PRODUCTION DATA SHEET
THE INFINITE POWER OF INNOVATION
Not Recommened For New Design
See The LX8580A
LINFINITY MICROELECTRONICS INC.
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
1
Copyright © 1999
Rev. 1.1, 2005-10-21
LX8580
7A VERY LOW DROPOUT POSITIVE ADJUSTABLE REGULATOR
DESCRIPTION
The LX8580 is a high-performance, very low
dropout voltage regulator, designed for use with
advanced microprocessors. This product can be
used with separate voltage supplies for the control
and power sections, allowing a power section
dropout voltage as low as 100mV. The LX8580
can also be used in a single voltage supply
configuration, with a dropout performance similar
to that of the LX8584 (1.3V at 7A).
The LX8580 is supplied in a five terminal TO-
220 package, which allows the implementation
of remote (Kelvin) voltage sensing. This sensing
compensates for output voltage variations due to
load changes and resistive voltage drops in
connectors and board traces. Typical load
regulation measured at the sense pin is less than
1mV for a load current step of 7mA to 7A.
The LX8580 is ideal for generating a
secondary 2 - 2.5V low voltage supply on a
motherboard where a 3.3V supply is already
available.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
KEY FEATURES
Low Dropout, 800mV Max. at 7A
Output Current in Dual Supply
Mode
Fast Transient Response
Remote Sensing
1mV Load Regulation
Adjustable Output
No Supply Sequencing Problems
in Dual Supply Mode
KEY FEATURES
Microprocessor Supplies
3.3V to 2.5V Processor Power
Supplies
High-Current Regulators
Post Regulators for Switching
Supplies
PRODUCT HIGHLIGHT
RA
LOAD
5
ADJUST
1
43
VCTRL VOUT + 1.3V Max
VPWR VOUT + VDROPOUT
RB
LX8580
VOUT
VCTRL
VPWR
2
SENSE
OUTPUT
BADJ
A
B
REFOUT RI
R
R
1VV +
+=
Special Capabilities of the LX8580 To Allow
44% Smaller LDO Th ermal Dissipat ion
PACKAGE ORDER INFO
P Plastic TO-220
5-Pin DD Plastic To-263
5-Pin
TA (°C) Dropout Voltage RoHS Compliant
Transition DC: 0543 RoHS Compliant
Transition DC: 0535
0 to 125 0.1V – 0.8V LX8580-00CP LX8580-00CDD
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX 8580-00CDD-TR)
7A V
ERY
L
OW
D
ROPOUT
P
OSITIVE
A
DJUSTABLE
R
EGULATOR
LX8580
PRODUCT DATABOOK 1996/1997
2
PRODUCTION DATA SHEET
Copyright © 1999
Rev. 1.1
ABSOLUTE MAXIMUM RATINGS (Note 1)
Power Dissipation ......................................................................................Internally Limited
VPWR Input Voltage ........................................................................................................... 7V
VCTRL Input Voltage......................................................................................................... 13V
Operating Junction Temperature
Plastic (P Package) ................................................................................................ 150°C
Storage Temperature Range ...................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C
PACKAGE PIN OUTS
Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect
to Ground. Currents are positive into, negative out of the specified terminal.
BLOCK DIAGRAM
Current
Limiting
Amplifier
Thermal Overload
Voltage
Regulation
Amplifier
Power
OUTPUT
SENSE
ADJUST
V
REF
Control
V
CTRL
V
PWR
VPWR
VCTRL
OUTPUT
ADJUST
SENSE
P PACKAGE
(Top View)
1
5
TAB IS OUTPUT
DD PACKAGE
(Top View)
VPWR
VCTRL
OUTPUT
ADJUST
SENSE
3
2
1
4
5
TAB IS OUTPUT
P PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB, θθ
θθ
θJT 3.0°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θθ
θθ
θJA 60°C/W
DD PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB, θθ
θθ
θJT 3.0°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θθ
θθ
θJA 60°C/W
Junction Temperature Calculation: TJ = TA + (P D x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow.
