MIC2950/2951
Micrel
MIC2950/2951
150mA Low-Dropout Voltage Regulator
General Description
The MIC2950 and MIC2951 are “bulletproof” micropower
voltage regulators with very low dropout voltage (typically
40mV at light loads and 250mV at 100mA), and very low
quiescent current. Like their predecessors, the LP2950 and
LP2951, the quiescent current of the MIC2950/MIC2951
increases only slightly in dropout, thus prolonging battery life.
The MIC2950/MIC2951 are pin for pin compatible with the
LP2950/LP2951, but offer lower dropout, lower quiescent
current, reverse battery, and automotive load dump protection.
The key additional features and protection offered include
higher output current (150mA), positive transient protection
for up to 60V (load dump), and the ability to survive an
unregulated input voltage transient of –20V below ground
(reverse battery).
The plastic DIP and SOIC versions offer additional system
functions such as programmable output voltage and logic
controlled shutdown. The 3-pin TO-92 MIC2950 is pin-
compatible with the older 5V regulators.
These system functions also include an error flag output that
warns of a low output voltage, which is often due to failing
batteries on the input. This may also be used as a power-on
reset. A logic-compatible shutdown input is also available
which enables the regulator to be switched on and off. This
part may also be pin-strapped for a 5 V output, or programmed
from 1.24 V to 29 V with the use of two external resistors.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
High accuracy 3.3, 4.85, or 5V, guaranteed 150mA output
Extremely low quiescent current
Low-dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Use as regulator or reference
Needs only 1.5µF for stability
Current and thermal limiting
Unregulated DC input can withstand –20V reverse battery
and +60V positive transients
Error flag warns of output dropout (MIC2951)
Logic-controlled electronic shutdown (MIC2951)
Output programmable from 1.24V to 29V (MIC2951)
Automotive Electronics
Battery Powered Equipment
Cellular Telephones
SMPS Post-Regulator
Voltage Reference
Avionics
High Efficiency Linear Power Supplies
Applications
3
Block Diagram
Unregulated
DC Supply
FB
IN
OUT
Error
Amp.
182k
SNS
TAP
330k
5V/150mA
Output
SHDN
TTL/CMOS
Control Logic
Input
60mV
60k
Error Detection
Comparator
ERR
1.5µF
GND
TTL/CMOS
Compatible
Error Output
1.23V
REF.
MIC2951-0x
February 1999
3-49
MIC2950/2951
The MIC2950 is available as either an -05 or -06 version. The
-05 and -06 versions are guaranteed for junction temperatures
from –40°C to +125°C; the -05 version has a tighter output and
reference voltage specification range over temperature. The
MIC2951 is available as an -02 or -03 version.
Micrel
The MIC2950 and MIC2951 have a tight initial tolerance
(0.5% typical), a very low output voltage temperature coefficient
which allows use as a low-power voltage reference, and
extremely good load and line regulation (0.04% typical). This
greatly reduces the error in the overall circuit, and is the result
of careful design techniques and process control.
Ordering Information
Part Number
MIC2950-05BZ
MIC2950-06BZ
MIC2951-02BM
MIC2951-03BM
MIC2951-02BN
MIC2951-03BN
MIC2951-03BMM
MIC2951-3.3BM
MIC2951-4.8BM
* junction temperature
Voltage
5.0V
5.0V
5.0V
5.0V
5.0V
5.0V
5.0V
3.3V
4.85V
Accuracy Temperature Range*
0.5%
1.0%
0.5%
1.0%
0.5%
1.0%
1.0%
1.0%
1.0%
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
TO-92
TO-92
8-pin SOIC
8-pin SOIC
8-pin plastic DIP
8-pin plastic DIP
8-lead MM8™
8-pin SOIC
8-pin SOIC
Pin Configuration
MIC2951-xx
OUT 1
MIC2950-xx
3
2
1
8
7
6
5
IN
FB
TAP
ERR
SNS 2
SHDN 3
IN
OUT
GND
GND 4
TO-92 (Z)
(Bottom View)
DIP (N), SOIC (M), MM8™ (MM)
(Top View)
Pin Description
Pin #
MIC2950
3
Pin #
MIC2951
1
2
3
2
4
5
6
7
1
8
Pin Name
OUT
SNS
SHDN
GND
ERR
TAP
FB
IN
Pin Function
Regulated Output
Sense (Input): Output-voltage sensing end of internal voltage divider for
fixed 5V operation. Not used in adjustable configuration.
Shutdown/Enable (Input): TTL compatible input. High = shutdown,
low or open = enable.
Ground
Error Flag (Output): Active low, open-collector output (low = error,
floating = normal).
