MAX8726EUE+

MAX8726EUE+ is a voltage regulator, belonging to the special purpose family of PMIC (Power Management IC) voltage regulators. It is a low-cost, low-voltage, low-power switching regulator for lithium-ion (Li-Ion) and Li-polymer rechargeable battery-powered applications. The device integrates a highly efficient switching regulator and up to four low-dropout linear regulators.

The MAX8726EUE+ operates over a wide input voltage range of 2.7V to 6V, and features a guaranteed output voltage accuracy of ±1%. The internal switching frequency is optimized to minimize external component size and cost. The device’s output is adjustable down to 0.6V, enabling a low quiescent current of 125μA (typ). It also features soft-start, output discharging, and overvoltage protection.

The MAX8726EUE+ is ideal for applications such as personal digital assistants (PDAs), handheld instruments, digital cameras, and global positioning systems (GPS). It offers robust regulation suitable for ad hoc battery operation and eliminates the need for multiple power supplies.

Operation and Working Principle

The MAX8726EUE+ provides a regulated output supplied from a Lithium-ion battery or other input supply sources. It consists of a high-efficiency switched-mode regulator and four low-dropout regulators (LDOs). The switching and linear regulators can be independently enabled/disabled. The output is operated by the application program or automatically regulated by the internal control logic.

The switched-mode regulator uses an internal pulse width modulation (PWM) controller to provide a constant output voltage. The PWM controller regulates the output voltage by adjusting the duty cycle of the switch node. The linear regulators provide independent regulation on the outputs of the switched-mode regulator.

The linear regulator outputs are programmable to provide either a continuous or dynamic supply. In continuous mode, the output is steady at a defined voltage. In dynamic mode, the output voltage varies over time as a function of load to maintain the maximum available current. The linear regulators also provide a low- ripple output and short load transients.

The MAX8726EUE+ includes a host of features to ensure optimal power management, such as overvoltage protection, current limit protection, over-temperature protection, and under-voltage lockout (UVLO). It also includes a time-out feature that shutoffs the output in case of an external fault.

Conclusion

The MAX8726EUE+ is designed primarily for low-voltage, low-power applications, such as PDAs, handheld instruments, digital cameras, and GPS devices. It combines a high-efficiency switched-mode regulator with four independent linear regulators, allowing the design of low-cost, reliable power solutions. It is particularly useful in applications where a wide input voltage range and adjustable output voltage are required.