LIN D O C #: 8382
LX8382-xx/8382A-xx
1 0 A L O W D R O P O U T P O S I T I V E R E G U L AT O R S
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DESCRIPTION
The LX8382/8382A series ICs are
positive regulators designed to provide
10A output current. All internal
circuitry is designed to operate down
to a 1V input-to-output differential, so
the LX8382/82A can operate with
greater efficiency than previously
available devices. The dropout voltage
for each product is fully specified as a
function of load current. Dropout is
guaranteed at a maximum of 1.4V
for the LX8382 and 1.2V for the
LX8382A at maximum output current,
decreasing at lower load currents.
Fixed versions are also available and
specified in the Available Options table
below. The LX8382/82A have 1%
initial voltage reference accuracy and
D
A T A
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H E E T
K E Y F E AT U R E S
■ THREE-TERMINAL ADJUSTABLE OR FIXED
OUTPUT VOLTAGE
■ GUARANTEED < 1.4V HEADROOM AT 10A
(LX8382)
■ GUARANTEED < 1.2V HEADROOM AT 10A
(LX8382A)
■ OUTPUT CURRENT OF 10A MINIMUM
p 0.015% LINE REGULATION
p 0.15% LOAD REGULATION
■ EVALUATION BOARD AVAILABLE:
REQUEST LXE9001 EVALUATION KIT
2% over line, load and temperature.
The LX8382/82A series devices are
pin-compatible with earlier 3-terminal
regulators, such as the 117 series
products. While a 10µF output
capacitor is required on both input and
output of these new devices, this
capacitor is generally included in most
regulator designs.
The LX8382/82A 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
LX8382/82A-xxC is specified over the
commercial range of 0°C to +125°C.
A P P L I C AT I O N S
■ PENTIUM® PROCESSOR APPLICATIONS
■ POST REGULATORS FOR SWITCHING
POWER SUPPLIES
■ BATTERY CHARGERS
■ CONSTANT CURRENT REGULATORS
■ CYRIX® 6x86TM
■ AMD-K6 TM
■ HIGH-CURRENT MICROPROCESSORS
PRODUCT HIGHLIGHT
3.3V, 10A R E G U L AT O R
A VA I L A B L E O P T I O N S
VIN ≥ 4.75V
1500µF
6.3V
6MV1500GX
from Sanyo
IN
LX8382-xx
OUT
3.1V at 10A
121Ω
1%
ADJ
178Ω
1%
Part #
LX8382/8382A-00
LX8382/8382A-33
2x 330µF, 6.3V
Oscon SA type
from Sanyo
-or3x 1500µF, 6.3V
6MV1500GX
from Sanyo
PER
PAR T #
Output
Voltage
Adjustable
3.3V
Other voltage options may be available —
Please contact factory for details.
Application of the LX8382 for a high-current microprocessor (e.g. AMD-K6)
with less than 130mV dynamic response to a 7.5A load transient.
PA C K A G E O R D E R I N F O R M AT I O N
TA (°C)
0 to 125
Dropout
Voltage
TO-220
P Plastic
3-pin
TO-247
V Plastic
3-terminal
1.4V
LX8382-xxCP
LX8382-xxCV
1.2V
LX8382A-xxCP
LX8382A-xxCV
"xx" refers to output voltage, please see table above.
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 © 1997
Rev. 1.0 8/97
11861 WESTERN A VENUE , G ARDEN G ROVE , CA. 92841
1
PRODUCT DATABOOK 1996/1997
LX8382-xx
1 0 A L O W D R O P O U T P O S I T I V E R E G U L AT O R S
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A B S O L U T E M A X I M U M R AT I N G S
D
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H E E T
PACKAGE PIN OUTS
(Note 1)
Power Dissipation .................................................................................. Internally Limited
Input Voltage ................................................................................................................ 10V
Input to Output Voltage Differential ........................................................................... 10V
Maximum Output Current ........................................................................................... 10A
Operating Junction Temperature
Plastic (P & V Packages) ....................................................................................... 150°C
Storage Temperature Range ...................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C
TAB IS V OUT
3
VIN
VOUT
ADJ / GND*
2
1
P PACKAGE
(Top View)
* Pin 1 is GND for fixed voltage versions.
