MAX8973A Datasheet, PDF (1/49 Pages) Maxim Integrated Products – 9A, Three-Phase Step-Down Switching Regulator

MAX8973A
EVALUATION KIT AVAILABLE
9A, Three-Phase Step-Down
Switching Regulator
General 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.
Features
● Up to 9A Output Current
● > 91% Peak Efficiency at 3.6V_IN, 1.2V_OUT
● 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 V_OUT: 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
● Smartphones
● Tablets
● Ultrabooks
Ordering Information and Typical Operating Circuit appear
at end of data sheet.
For related parts and recommended products to use with this part, refer
to www.maximintegrated.com/MAX8973.related.
19-6587; Rev 0; 2/13