THERMAL DATA
RoHS Peak Package Solder Reflow Temp. (40 seconds max. exposure).................... 260°C (+0, -5)
RoHS 100% Matte Tin Lead Finish
7A V
ERY
L
OW
D
ROPOUT
P
OSITIVE
A
DJUSTABLE
R
EGULATOR
LX8580
PRODUCT DATABOOK 1996/1997
3
Copyright © 1999
Rev. 1.1
PRODUCTION DATA SHEET
Reference Voltage VREF VCTRL = 2.75V, VPWR = 2V, ILOAD = 10mA, TJ = 25°C
VCTRL
= 2.7V to 6V,
VPWR
= 1.75V to 5.5V, I
OUT
= 10mA to 4A
VCTRL
= 2.7V to 6V,
VPWR
= 2.05V to 5.5V, I
OUT
= 10mA to 7A
Line Regulation VREF (VIN)
V
CTRL
= 2.5V to 12V, V
PWR
= 1.75V to 5.5V, I
LOAD
= 10mA, T
J
= 25°C
V
CTRL
= 2.5V to 12V, V
PWR
= 1.75V to 5.5V, I
LOAD
= 10mA
Load Regulation
V
REF
(I
OUT
)
VCTRL = 2.75V, VPWR = 2.1V, ILOAD = 10mA to 7A (VADJ = 0)
Thermal Regulation VOUT (Pwr) 30ms Pulse
Thermal Resistance RθJT Control Circuitry/Power Transistor
Ripple Rejection VCTRL = VPWR = 3.75V Avg, VRIPPLE = 1VP-P, VADJ = 0V, IOUT = 4A
Control Pin Current (Note 3) ICTRL VCTRL = 2.75V, VPWR = 2.05V, ILOAD = 100mA
VCTRL = 2.75V, VPWR = 2.05V, ILOAD = 4A
VCTRL = 2.75V, VPWR = 1.75V, ILOAD = 4A
VCTRL = 2.75V, VPWR = 2.05V, ILOAD = 7A
Adjust Pin Current IADJ VCTRL = 2.75V, VPWR = 2.05V, ILOAD = 0mA (VADJ = 0)
Current Limit Iθ(MAX) VCTRL = 2.75V, VPWR = 2.05V, VOUT = 100mV (VADJ = 0)
Dropout Voltage (Control Section) VCTRL - VOUT VPWR = 2.05V, ILOAD = 100mA
Minimum VCTRL (Note 2) VPWR = 2.05V, ILOAD = 1A
(VPWR - VOUT)V
PWR = 2.05V, ILOAD = 2.75A
VPWR = 2.05V, ILOAD = 4A
VPWR = 2.05V, ILOAD = 7A
Dropout Voltage (Power Section) VPWR - VOUT VCTRL = 2.75V, ILOAD = 100mA
Minimum VPWR (Note 2) VCTRL = 2.75V, ILOAD = 1A
(VPWR - VOUT)V
CTRL = 2.75V, ILOAD = 2.75A
(VADJ = 0) VCTRL = 2.75V, ILOAD = 4A, TJ = 25°C
VCTRL = 2.75V, ILOAD = 4A
VCTRL = 2.75V, ILOAD = 7A, TJ = 25°C
VCTRL = 2.75V, ILOAD = 7A
Minimum Load Current VCTRL = 5V, VPWR = 3.3V, VADJ = 0V
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures 0°C TA 125°C. Low duty cycle pulse testing
techniques are used which maintains junction and case temperatures equal to the ambient temperature.)
Parameter
Symbol
Test Conditions Units
LX8580
Min. Typ. Max.
1.243 1.250 1.257 V
1.237 1.250 1.263 V
1.237 1.250 1.263 V
13mV
26mV
27mV
0.002 0.020 %/W
0.65 2.70 °C/W
60 80 dB
310mA
30 60 mA
33 70 mA
60 120 mA
60 120 µA
7.1 9 A
0.90 1.15 V
1.00 1.15 V
1.05 1.18 V
1.06 1.20 V
1.10 1.30 V
0.05 0.17 V
0.10 0.22 V
0.20 0.38 V
0.30 0.40 V
0.30 0.50 V
0.52 0.62 V
0.56 0.80 V
510mA
Note 2. Dropout is caused by either minimum control voltage (VCTRL) or minimum power voltage (VPWR). Both parameters are specified with respect to
the output voltage. The specifications represent the minimum input/output voltage required to maintain 1% regulation.
Note 3. The control pin current is the drive current required for the output transistor. This current will track output current with roughly a 1:100 ratio.
The minimum value is equal to the quiescent current of the device.
7A V
ERY
L
OW
D
ROPOUT
P
OSITIVE
A
DJUSTABLE
R
EGULATOR
LX8580
PRODUCT DATABOOK 1996/1997
4
PRODUCTION DATA SHEET
Copyright © 1999
Rev. 1.1
SENSE 1
ADJUST 2
OUTPUT 3
VCTRL 4
VPWR 5
This pin is the positive side of the reference voltage for the device. With this pin it is possible to Kelvin-sense the output voltage
at load.
This pin is the negative side of the reference voltage for the device. Ripple rejection can be improved by adding a small bypass capacitor
from the Adjust pin to ground. The capacitor value should be selected so that CR 1 / 2πFRRA , where FR is the ripple frequency
and RA is the value of the resistor between the output and sense leads of the LX8580.
This is the power output of the device.
This pin is the voltage supply pin for the control circuitry of the device. The current flow into this pin will be about 1% of the output
current. For the device to regulate, the voltage at this pin must be between 1.0V and 1.3V greater than the output voltage.
This is the collector of the power section of the LX8580. The output load current is supplied through this pin. For the device to
regulate, the voltage at this pin must be between 0.1V and 0.8V greater than the output voltage (higher output currents require higher
voltages between VPWR and OUTPUT).
Pin # Description
FUNCTIONAL PIN DESCRIPTION
BASIC APPLICATION CIRCUIT
LX8580
LOAD
6000µF
(4X Sanyo 6mV 1500G
K
6.3V 1500µF)
5A
Tantalum
33µF 10V
5.0V
Tantalum
100µF
10V
V
OUT
= 2.775 2.89 (MAX)
2.67 (MIN)
1219
1%
1479
1%
V
PWR
V
CTRL
ADJUST
SYSTEM GROUND
0.259
"Electronic Heatsink"
Resistor reduces
thermal load
on LDO heatsink
to 6.9W
OUTPUT
SENSE
4 x 19 2W 5%
(Parallel Connected)
*Note
*Note: For improved transient response, add capacitor as shown (typical 15µF).
PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document
may not be modified in any way without the express written consent of LinFinity. Pr oduct processing does not necessarily include testing of all
parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time.