MIC2920A/29201/29202/29204
Micrel
January 1998
3-9
3
1
2
3
MIC2920A/29201/29202/29204
400mA Low-Dropout Voltage Regulator
Features
High output voltage accuracy
Guaranteed 400mA output
Low quiescent current
Low dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Current and thermal limiting
Input withstands 20V reverse battery and
60V positive transients
Error flag warns of output dropout
Logic-controlled electronic shutdown
Output programmable from 1.24V to 26V
(MIC29202/MIC29204)
Available in TO-220, TO-220-5, and surface-mount
TO-263-5, SOT-223, and SO-8 packages.
Applications
Battery-powered equipment
Cellular telephones
Laptop, notebook, and palmtop computers
PCMCIA V
CC
and V
PP
regulation/switching
Bar code scanners
Automotive electronics
SMPS post-regulators
Voltage reference
High-efficiency linear power supplies
General Description
The MIC2920A family are "bulletproof," efficient voltage
regulators with very low dropout voltage (typically 40mV at
light loads and 370mV at 250mA), and very low quiescent
current (140
A typical). The quiescent current of the MIC2920A
increases only slightly in dropout, prolonging battery life. Key
MIC2920A features include protection against reversed battery,
fold-back current limiting, and automotive "load dump"
protection (60V positive transient).
The MIC2920 is available in several configurations. The
MIC2920A-x.x devices are three pin fixed voltage regulators
available in 3.3V, 4.85V, 5V, and 12V outputs. The MIC29201
is a fixed regulator offering a logic compatible ON/OFF
(shutdown) input and an error flag output. This flag may also
be used as a power-on reset signal. A logic-compatible
shutdown input is provided on the adjustable MIC29202
which allows the regulator to be switched on and off. The
MIC29204 8-pin SOIC adjustable regulator includes both
shutdown and error flag pins and may be pin-strapped for 5V
output or programmed from 1.24V to 26V using two external
resistors.
MIC2920A-xxBT
(TO-220)
MIC29201/29202BT
(TO-220-5)
1 2 3 4 5
MIC29201/29202BU
(TO-263-5)
5-Lead Package Pinouts
MIC29201
MIC29202
1)
Error
Adjust
2)
Input
Shutdown
3)
Ground
Ground
4)
Output
Input
5)
Shutdown
Output
Tab is Ground on SOT-223, TO-220, and TO-263 packages.
1
3
2
TAB
INPUT
OUTPUT
GROUND
MIC2920A-x.xBS
(SOT-223)
Pin Configuration
1 2 3 4 5
INPUT
OUTPUT
GROUND
1
2
3
4
8
7
6
5
INPUT
NC
NC
ERROR
OUTPUT
SENSE
SHUTDOWN
GROUND
MIC29201-3.3BM (SO-8)
1
2
3
4
8
7
6
5
INPUT
ADJUST
5V TAP
ERROR
OUTPUT
SENSE
SHUTDOWN
GROUND
MIC29204BM (SO-8)
MIC2920A/29201/29202/29204
Micrel
3-10
January 1998
Ordering Information
Part Number
Voltage
Temperature Range*
Package
MIC2920A-3.3BS
3.3V
40
C to +125
C
SOT-223
MIC2920A-3.3BT
3.3V
40
C to +125
C
TO-220
MIC2920A-4.8BS
4.85V
40
C to +125
C
SOT-223
MIC2920A-4.8BT
4.85V
40
C to +125
C
TO-220
MIC2920A-5.0BS
5.0V
40
C to +125
C
SOT-223
MIC2920A-5.0BT
5.0V
40
C to +125
C
TO-220
MIC2920A-12BS
12V
40
C to +125
C
SOT-223
MIC2920A-12BT
12V
40
C to +125
C
TO-220
MIC29201-3.3BM
3.3V
40
C to +125
C
SO-8
MIC29201-3.3BT
3.3V
40
C to +125
C
TO-220-5
MIC29201-3.3BU
3.3V
40
C to +125
C
TO-263-5
MIC29201-4.8BT
4.85V
40
C to +125
C
TO-220-5
MIC29201-4.8BU
4.85V
40
C to +125
C
TO-263-5
MIC29201-5.0BT
5.0V
40
C to +125
C
TO-220-5
MIC29201-5.0BU
5.0V
40
C to +125
C
TO-263-5
MIC29201-12BT
12V
40
C to +125
C
TO-220-5
MIC29201-12BU
12V
40
C to +125
C
TO-263-5
MIC29202BT
Adj
40
C to +125
C
TO-220-5
MIC29202BU
Adj
40
C to +125
C
TO-263-5
MIC29204BM
5V and Adj
40
C to +125
C
SO-8
MIC29204BN
5V and Adj
40
C to +125
C
8-pin PDIP
Absolute Maximum Ratings
If Military/Aerospace specified devices
are required, contact your local Micrel
representative/distributor for availability
and specifications.
