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9A, Three-Phase Step-Down Switching Regulator

Meets Increasing Demand for Performance and Aggressive Form Factor Requirements in Next-Generation Smartphone Designs

Product Details

Key Features

Applications/Uses

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2.6
VIN (V) (max) 4.5
VOUT1 (V) (min) 0.6
VOUT1 (V) (max) 1.4
IOUT1 (A) (max) 9
Switch Type Internal
Preset VOUT (V) 1
Output Adjust. Method Digital/VID
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 2000
Design Tools EE-Sim
Package/Pins WLP/28
Budgetary
Price (See Notes)
0
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Simplified Block Diagram

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Parameters

Parametric specs for Step-Down Switching Regulators
VIN (V) (min) 2.6
VIN (V) (max) 4.5
VOUT1 (V) (min) 0.6
VOUT1 (V) (max) 1.4
IOUT1 (A) (max) 9
Switch Type Internal
Preset VOUT (V) 1
Output Adjust. Method Digital/VID
Synchronous Switching? Yes
# DC-DC Outputs 1
Switching Frequency (kHz) 2000
Design Tools generateDesignEESIMUrl('http://maxim.transim.com/pwm2/designreq/Index?partId=11346', '')
Package/Pins WLP/28
Budgetary
Price (See Notes)
0

Key Features

  • Up to 9A Output Current
  • > 91% Peak Efficiency at 3.6VIN, 1.2VOUT
  • Rotational Phase Spreading Maximizes Efficiency at Light Loads
  • Initial Accuracy of 0.5% at 1.2V Output
  • 0.8% Output Accuracy Over Line and Temperature at 1.2V Output
  • Enhanced Transient Response Minimizes Output Droop with Large Load Steps
  • Soft-Stop Recovers Output Capacitor Charge When Converter is Disabled
  • Programmable VOUT: 0.60625V to 1.4V (6.25mV step size)
  • Powers Up into Prebiased Output
  • 3.4MHz I²C 3.0-Compatible Serial Interface
  • Fixed 2MHz PWM Switching Frequency per Phase
  • Small (< 1µH) Inductor for Each Phase
  • Overcurrent, Short-Circuit, and Thermal Protection

Applications/Uses

  • Smartphones
  • Tablets
  • Ultrabooks

Description

The MAX8973A high-efficiency, three-phase, DC-DC step-down switching regulator delivers up to 9A of output current in a compact footprint with excellent transient response. Each phase operates at a 2MHz fixed frequency, allowing the use of small magnetic components. Maxim Integrated’s proprietary Rotational Phase Spreading algorithm optimizes efficiency at low output currents. Software-selectable forced-PWM mode allows either fixed-frequency operation, or improved efficiency at light load with a variable frequency in skip mode. The triple-inductor architecture reduces the size of the external components while providing the benefit of ripple current cancellation. The MAX8973A operates from a 2.6V to 4.5V input voltage range.

An I²C 3.0-compatible serial interface, supporting clock rates up to 3.4MHz, controls key regulator parameters such as output voltage, output slew rate, and on/off control. Output voltage is programmable from 0.60625V to 1.4V in 6.25mV increments. The default output voltage is factory programmable. An EN input enables and disables the output, while a DVS pin selects two different output voltages without relying on the serial interface.

Fully differential remote sense ensures precise DC regulation at the point of load. Total output error is less than 0.8% over, line, and temperature at 1.2V output. Output ripple is typically < 1% of the output voltage setting when the processor is in the Idle state (light loads) and < 0.5% at medium and high loads.

Other features include internal soft-start control circuitry to reduce inrush current, guaranteed monotonic voltage adjustment, over-current protection, and over-temperature protection. The MAX8973A operates over the -40°C to +85°C extended temperature range and is packaged in an ultra-small WLP package.

Simplified Block Diagram

MAX8973A: Typical Operating Circuit MAX8973A is an efficient three-phase DC-DC step-down switching regulator with 9A of output current in a small footprint | Typical Operating Circuit Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

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Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .