Texas Instruments LM25145

Description

The LM25145 42-V synchronous buck controller is designed to regulate from a high input voltage source or from an input rail subject to high voltage transients, minimizing the need for external surge suppression components. A high-side switch minimum on-time of 40 ns facilitates large step-down ratios, enabling the direct step-down conversion from a 24 V nominal input to low-voltage rails for reduced system complexity and solution cost. The LM25145 continues to operate during input voltage dips as low as 6 V, at nearly 100% duty cycle if needed, making it well suited for high-performance industrial control, robotic, datacom, and RF power amplifier applications.Forced-PWM (FPWM) operation eliminates frequency variation to minimize EMI, while a user-selectable diode emulation feature lowers current consumption at light-load conditions. Cycle-by-cycle overcurrent protection is accomplished by measuring the voltage drop across the low-side MOSFET or by using an optional current sense resistor. The adjustable switching frequency as high as 1 MHz can be synchronized to an external clock source to eliminate beat frequencies in noise-sensitive applications.

Features

• Versatile Synchronous Buck DC-DC Controller
• Wide Input Voltage Range of 6 V to 42 V
• Adjustable Output Voltage From 0.8 V to 40 V
• Meets EN55022 / CISPR 22 EMI Standards
• Lossless RDS(on) or Shunt Current Sensing
• Switching Frequency From 100 kHz to 1 MHz
• SYNC In and SYNC Out Capability
• 40-ns Minimum On-Time for High VIN / VOUT Ratio
• 140-ns Minimum Off-Time for Low Dropout
• 0.8-V Reference With ±1% Feedback Accuracy
• 7.5-V Gate Drivers for Standard VTH MOSFETs
• 14-ns Adaptive Dead-Time Control
• 2.3-A Source and 3.5-A Sink Capability
• Low-Side Soft-Start for Prebiased Start-Up
• Adjustable Soft-Start or Optional Voltage Tracking
• Fast Line and Load Transient Response
• Voltage-Mode Control With Line Feedforward
• High Gain-Bandwidth Error Amplifier
• Precision Enable Input and Open-Drain Power Good Indicator for Sequencing and Control
• Inherent Protection Features for Robust Design
• Hiccup Mode Overcurrent Protection
• Input UVLO With Hysteresis
• VCC and Gate Drive UVLO Protection
• Thermal Shutdown Protection With Hysteresis
• VQFN-20 Package With Wettable Flanks
• Create a Custom Design Using the LM25145 With WEBENCH® Power Designer

Typical applications

• Factory Automation,Test and Measurement, Industrial Motor Drives
• Telecom Infrastructure

More information

• Datasheet
• IC product information