Power Dissipation ................ Internally Limited, Note 1
Lead Temperature (Soldering, 5 seconds) ........ 260
C
Storage Temperature Range ............ 65
C to +150
C
Operating Junction Temperature Range
................................................. 40
C to +125
C
Thermal Characteristics:
SOT
-
223
JC
.................................................... 15
C/W
TO-220
JC
......................................................... 3
C/W
TO-263
JC
......................................................... 3
C/W
8-Pin SOIC
JA
................................................... Note 1
Input Supply Voltage ............................... 20V to +60V
Operating Input Supply Voltage ................... 2V
to 26V
Adjust Input Voltage (Notes 9 and 10)
...................................................... 1.5V to +26V
Shutdown Input Voltage ......................... 0.3V to +30V
Error Comparator Output Voltage .......... 0.3V to +30V
Across the full operating temperature, the minimum
input voltage range for full output current is 4.3V to 26V.
Output will remain in-regulation at lower output voltages
and low current loads down to an input of 2V at 25
C.
*
Junction temperatures
MIC2920A/29201/29202/29204
Micrel
January 1998
3-11
3
Limits in standard typeface are for T
J
= 25
C and limits in boldface apply over the full operating temperature range. Unless
otherwise specified, V
IN
= V
OUT
+ 1V, I
L
= 1mA, C
L
= 10
F. Adjustable version are set for an output of 5V. The MIC29202 V
SHUTDOWN
0.7V. The eight pin MIC29204 is configured with the Adjust pin tied to the 5V Tap, the Output is tied to Output Sense (V
OUT
= 5V), and V
SHUTDOWN
0.7V.
Symbol
Parameter
Conditions
Min
Typical
Max
Units
V
O
Output Voltage
Variation from factory trimmed V
OUT
1
1
%
Accuracy
2
2
1mA
I
L
400mA, across temp. range
2.5
2.5
MIC2920A-12 and 29201-12 only
1.5
1.5
3
3
1mA
I
L
400mA, across temp. range
4
4
V
O
Output Voltage
(Note 2)
20
100
ppm/
C
T
Temperature Coef.
V
OUT
> 10V only
80
350
V
O
Line Regulation
V
IN
= V
OUT
+ 1V to 26V
0.03
0.10
%
V
O
0.40
V
O
Load Regulation
I
L
= 1 to 250mA (Note 3)
0.04
0.16
%
V
O
0.30
V
IN
V
O
Dropout Voltage
I
L
= 1mA
100
150
mV
(Note 4)
180
I
L
= 100mA
250
V
OUT
> 10V only
350
I
L
= 250mA
370
V
OUT
> 10V only
500
I
L
= 400mA
450
600
750
I
GND
Ground Pin Current
I
L
= 1mA
140
200
A
(Note 5)
300
I
L
= 100mA
1.3
2
mA
2.5
I
L
= 250mA
5
9
12
I
L
= 400mA
13
15
I
GNDDO
Ground Pin
V
IN
= 0.5V less than designed V
OUT
180
400
A
Current at Dropout
(V
OUT
3.3V)
(Note 5)
I
O
= 1mA
I
LIMIT
Current Limit
V
OUT
= 0V
425
1000
mA
(Note 6)
1200
V
O
Thermal Regulation
(Note 7)
0.05
0.2
%/W
P
D
e
n
Output Noise
C
L
= 10
F
400
V RMS
Voltage
(10Hz to 100kHz)
C
L
= 100
F
260
I
L
= 100mA
Electrical Characteristics
MIC2920A/29201/29202/29204
Micrel
3-12
January 1998
Parameter
Conditions
Min
Typ
Max
Units
Reference Voltage
MIC29202
1.223
1.235
1.247
V
1.210
1.260
Reference Voltage
MIC29202 (Note 8)
1.204
1.266
V
Reference Voltage
MIC29204
1.210
1.235
1.260
V
1.200
1.270
Reference Voltage
MIC29204 (Note 8)
1.185
1.285
V
Adjust Pin
20
40
nA
Bias Current
60
Reference Voltage
(Note 7)
20
ppm/
C
Temperature
Coefficient
Adjust Pin Bias
0.1
nA/
C
Current Temperature
Coefficient
Error Comparator
MIC29201, MIC29204
Output Leakage
V
