Exar LP2950CN-3-3/TR 100ma, low dropout voltage regulator Datasheet

LP2950/LP2951
100mA, LOW DROPOUT VOLTAGE REGULATORS
OCTOBER 6, 2008
REV. G


•       
•    
•      
•      
•    
•    
•    µ  
•   Lead Free, RoHS Compliant Packages:
    
•    
•  
• 
•  
•  
•  
• 
•
• 
• 
• 
  
•      
•   
•      
Now Available in Lead Free Packaging
 
                  
                
                     
                  
        
                         
                    
              
   
UNREGULATED DC
8
INPUT
OUTPUT
7
+
FEEDBACK
5V @ 00mA
MAX
2
SENSE
+
_
FROM
CMOS OR
TTL
80kΩ
ERROR
AMPLIFIER
0kΩ
5V TAP
SHUTDOWN
+
0kΩ
0 mV
+
_
+ .2V
5
______
+
ERROR DETECTION
COMPARATOR
ERROR
µF
.
.
TO CMOS OR
TTL
REFERENCE
Rev G
LP2950-51 Low Dropout Linear Regulator
GROUND
© 2008 Exar Corporation

  
  
    
      
   
  
     
     
     
      
   
          



  
 
 
  
 
 
  
 ≤ ≤
  
 µ ≤ ≤ 
 ≤
  
 ≤ ≤
  
 µ ≤ ≤ 
 ≤


 



 





















































  
 
 
   





 
 ≤ ≤  





   
 µ ≤ ≤ 





 
 
   µ
   
   µ
   


















µ











 
 
 
 
 
  µ


µ 
  
   µ


µ 
   µ   
      


µ 
  
 
 
  

Rev G
   


 














LP2950-5 Low Dropout Linear Regulators

© 2008 Exar Corporation
LP2950/51
PARAMETER
CONDITIONS
(Note 2)
LP2951AC
Min. Typ.
Max.
8-Pin Versions only (Continued)
Reference Voltage
Temperature
Coefficient
Feedback Pin Bias
Current
Temperature
Coefficient
Error Comparator
Min.
LP2951C
Typ. Max.
UNITS
20
50
ppm/°C
0.1
0.1
nA/°C
Output Leakage
Current
Output Low Voltage
VOH = 30V
0.01
1
0.01
1
μA
VIN= 4.5V
IOL= 400 μA
150
250
150
250
mV
Upper Threshold
Voltage
Lower Threshold
Voltage
Hysteresis
(Note 7)
40
60
(Note 7)
75
(Note 7)
15
40
95
60
75
mV
95
15
mV
mV
Shutdown Input
Input logic Voltage
Shut down Pin Input
Current
Regulator Output
Current in Shutdown
Thermal
Resistance θJA
Low (Regulator ON)
High (Regulator OFF)
VS= 2.4V
VS= 30V
(Note 8)
8 Pin SOIC
3 Pin TO-92
2.0
1.3
0.7
30
675
3
50
800
10
2.0
1.3
0.7
30
675
3
50
800
10
V
V
μA
μA
μA
128. 4
°C/W
131.9
°C/W
Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.
Note 2: Unless otherwise specified all limits guaranteed for T J = 25°C, VIN= 6V, I L= 100 μA and CL = 1μF. Additional conditions for the 8-pin versions are feedback
tied to 5V tap and output tied to output sense (VOUT= 5V) and V SHUTDOWN ≤0.8V.
Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes i n output voltage due to heating effects are
covered under the specification for thermal regulation.
Note 4: Line regulation for the LP2951 is tested at IL= 1mA. For I L= 100 μA and TJ = 125°C, line regulation is guaranteed by design to 0.2%. See typical
performance characteristics for line regulation versus temperature and load current.
Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below its nominal value measured at 1V differential. At
very low values of programmed output voltage, the minimum input supply voltage of 2V (2.3V over temperature) must be taken into account.
Note 6: V REF ≤V OUT ≤(V IN- 1V), 2.3 ≤VIN≤30V, 100μA≤IL≤100mA, T J ≤T JMAX.
Note 7: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nomi nal reference voltage measured at 6V input. To
express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V OUT/VREF= (R 1+ R 2)/R2. For example, at a programmed output
voltage of 5V, the error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant as a percent of V OUTas V OUT
is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed.
Note 8: VSHUTDOWN ≥2V, V IN ≤30V, V OUT=0, Feedback pin tied to 5V Tap.
Note 9: All typical values are not guaranteed. The value could vary from lot to lot.
Rev G
LP2950-5 Low Dropout Linear Regulators
3
© 2008 Exar Corporation
 
