MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 1 M9999-021505
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-220-3, 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 VCC and VPP 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 regu-
lators with very low dropout voltage (typically 40mV at light
loads and 370mV at 250mA), and very low quiescent current
(140µA typical). The quiescent current of the MIC2920A in-
creases only slightly in dropout, prolonging battery life. Key
MIC2920A features include protection against reversed bat-
tery, 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 (shut-
down) 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)
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 32
TAB
INPUT OUTPUT
GROUND
MIC2920A-x.xBS
(SOT-223)
Pin Configuration
1
2
3
4
8
7
6
5
IN PUT
NC
NC
E R R O R
OU TP UT
S E N S E
SH UTDOWN
GROUND
MIC29201-3.3BM (SOIC-8)
1
2
3
4
8
7
6
5
IN PUT
ADJUST
5V TAP
E R R O R
OU TP UT
S E N S E
SH UTDOWN
GROUND
MIC29204BM (SOIC-8)
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
TAB
5
4
3
2
1
TAB
3
OUT
2
GND
1
IN
TAB
5
4
3
2
1
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 2 February 2005
Ordering Information
Part Number Voltage Junction Temp. Range Package
Standard Pb-Free
MIC2920A-3.3BS MIC2920A-3.3WS* 3.3V -40°C to +125°C SOT-223
MIC2920A-3.3BT MIC2920A-3.3WT* 3.3V -40°C to +125°C TO-220-3
MIC2920A-4.8BS MIC2920A-4.8WS* 4.85V -40°C to +125°C SOT-223
MIC2920A-4.8BT MIC2920A-4.8WT* 4.85V -40°C to +125°C TO-220-3
MIC2920A-5.0BS MIC2920A-5.0WS* 5.0V -40°C to +125°C SOT-223
MIC2920A-5.0BT MIC2920A-5.0WT* 5.0V -40°C to +125°C TO-220-3
MIC2920A-12BS MIC2920A-12WS* 12V -40°C to +125°C SOT-223
MIC2920A-12BT MIC2920A-12WT* 12V -40°C to +125°C TO-220-3
MIC29201-3.3BM MIC29201-3.3YM 3.3V -40°C to +125°C SO-8
MIC29201-3.3BT MIC29201-3.3WT* 3.3V -40°C to +125°C TO-220-5
MIC29201-3.3BU MIC29201-3.3WU* 3.3V -40°C to +125°C TO-263-5
MIC29201-4.8BT MIC29201-4.8WT* 4.85V -40°C to +125°C TO-220-5
MIC29201-4.8BU MIC29201-4.8WU* 4.85V -40°C to +125°C TO-263-5
MIC29201-5.0BT MIC29201-5.0WT* 5.0V -40°C to +125°C TO-220-5
MIC29201-5.0BU MIC29201-5.0WU* 5.0V -40°C to +125°C TO-263-5
MIC29201-12BT MIC29201-12WT* 12V -40°C to +125°C TO-220-5
MIC29201-12BU MIC29201-12WU* 12V -40°C to +125°C TO-263-5
MIC29202BT MIC29202WT* Adj -40°C to +125°C TO-220-5
MIC29202BU MIC29202WU* Adj -40°C to +125°C TO-263-5
MIC29204BM MIC29204YM 5V and Adj -40°C to +125°C SO-8
MIC29204BN MIC29204YN 5V and Adj -40°C to +125°C 8-pin PDIP
* Pb-Free RoHS compliant with high-melting solder exemption.
MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 3 M9999-021505
Absolute Maximum Ratings
Input Supply Voltage .................................................–20V to +60V
Adjust Input Voltage (Notes 9 and 10) ......................–1.5V to +26V
Power Dissipation ................................... Internally Limited, Note 1
Operating Junction Temperature Range ............. –40°C to +125°C
Lead Temperature (Soldering, 5 seconds) ............................260°C
Storage Temperature Range ............................... –65°C to +150°C
If Military/Aerospace specified devices are required, contact your local
Micrel representative/distributor for availability and specifications.
Operating Ratings
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 +30VOperating
Junction Temperature Range ............................. –40°C to +125°C
Thermal Characteristics:
SOT−223 θJC .............................................................. 15°C/W
TO-220 θJC ................................................................... 3°C/W
TO-263 θJC ................................................................... 3°C/W
8-Pin SOIC θJA .............................................................Note 1
† 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.
Electrical Characteristics
Limits in standard typeface are for TJ = 25°C and limits in boldface apply over the full operating temperature range. Unless otherwise
specified, VIN = VOUT + 1V, IL = 1mA, CL = 10µF. Adjustable versions are set for an ouptu of 5V. The MIC29202 VSHUTDOWN ≤ 0.7V. The
eight pin MIC29204 is configured with the Adjust pin tied to the 5V Tap, the Output is tied to Output Sense (VOUT = 5V), and VSHUTDOWN ≤
0.7V.
