ms delay, or using an external capacitor to set a delay between 1.25 ms and 10 s.
- What are the package options for the TPS3808G33DBVT?
The device is available in SOT-23 and 2-mm × 2-mm WSON packages.
- What is the operating temperature range of the TPS3808G33DBVT?
The operating temperature range is –40°C to 125°C.
- How does the manual reset (MR) input work?
The manual reset (MR) input asserts the RESET signal when driven low.
- What is the purpose of the open-drain RESET output?
The open-drain RESET output allows the reset signal to be pulled up to a voltage higher than VDD using an external pull-up resistor.
- How can the threshold voltage be adjusted for the TPS3808G01 version?
The threshold voltage for the TPS3808G01 can be adjusted using an external resistor divider to monitor any voltage rail down to 0.405 V.
- What precautions should be taken in the layout to ensure proper operation?
Ensure low-impedance connections to the VDD pin, use a 0.1-µF ceramic capacitor near the VDD pin, and minimize parasitic capacitance on the CT pin.
