General Description
The MAX42402/MAX42403 IC are a tiny synchronous buck converter with integrated high-side and low-side switches. The MAX42402/MAX42403 are designed to deliver up to 2.5A/3.5A with a wide, 4.5V to 36V input voltage range. Voltage quality can be monitored by observing the PGOOD signal. The IC can operate in dropout by running at 99% duty cycle, making it ideal for industrial applications.
The MAX42402/MAX42403 offer externally programmable output voltage. Fixed internal frequency options of 1.5MHz/400kHz are available, which allow for small external components and reduced output ripple.
When SYNC is low, the MAX42402/MAX42403 automatically enter skip mode at light loads with an ultra-low quiescent current of 27uA at no load. A pin-selectable forced-PWM mode is also available, which helps to improve EMI performance. The devices have a spread-spectrum frequency modulation option designed to minimize EMI-radiated emissions due to the modulation frequency.
The MAX42402/MAX42403 are available in a small, 3mm x 3mm FC2QFN package and uses very few external components.

Benefits and Features
• Multiple Functions for Small Size
• Operating Input Voltage Range: 4.5V to 36V
• Synchronous DC-DC Converter with Integrated FETs up to 2.5A/3.5A
• 27μA Quiescent Current in Skip Mode
• 1.5MHz/400kHz Switching Frequency
• Spread-Spectrum Option
• 3.5ms (1.5MHz)/2.5ms (400kHz) Internal Soft-Start
• Programmable 0.8V to 12V Output Voltage Range
• 99% Duty Cycle Operation with Low Dropout
• High Precision for Safety-Critical Applications
• Precision Enable Thresholds for Fully Programmable UVLO Thresholds
• Accurate Windowed PGOOD
• Forced-PWM and Skip Operation
• Overtemperature, Overvoltage, and Short-Circuit Protection
• 3mm x 3mm FC2QFN
• -40°C to +125°C Operating Temperature Range

Key Applications
• Industrial Automation
• Point-of-Load
• Distributed DC Power Systems