SQ2143
CMOS Positive
Elektronische Bauelemente
RoHS Compliant Product
Voltage Regulator
Description
The
SQ2143 series of positive,linear regulators feature low quiescent
current (35µA typ.) with low dropout voltage, making them ideal
f
or battery applications. These rugged devices have both Thermal Shutdown,
and Current Fold-back to prevent device failure under the "Worst" of
operating conditions.
The SQ2143 is stable with an output capacitance of 2.2µF or greater.
Features
* High Accurate
±
1.5%
* Over-Temperature Shutdown
Millimeter
Min.
Max.
2.70
3.10
2.60
3.00
1.40
1.80
0.30
0.55
0
0.10
0°
10°
Dimensions
Millimeter
1.90 REF.
1.20 REF.
0.12 REF.
0.37 REF.
0.60 REF.
0.95 REF.
*
Adjustable Output Voltage
* Very Low Dropout Voltage
*
Low Temperature Coefficient
* Short Circuit Current Fold-back
* Guaranteed 300mA output
* Current Limiting
REF.
A
B
C
D
E
F
REF.
G
H
I
J
K
L
Applications
* PC Peripherals
* Wireless Devices
D
* Portable Electronics
* Battery Powered Widgets
* Electronic Scales
* Instrumentation
* Cordless Phones
Functional Block Diagram
Typical
Application
Circuit
SQ2143
http://www.SeCoSGmbH.com/
Any changing of specification will not be informed individual
01-Jun-2002 Rev. A
Page 1 of
8
SQ2143
Elektronische Bauelemente
CMOS Positive
Voltage Regulator
Absolute Maximum Ratings
Parameter
Input Voltage
Output Current
Input, Output Voltage
Operating Ambient Temperature
Junction Temperature
Max. Junction Temperature
Thermal Resistance
Power Dissipation (
EDS Classification
Topr
Tj
Tj
Max.
o
Symbol
V
IN
I
OUT
Ratings
8
P
D
/(V
IN
-V
O
)
GND-0.3 to V
IN
+0.3
-40~+85
-40~+125
150
260
380
B
Unit
V
mA
o
o
V
C
C
C
o
o
T=100
C)
o
θ
ja
P
D
C
/W
mW
Electrical Characteristics Ta=25
C
unless otherwise noted
Parameter
Output Voltage
Symbol
V
O
I
GND
Io
I
LIM
REG
LOAD
Min.
-1.5%
_
Typ.
_
Max.
1.5%
_
_
_
Unit
V
uA
mA
mA
Condition
V
IN
=5V,Io=1mA
Ground Pin Current
Output Current
Current Limit
Load Regulation
Dropout Voltage
35
_
V
IN
=5V,Io=1mA~300mA
V
IN
=5V,Io>1.2
V
IN
=5V,Io>1.2
V
IN
=5V,Io=1mA~300mA
1.5V<
V
ON(NOM)
≤
2.0V
Io=300mA
300
300
_
_
_
_
_
450
0.2
_
_
_
_
1
1300
400
300
0.15
0.1
7
_
_
_
%
mV
V
DROPOUT
2.0V
<
V
ON(NOM)
≤
2.8V
Vo=V
ON(NOM)
-2%
2.8V<V
ON(NOM)
<3.8V
Vo<2.0V
Vo
≥
2.0V
Line Regulation
REG
LINE
V
IN
O
TS
O
TH
T
C
I
SC
PSRR
_
0.02
1
%
V
o
o
Input Voltage
Over Temperature Shutdown
Over Temperature Hystersis
Output Voltage
Temperature Coefficient
Short Circuit Current
2
Power Supply Rejection
Note
_
_
_
_
_
_
_
_
Io=5mA
V
IN
=V
OUT
(T)+1
to V
OUT
(T)+2
150
30
30
150
60
50
20
30
_
_
_
_
C
C
V
IN
=5V,V
OUT
<0.8V
f=100Hz
f=1kHz
f=10kHz
Co=2.2uF
V
IN
=5V
Io=100mA
Co=2.2uF
f=10Hz~100kHz
Io=10mA
C
BYP
=0uF
ppm/
o
C
mA
dB
uVrms
V
uA
uA
V
% V
ON(NOM)
% V
ON(NOM)
uA
V
300
_
_
_
_
Output Voltage Noise
EN Input Threshold
EN Input Bias Current
Shutdown Supply Current
Shutdown Output Voltage
Output Under Voltage
Output Over Voltage
ADJ Input Bias Current
ADJ Reference Voltage
Note:
eN
V
EH
V
EL
I
EH
I
EL
I
SD
Vo,
SD
V
UV
V
OV
I
ADJ
V
REF
_
2
0
_
_
_
V
IN
0.4
0.1
