L6713A STMicroelectronics, L6713A Datasheet - Page 26

• Manufacturer Part Number: L6713A
• Description: IC CTRLR 2/3PH W/DRIVERS 64-TQFP
• Manufacturer: STMicroelectronics

Specifications of L6713A

• Applications: Controller, Intel VR10, VR11, AMD CPU
• Voltage - Input: 12V
• Number Of Outputs: 3
• Voltage - Output: 0.3 ~ 1.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 64-TQFP Exposed Pad, 64-eTQFP, 64-HTQFP, 64-VQFP
• Output Current: 2 A
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Device description
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Device description
L6713A is two/three phase PWM controller with embedded high current drivers providing
complete control logic and protections for a high performance step-down DC-DC voltage
regulator optimized for advanced microprocessor power supply.
Multi phase buck is the simplest and most cost-effective topology employable to satisfy the
increasing current demand of newer microprocessors and modern high current VRM
modules.
It allows distributing equally load and power between the phases using smaller, cheaper and
most common external power MOSFETs and inductors. Moreover, thanks to the equal
phase shift between each phase, the input and output capacitor count results in being
reduced. Phase interleaving causes in fact input RMS current and output ripple voltage
reduction and show an effective output switching frequency increase: the 200kHz free-
running frequency per phase, externally adjustable through a resistor, results multiplied on
the output by the number of phases.
L6713A is a dual-edge asynchronous PWM controller featuring load transient boost
LTB Technology™ (patent pending): the device turns on simultaneously all the phases as
soon as a load transient is detected allowing to minimize system cost by providing the
fastest response to load transition.
Load transition is detected (through LTB pin) measuring the derivate dV/dt of the output
voltage and the dV/dt can be easily programmed extending the system design flexibility.
Moreover, load transient boost LTB Technology™ gain can be easily modified in order to
keep under control the output voltage ring back.
LTB Technology™ can be disabled and in this condition the device works as a dual-edge
asynchronous PWM.
The controller allows to implement a scalable design: a three phase design can be easily
downgraded to two phase simply by leaving one phase not mounted and leaving
PHASE_SEL pin floating.
The same design can be used for more than one project saving development and debug
time. In the same manner, a two phase design can be further upgraded to three phase
facing with newer and highly-current-demanding applications.
L6713A permits easy system design by allowing current reading across inductor in fully
differential mode. Also a sense resistor in series to the inductor can be considered to
improve reading precision.
The current information read corrects the PWM output in order to equalize the average
current carried by each phase limiting the error to ±3 % over static and dynamic conditions
unless considering the sensing element spread.
The controller includes multiple DACs, selectable through an apposite pin, allowing
compatibility with both Intel VR10,VR11 and AMD 6BIT processors specifications, also
performing D-VID transitions accordingly.
Low-side-less start-up allows soft-start over pre-biased output avoiding dangerous current
return through the main inductors as well as negative spike at the load side.
L6713A