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.
TAB ON REVERSE SIDE IS VOUT
T H E R MAL DATA
3
2
P PACKAGE:
1
THERMAL RESISTANCE-JUNCTION TO TAB, θJT
2.7°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA
60°C/W
VIN
VOUT
ADJ / GND*
V PACKAGE
(Top View)
* Pin 1 is GND for fixed voltage versions.
V PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB, θJT
1.6°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA
35°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θ JA numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow.
BLOCK D IA GR A M
VIN
Bias
Circuit
Thermal
Limit Circuit
Bandgap
Circuit
Control
Circuit
Output
Circuit
VOUT
SOA Protection
Circuit
ADJ or
GND*
Current
Limit Circuit
* This pin GND for fixed voltage versions.
2
Copyright © 1997
Rev. 1.0 8/97
PRODUCT DATABOOK 1996/1997
LX8382-xx
1 0 A L O W D R O P O U T P O S I T I V E R E G U L AT O R S
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ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for the LX8382/8382A-xxC with 0°C ≤ T A ≤ 125°C;
VIN - VOUT = 3V; IOUT = 10A. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient
temperature.)
LX8382-00 (Adjustable)
Parameter
Reference Voltage (Note 4)
Symbol
Test Conditions
VREF
IOUT = 10mA, TA = 25°C
10mA ≤ IOUT ≤ IOUT (MAX), 1.5V ≤ (VIN - VOUT), VIN ≤ 10V, P ≤ PMAX
Line Regulation (Note 2)
∆VREF (VIN) 1.5V ≤ (VIN - VOUT ), VIN ≤ 7V
Load Regulation (Note 2)
∆V REF VOUT ≥ V REF, VIN - VOUT = 3V, 10mA ≤ IOUT ≤ 10A, TA = 25°C
(IOUT) VIN - V OUT = 3V, 10mA ≤ IOUT ≤ 10A
Thermal Regulation
∆VOUT (Pwr) TA = 25°C, 20ms pulse
Ripple Rejection (Note 3)
VOUT = 5V, f =120Hz, COUT = 100µf Tantalum, VIN = 6.5V
CADJ = 10µF, TA = 25°C, IOUT = 10A
Adjust Pin Current
I ADJ
Adjust Pin Current Change (Note 4)
∆ IADJ 10mA ≤ IOUT ≤ IOUT (MAX) , 1.5V ≤ (VIN - VOUT), VIN ≤ 10V
Dropout Voltage
LX8382-00
∆V
∆VREF = 1%, IOUT = 10A
LX8382A-00
∆VREF = 1%, IOUT = 10A
Minimum Load Current
IOUT (MIN) VIN ≤ 10V
(VIN - VOUT) ≤ 7V
Maximum Output Current
IOUT (MAX)
Temperature Stability (Note 3)
∆VOUT (T)
Long Term Stability (Note 3)
∆VOUT (t) TA = 125°C, 1000 hours
RMS Output Noise (% of VOUT) (Note 3) VOUT (RMS) TA = 25°C, 10Hz ≤ f ≤ 10kHz
Min.
1.238
1.225
65
10
LX8382-00
Typ.
Max.
Units
1.250
1.250
0.015
0.15
0.3
0.01
83
1.262
1.270
0.2
0.4
0.5
0.02
V
V
%
%
%
%/W
dB
55
0.2
1.2
1.1
2
12
0.25
0.3
0.003
100
5
1.4
1.2
10
µA
µA
V
V
mA
A
%
%
%
1
LX8382-33 (3.3V Fixed)
Parameter
Output Voltage (Note 4)
Symbol
VOUT
Test Conditions
VIN = 5V, IOUT = 0mA, TA = 25°C
4.75V ≤ V IN ≤ 10V, 0mA ≤ IOUT ≤ 10A, P ≤ PMAX
Line Regulation (Note 2)
∆VOUT (V IN) 4.75V ≤ V IN ≤ 7V
Load Regulation (Note 2)
∆VOUT (IOUT) VIN = 5V, 0mA ≤ IOUT ≤ IOUT (MAX)
Thermal Regulation
∆VOUT (Pwr) TA = 25°C, 20ms pulse
Ripple Rejection (Note 3)
COUT = 100µF (Tantalum), IOUT = 10A
Quiescent Current
IQ
0mA ≤ IOUT ≤ IOUT (MAX) , 4.75V ≤ VIN ≤ 10V
Dropout Voltage
LX8382-33
∆V
∆VOUT = 1%, IOUT ≤ IOUT (MAX) , VIN ≤ 7V
LX8382A-33
∆VOUT = 1%, IOUT ≤ IOUT (MAX) , VIN ≤ 7V
Maximum Output Current
IOUT (MAX) VIN ≤ 7V
Temperature Stability (Note 3)
∆VOUT (T)
Long Term Stability (Note 3)
∆VOUT (t) TA = 125°C, 1000 hours
RMS Output Noise (% of VOUT) (Note 3) VOUT (RMS) TA = 25°C, 10Hz ≤ f ≤ 10kHz
Min.