OH
= 26V
0.01
1.00
A
Current
2.00
Output Low
V
IN
= 4.5V
150
250
mV
Voltage
I
OL
= 250
A
400
Upper Threshold
(Note 9)
40
60
mV
Voltage
25
Lower Threshold
(Note 9)
75
95
mV
Voltage
140
Hysteresis
(Note 9)
15
mV
Shutdown Input
MIC29201, MIC29202, MIC29204
Input Logic Voltage
1.3
V
Low (ON)
0.7
High (OFF)
2.0
Shutdown Pin
V
SHUTDOWN
= 2.4V
30
50
A
Input Current
100
V
SHUTDOWN
= 26V
450
600
A
750
Regulator Output
(Note 10)
3
10
A
Current in Shutdown
20
Electrical Characteristics
(Continued)
MIC29202, MIC29204
MIC2920A/29201/29202/29204
Micrel
January 1998
3-13
3
General Note: Devices are ESD protected; however, handling precautions are recommended.
Note 1:
Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not
apply when operating the device outside of its rated operating conditions. The maximum allowable power dissipation is a function of the
maximum junction temperature, T
J (MAX)
, the junction-to-ambient thermal resistance,
JA
, and the ambient temperature, T
A
. The maximum
allowable power dissipation at any ambient temperature is calculated using: P
(MAX)
= (T
J(MAX)
T
A
)
/
JA.
Exceeding the maximum allowable
power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The junction to ambient thermal
resistance of the MIC29204BM is 160
C/W mounted on a PC board.
Note 2:
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
Note 3:
Regulation is measured at constant junction temperature using low duty cycle pulse testing. Changes in output voltage due to
heating effects are covered by the thermal regulation specification.
Note 4:
Dropout Voltage is defined as the input to output differential at which the output voltage drops 100mV below its nominal value
measured at 1V differential. At low values of programmed output voltage, the minimum input supply voltage of 4.3V over temperature must
be taken into account. The MIC2920A operates down to 2V of input at reduced output current at 25
C.
Note 5:
Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus
the ground pin current.
Note 6:
The MIC2920A features fold-back current limiting. The short circuit (V
OUT
= 0V) current limit is less than the maximum current with
normal output voltage.
Note 7:
Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding
load or line regulation effects. Specifications are for a 200mA load pulse at V
IN
= 20V (a 4W pulse) for T = 10ms.
Note 8:
V
REF
V
OUT
(V
IN
1 V), 4.3V
V
IN
26V, 1 mA < I
L
400 mA, T
J
T
J MAX.
Note 9:
Comparator thresholds are expressed in terms of a voltage differential at the Adjust terminal below the nominal reference voltage
measured at 6V input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V
OUT
/V
REF
=
(R1 + R2)/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 V = 384 mV. Thresholds remain constant as a percent of V
OUT
as V
OUT
is varied, with the dropout warning occurring at typically
5% below nominal, 7.7% guaranteed.
Note 10: V
SHUTDOWN
2V, V
IN
26V,V
OUT
= 0, with Adjust pin tied to 5V Tap or to the R1, R2 junction (see Figure 3) with R1
150k
.
Note 11: When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode
clamped to ground.
Note 12: Maximum positive supply voltage of 60V must be of limited duration (< 100ms) and duty cycle (
1%). The maximum continuous
supply voltage is 26V.