Symbol Parameter Conditions Min Typ Max Units
VOOutput Voltage
Accuracy
Variation from factory trimmed VOUT -1
-2
1
2
%
1mA ≤ IL ≤ 400mA, across temp. range -2.5 2.5
MIC2920A-12 and 29201-12 only -1.5
-3
1.5
3
1mA ≤ IL ≤ 400mA, across temp. range -4 4
∆VO
∆T
Output Voltage
Temperature Coef.
(Note 2) 20 100 ppm/°C
VOUT > 10V only 80 350
∆VO
VO
Line Regulation VIN = VOUT + 1V to 26V 0.03 0.10
0.40
%
∆VO
VO
Load Regulation IL = 1 to 250mA (Note 3) 0.04 0.16
0.30
%
VIN - VODropout Voltage
(Note 4)
IL = 1mA
IL = 100mA
VOUT > 10V only
IL = 250mA
VOUT > 10V only
IL = 400mA
100
250
350
370
500
400
150
180
600
750
mV
IGND Ground Pin Current
(Note 5)
IL = 1mA
IL = 100mA
IL = 250mA
IL = 400mA
140
1.3
5
13
200
300
2
2.5
9
12
15
µA
mA
IGNDDO Ground Pin Current
at Dropout
(Note 5)
VIN = 0.5V less than designed VOUT
(VOUT = 3.3V)
IO = 1mA
180 400 µA
ILIMIT Current Limit VOUT = 0V
(Note 6)
425 100
1200
mA
∆VO
∆PD
Thermal Regulation (Note 7) 0.05 0.2 %/W
enOutput Noise Voltage
(10Hz to 100kHz)
IL = 100mA
CL = 10µF
CL = 100µF
400
260
µV RMS
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 4 February 2005
Parameter Conditions Min Typ Max Units
MIC29202, MIC29204
Reference Voltage MIC29202 1.223
1.210
1.235 1.247
1.260
V
Reference Voltage MIC29202 (Note 8) 1.204 1.266 V
Reference Voltage MIC29204 1.210
1.200
1.235 1.260
1.270
V
Reference Voltage MIC29204 (Note 8) 1.185 1.285 V
Adjust Pin
Bia Current
20 40
60
nA
Reference Voltage
Temperature
Coefficient
(Note 7) 20 ppm/°C
Adjust Pin Bias
Current Temperature
Coefficient
0.1 nA/°C
Error Comparator MIC29201, MIC29204
Output Leakage
Current
VOH = 26V 0.01 1.00
2.00
µA
Output Low
Voltage
VIN = 4.5V
IOL = 250µA
150 250
400
mV
Upper Threshold
Voltage
(Note 9) 40
25
60 mV
Lower Threshold
Voltage
(Note 9) 75 95
140
mV
Hysteresis (Note 9) 15 mV
Shutdown Input MIC29201, MIC29202, MIC29204
Input Logic Voltage
Low (ON)
High (OFF)
2.0
1.3
0.7
V
Shutdown Pin
Input Current
VSHUTDOWN = 2.4V 30 50
100
µA
VSHUTDOWN = 26V 450 600
750
µA
Regulator Output
Current in Shutdown
(Note 10) 3 10
20
µA
MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 5 M9999-021505
Notes:
General: 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, TJ (MAX), the junction-to-ambient thermal resistance, θJA, and the ambient temperature, TA. The maximum allowable
power dissipation at any ambient temperature is calculated using: P(MAX) = (TJ(MAX) – TA) / θJA. 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 (VOUT = 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 VIN = 20V (a 4W pulse) for T = 10ms.
Note 8: VREF ≤ VOUT ≤ (VIN – 1 V), 4.3V ≤ VIN ≤ 26V, 1 mA < IL ≤400 mA, TJ ≤ TJ 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 = VOUT /VREF = (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 VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below
nominal, 7.7% guaranteed.
Note 10: VSHUTDOWN ≥ 2V, VIN ≤ 26V,VOUT = 0, with Adjust pin tied to 5V Tap or to the R1, R2 junction (see Figure 3) with R1 ≥ 150kΩ.
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.
