August 16, 2013 – Linear Technology Korea (CEO Hong Sa-kwak) announced the launch of the LT3514, a triple-output 36V step-down switching regulator that provides 100% duty cycle operation. The LT3514 allows output voltage to be set as low as 0.8V, delivering continuous output current of 2A from one channel and 1A continuous output current from each of the other two channels. The device's 3.2V to 36V (40VMAX) input voltage range is ideal for automotive and industrial applications requiring multiple outputs. The LT3514's unique design includes an onboard boost regulator, enabling each channel to operate at 100% duty cycle and to function even at input voltages as low as 3.2V. This architecture makes the LT3514 well-suited for applications requiring continuous regulation under operating conditions such as automotive cold crank and stop-start scenarios.

The LT3514's switching frequency is user-programmable in the range of 250kHz to 2.2MHz and can be synchronized across the entire range. This allows designers to optimize efficiency while avoiding noise-sensitive critical frequency bands. The combination of the product's 28-pin 4mm x 5mm QFN package and high switching frequency provides a compact, thermally efficient footprint with small external inductors and capacitors for various output applications.

The LT3514 utilizes one 3A integrated switch and two 1.45A switches for step-down conversion, along with one 220mA switch for the internal boost circuit, integrating essential oscillator, control, and logic circuits on a single die. Special design techniques deliver efficiency up to 88% across a wide input voltage range. The LT3514's current-mode topology realizes fast transient response and excellent loop stability. Anti-phase switching reduces input ripple, and robust short-circuit protection enhances system reliability. Additional features include output voltage tracking, programmable low voltage lockout, and a Power Good pin that indicates when all outputs are in regulation.

Photo Caption: 36V, Triple 2A+1A+1A (IOUT), 2.2MHz Step-Down DC/DC Converter

Product Features: LT3514
• Wide input range: 3.2V to 36V (40VMAX)
• One 2A output & two 1A outputs
• 100% duty cycle operation
• Resistor-programmable fixed frequency
• Robust short-circuit protection
• Wide SYNC range: 250kHz to 2.2MHz
• Anti-phase switching reduces ripple
• 800mV FB voltage
• Independent Run/Soft-Start pin
• Shutdown with UVLO
• Internal compensation
• Thermal shutdown
• Small 28-pin (4mm × 5mm) thermally enhanced QFN & TSSOP-24 packages