LIN DOC #:
LX8554-xx
5A E
XTREMELY LOW DROPOUT POSITIVE REGULATORS
8554
THE INFINITE POWER OF INNOVATION
DESCRIPTION KEY FEATURES
The LX8554 series ICs are very low dropout three-terminal positive regulators with
5A rated output current. This product family is ideally suited for Pentium
sor and Power PC
TM
applications requir-
®
Proces-
ing fast transient response. The LX8554
is guaranteed to have a dropout volt-
age under 1V at 5A load, making it ideal
to provide well-regulated outputs of 2.5V
to 3.6V with input supply as low as 4.75V.
Fixed versions are also available and are
specified in the Available Options table
below.
Current limit is trimmed above 5.1A to
ensure adequate output current and con-
trolled short-circuit current. On-chip thermal limiting provides protection against
any combination of overload that would
create excessive junction temperatures.
The LX8554 series products are available in both through-hole and surfacemount versions of industry standard 3-pin
TO-220 / TO-263 power packages.
The LX8554 family of products are ideal
for use in multiple processor applications
where output voltage is jumper selected.
The LX8554 ICs offer precision output as
well as low supply operation (see application below). For higher current applications see the LX8584 series of products.
PRODUCT HIGHLIGHT
TYPICAL APPLICATION OF THE LX8554 IN A FLEXIBLE MOTHERBOARD WITH
OUTPUT VOLTAGE SELECTABLE VIA JUMPERS "JP1" AND "JP2"
P RODUCTION DATA SHEET
■■
■ THREE-TERMINAL ADJUSTABLE OR FIXED
■■
OUTPUT
■■
■ GUARANTEED
■■
■■
■ OUTPUT CURRENT OF 5A
■■
p FAST TRANSIENT RESPONSE
p 1% VOLTAGE REFERENCE INITIAL
ACCURACY
p OUTPUT SHORT-CIRCUIT PROTECTION
p BUILT-IN THERMAL SHUTDOWN
■ EVALUATION BOARD AVAILABLE:
REQUEST LXE9001 EVALUATION KIT
APPLICATIONS
■ PENTIUM PROCESSOR SUPPLIES
■ POWER PC SUPPLIES
■ MICROPROCESSOR SUPPLIES
■ LOW VOLTAGE LOGIC SUPPLIES
■ BATTERY POWERED CIRCUIT
■ POST REGULATOR FOR SWITCHING SUPPLY
≤≤
≤ 1V HEADROOM AT 5A
≤≤
VIN ³ 4.75 IN
1500µF, 6.3V
Sanyo MVGX Series
JP1 JP2 OUTPUT VOLTAGE
Open Open 3.6V
Open Short 3.45V
Short Short 3.3V
LX8554
OUT
ADJ
V
REF
R1
121
W
1%
200
W
1%
13
R2
1%
14.7
1%
W
JP1
V
= V
OUT
REF
W
JP2
R2
1 + + I
R1
PACKAGE ORDER INFORMATION
T
(°C)
A
Plastic TO-220
P
3-pin
0 to 125 LX8554-xxCP LX8554-xxCDD
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX8554-00CDDT)
"xx" refers to output voltage, please see table above.
V
O
(See Table Below)
3x 1500µF
6.3V
Sanyo
MVGX Series
R2
ADJ
Plastic T0-263
DD
3-pin
AVAILABLE OPTIONS PER PART #
Part #
LX8554-00 Adjustable
LX8554-33 3.3V
Other voltage options may be available —
Please contact factory for details.
Output
Voltage
Copyright © 1997
Rev. 1.1 1/97
FOR FURTHER INFORMATION CALL (714) 898-8121
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841
1
LX8554-xx
PRODUCT DATABOOK 1996/1997
5A E
XTREMELY LOW DROPOUT POSITIVE REGULATORS
RODUCTION DATA SHEET
P
ABSOLUTE MAXIMUM RATINGS (Note 1)
Power Dissipation .................................................................................. Internally Limited
Input Voltage................................................................................................................ 10V
Input to Output Voltage Differential ........................................................................... 10V
Operating Junction Temperature
Plastic (P Package) ................................................................................................ 150°C
Storage Temperature Range ...................................................................... -65°C to 150°C
Lead Temperature (Soldering, 10 seconds) ............................................................. 300°C
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.
THERMAL DATA
P PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB,
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθ
θ
θθ
JT
θθ
θ
θθ
JA
DD PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB,
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
Junction Temperature Calculation: TJ = TA + (P
numbers are guidelines for the thermal performance of the device/pc-board system.
The θ
JA
All of the above assume no ambient airflow.
can be improved with package soldered to 0.5IN2 copper area over backside ground
* θ
JA
plane or internal power plane. θ
mounting technique.
can vary from 20ºC/W to > 40ºC/W depending on
JA
θθ
θ
θθ
JT
θθ
θ
θθ
JA
x θ
).
D
JA
2.7°C/W
60°C/W
2.7°C/W
60°C/W *
PACKAGE PIN OUTS
TAB IS V
OUT
3
2
1
P PACKAGE
(Top View)
* Pin 1 is GND for fixed voltage versions.
