LX1671 EVA KIT

LX1671 EVA KIT Datasheet

LX1671/LX1672 CLQ MLPQ PACKAGE MULTIPLE OUTPUT LOADSHARETM PWM EVALUATION BOARD USERS GUIDE

Part	Datasheet
LX1671 EVA KIT	LX1671 EVA KIT (pdf)

Related Parts	Information
LX1672 EVAL KIT	LX1672 EVAL KIT

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LX1671/LX1672 CLQ MLPQ PACKAGE MULTIPLE OUTPUT LOADSHARETM PWM EVALUATION BOARD USERS GUIDE LX1671CPW, LX1671CLQ, LX1672-03CLQ, LX1672-03CPW, LX1672-05CPW, and LX1672-06CLQ are protected by U.S. Patents 6,285,571 & 6,292,378 LX1671 EVALUATION BOARD USER GUIDE TABLE OF CONTENTS Overview 3 LX1671 PWM LX1671 Features Evaluation Board Features LoadSHARE Bi-Phase Configuration Initial Setup Single Phase / Bi-Phase Required Test Equipment Optional Test Equipment Evaluation Board Load Line Over Current UVLO Oscilloscope Waveforms Schematic Bill Of Silk Screen and Etch Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX 714-893-2570 LX1671 EVALUATION BOARD USER GUIDE OVERVIEW The LX1671 evaluation board is designed to allow the user to get a detailed understanding of the operation of the LX1671 or LX1672 and to allow evaluation of several configurations that demonstrate the full capabilities of the controller. All three Pulse Width Modulator PWM phases and the Linear Regulator LDO can be completely evaluated. The LX1672 is a two phase version of the LX1671 Due to the flexibility of the LX1671 evaluation board a number of components must be selected for the specific mode of operation desired and to establish several variable parameters. The evaluation board is delivered with all required factory-installed components in a fully functional configuration. The LX1671 evaluation board can be delivered in a number of standard configurations. User changes to the standard board can be made for different applications and custom versions may be supplied in some situations. When the MLPQ package is used the LX1671 and the LX1672 have the same pinout so the circuit board can be used for either part. This document is intended to be used in conjunction with the LX1671 data sheet and LX1671 Product Design Guide or LX1672 if applicable . LX1671 PWM TOPOLOGY The LX1671 is a PWM controller offering a high level of integration. Three separate synchronous, voltage mode PWM controllers are integrated into a single package. Phases 1 and 2 can be used in a BiPhase mode with LoadSHARE or used as two separate single-phase controllers. Phase 3 is always used in single phase. The single-phase buck regulators are limited to approximately 15 Amps maximum output by the available gate drive the ability to operate in Bi-Phase allows output currents of 30 Amps by paralleling the output capabilities of two controller phases. There is also a controller for a linear regulator that utilizes an external pass transistor with a maximum output of approximately 5A. LX1671 FEATURES • Three synchronous PWM controllers • One LDO controller • Two PWM controllers can be operated in BiPhase to double the current output capability.• • In Bi-Phase the two PWMs operate 180 degrees out of phase to reduce input and output ripple current. • Each PWM controller can operate from a different input voltage when in single or BiPhase. • When in Bi-Phase the currents supplied by each phase can be unbalanced with the LoadSHARE topology. • 300 KHz PWM Switching frequency. • Hiccup current limiting in all PWM outputs. • Reference allows low output voltages down to volts.• • No current sense resistors RDS ON is used for current limit and hiccup mode. • Soft start on each PWM and Under Voltage Lockout on VCC and upper FET drivers• • Output voltage power-up sequencing by selecting soft-start capacitor value. • Reference input on Phase 2 for forced current sharing or DDR memory data bus termination. EVALUATION BOARD FEATURES• • The heat sinking on the LX1671/72 evaluation board allows up to 8A out for each PWM phase. Note The controller is capable of 15A out on all PWM phases but component selection and thermal limits on the evaluation board will prevent operating at full current. • Linear Regulator with pass transistor, limited to five watts power dissipation. • Provisions are made for different input voltages of 5 , and 12 volts to be used as input power for each of the three phases. Bootstrap diodes and capacitors can be installed depending on the input voltage selected. • Three terminal blocks are provided to allow connection of input 5, and 12 volt power. • Four terminal blocks are provided for connecting loads to the outputs. • A connector with jumpers allows enabling each PWM and the linear regulator independently. LOADSHARE BI-PHASE OPERATION For LoadSHARE operation it is necessary to use phases 1 and 2 because of the different configuration of the phase 2 error amplifier input. The phase 2 error amplifier does not internally connect to the reference like the other two phases but is brought out to the RF2 pin to allow a filtered feedback from phase 1 to be brought into the error amplifier. Phase 1 determines the output voltage and forces phase 2 to follow. When using Microsemi

