Overview
The LM5109BMA is a high-voltage gate driver designed by Texas Instruments. This device is optimized to drive both the high-side and low-side N-channel MOSFETs in synchronous buck or half-bridge configurations. It features a floating high-side driver capable of operating with rail voltages up to 90 V, making it suitable for various high-voltage applications. The LM5109BMA is known for its robust level shift technology, low power consumption, and excellent propagation delay matching, ensuring efficient and reliable operation.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Peak Output Current | 1 A (1.0 A Sink and 1.0 A Source) | A |
| Bootstrap Supply Voltage | Up to 108 V DC | V |
| Propagation Times | 30 ns Typical | ns |
| Rise and Fall Times | 15 ns (Driving 1000 pF Load) | ns |
| Propagation Delay Matching | 2 ns Typical | ns |
| Operating Temperature Range | -40°C to 125°C | °C |
| Package Type | 8-Pin SOIC and 8-Pin WSON | |
| Input Compatibility | TTL and CMOS |
Key Features
- Drives both high-side and low-side N-channel MOSFETs in synchronous buck or half-bridge configurations.
- 1-A peak output current with 1.0-A sink and 1.0-A source capabilities.
- Inputs compatible with independent TTL and CMOS input thresholds.
- Bootstrap supply voltage up to 108 V DC.
- Fast propagation times (30 ns typical) and excellent propagation delay matching (2 ns typical).
- Drives 1000-pF load with 15-ns rise and fall times.
- Supply rail undervoltage lockout (UVLO) on both low-side and high-side power rails.
- Low power consumption.
- Available in 8-pin SOIC and thermally-enhanced 8-pin WSON packages.
Applications
- Synchronous buck converters.
- Half-bridge and full-bridge configurations.
- Push-pull amplifiers.
- High-voltage power supplies.
- Motor control and drive systems.
- Power factor correction (PFC) circuits.
Q & A
- What is the peak output current of the LM5109BMA?
The peak output current of the LM5109BMA is 1 A, with 1.0 A sink and 1.0 A source capabilities.
- What are the compatible input thresholds for the LM5109BMA?
The inputs are compatible with independent TTL and CMOS input thresholds.
- What is the maximum bootstrap supply voltage for the LM5109BMA?
The maximum bootstrap supply voltage is up to 108 V DC.
- What are the typical propagation times and propagation delay matching for the LM5109BMA?
The typical propagation times are 30 ns, and the propagation delay matching is 2 ns.
- How does the LM5109BMA handle undervoltage conditions?
The device includes undervoltage lockout (UVLO) protection on both the low-side and high-side power rails.
- What are the recommended operating temperature ranges for the LM5109BMA?
The operating temperature range is from -40°C to 125°C.
- In what packages is the LM5109BMA available?
The device is available in 8-pin SOIC and thermally-enhanced 8-pin WSON packages.
- What type of capacitors should be used for the bootstrap and bias in the LM5109BMA circuit?
Ceramic capacitors with X7R dielectric are recommended.
- How should the bootstrap capacitor be charged in the LM5109BMA circuit?
The bootstrap capacitor is charged by the VDD through an external bootstrap diode every cycle when the low-side MOSFET turns on.
- What is the purpose of the level shift circuit in the LM5109BMA?
The level shift circuit allows control of the high-side output referenced to the switch node (HS), providing excellent delay matching with the low-side driver.