TAB IS V
OUT
3
2
1
DD PACKAGE
* Pin 1 is GND for fixed voltage versions.
(Top View)
V
V
ADJ / GND*
V
IN
V
OUT
ADJ / GND*
IN
OUT
2
Copyright © 1997
Rev. 1.1 1/97
PRODUCT DATABOOK 1996/1997
LX8554-xx
5A E
XTREMELY LOW DROPOUT POSITIVE REGULATORS
P RODUCTION DATA SHEET
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for the LX8554-xxC with 0°C ≤ TA ≤ 125°C; V
= 5A. Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.)
I
OUT
LX8554-00 (Adjustable)
Parameter
Reference Voltage V
Symbol
REFIOUT
10mA ≤ I
Line Regulation (Note 2)
Load Regulation (Note 2)
Thermal Regulation
∆V
∆V
∆V
)
I
REF(VIN
)
VIN - V
REF(IOUT
(Pwr)
TA = 25°C, 20ms pulse
OUT
Ripple Rejection (Note 3) V
C
Adjust Pin Current I
Adjust Pin Current Change ∆I
ADJ
ADJ
10mA ≤ I
Dropout Voltage ∆V ∆V
Minimum Load Current I
Maximum Output Current (Note 4) I
Temperature Stability (Note 3) ∆V
Long Term Stability (Note 3) ∆V
RMS Output Noise (% of V
) (Note 3) V
OUT
OUT(MIN)VIN
1.4V ≤ (V
OUT(MAX)
(T)
OUT
(t) TA = 125°C, 1000 hrs
OUT
OUT (RMS)TA
Test Conditions Units
= 10mA, TA = 25°C
≤ 5A, 1.5V ≤ (V
OUT
= 10mA, 1.5V ≤ (V
OUT
= 3V, 10mA ≤ I
OUT
= 3.3V, f =120Hz, C
OUT
= 10µF, I
ADJ
= 1%, I
REF
OUT
≤ 5A, 1.5V ≤ (V
OUT
OUT
≤ 7V
- V
IN
OUT
= 125°C, 10Hz ≤ f ≤ 10kHz
= 5A
= 5A
), V
IN
IN
≤ 7V
- V
OUT
OUT
- V
), V
OUT
IN
IN
≤ 7V
≤ 7V, P ≤ P
MAX
OUT
IN
), V
≤ 5A
= 100µf Tantalum, VIN = 5V
- V
), V
OUT
≤ 7V
IN
IN
LX8554-00
Min. Typ. Max.
1.238 1.250 1.262 V
1.225 1.250 1.275 V
0.035 0.2 %
0.1 0.5 %
0.01 0.02 %/W
60 83 dB
55 100 µA
0.2 5 µA
0.8 1 V
210mA
5.1 7 A
0.25 %
0.003 %
- V
= 3V;
IN
OUT
1%
LX8554-33 (3.3V Fixed)
Parameter
Output Voltage (Note 4) V
Line Regulation (Note 2) ∆V
Load Regulation (Note 2)
Thermal Regulation (Note 3)
Ripple Rejection (Note 3) C
Quiescent Current I
Dropout Voltage ∆V ∆V
Maximum Output Current I
Temperature Stability (Note 3) ∆V
Long Term Stability (Note 3) ∆V
RMS Output Noise (% of V
) (Note 3) V
OUT
Symbol
OUTVIN
(V
∆V
OUT(IOUT
∆V
OUT
OUT (MAX)VIN
OUT
OUT
OUT (RMS)TA
= 5V, I
OUT
4.75V ≤ VIN ≤ 10V, 0mA ≤ I
4.75V ≤ VIN ≤ 7V
OUT
)
IN
4.75V ≤ VIN ≤ 10V
)
V
= 5V, 10mA ≤ I
IN
(Pwr)
TA = 25°C, 20ms pulse
= 100µF (Tantalum), I
OUT
0mA ≤ I
Q
= 1%, I
OUT
OUT
≤ 7V
(T)
(t) TA = 125°C, 1000 hours
= 25°C, 10Hz ≤ f ≤ 10kHz
Test Conditions Units
= 0mA, TA = 25°C
≤ I
OUT
OUT (MAX)
≤ I
, 4.75V ≤ VIN ≤ 10V
OUT (MAX)
≤ I
OUT
OUT (MAX)
≤ 5A, TA = 25°C, P ≤ P
OUT
= 5A
OUT
, VIN - V
OUT
≤ 7V
MAX
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. I
is measured under the condition that V
OUT (MAX)
is forced below its nominal value by 100mV.
OUT
LX8554-33
Min. Typ. Max.
3.267 3.3 3.333 V
3.235 3.3 3.365 V
16mV
210mV
515mV
0.01 0.02 % / W
65 83 dB
410mA
0.8 1 V
5.1 7 A
0.25 %
0.3 1 %
0.003 %
Copyright © 1997
Rev. 1.1 1/97
3