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LX1671/LX1672 CLQ MLPQ PACKAGE MULTIPLE OUTPUT LOADSHARETM PWM EVALUATION BOARD USERS GUIDE

LX1671CPW, LX1671CLQ, LX1672-03CLQ, LX1672-03CPW, LX1672-05CPW, and LX1672-06CLQ are protected by U.S. Patents 6,285,571 & 6,292,378

LX1671 EVALUATION BOARD

USER GUIDE

TABLE OF CONTENTS

Overview 3 LX1671 PWM LX1671 Features Evaluation Board Features LoadSHARE Bi-Phase Configuration Initial Setup Single Phase / Bi-Phase Required Test Equipment Optional Test Equipment Evaluation Board Load Line Over Current UVLO Oscilloscope Waveforms Schematic Bill Of Silk Screen and Etch

Microsemi

Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX 714-893-2570

LX1671 EVALUATION BOARD

USER GUIDE

OVERVIEW

The LX1671 evaluation board is designed to allow the user to get a detailed understanding of the operation of the LX1671 or LX1672 and to allow evaluation of several configurations that demonstrate the full capabilities of the controller. All three Pulse Width Modulator PWM phases and the Linear Regulator LDO can be completely evaluated. The LX1672 is a two phase version of the LX1671

Due to the flexibility of the LX1671 evaluation board a number of components must be selected for the specific mode of operation desired and to establish several variable parameters. The evaluation board is delivered with all required factory-installed components in a fully functional configuration.

The LX1671 evaluation board can be delivered in a number of standard configurations. User changes to the standard board can be made for different applications and custom versions may be supplied in some situations. When the MLPQ package is used the LX1671 and the LX1672 have the same pinout so the circuit board can be used for either part.

This document is intended to be used in conjunction with the LX1671 data sheet and LX1671 Product Design Guide or LX1672 if applicable .

LX1671 PWM TOPOLOGY

The LX1671 is a PWM controller offering a high level of integration. Three separate synchronous, voltage mode PWM controllers are integrated into a single package. Phases 1 and 2 can be used in a BiPhase mode with LoadSHARE or used as two separate single-phase controllers. Phase 3 is always used in single phase. The single-phase buck regulators are limited to approximately 15 Amps maximum output by the available gate drive the ability to operate in Bi-Phase allows output currents of 30 Amps by paralleling the output capabilities of two controller phases. There is also a controller for a linear regulator that utilizes an external pass transistor with a maximum output of approximately 5A.

LX1671 FEATURES
• Three synchronous PWM controllers
• One LDO controller
• Two PWM controllers can be operated in BiPhase to double the current output capability.•
• In Bi-Phase the two PWMs operate 180 degrees out of phase to reduce input and output ripple current.
• Each PWM controller can operate from a different input voltage when in single or BiPhase.
• When in Bi-Phase the currents supplied by each phase can be unbalanced with the LoadSHARE topology.
• 300 KHz PWM Switching frequency.
• Hiccup current limiting in all PWM outputs.
• Reference allows low output voltages down to volts.•
• No current sense resistors RDS ON is used for current limit and hiccup mode.
• Soft start on each PWM and Under Voltage Lockout on VCC and upper FET drivers•
• Output voltage power-up sequencing by selecting soft-start capacitor value.
• Reference input on Phase 2 for forced current sharing or DDR memory data bus termination.

EVALUATION BOARD FEATURES•
• The heat sinking on the LX1671/72 evaluation board allows up to 8A out for each PWM phase. Note The controller is capable of 15A out on all PWM phases but component selection and thermal limits on the evaluation board will prevent operating at full current.
• Linear Regulator with pass transistor, limited to five watts power dissipation.
• Provisions are made for different input voltages of 5 , and 12 volts to be used as input power for each of the three phases. Bootstrap diodes and capacitors can be installed depending on the input voltage selected.
• Three terminal blocks are provided to allow connection of input 5, and 12 volt power.
• Four terminal blocks are provided for connecting loads to the outputs.
• A connector with jumpers allows enabling each PWM and the linear regulator independently.

LOADSHARE BI-PHASE OPERATION

For LoadSHARE operation it is necessary to use phases 1 and 2 because of the different configuration of the phase 2 error amplifier input. The phase 2 error amplifier does not internally connect to the reference like the other two phases but is brought out to the RF2 pin to allow a filtered feedback from phase 1 to be brought into the error amplifier. Phase 1 determines the output voltage and forces phase 2 to follow. When using

Microsemi

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Datasheet ID: LX1671EVAKIT 649006