ADJUST
SENSE
Q15A
OUT
Q24
Q26
R27
V TAP
R28
R18
20k
Q25
Q23
Q22
R15
100 k
R16
30 k
Q29
Q28
R17
10
R21 8
R17
12 k
Q31
Q30
R23 60 k
SHDN
R24
50 k
R22
150 k
Q21
Q19
C2
40 pF
R14
350
k
Q14
R13
100
k
Q18
R12
110
k
Q20
Q9
Q15B
Q8
Q7
R11
20.6
k
Q5
R8
31.4 k
R10
150
k
R9
27.8 k
Q11
Q12
Q13
R6
140
k
R5
180
k
R4
13 k
R3
50 k
Q2
C1
20
pF
Q4
Q3
R11
18
k
Q6
Q1
10
R1
20 k
R2
50 k
Q41
R30
30
k
Q40
Q34
GND
Q36
Q37
R25
2.8 k
Q38
ERROR
R26
60 k
Q39
Q42
Q16
Q17
50 k
10 k
IN
DENOTES CONNECTION ON
MIC2920A-xx AND MIC29201-xx
VERSIONS ONLY
Schematic Diagram
MIC2920A/29201/29202/29204
Micrel
3-14
January 1998
Typical Characteristics
0
100
200
300
400
500
0
100
200
300
400
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
0
100
200
300
400
500
600
700
-60 -30
0
30
60
90 120 150
DROPOUT VOLTAGE (mV)
TEMPERATURE (
C)
Dropout Voltage
vs. Temperature
I
LOAD
= 400mA
0
1
2
3
4
5
6
0
1
2
3
4
5
6
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout
Characteristics
I
LOAD
= 1mA
I
LOAD
= 400mA
0.1
1
10
20
1
10
100
400
GROUND CURRENT (mA)
OUTPUT CURRENT (mA)
Ground Current
vs. Output Current
0
50
100
150
200
0
1
2
3
4
5
6
7
8
GROUND CURRENT (
A)
SUPPLY VOLTAGE (V)
Ground Current
vs. Supply Voltage
V
OUT
= 5V
I
OUT
= 1mA
0
5
10
15
20
25
30
0
2
4
6
8
10
GROUND CURRENT (mA)
INPUT VOLTAGE (V)
Ground Current
vs. Supply Voltage
V
OUT
= 5V
I
OUT
= 400mA
0.00
0.05
0.10
0.15
0.20
-60 -30
0
30
60
90 120 150
GROUND CURRENT (mA)
TEMPERATURE (
C)
Ground Current
vs. Temperature
I
OUT
= 1mA
0
1
2
3
-60 -30
0
30
60
90 120 150
GROUND CURRENT (mA)
TEMPERATURE (
C)
Ground Current
vs. Temperature
I
LOAD
= 100mA
0
5
10
15
20
25
-60 -30
0
30
60
90 120 150
GROUND CURRENT (mA)
TEMPERATURE (
C)
Ground Current
vs. Temperature
I
LOAD
= 400mA
3.20
3.22
3.24
3.26
3.28
3.30
3.32
3.34
3.36
3.38
3.40
-60 -30
0
30
60
90 120 150
OUTPUT VOLTAGE (V)
TEMPERATURE (
C)
Fixed 3.3V Output Voltage
vs. Temperature
300
350
400
450
500
550
600
650
700
-60 -30
0
30
60
90 120 150
CURRENT (mA)
TEMPERATURE (
C)
Short Circuit and Maximum
Current vs. Temperature
V
OUT
= V
NOMINAL
0.5V
V
OUT
= 0V
3 SAMPLES
(HI/AVG/LO)
V
OUT
= 3.3V
-100
0
100
200
300
400
500
600
700
800
900
1000
-30
-20
-10
0
10
20
30
GROUND CURRENT (
A)
INPUT VOLTAGE (V)
Ground Current
vs. Supply Voltage
R
LOAD
= 100
MIC2920A/29201/29202/29204
Micrel
January 1998
3-15
3
-200
0
200
400
600
-5
0
5
10
15
20
25
OUTPUT (mA)
TIME (ms)
Load Transient
-200
-100
0
100
200
OUTPUT (mV)
C
OUT
= 10
F
1mA
-200
0
200
400
600
-5
0
5
10
15
20
25
OUTPUT (mA)
TIME (ms)
Load Transient
-100
-50
0
50
100
OUTPUT (mV)
C
OUT
= 100
F
1mA
0
10
20
30
40
50
-60 -30
0
30
60
90 120 150
ADJUST PIN CURRENT (nA)
TEMPERATURE (
C)
MIC29202 Adjust Pin
Current vs. Temperature
I
LOAD
= 1mA
-40
-20
0
20
40
OUTPUT (mV)
4
6
8
10
-0.2
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
INPUT (V)
TIME (ms)
Line Transient
C
OUT
= 10
F
I
L
= 10mA
-20
-10
0
10
20
OUTPUT (mV)
4
6
8
10
-0.2
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
INPUT (V)
TIME (ms)
Line Transient
C
OUT
= 100
F
I
L
= 10mA
0.01
0.1
1
10
1x10
0
10x10
0
100x10
0
1x10
3
10x10
3
100x10
3
1x10
6
OUTPUT IMPEDANCE (
)
FREQUENCY (Hz)
Output Impedance
vs. Frequency
I
LOAD
= 10mA
10
100
1
1k
10k 100k 1M
0
25
50
75
100
125
-60 -30
0
30
60
90 120 150
ENABLE CURRENT (
A)
TEMPERATURE (
C)
MIC29201/2 Shutdown Current
vs. Temperaure
V
EN
= 5V
V
EN
= 2V
-100
-80
-60
-40
-20
0
1E+1 1E+2 1E+3 1E+4 1E+5 1E+6
REJECTION (dB)
FREQUENCY (Hz)
Ripple Rejection
10
1M
1k
100
10k
100k
I
L
= 100mA
1mA
C
L
= 10
F
MIC2920A/29201/29202/29204
Micrel
3-16
