Dual Step-Down Converters with 6 LDOs for Baseband and Applications Processor

The MAX8967 is an µPMIC with two DC-to-DC step-down switching converters and six remote capacitor-capable LDOs. The step-down converters deliver up to 2A of output current independently. Two of the LDOs deliver a load current up to 300mA, while the remaining four deliver up to 150mA. Both step-down converters have remote sense, allowing loads to be placed away from the IC. The IC operates over a 2.6V to 5.5V input supply range.

Fixed-frequency 4.4MHz PWM operation and clocks that are 180° out of phase permit the use of small external components. Under light load conditions, the step-down converters automatically switch to skip mode operation. In skip mode operation, switching occurs only as needed, allowing efficient operation. Placing either of the step-down converters into green mode reduces the quiescent current consumption of that converter to 5µA (typ).

The IC supports dynamic adjustment of the output voltage through its I²C interface. Each step-down converter has two register settings for output voltage and a setting for ramp rate. Also, each step-down converter has a dedicated enable pin and a dedicated VID pin to toggle between the two programmed output voltages. Additionally, an interrupt output is provided, allowing the IC to signal its master.

Applications

* Cellular Handsets and Smartphones * Portable Devices * Tablets

* Multi-Output PMIC in a Compact Package

* Two 2A Step-Down Converters with Remote Output Voltage Sensing

* Two 300mA LDOs

* Four 150mA LDOs

* < 1µA Shutdown Current

* 2.32mm x 2.44mm Package

* Versatile Step-Down Converters

* Programmable Output Voltage (0.6V to 3.3875V) Through I²C Bus

* Programmable Output Voltage Slew Rate (12.5mV/µs to 50mV/µs)

* Dynamic Switching Between Two Output Voltages Through VID Pins

* Efficient Step-Down Converters

* Over 95% Efficiency with Internal Synchronous Rectifier

* Automatic Skip Mode at Light Loads

* Low 61µA (typ) Quiescent Current

* 5µA (typ) Green Mode per Step-Down Converter

* Programmable LDOs

* Programmable Output Voltage (0.8V to 3.95V in 50mV Steps)

* Programmable Soft-Start Slew Rate (5mV/µs–100mV/µs)

* Reduces Component Size and Board Area Solution

* 4.4MHz Step-Down Switching Allows for 1µH Inductors

* COUT = 1µF for All LDOs

* Reduced Board Space with Remote Capacitor LDOs

* Internal Feedback for Step-Down Converters and LDOs