LIN D
O C
#:
1431
LX1431
P
ROGRAMMABLE
R
EFERENCE
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O VA T I O N
P
R O D U C T I O N
D
A T A
S
H E E T
DESCRIPTION
The LX1431 is an adjustable shunt voltage
regulator featuring 100mA sink capability, a
0.4% initial reference voltage tolerance and
a 0.3% typical temperature stability. This
product, which is ideal for use in Pentium
廬
applications, is equipped with on-chip di-
vider resistors, enabling it to be configured
as a 5V shunt regulator. In this configura-
tion, the LX1431 has an initial voltage toler-
ance of
only
1% and requires no additional
exter nal components. The Linfinity
LX1431EB evaluation board and design kit
is available to assist engineers in quickly
configuring the most efficient, cost-effective
Pentium designs.
The output voltage of the LX1431 may be
set to any value between 2.5V and 36V
through the addition of two external resis-
tors, which is of particular importance in the
design of both adjustable and switching
power supplies. In addition, the nominal
internal current limit of 100mA may be de-
creased with the addition of a single exter-
nal resistor.
For applications requiring an adjustable
reference, the Linfinity LX6431CLP, a simpli-
fied three-pin programmable reference, may
be used. Because the LX6431 is pin-for-pin
compatible with Linfinity's earlier TL431, use
of this product provides designers a simple
migration path to the more robust LX6431.
A separate LX6431 data sheet is available
which details the specifics of this product.
In addition, Pentium designers may use
Linfinity's LX8585/8585A 4.6A or LX8584/
8584A 7A Low Dropout Regulators to achieve
the most optimum motherboard configura-
tion.
K E Y F E AT U R E S
p
GUARANTEED 0.4% INITIAL VOLTAGE
TOLERANCE
p
0.1鈩?TYPICAL DYNAMIC OUTPUT
IMPEDANCE
p
FAST TURN-ON
p
SINK CURRENT CAPABILITY, 1mA TO 100mA
p
LOW REFERENCE PIN CURRENT
A P P L I C AT I O N S
s
s
s
s
LINEAR REGULATORS
ADJUSTABLE POWER SUPPLIES
SWITCHING POWER SUPPLIES
LX1431EB EVALUATION BOARD FOR
PENTIUM APPLICATIONS AVAILABLE.
CONSULT FACTORY.
PRODUCT HIGHLIGHT
T
HE
LX8584A
5V
3
AND
LX1431
V
OUT
2
IN
75
AND
166MH
Z
P54C P
R O C E S S O R
A
P P L I C ATIONS
U
S I N G
3.3V C
ACHE
V
O
7A
(See Table Below)
PLACE IN 碌P SOCKET CAVITY
V
IN
LX8584A
1kW
ADJ
1
250pF
2
220碌F
10V
Low ESR
from
Sanyo
0.1碌F
50V
3
V
+
1
COL
REF
8
2.84kW
0.1%
1kW
0.01碌F
3x
330碌F, 6.3V
Low ESR
Oscon Type
from Sanyo
100碌F x 6
10V
AVX TYPE
TPS
1k
0.1%
碌P
Load
LX1431
SGND
5
FGND
6
21k
1%
JP1
1碌F x 10
SMD
V
O
3.50
3.38
JP1
Short
Open
TYPICAL APPLICATION
120/166MHz, VRE, 3.3V Cache
75/90/100/133MHz, STND, 3.3V Cache
Thick traces represent high current traces which
must be low resistance / low inductance traces in
order to achieve good transient response.
PA C K A G E O R D E R I N F O R M AT I O N
T
A
(擄C)
0 to 70
-40 to 85
M
Plastic DIP
8-pin
LX1431CM
LX1431IM
DM
Plastic SOIC
8-pin
LX1431CDM
LX1431IDM
Note: All surface mount packages are available in Tape & Reel.
Append the letter "T" to part number (i.e. LX1431CDMT).
F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1
Copyright 漏 1997
Rev. 1.2 4/97
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841
1
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