3.267
3.235
60
10
LX8382-33
Typ.
Max.
3.3
3.3
1
5
0.01
83
4
12
0.25
0.3
0.003
3.333
3.365
6
15
0.02
10
1.4
1.2
1
Units
V
V
mV
mV
%/W
dB
mA
V
V
A
%
%
%
Note 2. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to
heating effects are covered under the specification for thermal regulation.
Note 3. These parameters, although guaranteed, are not tested in production.
Note 4. See Maximum Output Current Section above.
Copyright © 1997
Rev. 1.0 8/97
3
PRODUCT DATABOOK 1996/1997
LX8382-xx
1 0 A L O W D R O P O U T P O S I T I V E R E G U L AT O R S
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R O D U C T I O N
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H E E T
A P P L I C AT I O N N O T E S
The LX8382/8382A series ICs are easy to use Low-Dropout (LDO)
voltage regulators. They have all of the standard self-protection
features expected of voltage regulators: short circuit protection,
safe operating area protection and automatic thermal shutdown
if the device temperature rises above approximately 165°C.
Use of an output capacitor is REQUIRED with the LX8382/82A
series. Please see the table below for recommended minimum
capacitor values.
These regulators offer a more tightly controlled reference
voltage tolerance and superior reference stability when measured
against the older pin-compatible regulator types that they replace.
STABILITY
The output capacitor is part of the regulator’s frequency compensation system. Many types of capacitors are available, with
different capacitance value tolerances, capacitance temperature
coefficients, and equivalent series impedances. For all operating
conditions, connection of a 220µF aluminum electrolytic capacitor
or a 47µF solid tantalum capacitor between the output terminal
and ground will guarantee stable operation.
If a bypass capacitor is connected between the output voltage
adjust (ADJ) pin and ground, ripple rejection will be improved
(please see the section entitled “RIPPLE REJECTION”). When ADJ
pin bypassing is used, the required output capacitor value
increases. Output capacitor values of 220µF (aluminum) or 47µF
(tantalum) provide for all cases of bypassing the ADJ pin. If an
ADJ pin bypass capacitor is not used, smaller output capacitor
values are adequate. The table below shows recommended
minimum capacitance values for stable operation.
RECOMMENDED CAPACITOR VALUES
INPUT
OUTPUT
ADJ
10µF
10µF
15µF Tantalum, 100µF Aluminum
47µF Tantalum, 220µF Aluminum
None
15µF
In order to ensure good transient response from the power supply
system under rapidly changing current load conditions, designers
generally use several output capacitors connected in parallel.
Such an arrangement serves to minimize the effects of the parasitic
resistance (ESR) and inductance (ESL) that are present in all
capacitors. Cost-effective solutions that sufficiently limit ESR and
ESL effects generally result in total capacitance values in the range
of hundreds to thousands of microfarads, which is more than
adequate to meet regulator output capacitor specifications. Output capacitance values may be increased without limit.
The circuit shown in Figure 1 can be used to observe the
transient response characteristics of the regulator in a power
system under changing loads. The effects of different capacitor
types and values on transient response parameters, such as
overshoot and undershoot, can be quickly compared in order to
develop an optimum solution.
4
Power Supply
IN
LX8382-xx
/82A-xx
OUT
ADJ
Minumum Load
(Larger resistor)
Full Load
(Smaller resistor)
RDSON
