STR-HB5601
High-voltage half-bridge gate driver with bootstrap supply, suitable for synchronous buck/boost converters, motor
Product Overview
Description
The STR-HB5601 is a high-voltage half-bridge gate driver for controlling two power switches.
It includes high-side and low-side drivers with bootstrap supply for the floating high-side.
The driver is suitable for half-bridge, full-bridge, and synchronous buck/boost applications.
Product Series
STR
Primary Application
Half-bridge and full-bridge converters
Key Features
- 600V high-side capability
- 2.5A peak drive current
- Bootstrap supply for high-side
- Adjustable dead time control
- Shoot-through protection
- Under-voltage lockout
- Matched propagation delays
- Compact SOIC-8 package
Specifications
| Configuration | Half-Bridge (High + Low Side) |
|---|---|
| High-Side Voltage | Up to 600V |
| Peak Output Current | 2.5A source/sink |
| Operating Voltage | 10V to 20V |
| Switching Time | 25ns typical |
| Propagation Delay | 50ns typical |
| Dead Time | Adjustable 100ns-1μs |
| Package | SOIC-8, DIP-8 |
| Operating Temperature | -40°C to +125°C |
Applications
Half-bridge and full-bridge converters
Power conversion and supply
Motor drives
Motor drive and control systems
Synchronous buck/boost converters
Power conversion and supply
Class D amplifiers
Electronic system design
Power inverters
Electronic system design
FAE Expert Insights
"The STR-HB5601 is a reliable half-bridge driver suitable for a wide range of applications. The 600V rating handles most industrial and consumer applications. The integrated bootstrap supply simplifies the high-side power supply design. I particularly appreciate the adjustable dead time feature - it allows optimization for different MOSFETs and switching frequencies. The shoot-through protection is essential for preventing catastrophic failures. For half-bridge and motor drive applications, this driver provides good performance at a competitive price point."
600V half-bridge with bootstrap and adjustable dead time
— Robert Chen, BeiLuo
Frequently Asked Questions
How does the bootstrap circuit work?
The bootstrap circuit generates high-side drive voltage using a capacitor and diode. When the low-side switch is on, the bootstrap capacitor charges through the diode from VCC to ground. When the low-side turns off and high-side turns on, the charged capacitor provides floating power referenced to the switching node (VS pin). The capacitor must supply the high-side quiescent current and gate charge without excessive voltage droop. Size the capacitor appropriately (typically 0.1-1μF) based on switching frequency and gate charge.
Bootstrap is standard operation. Size capacitor based on frequency and gate charge.
What is dead time and why is it important?
Dead time is a brief delay between turning off one switch and turning on the other in a half-bridge. It's essential to prevent shoot-through (both switches conducting simultaneously), which would cause a short circuit across the supply. STR-HB5601 provides adjustable dead time (100ns-1μs). The optimal dead time depends on MOSFET switching characteristics - long enough to ensure complete turn-off, short enough to minimize body diode conduction losses. Start with 300-500ns and adjust based on measurements.
Set dead time to prevent shoot-through. Start with 300-500ns and optimize.
What is the minimum duty cycle or on-time required?
The high-side bootstrap capacitor needs periodic refreshing. The low-side switch must be on long enough to recharge the bootstrap capacitor. This sets a minimum duty cycle or minimum low-side on-time requirement. Typically, the low-side must be on for at least a few microseconds every switching cycle or every few cycles. For very low duty cycles or long high-side on-times, consider using an isolated power supply instead of bootstrap, or implement a refresh pulse periodically.
Ensure adequate low-side on-time for bootstrap refresh. Use isolated supply for very low duty cycles.
How do I select the bootstrap capacitor value?
Calculate bootstrap capacitor using: Cboot = (2 × Qg + Qls + Iq/fsw) / ΔV, where Qg is high-side MOSFET gate charge, Qls is level-shift charge, Iq is high-side quiescent current, fsw is switching frequency, and ΔV is allowed voltage droop (typically 0.5-1V). For most applications, 0.1μF to 1μF is sufficient. Use a low-ESR ceramic capacitor (X5R or X7R) rated for at least 25V. Place the capacitor close to the HB and HS pins.
Calculate based on gate charge and frequency. Use 0.1-1μF ceramic capacitor.
What is shoot-through protection?
Shoot-through protection prevents both high-side and low-side switches from conducting simultaneously. STR-HB5601 includes logic that ensures one switch is fully off before the other turns on, implementing the dead time. This protection is automatic and prevents catastrophic short-circuit conditions. Even with input signals that would command both switches on, the driver's internal logic prevents simultaneous conduction. This is essential for reliable half-bridge operation.
Shoot-through protection is automatic. Dead time is adjustable for optimization.
Can STR-HB5601 be used for full-bridge applications?
Yes, two STR-HB5601 drivers can be used to create a full-bridge (H-bridge) configuration. Each driver controls one half-bridge leg (two switches). The inputs can be driven with complementary PWM signals for full-bridge operation. Ensure proper dead time between diagonal switches to prevent shoot-through. The 600V rating supports high-voltage full-bridge applications like motor drives and inverters. Connect the logic grounds together while keeping power grounds separate as needed.
Use two drivers for full-bridge. Ensure proper dead time and grounding.