LX1672-03CPW Microsemi Analog Mixed Signal Group, LX1672-03CPW Datasheet - Page 13
![IC CTRLR PS TRIPLE OUTPT 28TSSOP](/photos/7/53/75387/lx1672-03cpw_sml.jpg)
LX1672-03CPW
Manufacturer Part Number
LX1672-03CPW
Description
IC CTRLR PS TRIPLE OUTPT 28TSSOP
Manufacturer
Microsemi Analog Mixed Signal Group
Series
LoadSHARE™r
Datasheet
1.LX1672-03CPW.pdf
(20 pages)
Specifications of LX1672-03CPW
Pwm Type
Voltage Mode
Number Of Outputs
3
Frequency - Max
345kHz
Duty Cycle
85%
Voltage - Supply
4.5 V ~ 5.5 V
Buck
Yes
Boost
No
Flyback
No
Inverting
No
Doubler
No
Divider
No
Cuk
No
Isolated
No
Operating Temperature
0°C ~ 70°C
Package / Case
28-TSSOP
Frequency-max
345kHz
For Use With
LX1671 EVA KIT - KIT EVAL FOR SWITCHING REGULATOR
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Copyright © 2000
Rev. 1.0, 2005-08-10
proportional between full load and no load is shown in figure 9.
The DC voltage difference between LPF1 and VOUT is a voltage
that is proportional to the current flowing in the Phase 1 inductor.
This voltage can be amplified and used to offset the voltage at
LPF2 through a large impedance that will not significantly alter
the characteristics of the low pass filter. At no load there will be
no offset voltage and no offset current between the two phases.
This will give the highest efficiency at no load.
B
I
-P
The best topology for generating a current ratio at full load and
HASE
Switch
Switch
Side
L2,
Side
TM
L1,
, L
OAD
SHARE™ ( P
Ra
62k
4700pF
62k
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
4700pF
LPF1
LPF2
ROPORTIONAL
T H E O R Y O F O P E R A T I O N
-
RF2
Figure 9 –LoadSHARE™ Using Proportional Control
62k
FB2
M
ETHOD
Rin
Integrated Products Division
-
)
Phase 2
Error Amp
1M
®
Microsemi
Rb
-
Offset Amp
amplifier output and the negative input of the Phase 2 error
amplifier. This will improve the transient response of the Phase 2
output current, so that it will share more equally with phase 1
current during a transient condition.
to prevent loading the low pass filter.
amplifier, and the value of Ra and Rb, will determine the ratio of
currents between the phases at full load. Two external amplifiers are
required or this method.
Rf
Also a speed up capacitor can be used between the offset
The use of a MOSFET input amplifier is required for the buffer
PWM
Input
Multiple Output LoadSHARE™ PWM
( C O N T I N U E D )
Vos
Generator
P
RODUCTION
Voltage
Offset
+46.7mV
+73.3mV
1.5V
1.5V
V
V2
1
+
-
+3.3V @ 11W
D
+5V @ 7W
ATA
Phase 1
Phase 2
ESR L1
ESR L2
10mΩ
10mΩ
S
HEET
The gain of the offset
4.67A
7.33A
LX1672
1.5V @ 12A
Page 13
Vout
18W