Overview
The LM809M3X-4.38/NOPB is a microprocessor supervisory circuit produced by Texas Instruments. It is designed to monitor the power supplies in microprocessor and digital systems, providing a reset signal during power-up, power-down, and brown-out conditions. This component is part of the LM809 and LM810 series, which offer precision monitoring of supply voltages with various threshold options.
The LM809M3X-4.38/NOPB specifically has a reset threshold of 4.38 V, making it suitable for monitoring 5-V supply voltages. It features an active-low RESET output and is fully specified over temperature, ensuring reliable operation in a wide range of environments.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Reset Threshold | TA = 25°C | 4.31 | 4.38 | 4.45 | V |
| Reset Threshold | TA = –40°C to 85°C | 4.25 | - | 4.50 | V |
| Reset Threshold | TA = 85°C to 105°C | 4.16 | - | 4.56 | V |
| Reset Active Timeout Period | TA = –40°C to 85°C | 140 | 240 | 560 | ms |
| Supply Current | Typical at TA = 25°C | - | 15 | - | µA |
| RESET Output Voltage Low | VCC = VTH(min), ISINK = 1.2 mA | 0.3 | - | - | V |
| Package Type | - | - | - | SOT-23 (DBZ) | - |
| Body Size | - | - | - | 2.92 mm × 1.30 mm | - |
Key Features
- Precision monitoring of supply voltages with available threshold options: 2.63 V, 2.93 V, 3.08 V, 4.38 V, and 4.63 V.
- Active-low RESET output for the LM809 series.
- Fully specified over temperature range of –40°C to 105°C.
- Minimum power-on reset pulse width of 140 ms, with a typical value of 240 ms.
- Low supply current of 15 µA typical.
- Power supply transient immunity.
- RESET output valid for VCC ≥ 1 V.
Applications
- Factory Automation
- Building Automation
- Programmable Logic Control
- Renewable Energy
- Microprocessor Systems
- Computers and Controllers
- Intelligent Instruments
- Portable/Battery-Powered Equipment
- Automotive Systems
Q & A
- What is the primary function of the LM809M3X-4.38/NOPB?
The primary function is to monitor the power supply voltage and provide a reset signal to the microprocessor during power-up, power-down, and brown-out conditions.
- What is the reset threshold voltage for the LM809M3X-4.38/NOPB?
The reset threshold voltage is 4.38 V.
- What is the typical supply current of the LM809M3X-4.38/NOPB?
The typical supply current is 15 µA.
- What is the minimum power-on reset pulse width?
The minimum power-on reset pulse width is 140 ms.
- What is the package type of the LM809M3X-4.38/NOPB?
The package type is SOT-23 (DBZ).
- What are the typical operating temperature ranges for the LM809M3X-4.38/NOPB?
The component is fully specified over a temperature range of –40°C to 105°C.
- Is the RESET output valid for VCC below 1 V?
No, the RESET output is valid for VCC ≥ 1 V.
- What are some common applications of the LM809M3X-4.38/NOPB?
Common applications include factory automation, building automation, programmable logic control, renewable energy, microprocessor systems, and automotive systems.
- How does the LM809M3X-4.38/NOPB handle power supply transients?
The component has built-in power supply transient immunity.
- What is the difference between the LM809 and LM810 series?
The LM809 series has an active-low RESET output, while the LM810 series has an active-high RESET output.
