Features

• Single Resistor Programmable VOUT: 0V to VIN – 0.5V
• Silent Switcher® Architecture
• I_ISET Accuracy: ±1%
• Tight V_OUT Regulation Across V_OUT Range
• Output Current Monitor Accuracy: ±5%
• Programmable Wire Drop Compensation
• Easy to Parallel for Higher Current and Heat Spreading
• Input Supply Voltage Regulation Loop
• High Efficiency: Up to 96%
• Output Current: ±5A
• Integrated N-MOSFETs (60mΩ Top & 30mΩ Bottom)
• Adjustable Switching Frequency: 400KHz to 4MHz
• V_IN Range: 4V to 15V
• Current Mode Operation for Excellent Line and Load Transient Response
• Shutdown Mode Draws Less Than 1µA Supply Current
• Low Profile 24-Lead 3mm × 5mm QFN Package

Typical Application

Description

TheLTC3623 is a high efficiency, monolithic synchronous buck regulator in which the output voltage is programmed with a single external resistor. The accurate internally generated 50µA current source on the ISET pin allows the user to program an output voltage from 0V to 0.5V below V_IN. The user can also directly drive the ISET pin with an external voltage supply to program the converter’s V_OUT. The V_OUT voltage is fed directly back to the error amplifier to be regulated to the ISET voltage. The operating supply voltage range for the SV_IN pin is from 15V down to 4V, while the PV_IN pin’s voltage range is 15V down to 1.5V, making it suitable for dual Li-Ion batteries and for taking power from a 12V or 5V rail.

The operating frequency is programmable from 400KHz to 4MHz with an external RT resistor. Higher switching frequencyallowstheuseofsmallersurfacemountinductors while lower frequency allows for higher power efficiency. The unique constant-frequency/controlled on-time architecture is ideal for high step-down ratio applications that are operating at high frequency while demanding fast transient response.