3.3V/4.85/5V Tap: Output of internal voltage divider when the regulator is
configured for fixed operation. Not used in adjustable configuration.
Feedback (Input): 1.235V feedback from internal voltage divider’s TAP (for
fixed operation) or external resistor network (adjustable configuration).
Unregulated Supply Input
3-50
February 1999
MIC2950/2951
Micrel
Absolute Maximum Ratings
(Note 1)
Input Suppy Voltage (V
IN
)
Note 5
................. –20V to +60V
Feedback Input Voltage (V
FB
)
Note 6, 7
...... –1.5V to +26V
Shutdown Input Voltage (V
SHDN
)
Note 6
..... –0.3V to +30V
Power Dissipation (P
D
)
Note 4
................ Internally Limited
Storage Temperature .............................. –65°C to + 150°C
Lead Temperature (soldering, 5 sec.) ....................... 260°C
ESD,
Note 3
Operating Ratings
(Note 2)
Input Supply Voltage (V
IN
) ........................... +2.0V to +30V
Junction Temperature (T
J
) .......................................
Note 4
MIC2950-05/MIC2950-06 ..................... –40°C to +125°C
MIC2951-02/MIC2950-03 ..................... –40°C to +125°C
Electrical Characteristics
V
IN
= 6V; I
L
= 100µA; C
L
= 1µF; T
J
= 25°C,
bold
values indicate –40°C
≤
T
J
≤
+125°C;
Note 8;
unless noted.
Parameter
Output Voltage
Condition
MIC295x-02/-05 (±0.5%), T
J
= 25°C
MIC295x-03/-06 (±1%), T
J
= 25°C
MIC2951-3.3 (±1%), T
J
= 25°C
MIC2951-4.8 (±1%), T
J
= 25°C
Output Voltage
MIC295x-02/-05 (±0.5%), –25°C
≤
T
J
≤
+85°C
MIC295x-03/-06 (±1%), –25°C
≤
T
J
≤
+85°C
MIC2951-3.3 (±1%), –25°C
≤
T
J
≤
+85°C
MIC2951-4.8 (±1%), –25°C
≤
T
J
≤
+85°C
Output Voltage
Over Full Temperature Range
MIC295x-02/-05 (±0.5%), –40°C to +125°C
MIC295x-03/-06 (±1%), –40°C to +125°C
MIC2951-3.3 (±1%), –40°C to +125°C
MIC2951-4.8 (±1%), –40°C to +125°C
Output Voltage
Over Load Variation
MIC295x-02/-05 (±0.5%), 100µA
≤
I
L
≤
150mA, T
J
≤
T
J(max)
MIC295x-03/-06 (±1%), 100µA
≤
I
L
≤
150mA, T
J
≤
T
J(max)
MIC2951-3.3 (±1%), 100µA
≤
I
L
≤
150mA, T
J
≤
T
J(max)
MIC2951-4.8 (±1%), 100µA
≤
I
L
≤
150mA, T
J
≤
T
J(max)
Output Voltage
Temperature Coefficient
MIC295x-02/-05 (±0.5%),
Note 9
MIC295x-03/-06 (±1%),
Note 9
MIC2951-3.3 (±1%),
Note 9
MIC2951-4.8 (±1%),
Note 9
Line Regulation
MIC295x-02/-05 (±0.5%),
Note 10, 11
MIC295x-03/-06 (±1%),
Note 10, 11
MIC2951-3.3 (±1%),
Note 10, 11
MIC2951-4.8 (±1%),
Note 10, 11
Min
4.975
4.950
3.267
4.802
4.950
4.925
3.251
4.777
4.940
4.900
3.234
4.753
4.930
4.880
3.221
4.733
20
50
50
50
0.03
0.04
0.04
0.04
Typ
5.000
5.000
3.300
4.850
Max
5.025
5.050
3.333
4.899
5.050
5.075
3.350
4.872
5.060
5.100
3.366
4.947
5.070
5.120
3.379
4.967
100
150
150
150
0.10
0.20
0.20
0.40
0.20
0.40
0.20
0.40
Units
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
ppm/°C
ppm/°C
ppm/°C
ppm/°C
%
%
%
%
%
%
%
%
3
February 1999
3-51
MIC2950/2951
Parameter
Load Regulation
Condition
MIC295x-02/-05 (±0.5%), 100µA
≤
I
L
≤
150mA,
Note 10
MIC295x-03/-06 (±1%), 100µA
