DESCRIPTION KEY FEATURES
■ THREE-TERMINAL ADJUSTABLE OR FIXED
OUTPUT
■
GUARANTEED < 1.2V HEADROOM AT 4.6A
(LX8585A)
■
GUARANTEED < 1.4V HEADROOM AT 4.6A
(LX8585)
■ GUARANTEED < 1.3V HEADROOM AT 3A
■ OUTPUT CURRENT OF 4.6A MINIMUM
p FAST TRANSIENT RESPONSE
p 1% VOLTAGE REFERENCE INITIAL
ACCURACY
p OUTPUT SHORT CIRCUIT PROTECTION
p BUILT-IN THERMAL SHUTDOWN
The LX8585/85A Series ICs are low drop-
out three-terminal regulators with a mini-
mum of 4.6A output current. Pentium
®
Processor and Power PC
TM
applications
requiring fast transient response are ide-
ally suited for this product family. The
LX8585A is guaranteed to have < 1.2V
at 4.6A, while the LX8585 are specified
for 1.4V, making them ideal to provide
well regulated outputs of 2.5V to 3.6V
using a 5V input supply. Fixed versions
are also available and specified in the
Available Options table below.
Current limit is trimmed above 4.6A to
ensure adequate output current and con-
trolled short-circuit current. On-chip
thermal limiting provides protection
against any possible overload that would
create excessive junction temperatures.
The LX8585/85A family is available in
both through-hole and surface-mount
versions of the industry standard 3-pin
TO-220 / TO-263 power packages.
The LX1431 Programmable Reference
and LX8585A Series products offer pre-
cision output voltage and are ideal for
use in VRE applications (see application
below). For higher current applications,
see the LX8584 data sheet.
APPLICATIONS
■ PENTIUM PROCESSOR SUPPLIES
■ POWER PC SUPPLIES
■ MICROPROCESSOR SUPPLIES
■ LOW VOLTAGE LOGIC SUPPLIES
■ BATTERY POWERED CIRCUIT
■ POST REGULATOR FOR SWITCHING SUPPLY
■ CYRIX
®
6x86
TM
SUPPLIES
■ AMD-K5
TM
SUPPLIES
4.6A L
OW
D
ROPOUT
P
OSITIVE
R
EGULATORS
P RODUCTION DATA SHEET
THE INFINITE POWER OF INNOVATION
LX8585-xx/8585A-xx
LIN DOC #:
8585
PRODUCT HIGHLIGHT
THE APPLICATION OF THE LX8585A & LX1431 IN A
75 & 166MHZ P54C PROCESSORS USING 5V CACHE
µP
Load
100µF x 6
10V
AVX TYPE
TPS
1µF x 10
SMD
1k
0.1%
2.84k
Ω
0.1%
COL
V
+
V
+
V
+
SGND FGND
REF
LX1431
V
IN
V
OUT
ADJ
1k
Ω
1k
Ω
0.01µF
2x
330µF, 6.3V
Low ESR
Oscon Type
from Sanyo
23
1
65
8
1
3
0.1µF
50V
220µF
10V
Low ESR
from
Sanyo
5V
PLACE IN µP SOCKET CAVITY
LX8585A
2
250pF
21k
1%
JP1
V
O
4.6A
(See Table Below)
Thick traces represent high current traces which must be low resistance / low
inductance traces in order to achieve good transient response.
V
OUT
JP1 TYPICAL APPLICATION
3.50 Short 120/166MHz, VRE, 5V Cache
3.38 Open 75/90/100/133MHz, STND, 5V Cache
PACKAGE ORDER INFORMATION
T
A
(°C)
Plastic TO-220
3-pin
P
Plastic T0-263
3-pin
DD
0 to 125 1.4V LX8585-xxCP LX8585-xxCDD
1.2V LX8585A-xxCP LX8585A-xxCDD
Dropout
Voltage
Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LX8585A-00CDDT)
"xx" refers to output voltage, please see table above.
LX8585/85A-00 Adjustable
LX8585/85A-15 1.5V
LX8585/85A-33 3.3V
Part #
Output
Voltage
AVAILABLE OPTIONS PER PART #
Other voltage options may be available —
Please contact factory for details.
Copyright © 1997
Rev. 2.2 12/97
1
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
L INFINITY MICROELECTRONICS INC.
IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com.