Microsemi
Linfinity Microelectronics Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
Copyright 2000
Rev. 2.1d, 2001-03-15
WWW.
Microsemi
.
COM
LX8384x-xx
5A Low Dropout Positive Regulators
P
R
D
TI
N
A MICROSEMI COMPANY
The LX8384/84A/84B Series ICs are
positive regulators designed to provide 5A
output current. These regulators yield
higher efficiency than currently available
devices with all internal circuitry designed
to operate down to a 1V input-to-output
differential. In each of these products, the
dropout voltage is fully specified as a
function of load current. Dropout is
guaranteed at a maximum of 1.3V (8384A)
and 1.5V (8384
)
at maximum output
current, decreasing at lower load currents.
In addition, on-chip trimming adjusts the
reference voltage tolerance to 1% maximum
at room temperature and 2% maximum over
the 0 to 125°C range for the LX8384A,
making this ideal for the Pentium P54C-
VRE specification. The LX8384B offers
0.8% tolerance at room temperature and
1.0% maximum over line, load and
temperature. Fixed versions are also
available and specified in the Available
Options table below.
The LX8384/84A/84B Series devices are
pin-compatible with earlier 3-terminal
regulators, such as the 117 series products,
but they do require input and output
capacitors. A minimum 10µF capacitor is
required on the input and a 15µF or greater
on the output of these new devices for
stability. Although, these capacitors are
generally included in most regulator
designs.
The LX8384/84A/84B Series quiescent
current flows into the load, thereby
increasing efficiency. This feature contrasts
with PNP regulators where up to 10% of the
output current is wasted as quiescent
current. The LX8384-xxI is specified over
the industrial temperature range of -25°C to
125°C, while the LX8384-xxC/84A-
xxC/84B-xxC is specified over the
commercial range of 0°C to 125°C.
IMPORTANT:
For the most current data, consult
MICROSEMI
’s website:
http://www.microsemi.com
*1500µF
6MV1500GX
Sanyo
LX8384A
121
Ω
0.1%
218
Ω
0.1%
IN
ADJ
OUT
5V
3.5V
at 5A
1500µF
5x 6MV1500GX
Sanyo
+
+
* Capacitors must have < 20m
Ω
Total ESR for the VRE Specification
An Application of the LX8384A for the Pentium P54C Processors Meeting VRE Specification.
Three-Terminal Adjustable Or
Fixed Output
Guaranteed < 1.3V Headroom a
5A (LX8384A)
Guaranteed 2.0% Max.
Reference Tolerance (LX8384A)
Guaranteed 1.0% Max.
Reference Tolerance (LX8384B)
0.015% Line Regulation
0.15% Load Regulation
Pentium
®
Processor VRE
Application
High Efficiency Linear
Regulators
Power Regulators For Switching
Power Supplies
Battery Chargers
Constant Current Regulators
Cyrix
®
6x86™
AMD-K5™
LX8384/84A/84B-00 Adjustable
LX8384/84A/84B-15 1.5V
LX8384/84A/84B-33 3.3V
Table 1
- Available Options
T
A
(
°
C)
Max Ref
Accuracy
Max Dropout
Voltage
DT
Plastic TO-252
(D-Pak) 3-Pin
P
Plastic TO-220
3-Pin
DD
Plastic TO-263
3-Pin
0 to 125 2.0% 1.5V LX8384-xxCDT LX8384-xxCP LX8384-xxCDD
2.0% 1.3V LX8384A-xxCDT LX8384A-xxCP LX8384A-xxCDD
1.0% 1.3V LX8384B-xxCDT LX8384B-xxCP LX8384B-xxCDD
-25 to 125 2.0% 1.5V LX8384-xxIDT LX8384-xxIP LX8384-xxIDD
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX8384-xxCPT)
L
L
X
X
8
8
3
3
8
8
4
4
X
X