January 1998
OUTPUT
VOLTAGE
INPUT
VOLTAGE
ERROR
NOT
VALID
NOT
VALID
5V
1.3V
4.75V
system requirements, this resistor may be returned to the 5V
output or some other supply voltage. In determining a value
for this resistor, note that while the output is rated to sink
250
A, this sink current adds to battery drain in a low battery
condition. Suggested values range from 100k to 1M
. The
resistor is not required if this output is unused.
Programming the Output Voltage (MIC29202/29204)
The MIC29202/29204 may be programmed for any output
voltage between its 1.235V reference and its 26V maximum
rating, using an external pair of resistors, as shown in
Figure 3.
The complete equation for the output voltage is
V
OUT
= V
REF
{ 1 + R
1
/R
2
}
|
I
FB
|
R
1
where V
REF
is the nominal 1.235 reference voltage and I
FB
is
the Adjust pin bias current, nominally 20nA. The minimum
recommended load current of 1
A forces an upper limit of
1.2M
on the value of R
2
, if the regulator must work with no
load (a condition often found in CMOS in standby), I
FB
will
produce a 2% typical error in V
OUT
which may be eliminated
at room temperature by trimming R
1
. For better accuracy,
choosing R
2
= 100k reduces this error to 0.17% while
increasing the resistor program current to 12
A. Since the
MIC29202/29204 typically draws 110
A at no load with
SHUTDOWN open-circuited, this is a negligible addition. The
MIC29204 may be pin-strapped for 5V using the internal
voltage divider by tying Pin 1 (output) to Pin 2 (sense) and Pin
7 (Adjust) to Pin 6 (V Tap).
Configuring the MIC29201-3.3BM
For the MIC29201-3.3BM, the output (Pin 1) and sense pin
(pin 2),
must be connected to ensure proper operation. They
are not connected internally.
Reducing Output Noise
In reference applications it may be advantageous to reduce
the AC noise present at the output. One method is to reduce
the regulator bandwidth by increasing the size of the output
Figure 1. ERROR Output Timing
*
*
* SEE APPLICATIONS INFORMATION
Applications Information
External Capacitors
A 10
F (or greater) capacitor is required between the
MIC2920A output and ground to prevent oscillations due to
instability. Most types of tantalum or aluminum electrolytics
will be adequate; film types will work, but are costly and
therefore not recommended. Many aluminum electrolytics
have electrolytes that freeze at about 30
C, so solid tantalums
are recommended for operation below 25
C. The important
parameters of the capacitor are an effective series resistance
of about 5
or less and a resonant frequency above 500kHz.
The value of this capacitor may be increased without limit.
At lower values of output current, less output capacitance is
required for output stability. The capacitor can be reduced to
2.2
F for current below 10mA or 1
F for currents below
1mA. Adjusting the MIC29202/29204 to voltages below 5V
runs the error amplifier at lower gains so that more output
capacitance is needed. For the worst-case situation of a
500mA load at 1.23V output (Output shorted to Adjust) a 47
F
(or greater) capacitor should be used.
The MIC2920A/29201 will remain in regulation with a minimum
load of 1mA. When setting the output voltage of the MIC29202/
29204 versions with external resistors, the current through
these resistors may be included as a portion of the minimum
load.
A 0.1
F capacitor should be placed from the MIC2920A input
to ground if there is more than 10 inches of wire between the
input and the AC filter capacitor or if a battery is used as the
input.
