LX1736 Datasheet, PDF (1/6 Pages) Microsemi Corporation – VREF @ 800mV, 900mA, 1.0MHZ PWM a Current Mode PWM Buck regulator that switches to PFM mode under light loads

LX1736
® VREF @ 800mV, 900mA, 1.0MHZ PWM
TM
PRODUCTION DATA SHEET
DESCRIPTION
The LX1736 operates as a Current The regulator is capable of providing an
Mode PWM Buck regulator that output load current of 900mA and has
switches to PFM mode under light no minimum load current requirement
loads. The entire regulator function is for stable operation. Current limit
implemented with only a few, low- senses on a cycle-by cycle basis to
cost external components.
protect the switch. Power conversion
The LX1736 responds quickly to efficiency is maximized with PFM
dynamic load changes using a high mode of operation and low regulator
bandwidth error amplifier and internal quiescent current.
compensation. Tight output voltage The LX1736 operational supply voltage
regulation is maintained with the range covers 4.0V to 6.0V, features
temperature compensated 800mV, include: power on delay; soft start to
bandgap reference achieving +/-3.5% limit inrush currents and thermal
regulation tolerance for all line, load shutdown during fault conditions.
and thermal conditions. The output The 6-pin JEDEC MO-229 package
voltage is easily programmed, from provides a small form factor and low
800mV to 90% of V_IN with two profile at 3x3x1mm with excellent
external resistors
power dissipation capability on surface
mount PCB’s.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
KEY FEATURES
ƒ Few External Components
ƒ 800mv Internal Reference
ƒ Tight Regulation over Line,
Load and Temperature
ƒ 4.5V to 5.5V Input Range
ƒ Internal Soft Start Controls
Inrush Current
ƒ High Efficiency
ƒ Low Quiescent Current, 600μA
ƒ Fully Fault Protected
ƒ Thin MO-229, 6-Pin Package
APPLICATIONS
ƒ Point of Load Regulation
ƒ DSP, ASIC and Core Voltage
Supplies
ƒ Hard Disk Drives
ƒ Set Top Boxes
ƒ RoHS compliant product
4V to 6V
PRODUCT HIGHLIGHT
4 ^VPWR
N/C 6
5 ^VCC
4.7uF
2 GND
SW 3
FB 1
3.3uH
10.0K
17.8K
1.25V
@
875mA
30uF
Ground
Plane
Tie-in
Figure 1 – LX1736 Application Circuit and Typical Efficiency Performance
95%
85%
75%
65%
55%
45%
35%
25%
1
Efficiency @ ^VIN=5V,
VO=1.25V (Lower)
VO=3.3V (Upper)
10
100
OUTPUT CURRENT, mA
PACKAGE ORDER INFO
T_A (°C)
Plastic MLPD
LD _{6 pin 3mm x 3mm}
RoHS Compliant / Pb-free
0 to 125
LX1736CLD
Note: Available in Tape & Reel. Append the letters “TR” to
the part number. (i.e. LX1736CLD-TR)
Package Marking
1736
xxxx
MSC
Copyright © 2005
Rev. 1.0, 1/3/2007
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
1000
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