LM5109ASDX

Overview

The LM5109ASDX is a high-voltage half-bridge gate driver designed to drive both high-side and low-side N-channel MOSFETs in synchronous buck or half-bridge configurations. It features independent TTL-compatible inputs for robust control. The device supports bootstrap supply voltages up to 108V DC, enabling operation with rail voltages up to 100V. It delivers a peak output current of 1A for both sourcing and sinking. Key electrical parameters include a typical propagation time of 30 ns, rise and fall times of 15 ns when driving a 1000 pF load, and excellent propagation delay matching of 2 ns typical. It operates within a junction temperature range of -40°C to 125°C.

Feature Summary

• Drives high-side and low-side N-channel MOSFETs independently
• TTL compatible input thresholds for direct logic interfacing
• Bootstrap supply voltage capability up to 108V DC
• Under-voltage lockout protection on both power rails

Applications

• Current fed push-pull converters
• Half and full bridge power converters
• Solid state motor drives
• Two switch forward converters

Procurement Notes

Verify the specific suffix 'SDX' against the manufacturer's official orderable part list, as standard datasheets often reference 'SD' or 'SD/NOPB'. Confirm RoHS compliance status, as some legacy suffixes may not meet current environmental standards. Ensure the package type matches the thermal requirements of the target application. Cross-reference the exact part number with the latest Texas Instruments documentation to confirm availability and pinout compatibility.

Selection Notes

Select this component for applications requiring cost-effective high-voltage gate driving with precise timing. The 1A peak current is suitable for medium-power MOSFETs. The TTL compatibility simplifies interface design with standard microcontrollers. Consider the WSON-8 package for space-constrained designs requiring thermal enhancement. Verify that the 100V rating aligns with the system bus voltage.

Part Context

The LM5109 series is a family of high-voltage half-bridge gate drivers from Texas Instruments. It serves as a successor or alternative to older drivers like the ISL6700, offering improved propagation delay matching and lower power consumption. The device is part of the broader LM51xx portfolio designed for high-voltage power management applications.

Replacement Considerations

LM5109ASD/NOPB is a confirmed direct replacement with updated environmental compliance.