Overview
The TPS3808G18DBVRG4, produced by Texas Instruments, is a low-quiescent-current, programmable-delay microprocessor supervisory circuit. This device is designed to monitor system voltages and assert a RESET signal when the monitored voltage drops below a preset threshold or when the manual reset (MR) pin is driven low. The TPS3808 family is known for its high threshold accuracy and very low quiescent current, making it suitable for battery-powered and power-sensitive applications.
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 | 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 TPS3808G18: 1.67 V | 1.67 | V | ||
| Threshold Accuracy | VIT ≤ 3.3 V | –1.5% | ±0.5% | 1.5% | % |
| Reset Delay Time | CT = Open | 12 | 20 | 28 | ms |
| Temperature Range | –40°C | 125°C | °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
- User-adjustable reset delay time using an external capacitor
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 TPS3808G18DBVRG4?
The primary function is to monitor system voltages and assert a RESET signal when the monitored voltage drops below a preset threshold or when the manual reset (MR) pin is driven low.
- What is the typical quiescent current of the TPS3808G18DBVRG4?
The typical quiescent current is 2.4 μA.
- 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 is the threshold voltage for the TPS3808G18DBVRG4?
The threshold voltage for the TPS3808G18DBVRG4 is 1.67 V.
- What is the temperature range for the TPS3808G18DBVRG4?
The temperature range is –40°C to 125°C.
- What types of packages are available for the TPS3808G18DBVRG4?
The device is available in SOT-23 and 2-mm × 2-mm WSON packages.
- How does the TPS3808G18DBVRG4 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 purpose of the MR pin?
The MR pin is for manual reset and can be driven low to assert the RESET signal.
- What is the significance of the high threshold accuracy?
The high threshold accuracy ensures reliable operation and precise voltage monitoring.
- In which applications is the TPS3808G18DBVRG4 commonly used?
It is commonly used in DSP or microcontroller applications, notebook and desktop computers, PDAs, hand-held products, portable and battery-powered products, and FPGA and ASIC applications.
