lx1673 Microsemi Corporation, lx1673 Datasheet

no-image

lx1673

Manufacturer Part Number
lx1673
Description
High Frequency Pwm Regulator
Manufacturer
Microsemi Corporation
Datasheet
Copyright © 2004
Rev 1.0, 3/18/2005
power supply controller IC featuring one
PWM switching regulator stage with an
additional onboard linear regulator
driver.
available (up to 900kHz) the LX1673
can be optimized for both cost and PCB
space.
pensation, a wide selection of external
components can be chosen for use in
any application while maintaining
stable operation.
programmable soft-start and power
sequence capabilities. The LDO and
PWM have independent enable pins.
IMPORTANT: For the most current data, consult MICROSEMI’s website:
The LX1673 is a highly integrated
With several switching frequencies
The LX1673 incorporates a fully
TM
Utilizing
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1673-03CPW-TR)
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
external
V
-40 to 85
-40 to 85
-40 to 85
OUT2
T
A
(°C)
D E S C R I P T I O N
LDDIS
DIS
+3.3V
com-
PWRGD
PWM output is capable of sourcing up to
15A.
additional Linear Regulator Controller
output, which when coupled with an
inexpensive MOSFET is capable of
supplying up to an additional 5A for I/O,
memory, and other supplies surrounding
today’s microprocessor designs.
programmed via a simple voltage-divider
network.
is implemented utilizing MOSFET R
impedance. This enables the LX1673 to
monitor maximum current limit conditions
without the use of expensive current sense
resistors.
Frequency (kHz)
+12V
With onboard gate drivers, the switching
Each regulator output voltage is
Integrated hiccup mode current limiting
Switching
P R O D U C T H I G H L I G H T
+5V
300
600
900
Integrated Products Division
1
2
3
4
5
The LX1673 also features an
PACKAGE ORDER INFO
LDDIS
LDGD
LDFB
DGND
AGND
LDVCC PWGD VC1 TDRV PGND
20
6
DIS
®
Microsemi
http://www.microsemi.com
19
7
SS
LX1673
18
8
EA+
17
9
EA-
PW
16
10
RoHS Compliant / Pb-free
EAO
BDRV
VCCL
CS
VCC
VS
LX1673-03CPW
LX1673-06CPW
LX1673-09CPW
15
14
13
12
11
Plastic TSSOP
20-Pin
High Frequency PWM Regulator
+5V
+5V
DS(ON)
P
RODUCTION
LQ
RoHS Compliant / Pb-free
+3.3V
LX1673-03CLQ
LX1673-06CLQ
LX1673-09CLQ
Two Independently Regulated
Outputs
Outputs As Low As 0.8V
Generated From An Internal 1%
Reference
Integrated High Current MOSFET
Drivers
300KHz, 600KHz, and 900KHz
High Frequency Operation
Minimizes External Component
Requirements
Soft-Start and Power Sequencing
Control
Adjustable Linear Regulator Driver
Output
No current-sense resistors
Video Card Power Supplies
PC Peripherals
Computer Add-On Cards
3.3V Power Conversion
DDR Memory Termination
APPLICATIONS/BENEFITS
D
Plastic MLPQ
20-Pin
ATA
K E Y F E A T U R E S
V
OUT1
S
HEET
LX1673
Page 1

Related parts for lx1673

lx1673 Summary of contents

Page 1

... DIS T (° Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1673-03CPW-TR) Copyright © 2004 Rev 1.0, 3/18/2005 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 ® High Frequency PWM Regulator P RODUCTION ...

Page 2

... A 90°C/W MBIENT JA , θ A 35°C/W MBIENT θ Microsemi Integrated Products Division LX1673 RODUCTION ATA HEET LDGD 1 LDFB LDDIS DGND AGND ACKAGE (Top View) N.C. – No Internal Connection N/U – ...

Page 3

... ESCRIPTION 1K Ω 20K resistor and the external capacitor set the time constant for soft-start Ω 100K Microsemi Integrated Products Division LX1673 D S RODUCTION ATA HEET must be in series with this pin. exceeds the UVLO threshold. CC pull down resistor. Ω ...

Page 4

... Static and Dynamic CC I LDVCC T =25 ° 0°C ≤ T ≤ 70°C A 3000pF Load 2 Volt Level All Frequencies LX1673-03 Load = 3000pF LX1673-06 Load = 3000pF LX1673-09 Load = 3000pF V Common Mode Voltage = 1V OS UGBW V I Source = 2mA Sink = 10uA OL Input Offset Voltage < 20mV 0 and 3 ...

Page 5

... 0.4V LDRV OUT Threshold DIS Internal Pull down Resistance Threshold LDDIS Internal Pull down Resistance I = 3mA Microsemi Integrated Products Division LX1673 D S RODUCTION ATA HEET ≤ ≤ T 70°C except where A LX1673 Min Typ Max 4.0 4.0 4.25 4.5 0 2.5 100 0.4 0.05 Units Ω ...

Page 6

... FAULT TEMP SS1 DIS PWGD Figure 1 – Block Diagram of PWM Phase LDGD V REF - LDFB +5V LDDIS Figure 2 – LDO Controller Block Diagram Microsemi Integrated Products Division LX1673 RODUCTION ATA HEET I SET Vin (5V) VC1 C IN TDRV L1 ESR C BDRV OUT PGND ...

Page 7

... LDVCC PWGD VC1 TDRV PGND 1 15 LDGD BDRV 2 14 LDFB VCCL + LX1673 LDDIS VCC 4 12 DGND AGND CS DIS SS EA+ EA- EAO Figure 4 – Schematic for 5 Volt only Input Microsemi Integrated Products Division LX1673 D S ATA HEET PWM Vout PWM Vout Page 7 ...

Page 8

... NDER OLTAGE OCKOUT At power up, the LX1673 monitors the supply voltage for VCC, VCCL, LDVCC and VC1 (there is no requirement for sequencing the supplies). Before all supplies reach their under- voltage lock-out (UVLO) thresholds, the soft-start (SS) pin is held low to prevent soft-start from beginning, the oscillator is disabled and all MOSFETs are held off. There is an internal delay that will filter out transients less that 1.5µ ...

Page 9

... The output voltage will follow the voltage at the SS pin if the required inductor current does not exceed the maximum allowable current for the inductor. Microsemi Integrated Products Division LX1673 RODUCTION ATA ...

Page 10

... O D UTPUT ISABLE The LX1673 PWM MOSFET driver outputs are shut off by pulling the disable (DIS) pin above 1.2V. There is a down resistor on this input. The LDO voltage regulator has its own Disable pin (LDDIS) for control of this output voltage. Pulling this pin above 3 V disables the LDO ...

Page 11

... RODUCTION current limit is not used connect the VS and VC pins together and to VCC. Do not leave them floating. A floating VS pin will result in operation resembling a hiccup condition. Microsemi Integrated Products Division LX1673 D S ATA HEET Page 11 ...

Page 12

... Dim Dim Θ1 *LC solder coverage. Microsemi Integrated Products Division LX1673 RODUCTION ATA HEET M I ILLIMETERS NCHES MIN MAX MIN A 0.80 1.00 0.031 0 0.05 0 0.25 REF 0.010 b 0.23 0.38 0.009 D 5.00 BSC 0.197 1.25 3.25 ...

Page 13

... Copyright © 2004 Rev 1.0, 3/18/2005 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 ® High Frequency PWM Regulator P RODUCTION Microsemi Integrated Products Division LX1673 D S ATA HEET Page 13 ...

Related keywords