  
10
250
6
225
R L=
3
R L =50kΩ
2
R L = 50k Ω
175
GROUND PIN CURRENT (mA)
4
150
125
100
RL =
8
INPUT CURRENT (µA)
200
8
OUTPUT VOLTAGE (VOLTS)
5
75
50
1
1
0.1
25
0
0
2
3
4
5
1
0
6
2
320
240
INPUT CURRENT (mA)
GROUND CURRENT (µA)
280
I L = 1mA
200
160
IL= 0
120
80
40
1
2
3
5
6 7
8
4
5
0.01
0.1
9 10
6
7
8
100
16
R L =50 Ω
VOUT = 5V
12
V IN = 6V
I L = 100mA
8
4
0
1
2
3
4
5
6
7
8
-75 -50 -25
9 10
0
25 50 75 100 125 150
TEMPERATURE (ºC)
INPUT VOLTAGE (VOLTS)
Ground Current
10
Quiescent Current
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
INPUT VOLTAGE (VOLTS)
1
LOAD CURRENT (mA)
Input Current
Dropout Characteristics
0
4
INPUT VOLTAGE (VOLTS)
INPUT VOLTAGE (VOLTS)
0
3
GROUND CURRENT (mA)
1
0
Ground Current
Input Current
190
16
12
10
QUIESCENT CURRENT (µA)
GROUND CURRENT (mA)
14
I L =100mA
8
6
4
170
V IN =6V
I L =100uA
150
130
2
0
0
1
2
3
4
5
6
7
-75 -50 -25
8
Ground Current
Rev G
0
25 50 75 100 125 150
TEMPERATURE (ºC)
INPUT VOLTAGE
Quiescent Current
LP2950-5 Low Dropout Linear Regulators
4
© 2008 Exar Corporation

   
170
500
600
I L = 100mA
160
400
300
~
~
100
50
I L = 100 µA
SHORT CIRCUIT CURRENT (mA)
400
DROP-OUT VOLTAGE (mV)
300
200
TJ = 25ºC
100
0
0
-75 -50 -25
0
100µA
25 50 75 100 125 150
1mA
TEMPERATURE (ºC)
10mA
140
130
120
110
110
-75 -50 -25
100mA
OUTPUT CURRENT
8
2.5
100
mV
T A = 125ºC
50
mV
SINK CURRENT (mA)
2.0
4
HYSTERESIS
2
0
1.5
T A = 25ºC
1.0
T A = -55ºC
0.5
0.0
0
1
2
3
4
5
0
8V
4V
0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
INPUT VOLTAGE (V)
C L = 1 µF
I L = 1mA
V OUT = 5V
-50
mV ~
~
6V
PULLUP RESISTOR TO
SEPARATE 5V SUPPLY
-2
200
OUTPUT LOW VOLTAGE (V)
10
400
600
800
TIME(µs)
LP2951 Comparator Sink Current
Error Comparator Output
25 50 75 100 125 150
Short Circuit Current
V OUT = 5V
6
0
TEMPERATURE (ºC)
Drop-Out Voltage
Drop-Out Voltage
COMPARATOR OUTPUT (V)
150
INPUT OUTPUT VOLTAGE
VOLTAGE CHANGE
DROP-OUT VOLTAGE (mV)
500
Line Transient Response
90
90
80
80
70
70
I O = 1mA
I O = 100mA
1
0.5
V OUT = 5V
C L = 1 µF
0.2
0.1
0.05
50
40
I L = 100 µA
C L = 1 µF
V IN = 6V
V OUT = 5V
10
100
1K
10K
FREQUENCY (Hz)
Output Impedance
100K
1M
C L = 1µF
V IN = 6V
V OUT = 5V
I L = 1mA
60
50
40
30
20
0.01
Rev G
IL= 0
60
30
0.02
RIPPLE REJECTION (dB)
5
2
RIPPLE REJECTION (dB)
OUTPUT IMPEDANCE (OHMS)
IO = 100 µA
I L = 10mA
20
10 1
10 2
10 3
10 4
10 5
10 6
FREQUENCY (Hz)
10 1
10 2
10 3
10 4
10 5
10 6
FREQUENCY (Hz)
Ripple Rejection
Ripple Rejection
LP2950-5 Low Dropout Linear Regulators
© 2008 Exar Corporation

