LIN D O C #: 8941
LX8941
A D J U S TA B L E LO W D R O P O U T R E G U L AT O R
T
H E
I
N F I N I T E
P
O W E R
O F
I
P
N N O VA T I O N
R E L I M I N A R Y
DESCRIPTION
A T A
S
H E E T
K E Y F E AT U R E S
■ 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
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.
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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
supplies require a low input-output
D
NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.
PRODUCT HIGHLIGHT
D R O P O U T V O LTA G E V S . O U T P U T C U R R E N T
V S . T E M P E R AT U R E
5V
IN
LX8941
600
OUT
4V
500
125°C
ON
ADJ
22µF
OFF
Dropout Voltage - (mV)
10µF
400
25°C
300
200
-40°C
100
0
500
100
1000
O
Output Current - (mA)
PA C K A G E O R D E R I N F O R M A T I O N
T A (°C)
0 to 70
TO-220
P Plastic
5-pin
LX8941CP
TO-263
DD Plastic
5-pin
LX8941CDD
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LX8941CDDT)
Copyright © 1999
Rev. 0.6 4/99
LINFINITY MICROELECTRONICS INC.
11861 W ESTERN A VENUE, G ARDEN G ROVE, CA. 92841, 714-898-8121, F AX: 714-893-2570
1
PRODUCT DATABOOK 1996/1997
LX8941
A D J U S TA B L E LO W D R O P O U T R E G U L AT O R
P
R E L I M I N A R Y
A B S O LUT E M AXIM UM R ATINGS
D
A T A
S
H E E T
PACKAGE PIN OUTS
(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
TAB IS GND
ON/OFF
ADJ
GND
VO
VIN
5
1
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.
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P PACKAGE
(Top View)
THERMAL DATA
P PACKAGE:
TAB IS GND
THERMAL RESISTANCE-JUNCTION TO TAB, θJT
4.5°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA
60°C/W
DD PACKAGE:
THERMAL RESISTANCE-JUNCTION TO TAB, θJT
4.5°C/W
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA
60°C/W
5
ON/OFF
4
ADJ
3
GND
2
VO
1
VIN
DD PACKAGE
(Top View)
Junction Temperature Calculation: TJ = TA + (P D x θ JA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow.
BLOCK DIAGRAM
* Required if regulator is located far from power supply
filter.
INPUT VOLTAGE
1
O
VIN
C1*
0.1µF
THERMAL
SHUTDOWN
ON
2
ON/
OFF
5
4
ON/OFF
CIRCUIT
OFF
3
VO
ADJ
OUTPUT
VOLTAGE
C2
10µF
GND
LX8941
2
Copyright © 1999
Rev. 0.6 4/99
PRODUCT DATABOOK 1996/1997
LX8941
A D J U S TA B L E LO W D R O P O U T R E G U L AT O R
P
R E L I M I N A R Y
D
A T A
S
H E E T
R E C O M M E N D E D O P E R AT I N G C O N D I T I O N S
Parameter
Symbol
Input Voltage (Note 2)
Load Current (with adequate heatsinking)
Input Capacitor (VIN to GND)
Output Capacitor with ESR of 10Ω max., (VOUT to GND)
VIN
Recommended Operating Conditions
Min.
Typ.
Max.
3.8
5
0.1
10
26
1000
Units
V
mA
µF
µF
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Note 2. VIN (MIN) = VOUT + 1.2∆V (MAX). See Dropout Voltage maximum limit.
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 OUT
= 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
ADJ Pin Voltage
Line Regulation
Load Regulation
Dropout Voltage
VO
∆VOI
∆VOL
∆V
Quiescent Current
I ADJ
I CL
VO RMS
IO = 0A, TA = 25ºC
VO + 2V ≤ V IN ≤ 26V, IO = 5mA
50mA ≤ IO ≤ 1A, VO = VADJ
IO = 100mA
IO = 500mA
IO = 1A
IO ≤ 5mA, 7 ≤ VIN ≤ 26V
IO = 500mA
IO = 1000mA
VIN = 10V, IO = 1A
VIN = 26V
10Hz - 100kHz, IO = 5mA
RR
fO = 120Hz, 1VRMS, IO = 100mA
IQ
Adjust Pin Current
Current Limit
Output Noise Voltage (Note 3)
Long Term Stability (Note 3)
Ripple Rejection (Note 3)
Test Conditions
Min.
1.225
1
LX8941
Typ.
1.25
1
10
150
275
400
3
30
115
2
1.2
150
20
66
Max.
1.275
50
50
300
500
800
15
50
180
20
Units
V
mV
mV
mV
mV
mV
mA
mA
mA
µA
A
µVRMS
mV/1000hr
dB
Enable Logic Section
2
On Threshold Voltage
On Threshold Current
Off Threshold Voltage
Off Threshold Current
50
0.8
O
-10
V
µA
V
µA
Note 3. These parameters, although guaranteed, are not tested in production.
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.
Copyright © 1999
Rev. 0.6 4/99
3