Overview
The LM5109BSDX from Texas Instruments is a high-voltage, 1-A peak half-bridge gate driver designed to drive both the high-side and low-side N-channel MOSFETs in synchronous buck, half-bridge, or full-bridge configurations. This device is cost-effective and features robust level shift technology, operating at high speeds while consuming low power. It provides clean level transitions from the control input logic to the high-side gate driver and includes undervoltage lockout (UVLO) protection on both the low-side and high-side power rails. The LM5109BSDX is available in 8-pin SOIC and thermally-enhanced 8-pin WSON packages, making it suitable for a variety of high-voltage applications.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Peak Output Current | 1 A (1.0 A Sink and 1.0 A Source) | |
| Bootstrap Supply Voltage | Up to 108 V DC | |
| Propagation Times | 30 ns Typical | |
| Rise and Fall Times | 15 ns (Driving 1000-pF Load) | |
| Propagation Delay Matching | 2 ns Typical | |
| Undervoltage Lockout (UVLO) | Typically 6.7 V | |
| Operating Temperature Range | -40°C to 125°C | |
| Package Types | 8-pin SOIC, 8-pin WSON |
Key Features
- Drives both high-side and low-side N-channel MOSFETs in synchronous buck or half-bridge configurations.
- Inputs compatible with independent TTL and CMOS.
- Fast propagation times and excellent propagation delay matching.
- Low power consumption and high noise immunity.
- Undervoltage lockout (UVLO) protection on both low-side and high-side power rails.
- Robust level shift technology for high-speed operation.
- Available in 8-pin SOIC and thermally-enhanced 8-pin WSON packages.
Applications
- Synchronous buck converters.
- Half-bridge and full-bridge configurations.
- High-voltage power supplies.
- Motor control and drive systems.
- Power factor correction (PFC) circuits.
- High-frequency switching applications requiring low power dissipation and thermal stress reduction.
Q & A
- What is the peak output current of the LM5109BSDX?
The peak output current is 1 A, with 1.0 A sink and 1.0 A source capabilities.
- What is the maximum bootstrap supply voltage for the LM5109BSDX?
The maximum bootstrap supply voltage is up to 108 V DC.
- What are the typical propagation times for the LM5109BSDX?
The typical propagation times are 30 ns.
- How does the LM5109BSDX handle undervoltage conditions?
The device includes undervoltage lockout (UVLO) protection on both the low-side and high-side power rails, inhibiting the outputs until sufficient supply voltage is available.
- What are the recommended operating temperature ranges for the LM5109BSDX?
The operating temperature range is from -40°C to 125°C.
- What types of packages are available for the LM5109BSDX?
The device is available in 8-pin SOIC and thermally-enhanced 8-pin WSON packages.
- What kind of input compatibility does the LM5109BSDX have?
The inputs are compatible with independent TTL and CMOS.
- How does the LM5109BSDX manage high-speed operation?
The device uses robust level shift technology to operate at high speeds while consuming low power and providing clean level transitions.
- What is the purpose of the external bootstrap diode in the LM5109BSDX circuit?
The external bootstrap diode is necessary to charge the high-side gate drive bootstrap capacitor during each switching cycle.
- How should the external gate driver resistor be selected for the LM5109BSDX?
The external gate driver resistor should be sized to reduce ringing caused by parasitic inductances and capacitances and to limit the current coming out of the gate driver.
