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