0.5
1
0.1
85
_
_
V
IN
=2.7V to 7V
V
EN
=V
IN
,V
IN
=2.7V to 7V
V
EN
=0V,V
IN
=2.7V to 7V
V
IN
=5V,Vo=0V,V
EN
<V
EL
Io=35uA ,V
EN
<V
EL
0.5
_
_
_
0
_
115
_
1.0
1.215
1.2
1.23
1.V
IN(MON)
=V
OUT
+V
DROPOUT
2.To prevent the Short Current protection feature from being prematurely activated,
the input voltage must be applied before a current source loas is applied.
Any changing of specification will not be informed individual
http://www.SeCoSGmbH.com/
01-Jun-2002 Rev. A
Page
2
of
8
SQ2143
Elektronische Bauelemente
CMOS Positive
Voltage Regulator
Ordering Information(contd.)
Part Number
SQ2143-AD
Marking
3DAD2
XXXX
Output Voltage
Adjustable
Part Number
Marking
Output Voltage
Detailed Description
The SQ2143 of COMS regulators contain a PMOS pass transistor,voltage reference, error amplifier,over-current protection and
thermal shutdown and Power Good function. The P-channel pass transistor receives data from the error amplifier,over-current shutdown,
and thermal protection circuits. During normal operation, the error
amplifier compares the output voltage to a precision reference.
o
Over-current and Thermal shutdown
circuits become active when the junction temperature exceeds150 C, or the current exceeds 300mA.
During thermal shutdown, the output voltage remains low. Normal operation is restored when the junction temperature drops below 120
o
C.
The SQ2143 switches from voltage mode to current mode when the load exceeds the rated output current. This prevents over-stress.
The SQ2143 also incorporates current fold-back to reduce power dissipation when the output is short circuited.This feature becomes active
when the output drops below 0.8 volts, and reduces the current flow by 65%. Full current is restored when the voltage exceeds 0.8 volts.
External Capacitors
The SQ2143 is stable with an output capacitance to ground of 2.2uF or greater. Ceramic capacitors have the lowest ESR, and will offer
the best AC performance. Conversely, Aluminum Elertrolytic capacitors exhibit the highest ESR, resulting in the poorest AC response.
Unfortunately, large value ceramic capacitors are comparatively expensive. One option is to parallel a 0.1 uF ceramic capacitor with a
10 uF Aluminum Electrolytic. The benefit is low ESR, high capacitance, and low overall cost. A second capacitor is recommended
between the input and ground to stabilize Vin. The input capacitor should be at least 0.1uF to have a beneficial effect. All capacitors
should be placed in close proximity to the pins. A "Quiet" ground termination is desirable . The can be achieved with a "Star" connection.
Enable
The Enable pin normally floats high. When actively, pulled low, the PMOS pass transistor shuts off, and all internal circuits are powered
down. In this state, the quiescent current is less than 1uA. This pin behaves much like an electronic switch.
ht tp://www.SeCoSGmbH.com/
Any changing of specification will not be informed individual
01-Jun-2002 Rev. A
Page
3
of
8
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