Overview
The LM5109BMA/NOPB is a high-voltage, 1-A peak half-bridge 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, half-bridge, full-bridge, and other power conversion topologies. The LM5109BMA/NOPB features independent control of each output channel through TTL and CMOS-compatible input thresholds, making it versatile for various power management applications. It includes undervoltage lockout (UVLO) protection on both the low-side and high-side power rails to ensure reliable operation and prevent MOSFET damage during power-up and power-down sequences.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Peak Output Current | 1.0 A (Sink and Source) | A |
| High-Side Voltage | Up to 108 V | V |
| Low-Level Output Voltage (VOLH) | 0.65 V | V |
| High-Level Output Voltage (VOHH) | 1.2 V | V |
| Quiescent Current (IHBS) | 10 µA | µA |
| Operating Frequency | Up to 500 kHz | kHz |
| Recommended VDD Supply Voltage | 8 V to 14 V | V |
| Absolute Maximum VDD Voltage | 18 V | V |
| ESD Rating (Human-Body Model) | ±1500 V | V |
Key Features
- Independent control of high-side and low-side outputs with TTL and CMOS-compatible input thresholds.
- Undervoltage lockout (UVLO) protection on both high-side and low-side power rails.
- High-peak current capability (1 A) for efficient switching of power MOSFETs.
- Robust level shifter for high-speed operation with low power consumption.
- Bootstrap capacitor required for high-side gate drive, with recommended ceramic capacitors (X7R dielectric).
- Low ESR ceramic surface-mount capacitors recommended for VDD bypassing.
- Thermal management features, including exposed pad for heat dissipation.
Applications
- Synchronous buck converters.
- Half-bridge and full-bridge configurations.
- Push-pull, two-switch forward, and active clamp topologies.
- Power management in DC-DC converters, motor drives, and other high-voltage applications.
Q & A
- What is the peak output current of the LM5109BMA/NOPB?
The peak output current is 1.0 A (both sink and source).
- What is the maximum high-side voltage the LM5109BMA/NOPB can handle?
The device can operate with high-side voltages up to 108 V.
- What is the recommended supply voltage range for the VDD pin?
The recommended VDD supply voltage range is from 8 V to 14 V.
- Does the LM5109BMA/NOPB have undervoltage lockout (UVLO) protection?
- What type of capacitors are recommended for the bootstrap and VDD bypass?
Ceramic surface-mount capacitors with X7R dielectric are recommended.
- How should the bootstrap capacitor be placed?
The bootstrap capacitor should be placed as close to the HB and HS pins as possible.
- What is the purpose of the level shifter in the LM5109BMA/NOPB?
The level shifter allows for high-speed operation and clean level transitions from the control logic to the high-side gate driver.
- What are the typical applications of the LM5109BMA/NOPB?
Typical applications include synchronous buck converters, half-bridge and full-bridge configurations, and other high-voltage power management applications.
- How does the LM5109BMA/NOPB manage thermal dissipation?
The device has an exposed pad for heat dissipation, which should be soldered to the ground plane on the PCB to improve thermal management.
- What is the ESD rating of the LM5109BMA/NOPB according to the human-body model?
The ESD rating is ±1500 V according to the human-body model.