Error Detection Comparator Output
(MIC29201/MIC29204)
A logic low output will be produced by the comparator whenever
the MIC29201/29204 output falls out of regulation by more
than approximately 5%. This figure is the comparator's built-
in offset of about 75mV divided by the 1.235V reference
voltage. (Refer to the block diagram on Page 1). This trip level
remains "5% below normal" regardless of the programmed
output voltage of the MIC29201/29204. For example, the
error flag trip level is typically 4.75V for a 5V output or 11.4V
for a 12V output. The out of regulation condition may be due
either to low input voltage, extremely high input voltage,
current limiting, or thermal limiting.
Figure 1 is a timing diagram depicting the ERROR signal and
the regulated output voltage as the MIC29201/29204 input is
ramped up and down. The ERROR signal becomes valid (low)
at about 1.3V input. It goes high at about 5V input (the input
voltage at which V
OUT
= 4.75). Since the MIC29201/29204's
dropout voltage is load-dependent (see curve in Typical
Performance Characteristics), the input voltage trip point
(about 5V) will vary with the load current. The output voltage
trip point (approximately 4.75V) does not vary with load.
The error comparator has an NPN open-collector output
which requires an external pull-up resistor. Depending on
MIC2920A/29201/29202/29204
Micrel
January 1998
3-17
3
SHUT-
DOWN
V
GND
4
7
8
OUT
+VIN
ADJUST
1
3
SHUTDOWN
INPUT
100pF
2N2222
1%
300k
5.3V
1%
180k
+
10F
470 k
HIGH = OFF
LOW = ON
LOW = 3.3V OUT
220k
1%
VCC OUT
HIGH = 5V OUT
Automotive Applications
The MIC2920A is ideally suited for automotive applications for
a variety of reasons. It will operate over a wide range of input
voltages with very low dropout voltages (40mV at light loads),
and very low quiescent currents (100
A typical). These features
are necessary for use in battery powered systems, such as
automobiles. It is a "bulletproof" device with the ability to
survive both reverse battery (negative transients up to 20V
below ground), and load dump (positive transients up to 60V)
conditions. A wide operating temperature range with low
temperature coefficients is yet another reason to use these
versatile regulators in automotive designs.
capacitor. This is relatively inefficient, as increasing the
capacitor from 1
F to 220
F only decreases the noise from
430
V to 160
V
RMS
for a 100kHz bandwidth at 5V output.
Noise can be reduced fourfold by a bypass capacitor across
R
1
, since it reduces the high frequency gain from 4 to unity.
Pick
or about 0.01
F. When doing this, the output capacitor must
be increased to 10
F to maintain stability. These changes
reduce the output noise from 430
V to 100
V rms for a
100kHz bandwidth at 5V output. With the bypass capacitor
added, noise no longer scales with output voltage so that
improvements are more dramatic at higher output voltages.
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40
m
V TO 400
m
V,
DEPENDING ON LOAD CURRENT.
870 25
NOTE: PINS 2 AND 6 ARE LEFT OPEN
IN
OUT
GND ADJUST
ERROR
5
3
4
1
8
SHUTDOWN
V
V
ERROR
OUTPUT
SHUTDOWN
INPUT
IN
+V
100k
OUT
V
1.2
26V
1
R 100
pF
10F
2
R
1.23V
REF
V
7
VOUT = VREF x (1 + )
1
R
2
R
OFF
ON
OUT
GND
+VIN
*V
5V
OUT
V
V
10F
+
IN
V
OUT
= 5V
Figure 2. MIC2920A-5.0 Fixed +5V Regulator
Figure 3. MIC29202/29204 Adjustable Regulator. Pinout is for
MIC29204.
Typical Applications
Figure 5. MIC29202/29204 5.0V or 3.3V Selectable Regulator
with Shutdown. Pinout is for MIC29204.
Figure 4. MIC29204 Wide Input Voltage Range Current Limiter
PIN 3 LOW= ENABLE OUTPUT. Q1 ON = 3.3V, Q1 OFF = 5.0V.
MIC2951
OUT
FB
SD
ERROR
5
1
3
7
GND
4
+VIN
8
+VIN
*V
VIN
OUT
V
ERROR
OUTPUT
SHUTDOWN
INPUT
OFF
ON
C
BYPASS
1
2 R
1
200 Hz
ADJUST
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