   
1.9
FEEDBACK CURRENT (µA)
2.1
0
-10
-20
40
100
20
-100
~~
100
mA
0
-60
~
~
100
100
µA
µA
0
1
2
3
4
5
4
8
12
16
120
100
OUTPUT CURRENT (mA)
100
T A = 85 ºC
15
20
INPUT VOLTAGE (V)
LP2950 Maxium Rated Output
25
DIP SOLDERED
TO PC BOARD
T JMAX = 125º C
V OUT = 5V
30
80
60
T A = 25ºC
40
T A = 50ºC
20
0
0
10
0
Enable Transient
200
T A =25 ºC
5
2
TIME (us)
PIN 2 TO PIN 4 RESISTANCE (kΩ)
40
I L = 10mA
V IN = 8V
V OUT = 5V
C L= 10 µF
0
300
Vout=5V
0
1
8-PIN
MOLDED
T JMAX = 125 ºC
20
2
-100 0 100 200 300 400 500 600 700
400
TO-92 PACKAGE
0.25" LEADS SOLDERED
TO PC BOARD
60
3
20
Load Transient Response
120
80
5
4
TIME (ms)
Load Transient Response
100
C L= 1 µF
-2
0
TIME (ms)
OUTPUT CURRENT (mA)
C L = 10 µF
V OUT = 5V
µA
100
Rev G
SHUTDOWN OUTPUT
PINOUT VOLTAGE (V) VOLTAGE (V)
6
150
LOAD OUTPUT VOLTAGE
CURRENT CHANGE (mV)
LOAD OUTPUT VOLTAGE
CURRENT CHANGE (mV)
7
-40
1.0
LP2951 Feedback Pin Current
80
C L = 1 µF
V OUT = 5V
0.5
FEEDBACK VOLTAGE (V)
60
-20
0
-1.5 -1.0 -0.5
-2.0
250
-50
T A = 55ºC
-200
200
0
T A = 25ºC
-150
TEMPEATURE (ºC)
LP2951 Feedback Bias Current
50
TA=1 25ºC
-100
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE
LP2951 Minimum Operating Voltage
-50
-250
-30
1.7
-75 -50 -25 0 25 50 75 100 125 150
PIN 7 DRIVEN BY EXTERNAL
SOURCE (REGULATOR RUN
OPEN LOOP)
0
10
BIAS CURRENT (nA)
MINIMUM OPERATING VOLTAGE (V)
50
20
2.3
T A = 85ºC
0
-75 -50 -25 0
25 50 75 100 125 150
0
TEMPERATURE (ºC)
LP2951 Divider Resistance
10
15
20
25
30
INPUT VOLTAGE (V)
LP2950 Maxium Rated Output Current
LP2950-5 Low Dropout Linear Regulators
6
5
© 2008 Exar Corporation



















    µ

   µ
   µ





 
 µ
 
 
    
 
 
 


    µ



    µ

    


  
   
    µ


 
  
   



         
 
  µ

 
 


 
   
 
   





    µ
    

   


    µ
   
   











 
 
  
 
Rev G
 
 
 
 
 
 
LP2950-5 Low Dropout Linear Regulators
7
© 2008 Exar Corporation

 
 
       µ  
        
         
     °    
          
°     Ω     
          
        
        
   
          
           
    µ   µ     
          
             µ 
           

          
         
           
             µ 
           
    Ω         

        
           
        
          
         µ 

     
           
                
           
             
            
    
           
            
           
        
          
            
        
              
             µ 
          
 
   ×    
           
       µ    
 Ω              
           
             
           
µ      µ      
       
          
         
           
          
           
µ

  
              
