Texas Instruments LM5122

Description

The LM5122 is a multiphase capable synchronous boost controller intended for high-efficiency synchronous boost regulator applications. The controlmethod is based upon peak current mode control. Current mode control provides inherent line feed-forward, cycle-by-cycle current limiting and ease of loop compensation.

The switching frequency is programmable up to 1MHz. Higher efficiency is achieved by two robust Nchannel MOSFET gate drivers with adaptive dead-time control. A user-selectable diode emulation mode also enables discontinuous mode operation for improved efficiency at light load conditions.

An internal charge pump allows 100% duty cycle for high-side synchronous switch (Bypass operation). A 180º phase shifted clock output enables easy multi-phase interleaved configuration. Additional features include thermal shutdown, frequency synchronization, hiccup mode current limit and adjustable line undervoltage lockout.

Features

• AEC-Q100 Grade 1 (TA = –40°C to 125°C)
• Maximum Input Voltage : 65 V
• Min Input Voltage : 3.0 V (4.5 V for startup)
• Output Voltage up to 100 V
• Bypass (VOUT = VIN) Operation
• 1.2 V Reference with ±1.0% Accuracy
• Free Run/SynchronizableSwitching to 1 MHz
• Peak Current Mode Control
• Robust 3 A Integrated Gate Drivers
• Adaptive Dead-Time Control
• Optional Diode Emulation Mode
• Programmable Cycle-by-Cycle Current Limit
• Hiccup Mode Overload Protection
• Programmable Line UVLO
• Programmable Soft-Start
• Thermal Shutdown Protection
• Low Shutdown Quiescent Current: 9 µA
• Programmable Slope Compensation
• Programmable Skip Cycle Mode Reduces Standby Power
• Allows External VCC Supply
• Inductor DCR Current Sensing Capability
• Multiphase Capability
• Thermally Enhanced 20-Pin HTSSOP

Remarks:1)fSW2 Switching frequency 2 is choosed due to max value

2)From Figure 38. Non-Isolated Synchronous Flyback Converter Simplified SchematicOnly I/O is given, but it's a coupled inductor(transformer)

Typical applications

• 12 V, 24 V, and 48 V Power Systems
• Automotive Start-Stop
• High Current Boost Power Supply
• Audio Power Supply

More information

• Datasheet
• IC product information