MIC2937A/29371/29372
Micrel, Inc.
MIC2937A/29371/29372
750mA Low-Dropout Voltage Regulator
General Description
Features
The MIC2937A family are “bulletproof” efficient voltage regulators with very low dropout voltage (typically 40mV at light
loads and 300mV at 500mA), and very low quiescent current
(160µA typical). The quiescent current of the MIC2937A increases only slightly in dropout, thus prolonging battery life.
Key MIC2937A features include protection against reversed
battery, fold-back current limiting, and automotive “load dump”
protection (60V positive transient).
•
•
•
•
•
•
•
•
The MIC2937 is available in several configurations. The
MIC2937A-xx devices are three pin fixed voltage regulators
with 3.3V, 5V, and 12V outputs available. The MIC29371 is
a fixed regulator offering logic compatible ON/OFF switching
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 MIC29372, which enables the
regulator to be switched on and off.
•
•
•
•
High output voltage accuracy
Guaranteed 750mA output
Low quiescent current
Low dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Current and thermal limiting
Input can withstand –20V reverse battery and +60V positive transients
Error flag warns of output dropout
Logic-controlled electronic shutdown
Output programmable from 1.24V to 26V(MIC29372)
Available in TO-220, TO-263, TO-220-5, and TO-263-5
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-Regulator/ DC to DC Modules
High Efficiency Linear Power Supplies
Pin Configuration
1 2 3
1 2 3 4 5
INPUT GROUND OUTPUT
TO-263 Package
(MIC2937A-xxBU/WU)
TO-263-5 Package
(MIC29371/29372BU/WU)
Five Lead Package Pin Functions:
MIC29371 MIC29372
1) Error
Adjust
2) Input
Shutdown
3) Ground
Ground
4) Output
Input
5) Shutdown Output
1 2 3
INPUT GROUND OUTPUT
TO-220 Package
(MIC2937A-xxBT/WT)
1 2 3 4 5
TO-220-5 Package
(MIC29371/29372BT/WT)
The TAB is Ground on the TO-220 and TO-263 packages.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
May 2006
1
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
Ordering Information
Part Number
Voltage
Junction Temp. Range
Package
MIC2937A-3.3WU
3.3V
–40ºC to +125ºC
TO-263-3
MIC2937A-3.3BT
MIC2937A-3.3WT
3.3V
–40ºC to +125ºC
TO-220-3
MIC2937A-5.0BU
MIC2937A-5.0WU
5.0V
–40ºC to +125ºC
TO-263-3
MIC2937A-5.0BT
MIC2937A-5.0WT
5.0V
–40ºC to +125ºC
TO-220-3
MIC2937A-12BU
MIC2937A-12WU
12V
–40ºC to +125ºC
TO-263-3
MIC2937A-12BT
MIC2937A-12WT
12V
–40ºC to +125ºC
TO-220-3
MIC29371-3.3BU
MIC29371-3.3WU
3.3V
–40ºC to +125ºC
TO-263-5
MIC29371-3.3BT
MIC29371-3.3WT
3.3V
–40ºC to +125ºC
TO-220-5
MIC29371-5.0BU
MIC29371-5.0WU
5.0V
–40ºC to +125ºC
TO-263-5
MIC29371-5.0BT
MIC29371-5.0WT
5.0V
–40ºC to +125ºC
TO-220-5
MIC29371-12BU
MIC29371-12WU
12V
–40ºC to +125ºC
TO-263-5
MIC29371-12BT
MIC29371-12WT
12V
–40ºC to +125ºC
TO-220-5
MIC29372BU
MIC29372WU
ADJ
–40ºC to +125ºC
TO-263-5
MIC29372BT
MIC29372WT
ADJ
–40ºC to +125ºC
TO-220-5
Standard
RoHS Compliant*
MIC2937A-3.3BU
* RoHS compliant with ‘high-melting solder’ exemption.
MIC2937A/29371/29372
2
May 2006
MIC2937A/29371/29372
Micrel, Inc.