A D J U S T
SENSE
Q15A
OUT
Q24
Q26
R27
V TAP
R28
R18
20kΩ
Q25
Q23
Q22
R15
100 kΩ
R16
30 kΩ
Q29
Q28
R17
10 Ω
R21 8 Ω
R17
12 kΩ
Q31
Q30
R23 60 kΩ
SHDN
R24
50 kΩ
R22
150 kΩ
Q21
Q19
C2
40 pF
R14
350
kΩ
Q14
R13
100
kΩ
Q18
R12
110
kΩ
Q20
Q9
Q15 B
Q8
Q7
R11
20.6
kΩ
Q5
R8
31.4 kΩ
R10
150
kΩ
R9
27.8 kΩ
Q11
Q12
Q13
R6
140
kΩ
R5
180
kΩ
R4
13 kΩ
R3
50 kΩ
Q2
C1
20
pF
Q4
Q3
R11
18
kΩ
Q6
Q1
10
R1
20 kΩ
R2
50 kΩ
Q41
R30
30
kΩ
Q40
Q34
GND
Q36
Q37
R25
2.8 kΩ
Q38
E R R O R
R26
60 kΩ
Q39
Q42
Q16
Q17
50 kΩ
10 kΩ
IN
DENO T E S C O NN E C T I ON ON
MIC2920A-xx AND MIC29201-xx
VE R S I ONS ON L Y
Schematic Diagram
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 6 February 2005
Typical Characteristics
0
100
200
300
400
500
0 100 200 300 400
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage
vs . Output C urrent
0
1
2
3
4
5
6
0123456
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Dropout
C harac teris tics
ILOAD = 1mA
ILOAD = 400mA
0.1
1
10
20
1 10 100 400
GROUND CURRENT (mA)
OUTPUT CURRENT (mA)
G round C urrent
vs . Output C urrent
0
50
100
150
200
012345678
GROUND CURRENT (µA)
SUPPLY VOLTAGE (V)
G round C urrent
vs . S upply Voltage
VOUT = 5V
IOUT = 1mA
0
5
10
15
20
25
30
0246810
GROUND CURRENT (mA)
INPUT VOLTAGE (V)
G round C urrent
vs . S upply Voltage
VOUT = 5V
IOUT = 400mA
0.00
0.05
0.10
0.15
0.20
-60 -30 0 30 60 90 120 150
GROUND CURRENT (mA)
TEMPERATURE (°C)
G round C urrent
vs . T emperature
IOUT = 1mA
-100
0
100
200
300
400
500
600
700
800
900
1000
-30 -20 -10 0 10 20 30
GROUND CURRENT (µA)
INPUT VOLTAGE (V)
G round C urrent
vs . S upply Voltage
RLOAD = 100Ω
MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 7 M9999-021505
-200
0
200
400
600
-5 0 5 10 15 20 25
OUTPUT (mA)
TIME (ms)
L oad T rans ient
-200
-100
0
100
200
∆ OUTPUT (mV)
COUT = 10µF
1mA
-200
0
200
400
600
-5 0 5 10 15 20 25
OUTPUT (mA)
TIME (ms)
L oad T rans ient
-100
-50
0
50
100
∆ OUTPUT (mV)
COUT = 100µF
1mA
0
10
20
30
40
50
-60 -30 0 30 60 90 120 150
ADJUST PIN CURRENT (nA)
TEMPERATURE (°C)
MIC 29202 A djus t P in
C urrent vs . T emperature
ILOAD = 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)
L ine T rans ient
COUT = 10 µF
IL= 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)
L ine T rans ient
COUT = 100 µF
IL= 10mA
0.01
0.1
1
10
1x10 0
10x10 0
100x10 0
1x10 3
10x10 3
100x10 3
1x10 6
OUTPUT IMPEDANCE (Ω)
FREQUENCY (Hz)
Output Impedance
vs . F requency
ILOAD = 10mA
10 100
11k 10k 100k 1M
0
25
50
75
100
125
-60 -30 0 30 60 90 120 150
ENABLE CURRENT (µA)
TEMPERATURE (°C)
MIC 29201/2 S hutdown C urrent
vs . Temperaure
VE N = 5V
VE N = 2V
-100
-80
-60
-40
-20
0
1E+1 1E+2 1E+3 1E+4 1E+5 1E+6
REJECTION (dB)
FREQUENCY (Hz)
R ipple R ejec tion
10 1M
1k
100 10k 100k
IL= 100mA
1mA
CL= 10µF
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 8 February 2005
or some other supply voltage. In determining a value for this
resistor, note that while the output is rated to sink 250µA, this
sink current adds to battery drain in a low battery condition.
Suggested values range from 100k to 1MΩ. 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 maxi-
mum rating, using an external pair of resistors, as shown in
Figure 3.
