
The LX1662/62A and LX1663/63A are
Monolithic Switching Regulator Con-
troller IC’s
designed to provide a low cost,
high performance adjustable power supply
for advanced microprocessors and other
applications requiring a very fast transient
response and a high degree of accuracy.
Short-Circuit Current Limiting with-
out Expensive Current Sense Resistors.
Current-sensing mechanism can use PCB
trace resistance or the parasitic resistance of
the main inductor. The
LX1662A
and
LX1663A
have reduced current sense com-
parator threshold for optimum perfor-
mance using a PCB trace. For applications
requiring a high degree of accuracy, a
conventional sense resistor can be used to
sense current.
Programmable Synchronous Recti-
fier Driver for CPU Core.
The main
output is adjustable from 1.3V to 3.5V using
a 5-bit code. The IC can read a VID signal
set by a DIP switch on the motherboard, or
hardwired into the processor’s package (as
in the case of Pentium
Pro and Pentium II
processors). The 5-bit code adjusts the
output voltage between 1.30 and 2.05V in
50mV increments and between 2.0 and 3.5V
in 100mV increments, conforming to the
I
5-bit Programmable Output For CPU Core
Supply
I
No Sense Resistor Required For Short-
Circuit Current Limiting
I
Designed To Drive Either Synchronous Or
Non-Synchronous Output Stages
I
Lowest System Cost Possible For Price-
Sensitive Pentium And Pentium II Class
Applications
I
Soft-Start Capability
I
Modulated, Constant Off-Time Architecture
For Fast Transient Response And Simple
System Design
I
Available Over-Voltage Protection (OVP)
Crowbar Driver And Power Good Flag
(LX1663 only)
I
Small, Surface-Mount Packages
Intel Corporation specification. The device
can drive dual MOSFET’s resulting in typical
efficiencies of 85 - 90% even with loads in
excess of 10 amperes. For cost sensitive
applications, the bottom MOSFET can be
replaced with a Schottky diode (non-syn-
chronous operation).
Smallest Package Size.
The LX1662 is
available in a narrow body 14-pin surface
mount IC package for space sensitive appli-
cations. The LX1663 provides the additional
functions of Over Voltage Protection (OVP)
and Power Good (PWRGD) output drives
for applications requiring output voltage
monitoring and protection functions.
Ultra-Fast Transient Response Re-
duces System Cost.
The modulated off-
time architecture results in the fastest tran-
sient response for a given inductor, reduc-
ing output capacitor requirements, and re-
ducing the total regulator system cost.
Over-Voltage Protection and Power
Good Flag.
The OVP output in the LX1663
& LX1663A can be used to drive an SCR
crowbar circuit to protect the load in the
event of a short-circuit of the main MOSFET.
The LX1663 & LX1663A also have a logic-
level Power Good Flag to signal when the
output voltage is out of specified limits.
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O V A T I O N
LX1662/62A, LX1663/63A
I
Socket 7 Microprocessor Supplies
(including Intel Pentium Processor, AMD-
K6
TM
Processors)
I
Pentium II and Deschutes Processor & L2-
Cache Supplies
I
Voltage Regulator Modules
I
General Purpose DC:DC Converter
Applications
And Cyrix
6x86
TM
, Gx86
TM
and M2
TM
Plastic DIP
14-pin
N
Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX1662CDT)
Plastic DIP
16-pin
N
Plastic SOIC
14-pin
D
Plastic SOIC
16-pin
D
!"""
#$%%""
1
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841, 714-898-8121, F
AX
: 714-893-2570
L
I N
F
I N I T Y
M
I C R O E L E C T R O N I C S
I
N C
.
IMPORTANT:
For the most current data, consult LinFinity's web site:
http://www.linfinity.com.
SS
INV
V
CC_CORE
VID0
VID1
VID2
VID3
TDRV
GND
V
CC
C
T
VID4
BDRV
V
C1
U1
LX1662
VID3
VID4
C
1μF
12V
R
1
V
OUT
5V
14-pin, Narrow Body SOIC
Q
1
IRL3102
L
1
, 2.5μH
6.3V, 1500μF x 3**
**Four capacitors for Pentium II
14
13
12
11
10
9
1
2
3
4
5
6
7
8
C
680pF
VID2
VID1
VID0
C
3
0.1μF
2.5m
Supply Voltage
for CPU Core
6.3V
1500μF x3
Q
IRL3303
C
1
C
2
L
2
1μH
#
)