Absolute Maximum 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 +30V
Power Dissipation (Note 1)...............................................Internally Limited
Lead Temperature (Soldering, 5 seconds).........................................260°C
Storage Temperature Range.............................................–65°C to +150°C
Operating Junction Temperature Range ..........................–40°C to +125°C
TO-220 θJC .....................................................................................2.5°C/W
TO-263 θJC .....................................................................................2.5°C/W
Input Supply Voltage..............................................................–20V to +60V
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 = 5mA, CL = 10µF. The MIC29372 are programmed for a 5V output voltage, and VSHUTDOWN ≤ 0.6V
(MIC29371-xx and MIC29372 only).
Symbol
VO
Parameter
Output Voltage
Accuracy
Conditions
Variation from factory trimmed VOUT
5mA ≤ IL ≤ 500mA
MIC2937A-12 and 29371-12 only:
ΔVO
ΔT
ΔVO
VO
ΔVO
VO
VIN – VO
Output Voltage
Temperature Coef.
Line Regulation
Load Regulation
Dropout Voltage
(Note 4)
5mA ≤ IL ≤ 500mA
(Note 2)
Output voltage > 10V
VIN = VOUT + 1V to 26V
IGNDDO
ILIMIT
ΔVO
ΔPD
en
Ground Pin Current
(Note 5)
Ground Pin
Current at Dropout
(Note 5)
Current Limit
Thermal Regulation
Output Noise
Voltage
(10Hz to 100kHz)
IL = 100mA
May 2006
Typical
20
80
0.03
IL = 5 to 500mA
(Note 3)
IL = 5mA
0.04
IL = 100mA
IL = 750mA
200
240
300
420
370
IL = 5mA
160
IL = 500mA
IGND
Min
–1
–2
–2.5
–1.5
–3
–4
80
Output voltage > 10V
Output voltage > 10V
IL = 100mA
1
IL = 500mA
8
IL = 750mA
VIN = 0.5V less than designed VOUT
(VOUT ≥ 3.3V)
IO = 5mA
VOUT = 0V
(Note 6)
(Note 7)
0.05
CL = 10µF
400
CL = 100µF
260
3
15
200
1.1
Max
1
2
2.5
1.5
3
4
100
350
0.10
0.40
0.16
0.30
150
180
600
750
250
300
2.5
3
13
16
25
500
1.5
2
0.2
Units
%
ppm/°C
%
%
mV
µA
mA
µA
A
%/W
µV RMS
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
Electrical Characteristics (Continued)
MIC29372
Parameter
Conditions
Reference Voltage
Reference Voltage
(Note 8)
Min
Typical
Max
1.223
1.210
1.235
1.247
1.260
V
V max
1.266
V
40
60
nA
1.204
Adjust Pin
Bias Current
Reference Voltage
Temperature
Coefficient
20
(Note 7)
Adjust Pin Bias
Current Temperature
Coefficient
Error Comparator
Units
20
ppm/°C
0.1
nA/°C
MIC29371
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)
Lower Threshold
Voltage
(Note 9)
75
Hysteresis
(Note 9)
15
Shutdown Input
Input Logic Voltage
Low (ON)
Shutdown Pin
Input Current
Regulator Output
Current in Shutdown
40
25
60
mV
95
140
mV
mV
MIC29371/MIC29372
1.3
2.0
High (OFF)
0.7
V
VSHUTDOWN = 2.4V
30
50
100
µA
VSHUTDOWN = 26V
450
600
750
µA
3
10
20
µA
(Note 10)
MIC2937A/29371/29372
4
May 2006
MIC2937A/29371/29372
Micrel, Inc.
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.
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 100 mV 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 MIC2937A 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 source is the sum of the load current
plus the ground pin current.
Note 6: The MIC2937A family 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, 5mA < IL ≤ 750 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 (for a 5V regulator). 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: Circuit of Figure 3 with R1 ≥ 150kΩ. VSHUTDOWN ≥ 2V and VIN ≤ 26V,VOUT = 0.
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.