≤
I
L
≤
150mA,
Note 10
MIC2951-3.3 (±1%), 100µA
≤
I
L
≤
150mA,
Note 10
MIC2951-4.8 (±1%), 100µA
≤
I
L
≤
150mA,
Note 10
Dropout Voltage
MIC295x-02/-03/-05/-06, I
L
= 100µA,
Note 12
MIC295x-02/-03/-05/-06, I
L
= 100mA,
Note 12
MIC295x-02/-03/-05/-06, I
L
= 150mA,
Note 12
MIC2951-3.3 (±1%), I
L
= 100µA,
Note 12
MIC2951-3.3 (±1%), I
L
= 100mA,
Note 12
MIC2951-3.3 (±1%), I
L
= 150mA,
Note 12
MIC2951-4.8 (±1%), I
L
= 100µA,
Note 12
MIC2951-4.8 (±1%), I
L
= 100mA,
Note 12
MIC2951-4.8 (±1%), I
L
= 150mA,
Note 12
Ground Current
MIC295x-02/-03/-05/-06, I
L
= 100µA
MIC295x-02/-03/-05/-06, I
L
= 100mA
MIC295x-02/-03/-05/-06, I
L
= 150mA
MIC2951-3.3 (±1%), I
L
= 100µA
MIC2951-3.3 (±1%), I
L
= 100mA
MIC2951-3.3 (±1%), I
L
= 150mA
MIC2951-4.8 (±1%), I
L
= 100µA
MIC2951-4.8 (±1%), I
L
= 100mA
MIC2951-4.8 (±1%), I
L
= 150mA
Dropout Ground Current
MIC295x-02/-03/-05/-06 (±0.5%), V
IN
= 4.5V, I
L
= 100µA
MIC2951-3.3 (±1%), V
IN
= 3.0V, I
L
= 100µA
MIC2951-4.8 (±1%), V
IN
= 4.3V, I
L
= 100µA
Min
Typ
0.04
0.10
0.10
0.10
40
250
300
40
250
320
40
250
300
120
1.7
4
100
1.7
4
120
1.7
4
280
150
280
Max
0.10
0.20
0.20
0.30
0.20
0.30
0.20
0.30
80
140
300
450
600
80
150
350
450
600
80
140
300
450
600
180
300
2.5
3.5
6
8
180
300
2.5
6
10
180
300
2.5
3.5
6
8
350
400
350
400
350
400
Micrel
Units
%
%
%
%
%
%
%
%
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
mV
µA
µA
mA
mA
mA
mA
µA
µA
mA
mA
mA
µA
µA
mA
mA
mA
mA
µA
µA
µA
µA
µA
µA
3-52
February 1999
MIC2950/2951
Parameter
Current Limit
Thermal Regulation
Output Noise
Condition
V
OUT
= 0V
Note 13
10Hz to 100kHz, C
L
= 1.5µF
10Hz to 100kHz, C
L
= 200µF
10Hz to 100kHz, C
L
= 3.3µF,
0.01µF bypass Feedback to Output
Reference Voltage
MIC295x-02/-05 (±0.5%)
MIC295x-03/-06 (±1%)
MIC2951-3.3 (±1%)
MIC2951-4.8 (±1%)
Reference Voltage
MIC295x-02/-05 (±0.5%),
Note 14
MIC295x-03/-06 (±1%),
Note 14
MIC2951-3.3 (±1%),
Note 14
MIC2951-4.8 (±1%),
Note 14
Feedback Bias Current
Reference Voltage
Temperature Coefficient
MIC295x-02/-05 (±0.5%),
Note 9
MIC295x-03/-06 (±1%),
Note 9
MIC2951-3.3 (±1%),
Note 9
MIC2951-4.8 (±1%),
Note 9
Feedback Bias Current
Temperature Coefficient
Error Comparator (Flag)
Output Leakage Current
Error Comparator (Flag)
Output Low Voltage
Error Comparator
Upper Threshold Voltage
Error Comparator
Lower Threshold Voltage
Error Comparator Hysteresis
V
OH
= 30V
V
IN
= 4.5V, I
OL
= 200µA
Note 15
Note 15
Note 15
40
25
1.220
1.200
1.210
1.200
1.210
1.200
1.210
1.200
1.190
1.185
1.185
1.185
20
20
50
50
50
0.1
0.01
150
60
75
15
95
140
1.00
2.00
250
400
Min
Typ
300
0.05
430
160
100
1.235
1.235
1.235
1.235
1.250
1.260
1.260
1.270
1.260
1.270
1.260
1.270
1.270
1.285
1.285
1.285
40
60
Max
400
450
0.20
Micrel
Units
mA
mA
%/W
µV
RMS
µV
RMS
µV
RMS
V
V
V
V
V
V
V
V
V
V
V
V
nA
nA
ppm/°C
ppm/°C
ppm/°C
ppm/°C
nA/°C
µA
µA
mV
mV
mV
mV
mV
mV
mV
3
February 1999
3-53
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