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
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