LX1671 EVA KIT Microsemi Analog Mixed Signal Group, LX1671 EVA KIT Datasheet - Page 3

• Manufacturer Part Number: LX1671 EVA KIT
• Description: KIT EVAL FOR SWITCHING REGULATOR
• Manufacturer: Microsemi Analog Mixed Signal Group
• Series: LoadSHARE™r

Specifications of LX1671 EVA KIT

• Main Purpose: DC/DC, Step Down with LDO
• Regulator Topology: Buck
• Frequency - Switching: 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: LX1671, LX1672
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Voltage - Output: -
• Voltage - Input: -
• Power - Output: -
• Outputs And Type: -
• Other names: LX1671EVAKIT; LXE1671 EVAL KIT; LXE1671 EVAL KIT

LX1671 EVALUATION BOARD
O
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
demonstrate the full capabilities of the controller. All
three Pulse Width Modulator (PWM) phases and the
Linear
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
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 T
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 Bi-
Phase 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 F
Copyright © 2002
Rev 1.0, 2/24/2006
VERVIEW
• Three synchronous PWM controllers
• One LDO controller
• Two PWM controllers can be operated in Bi-
• In Bi-Phase the two PWMs operate 180
Phase to double the current output capability.·
degrees out of phase to reduce input and
output ripple current.
Regulator
EATURES
with
of
OPOLOGY
all
several
(LDO)
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: [phone]
required
can
configurations
be
factory-installed
completely
that
Integrated Products
Microsemi
E
L
For LoadSHARE operation it is necessary to use
phases 1 and 2
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
OAD
VALUATION
• Hiccup current limiting in all PWM outputs.
• Each PWM controller can operate from a
• When in Bi-Phase the currents supplied by
• 300 KHz PWM Switching frequency.
• Reference allows low output voltages down to
• No current sense resistors; R
• Soft start on each PWM and Under Voltage
• Output voltage power-up sequencing by
• Reference input on Phase 2 for forced current
• The heat sinking on the LX1671/72 evaluation
• Linear Regulator with pass transistor, limited
• Provisions are made for different input
• Three terminal blocks are provided to allow
• Four
• A connector with jumpers allows enabling
different input voltage when in single or Bi-
Phase.
each phase can be unbalanced with the
LoadSHARE™ topology.
0.8 volts.·
current limit and hiccup mode.
Lockout on VCC and upper FET drivers·
selecting soft-start capacitor value.
sharing or DDR memory data bus termination.
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.
to five watts power dissipation.
voltages of 3.3, 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.
connection of input 3.3, 5, and 12 volt power.
connecting loads to the outputs.
each
independently.
SHARE (B
terminal
PWM
B
OARD
I
-P
and
blocks
HASE
F
because of the different
EATURES
the
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are
PERATION
linear
DS(ON)
USER GUIDE
·
provided
is used for
regulator
Page 3
for