Overview
The LM5114BMFX/NOPB, produced by Texas Instruments, is a single low-side gate driver designed to drive low-side MOSFETs in various power conversion configurations. It is particularly suited for boost-type converters and secondary synchronous FETs in isolated topologies. The device features both inverting and non-inverting inputs, making it versatile for different gate drive requirements. With its high peak current capability and fast switching speeds, the LM5114 is ideal for high-frequency operations and can drive multiple FETs in parallel, including low-side enhancement mode Gallium Nitride (GaN) FETs.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VDD Operating Voltage | 4.0 | - | 12.6 | V |
| UVLO (VDD Undervoltage Lockout) | 3.25 | 3.6 | 4.00 | V |
| Peak Sink and Source Drive Current | - | 7.6-A / 1.3-A | - | A |
| Propagation Delay | 5 | 12 | 30 | ns |
| Break-before-make Time | - | 4.2 | - | ns |
| Input Hysteresis | - | 0.68 | - | V |
| Operating Temperature Range | -40 | - | 125 | °C |
| Package Type | - | SOT-23, WQFN-6 | - | - |
Key Features
- Independent source and sink outputs for controllable rise and fall times
- 4-V to 12.6-V single power supply
- 7.6-A/1.3-A peak sink/source drive current
- 0.23-Ω open-drain pulldown sink output and 2-Ω open-drain pullup source output
- 12-ns (typical) propagation delay and matching delay time between inverting and non-inverting inputs
- TTL/CMOS logic inputs with up to 14-V logic input capability regardless of VDD voltage
- Low input capacitance: 2.5-pF (typical)
- Pin-to-pin compatible with MAX5048
- Available in 6-pin SOT-23 and WQFN-6 packages with an exposed pad for thermal dissipation
Applications
- Boost converters
- Flyback and forward converters
- Secondary synchronous FETs drive in isolated topologies
- Motor control
Q & A
- What is the primary function of the LM5114?
The LM5114 is a single low-side gate driver designed to drive low-side MOSFETs in boost-type configurations or secondary synchronous MOSFETs in isolated topologies.
- What are the input voltage ranges for the LM5114?
The LM5114 operates with a single power supply voltage ranging from 4-V to 12.6-V and can withstand input voltages up to 14-V regardless of the VDD voltage.
- What are the peak current capabilities of the LM5114?
The LM5114 has a peak sink and source drive current capability of 7.6-A and 1.3-A, respectively.
- What is the propagation delay of the LM5114?
The propagation delay of the LM5114 is typically 12 ns, with a range of 5 ns to 30 ns.
- What are the package options for the LM5114?
The LM5114 is available in 6-pin SOT-23 and WQFN-6 packages with an exposed pad for thermal dissipation.
- What is the operating temperature range of the LM5114?
The LM5114 operates over a temperature range of -40°C to 125°C.
- Can the LM5114 drive GaN FETs?
- What is the purpose of the under-voltage lockout (UVLO) feature in the LM5114?
The UVLO feature ensures that the device does not operate when the VDD voltage is below a certain threshold, preventing malfunction and protecting the device.
- How does the LM5114 handle input hysteresis?
The LM5114 has an input hysteresis of 0.68 V to prevent oscillations and ensure stable operation.
- What are some common applications of the LM5114?
The LM5114 is commonly used in boost converters, flyback and forward converters, secondary synchronous FETs in isolated topologies, and motor control applications.
- How important is PCB layout for the LM5114?
PCB layout is crucial for the LM5114 to achieve reliable operation, especially when driving GaN FETs, as it needs to minimize stray inductance and ensure tight gate drive loops.