The complete equation for the output voltage is
VOUT = VREF × { 1 + R1/R2 } – |IFB| R1
where VREF is the nominal 1.235 reference voltage and IFB is
the Adjust pin bias current, nominally 20nA. The minimum rec-
ommended load current of 1µA forces an upper limit of 1.2MΩ
on the value of R2, if the regulator must work with no load (a
condition often found in CMOS in standby), IFB will produce
a –2% typical error in VOUT which may be eliminated at room
temperature by trimming R1. For better accuracy, choosing R2
= 100k reduces this error to 0.17% while increasing the resistor
program current to 12µA. Since the MIC29202/29204 typically
draws 110µA 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
capacitor. This is relatively inefficient, as increasing the capaci-
Figure 1. ERROR Output Timing
* SEE APPLICATIONS INFORMATION
Applications Information
External Capacitors
A 10µF (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 recom-
mended. 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 5Ω 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 2.2µF for current below 10mA or 1µF for currents below
1mA. Adjusting the MIC29202/29204 to voltages below 5V
runs the error amplifier at lower gains so that more output ca-
pacitance is needed. For the worst-case situation of a 500mA
load at 1.23V output (Output shorted to Adjust) a 47µF (or
greater) capacitor should be used.
The MIC2920A/29201 will remain in regulation with a mini-
mum 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 0.1µF 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 when-
ever 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, cur-
rent 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 VOUT = 4.75). Since the MIC29201/29204’s
dropout voltage is load-dependent (see curve in Typical Per-
formance 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 system
requirements, this resistor may be returned to the 5V output
4.75V
E R R O R
OUTPU T
VOLTAGE
IN PUT 5V
1.3V
VOLTAGE
NOT *
VALID NOT *
VALID
MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 9 M9999-021505
SHUT-
DOWN
V
GND
47
8
OUT
+VIN
ADJUST
1
3
SHUTDOWN
INPUT
100pF
2N2222
1%
300kΩ
≥ 5.3V
1%
180kΩ
+
10µF
470 kΩ
HIGH = OFF
LOW = ON
LOW = 3. 3V OU T
220kΩ
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 (100µA typical). These
features are necessary for use in battery powered systems,
such as automobiles. It is a “bulletproof” device with the abil-
ity 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.
tor from 1µF to 220µF only decreases the noise from 430µV
to 160µVRMS for a 100kHz bandwidth at 5V output. Noise can
be reduced fourfold by a bypass capacitor across R1, since it
reduces the high frequency gain from 4 to unity. Pick
or about 0.01µF. When doing this, the output capacitor must
be increased to 10µF to maintain stability. These changes re-
duce the output noise from 430µV to 100µV rms for a 100kHz
bandwidth at 5V output. With the bypass capacitor added,
noise no longer scales with output voltage so that improve-
ments are more dramatic at higher output voltages.
NOTE: PINS 2 AND 6 ARE LEFT OPEN
IN
OUT
GND ADJ UST
E R R O R
5
3
4
1
8
SHUTDOWN
V
V
E R R O R
OUTP U T
SHUTDOWN
IN PUT
IN
+V
100kΩ
OUT
V
1.2
26V
1
R 100
pF
10µF
2
R
1.23V
R E F
V
7
VOUT = VR E F x (1 + )
1
R
2
R
O F F
ON
IN
OUT
GND
V
+V
IN
V
OUT
V
= 5V
10µF
+
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.
CBYPASS
1
2πR1 • 200 Hz
=
IN
OUT
GND ADJU ST
E R R O R
5
3
4
1
8
SD
V
+V
E R R O R
OUT PUT
SHUTDOWN
INPUT
IN
+V
OUT
*V
7
O F F
ON
IN
= V
* Min i mum In put-Ou tput V oltage ranges from 40mV to 400mV, depen ding on load c urrent
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 10 February 2005
Package Information
8-Pin SOIC (M)
16°
10°
0.84 (0.033)
0.64 (0.025)
1.04 (0.041)
0.85 (0.033)
2.41 (0.095)
2.21 (0.087)
4.7 (0.185)
4.5 (0.177)
6.70 (0.264)
6.30 (0.248)
7.49 (0.295)
6.71 (0.264)
3.71 (0.146)
3.30 (0.130)
3.15 (0.124)
2.90 (0.114)
10°
MAX
0.10 (0.004)
0.02 (0.0008)
0.38 (0.015)
0.25 (0.010)
C
L
DIMENSIONS:
MM (INCH)
C
L
1.70 (0.067)
1.52 (0.060)
0.91 (0.036) MIN
SOT-223 (S)
MIC2920A/29201/29202/29204 Micrel, Inc.
February 2005 11 M9999-021505
3-Lead TO-220 (T)
5-Lead TO-220 (T)
MIC2920A/29201/29202/29204 Micrel, Inc.
M9999-021505 12 February 2005
1
θ
θ1
3
θ
4θ
1
θ
2
θ
3
θ
4θ
2θ
1θ
5-Lead TO-263 (U)
MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 1998 Micrel Incorporated