            
              
          
µ   µ      µ  µ 
           
           
    









 ≅   π × 

  µ        
  µ       
   µ  µ    
          
          
 
   
    
   
         
            
           
Rev G
LP2950-5 Low Dropout Linear Regulators
© 2008 Exar Corporation

 
+V IN
100K
8
+V IN
5 ______
ERROR
ERROR
OUTPUT
V OUT
1.24 to 2 9V
1
LP2951
SHUTDOWN
3
INPUT
+
R1
SD
GND
4
3.3µF
.01µF
FB
7
1.23V
R2
V REF
   
+V IN
470kΩ
+V IN
8
5 ______
470kΩ
ERROR
+V IN
V OUT
V OUT
1
8
3
RESET
SD
4
ERROR
OUTPUT
R1
GND
5 ______
ERROR
LP2951
+V IN
V OUT
+
LP2951
1µF
FB
SHUTDOWN
7
INPUT
3
SD
GND
4
R2
FB
7
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40mV to 400mV.
DEPENDING ON LOAD CURRENT. CURRENT LIMIT IS TYPICALLY 150mA
       
Rev G
*V OUT = V IN
1
       
LP2950-5 Low Dropout Linear Regulators
© 2008 Exar Corporation

  
+
6V
SEALED
LEADACID
BATTERY
SOURCE
1.5kΩ
120kΩ
8
1N457
FB
+V IN
SPX385
V OUT
1
MAIN V+
LP2951
SENSE
400kΩ
FOR 5.5 V
3
MEMORY V+
2
+
1µF
SD
100kΩ
GND
20kΩ
NI-CAD
BACKUP
BATTERY
4
    

Ω 



 







  





Ω 







Ω 
Ω 








Ω 

Ω 

Ω 




Ω 






 Ω 
            
 
          
 Ω 
      
Rev G
LP2950-5 Low Dropout Linear Regulators
1
© 2008 Exar Corporation

  
+V IN
8
AUX SHUTDOW
INPUT
0K Ω.
+V IN
_______ 5
ERROR
SD
OFF
.
LP295
ON
V OUT
GND
FB
+
TEMP
SENSOR
5 DEGREE SHUTDOWN FLAG
EXTERNAL CIRCUIT
PROTECTED FROM
OVER TEMPERATURE
(V+ GOES OFF WHEN
TEMP > 25)
7
AS5
OR
RELAY
8.2K Ω
-
     
+5V
UNREGULATED INPUT
.7mA
20mA
8
OUTPUT
8
IN
+V IN
V OUT
0KΩ
27KΩ
LP295
N00
LP295
0.µF
FB
7
5V
2
SENSE
V TAP
2
GND
2N52
(2)
V OUT
FB
GND
7
OUTPUT
+
0K Ω
N57
.7µF
LOAD
50mA
TO
00 mA
MIN VOLTAGE = V
         

