MAX739CWE+

MAX739CWE+ Application Field and Working Principle

Maxim Integrated\'s MAX739CWE+ is a monolithic DC-DC switching regulator designed to provide high-efficiency, wide input voltage (1.5V to 5.5V) step-down regulation for applications powered by a single Li-ion cell, two to four AA cells, or up to 8V. This feature-packed device includes a Step-Down Switching Regulator, LDO Autoswitch, and an I2C-programmable power-on-reset (Power-On-Reset or POR) circuit. Its Step-Down Switching Regulator provides a wide input voltage range from 1.5V to 5.5V and a low dropout voltage of 1.2V for efficient operation. The device is capable of providing up to 2A of current, and the output is adjustable to 1V to 5V. The LDO Autoswitch automatically switches to the LDO when the input voltage drops below the internal POR threshold voltage, which conserves battery life while guaranteeing a clean power supply with less than 1mV of output noise. While the I2C-programmable POR circuit monitors the input supply and shuts down the device when the input voltage drops below a user-defined voltage. This MAX739CWE+ device also features a low operating current of 26uA, making it suitable for battery-powered applications. Furthermore, the device offers internal overcurrent protection and short-circuit protection and is offered in space-saving 24-bump 0.4mm pitch WLP. This MAX739CWE+ is ideal for applications such as cell phones and PDAs, portable media players, and a wide variety of battery-operated systems and equipment.

Application Fields and Advantages

The MAX739CWE+ can be used in a variety of applications such as cell phones and PDAs, portable media players, and a wide variety of battery-operated systems and equipment. The wide input voltage range from 1.5V to 5.5V and low dropout voltage of 1.2V make it ideal for battery-powered applications. Furthermore, its low operating current of 26uA ensures low power consumption and extended battery life, while its I2C-programmable POR circuit provides power-on reset protection. Additionally, it offers internal overcurrent protection and short-circuit protection, guaranteed to keep the device running smoothly even in the toughest operating conditions.

Working Principle

The MAX739CWE+ is composed of three main sections, the Step Down Switching Regulator, the LDO Autoswitching circuit, and the I2C-programmable power-on-reset (Power-On-Reset or POR) circuit. The Step Down Switching Regulator consists of an N-channel MOSFET power switch, a reference voltage, an error amplifier, an oscillator, a logic control, and a maximum duty-cycle circuit. The switching regulator is designed to provide a clean and efficient regulated power supply with less than 1mV of output noise.

The LDO Autoswitch circuit automatically switches to the low dropout regulator (LDO) when the input voltage drops below the internal POR threshold voltage. This provides a cleaner power supply than traditional linear regulators, while still providing efficient operation.

Finally, the I2C-programmable POR circuit monitors the input supply and shuts down the device when the input voltage drops below a user-defined voltage. This feature ensures that the device does not draw excessive current from the battery, thus extending the battery life.

Conclusion

Maxim Integrated’s MAX739CWE+ is a feature-packed monolithic DC-DC switching regulator that can provide up to 2A of current and adjustable output from 1V to 5V. The device is designed to provide efficient step-down regulation for applications powered by a single Li-ion cell, two to four AA cells, or up to 8V. It features a Step-Down Switching Regulator, LDO Autoswitch, and an I2C-programmable power-on-reset (Power-On-Reset or POR) circuit, making it suitable for applications such as cell phones, PDAs, and portable media players. Additionally, its low operating current, short-circuit protection, and overcurrent protection make it ideal for battery-powered applications.