LX1660 Datasheet, PDF (1/15 Pages) Microsemi Corporation – ADVANCED PWM CONTROLLER

T H E I N F I N I T E P O W E R O F I N N O VAT I O N
L I N D O C #: 1660
LX1660/1661
ADVANCED PWM CONTROLLER
PR O D U C T I O N D ATA S H E E T
DESCRIPTION
The LX1660 and LX1661 Are Mono-
lithic Switching Regulator Controller
ICs designed to provide low-cost, high-
performance adjustable power supply for
microprocessors and other applications
requiring a fast transient response and a
high degree of accuracy. They provide
an adjustable synchronous Pulse Width
Modulator output suitable for a power
supply for Pentium^® or other micropro-
cessors.
Synchronous Rectifier Driver For
CPU Core. The devices can drive dual
MOSFETs resulting in typical efficiencies
of 85 - 90%, even with loads in excess of
10A. Synchronous shutdown results in
increased efficiency in light load applica-
tions.
Short-Circuit Current Limiting
Without Expensive Current Sense Re-
sistors. The current sensing mechanism
can use a PCB trace resistance or the para-
sitic resistance of the main inductor. For
applications requiring a high degree of
accuracy, a conventional sense resistor
can be used.
Hiccup Mode Fault Protection. The
hiccup mode is programmable and with
pulse-by-pulse current limiting will help
protect the power supply system and load
in the even of a short circuit.
Ultra-Fast Transient Response Re-
duces System Cost. The fixed frequency
modulated off-time architecture results in
the fastest transient response for a given
inductor. Adaptive voltage positioning
(LX1661 only) requires fewer low-ESR ca-
pacitors to meet stringent transient over-
and under-shoot specifications.
IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com.
LX1661 IN SOCKET 7
PROCESSOR SUPPLY
APPLICATION
OUTEN
PRODUCT HIGHLIGHT
12V
KEY FEATURES
s Designed To Drive A Synchronous Rectifier
Stage — Can Also Be Used In Non-
Synchronous Applications
s Soft-Start Capability
s Hiccup-Mode Fault Protection
s No Current-Sense Resistor Required For
Current Limiting
s Modulated Constant Off-Time Control
Mechanism For Fast Transient Response And
Simple System Design
s 2V, 0.5% Internal Voltage Reference Brought
Out
A P P L I C AT I O N S
s Pentium Processor Supplies
s AMD-K6^TM Supplies
s Cyrix^® 6x86^TM Supplies
s Voltage Regulator Modules
s General Purpose DC:DC Supplies
C2
C7
V_IN 5V
R14, 1%
See Table 5
R15
2.0k
1%
R16
10k
C3
0.1µF
C4
390pF
C8
390pF
U1
LX1661
1 _EN
2 _OTADJ
3 _SGND
4 _VREF
5 _INV
6 _NINV
7 _HICCUP
8 _CT
V_C1 ¹⁶
TDRV ¹⁵
PGND ¹⁴
BDRV ¹³
V_CC ¹²
SYNCEN ¹¹
CS+ ¹⁰
CS- ⁹
16-pin SOIC
Q1
IRL3103
16V, 1000µF
Sanyo MV-GX or equivalent
V_OUT
C9
1µF
L1
R1, 5m
5µH Toroid
C5
C6
D1
R5, 1k
C1
390pF
R6, 1k
16V, 1000µF
Sanyo MV-GX or
equivalent
PACKAGE ORDER INFORMATION
T_A (°C)
N
Plastic DIP
16-pin
D
Plastic SOIC
16-pin
0 to 70
LX166xCN
LX166xCD
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX166xCDT)
LINFINITY MICROELECTRONICS INC.
Copyright © 1998
Rev. 1.1 7/98
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: [phone]
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