042408 Rev F
     
LP2950-51 Low Dropout Linear Regulator
11
© 2008 Exar Corporation
PaCKaGE: 3 PIN TO-92
Rev G
LP2950-5 Low Dropout Linear Regulators
1
© 2008 Exar Corporation
PaCKaGE: 3 PIN TO-92 AMMO PACK
Rev G
LP2950-5 Low Dropout Linear Regulators
1
© 2008 Exar Corporation
PaCKaGE: 8 PIN NSOIC
Rev G
LP2950-5 Low Dropout Linear Regulators
13
© 2008 Exar Corporation
ORDERING INFORMATION
Part Number
Accuracy
Output
Package Shipping Status
Voltage
LP2950ACN-L-3-3
0.50%
3.3V
Lead Free
3 Pin TO-92
LP2950ACN-L-3-3/TR
0.50%
3.3V
Lead Free
Tape & Reel
3 Pin TO-92
Active
LP2950ACN-L-5-0
0.50%
5.0V
Lead Free
3 Pin TO-92
Active
LP2950ACN-L-5-0/TR
0.50%
5.0V
Lead Free
Tape & Reel
3 Pin TO-92
Active
LP2950CN-L-3-3
1%
3.3V
Lead Free
3 Pin TO-92
Active
LP2950CN-L-3-3/TR
1%
3.3V
Lead Free
Tape & Reel
3 Pin TO-92
Active
LP2950CN-L-5-0
1%
5.0V
Lead Free
3 Pin TO-92
Active
LP2950CN-L-5-0/TR
1%
5.0V
Lead Free
Tape & Reel
3 Pin TO-92
Active
LP2951ACS-L-3-3
0.50%
3.3V
Lead Free
8 Pin SOIC
Active
LP2951ACS-L-3-3/TR
0.50%
3.3V
Lead Free
Tape & Reel
8 Pin SOIC
Active
LP2951ACS-L-5-0
0.50%
5.0V/ADJ
Lead Free
8 Pin SOIC
Active
LP2951ACS-L-5-0/TR
0.50%
5.0V/ADJ
Lead Free
Tape & Reel
8 Pin SOIC
Active
LP2951CS-L-3-3
1%
3.3V
Lead Free
8 Pin SOIC
Active
LP2951CS-L-3-3/TR
1%
3.3V
Lead Free
Tape & Reel
8 Pin SOIC
Active
LP2951CS-L-5-0
1%
5.0V/ADJ
Lead Free
8 Pin SOIC
Active
LP2951CS-L-5-0/TR
1%
5.0V/ADJ
Lead Free
Tape & Reel
8 Pin SOIC
Rev G
LP2950-5 Low Dropout Linear Regulators
14
Bulk
Active
Bulk
Bulk
Bulk
Bulk
Bulk
Bulk
Bulk
Active
© 2008 Exar Corporation
ORDERING INFORMATION
(continued)
Part Number
Accuracy
Output
Package Shipping Status
Voltage
LP2950ACN-3-3
0.50%
3.3V
3 Pin TO-92
Bulk
EOL
LP2950ACN-5-0
0.50%
5.0V
3 Pin TO-92
Bulk
EOL
LP2950CN-3-3
1%
3.3V
3 Pin TO-92
Bulk
EOL
LP2950CN-3-3/TR
1%
3.3V
3 Pin TO-92 Tape & Reel
EOL
LP2950CN-5-0
1%
5.0V
3 Pin TO-92
EOL
LP2950CN-5-0/TR
1%
5.0V
3 Pin TO-92 Tape & Reel
EOL
LP2951ACS-3-3
0.50%
3.3V
8 Pin SOIC
Bulk
EOL
LP2951ACS-5-0
0.50%
5.0V/ADJ 8 Pin SOIC
Bulk
EOL
Bulk
EOL
Bulk
LP2951CS-3-3
1%
3.3V
8 Pin SOIC
LP2951CS-3-3/TR
1%
3.3V
8 Pin SOIC Tape & Reel
LP2951CS-5-0
1%
5.0V/ADJ 8 Pin SOIC
LP2951CS-5-0/TR
1%
5.0V/ADJ 8 Pin SOIC Tape & Reel
Bulk
EOL
EOL
EOL
LP2950ACN-3-3/TR
0.50%
3.3V
3 Pin TO-92 Tape & Reel
OBS
LP2950ACN-5-0/TR
0.50%
5.0V
3 Pin TO-92 Tape & Reel
OBS
LP2951ACS-3-3/TR
0.50%
3.3V
8 Pin SOIC Tape & Reel
OBS
LP2951ACS-5-0/TR
0.50%
5.0V/ADJ 8 Pin SOIC Tape & Reel
OBS
Exar Corporation
Headquarters and
Sales Office
48720 Kato Road
Fremont, CA 94538
main: 510-668-7000
fax: 510-668-7030
EXAR Corporation reserves the right to make changes to the products contained in this publication in order
to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any
circuits described herein, conveys no license under any patent or other right, and makes no representation
that the circuits are free of patent infringement. Charts and schedules contained here in are only for
illustration purposes and may vary depending upon a user’s specific application. While the information in this
publication has been carefully checked; no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the
failure or malfunction of the product can reasonably be expected to cause failure of the life support system or
to significantly affect its safety or effectiveness. Products are not authorized for use in such applications
unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or
damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation
is adequately protected under the circumstances.
Rev G
LP2950-5 Low Dropout Linear Regulators
1
© 2008 Exar Corporation