Overview
The LMG1205YFXR from Texas Instruments is a high-performance, 1.2-A to 5-A, 90-V half-bridge gate driver designed to drive both the high-side and low-side enhancement mode Gallium Nitride (GaN) FETs in synchronous buck, boost, or half-bridge configurations. This device features an integrated 100-V bootstrap diode and independent inputs for the high-side and low-side outputs, providing maximum control flexibility. The high-side bias voltage is generated using a bootstrap technique and is internally clamped at 5 V to prevent the gate voltage from exceeding the maximum gate-source voltage rating of the GaN FETs. The LMG1205YFXR is available in a compact 12-pin DSBGA package, offering a minimized package inductance and a small footprint.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | DSBGA (YFX) | - |
| Pins | 12 | - |
| Operating Temperature Range | -40 to 125 | °C |
| Peak Source Current | 1.2 | A |
| Peak Sink Current | 5 | A |
| High-Side Floating Bias Voltage Rail | Up to 100 | VDC |
| Pulldown Resistance | 0.6 | Ω |
| Pullup Resistance | 2.1 | Ω |
| Propagation Times | 35 ns (typical) | ns |
| Propagation Delay Matching | 1.5 ns (typical) | ns |
| Supply Rail Undervoltage Lockout (UVLO) | 3.8 V (VDD), 3.2 V (Bootstrap) | V |
Key Features
- Independent high-side and low-side TTL logic inputs
- 1.2-A peak source, 5-A sink current
- High-side floating bias voltage rail operates up to 100 VDC
- Internal bootstrap supply voltage clamping
- Split outputs for adjustable turnon, turnoff strength
- 0.6-Ω pulldown, 2.1-Ω pullup resistance
- Fast propagation times (35 ns typical)
- Excellent propagation delay matching (1.5 ns typical)
- Supply rail undervoltage lockout
- Low power consumption
Applications
- Current-fed push-pull converters
- Half and full-bridge converters
- Synchronous buck converters
- Two-switch forward converters
- Forward with active clamp converters
Q & A
- What is the LMG1205YFXR designed for?
The LMG1205YFXR is designed to drive both the high-side and low-side enhancement mode Gallium Nitride (GaN) FETs in synchronous buck, boost, or half-bridge configurations.
- What is the package type and pin count of the LMG1205YFXR?
The LMG1205YFXR is available in a 12-pin DSBGA (YFX) package.
- What are the peak source and sink currents of the LMG1205YFXR?
The peak source current is 1.2 A, and the peak sink current is 5 A.
- What is the operating temperature range of the LMG1205YFXR?
The operating temperature range is -40°C to 125°C.
- What is the high-side floating bias voltage rail capability?
The high-side floating bias voltage rail operates up to 100 VDC.
- What are the pulldown and pullup resistances of the LMG1205YFXR?
The pulldown resistance is 0.6 Ω, and the pullup resistance is 2.1 Ω.
- What are the typical propagation times and propagation delay matching of the LMG1205YFXR?
The typical propagation times are 35 ns, and the propagation delay matching is 1.5 ns.
- Does the LMG1205YFXR have undervoltage lockout (UVLO) protection?
Yes, the LMG1205YFXR has UVLO protection on both the VDD and bootstrap supplies.
- What are some common applications of the LMG1205YFXR?
Common applications include current-fed push-pull converters, half and full-bridge converters, synchronous buck converters, two-switch forward converters, and forward with active clamp converters.
- How does the internal bootstrap supply voltage clamping work?
The internal bootstrap supply voltage clamping prevents the bootstrap voltage from exceeding 5 V by opening an internal switch in series with the internal bootstrap diode when the threshold is exceeded.
