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LIN DOC #:
LX8941
A
DJUSTABLE LOW DROPOUT REGULATOR
8941
T HE I NFINITE P OWER OF I NNOVATION
DESCRIPTION KEY FEATURES
The LX8941 is an adjustable, low
dropout regulator rated for more than
1A of output current. It can regulate
with as low as 0.8V headroom between
the input and output voltages, at 1A
output current, thus minimizing power
dissipation. In addition, it can be used
in applications where worst case
differential to maintain regulation. This
feature makes it ideal for some
processor applications that require 4V
operation from a 5V supply. In
addition, the LX8941 provides an on/off
switch that reduces the IC quiescent
current when activated, making it ideal
for battery operated applications.
supplies require a low input-output
NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.
PRODUCT HIGHLIGHT
5V 4
IN
LX8941
OUT
10µF
ON
ADJ
22µF
OFF
P RELIMINARY DATA SHEET
■■
■ 2% Internally Trimmed Output
■■
■■
■ Output Current In Excess Of 1A
■■
■■
■ Input-Output Differential
■■
Less Than 0.8V At 1A
p Reverse Battery Protection
p Short Circuit Protection
p Internal Thermal Overload Protection
p Available In 5-Lead Plastic TO-220 And
Surface-Mount TO-263
DROPOUT VOLTAGE VS. OUTPUT CURRENT
VS
600
500
400
300
200
Dropout Voltage - (mV)
100
. TEMPERATURE
125°C
25°C
-40°C
Copyright © 1999
Rev. 0.6 4/99
0
100
Output Current - (mA)
500
PACKAGE ORDER INFORMATION
T
(°C)
A
Plastic TO-220
P
5-pin
Plastic TO-263
DD
5-pin
0 to 70 LX8941CP LX8941CDD
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX8941CDDT)
L INF INITY MICROELECTRONICS INC.
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570
1000
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LX8941
PRODUCT DATABOOK 1996/1997
A
DJUSTABLE LOW DROPOUT REGULATOR
RELIMINARY DATA SHEET
P
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Voltage (VIN) ....................................................................................................... 26V
Operating Junction Temperature
Plastic (P, DD 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,
DD PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB,
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
Junction Temperature Calculation: TJ = TA + (P
The θ
numbers are guidelines for the thermal performance of the device/pc-board system.
JA
All of the above assume no ambient airflow.
θθ
θ
θθ
JT
θθ
θ
θθ
JA
θθ
θ
θθ
JT
θθ
θ
θθ
JA
x θ
).
D
JA
4.5°C/W
60°C/W
4.5°C/W
60°C/W
PACKAGE PIN OUTS
TAB IS GND
5
1
P PACKAGE
(Top View)
TAB IS GND
5
4
3
2
1
DD PACKAGE
(Top View)
ON/OFF
ADJ
GND
V
O
V
IN
ON/OFF
ADJ
GND
V
O
V
IN
C1*
0.1µF
ON
OFF
ON/
OFF
INPUT VOLTAGE
1
THERMAL
SHUTDOWN
5
BLOCK DIAGRAM
V
IN
ON/OFF
CIRCUIT
LX8941
* Required if regulator is located far from power supply
filter.
V
O
2
OUTPUT
VOLTAGE
C2
10µF
4
3
ADJ
GND
2
Copyright © 1999
Rev. 0.6 4/99
Page 3
PRODUCT DATABOOK 1996/1997
LX8941
A
DJUSTABLE LOW DROPOUT REGULATOR
P RELIMINARY DATA SHEET
RECOMMENDED OPERATING CONDITIONS
Parameter
Input Voltage (Note 2) V
Symbol
IN
Load Current (with adequate heatsinking)
Input Capacitor (VIN to GND)
Output Capacitor with ESR of 10Ω max., (V
Note 2. V
IN (MIN)
= V
+ 1.2∆V
OUT
. See Dropout Voltage maximum limit.
(MAX)
to GND)
OUT
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, these specifications apply over the operating ambient temperature of 0°C to +125°C for LX8941CP; VIN = 10V, IO = 1A, C
= 22µF, and are for DC characteristics only. (Low duty cycle pulse testing techniques are used which maintains junction and case temperatures equal
to the ambient temperature.)
Parameter
Symbol
Test Conditions Units
ADJ Pin Voltage VOIO = 0A, TA = 25ºC
Line Regulation ∆V
Load Regulation ∆VOL50mA ≤ IO ≤ 1A, V
Dropout Voltage ∆VI
+ 2V ≤ VIN ≤ 26V, I
OIVO
= 100mA
O
O
= V
= 5mA
O
ADJ
IO = 500mA
IO = 1A
Quiescent Current I
≤ 5mA, 7 ≤ VIN ≤ 26V
QIO
IO = 500mA
IO = 1000mA
Adjust Pin Current I
Current Limit I
Output Noise Voltage (Note 3) V
ADJVIN
O RMS
= 10V, IO = 1A
VIN = 26V
CL
10Hz - 100kHz, IO = 5mA
Long Term Stability (Note 3)
Ripple Rejection (Note 3) RRfO = 120Hz, 1V
, IO = 100mA
RMS
Enable Logic Section
On Threshold Voltage
On Threshold Current
Off Threshold Voltage
Off Threshold Current
Note 3. These parameters, although guaranteed, are not tested in production.
Recommended Operating Conditions
Min. Typ. Max.
3.8 26 V
5 1000 mA
0.1 µF
10 µF
LX8941
Min. Typ. Max.
1.225 1.25 1.275 V
150 mV
10 50 mV
150 300 m V
275 500 m V
400 800 m V
315 mA
30 50 mA
115 180 mA
220 µA
1 1.2 A
150 µV
20 mV/1000hr
66 dB
2V
50 µA
0.8 V
-10 µA
Units
RMS
OUT
Copyright © 1999
Rev. 0.6 4/99
PRELIMINARY DATA - Information contained in this document is pre-production data, and is proprietary to LinFinity. It may
not modified in any way without the express written consent of LinFinity. Product referred to herein is offered in sample form
only, and Linfinity reserves the right to change or discontinue this proposed product at any time.
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