Schematic Diagram
FEEDBACK
IN
R18
20 kΩ
Q15A
Q15B
Q24
Q25
Q9
Q3
R11
18
kΩ
Q4
Q5
Q1
10
R2
50 kΩ
Q40
Q17
Q16
R27
R17
12 kΩ
Q14
V TAP
R28
Q20
R5
180
kΩ
R6
140
kΩ
Q13
R12
110
kΩ
Q11
R13
100
kΩ
Q18
R3
50 kΩ
Q21
C2
40 pF
R9
27.8 k Ω
Q12
Q22
R10
150
kΩ
R8
31.4 k Ω
Q41
R30
30
kΩ
SENSE
Q8
R11
20.6
kΩ
Q2
R1
20 kΩ
Q42
OUT
Q7
C1
20
pF
Q6
Q26
Q23
R15
100 k Ω
R14
350
kΩ
R16
30 kΩ
Q29
Q19
R17
10Ω
Q28
R4
13 kΩ
R21 8 Ω
50 kΩ
Q30
Q37
10 kΩ
R22
150 k Ω
Q36
R24
50 kΩ
R23 60 k Ω
SHDN
ERROR
Q38
Q34
R26
60 kΩ
DENOTES CONNECTION ON
MIC2937A-xx AND MIC29371-xx
VERSIONS ONLY
R25
2.8 kΩ
GND
Q39
May 2006
Q31
5
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
Typical Characteristics
DROPOUT VOLTAGE (mV)
0
0
0.1
1
GROUND CURRENT (mA)
0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
100
0
10
100
1000
OUTPUT CURRENT (mA)
0.15
0.10
ILOAD = 5mA
0.00
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
MIC2937A/29371/29372
2 3 4 5 6 7
SUPPLY VOLTAGE (V)
1.2
0.6
VOUT = VNOMINAL – 0.5V
VOUT = 0V
0.4
0.2
FIXED 5V
VERSION
0.0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
6
2
ILOAD = 750mA
1
0
1
2
3
4
5
INPUT VOLTAGE (V)
6
Ground Current
vs. Supply Voltage
25
20
15
10
5
30
25
0
FIXED 5V
ILOAD = 750mA
2
4
6
8
INPUT VOLTAGE (V)
10
Ground Current
vs. Temperature
ILOAD = 750mA
20
15
10
5
0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
Short Circuit and Maximum
Current vs. Temperature
1.0
0.8
ILOAD = 5mA
3
0
8
2.0
1.8
1.6
1.4
ILOAD = 100mA
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
1.4
CURRENT (A)
OUTPUT VOLTAGE (V)
Fixed 3.3V Output Voltage
vs. Temperature
3.40
3.38
3.36
3.34
3.32
3.30
3.28
3.26
3.24
3.22
3.20
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
1
Ground Current
vs. Temperature
Ground Current
vs. Temperature
0.20
FIXED 5V VERSION
ILOAD = 5mA
0
4
30
150
50
5
0
Ground Current
vs. Supply Voltage
200
GROUND CURRENT (µA)
GROUND CURRENT (mA)
1
0.05
100
200
400
600
800
OUTPUT CURRENT (mA)
10
0.25
200
Ground Current
vs. Output Current
30
ILOAD = 750mA
300
GROUND CURRENT (mA)
100
400
GROUND CURRENT (mA)
200
500
500
GROUND CURRENT (µA)
300
Dropout
Characteristics
6
600
GROUND CURRENT (mA)
DROPOUT VOLTAGE (mV)
400
Dropout Voltage
vs. Temperature
700
OUTPUT VOLTAGE (V)
Dropout Voltage
vs. Output Current
500
400
Ground Current
vs. Input Voltage
RLOAD = 100Ω
300
200
100
0
-100
-30 -20 -10 0
10 20
INPUT VOLTAGE (V)
30
May 2006
MIC2937A/29371/29372
Micrel, Inc.
25
VEN = 2V
0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
0
-300
1000
750
500
5mA
250
0
-250
-5
MIC29372/3 Adjust Pin
Current vs. Temperature
40
COUT = 10 µF
-150
∆ OUTPUT (mV)
ADJUST PIN CURRENT (nA)
50
OUTPUT (mA) ∆ OUTPUT (mV)
50
VEN = 5V
150
Load Transient
40
0
5
TIME (ms)
10
COUT = 10 µF
IL = 5mA
20
0
0
-60 -30 0 30 60 90 120 150
TEMPERATURE °C)
(
8
6
4
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
TIME (ms)
-200
1000
750
500
5mA
250
0
-250
-5
20
10
0
5
TIME (ms)
10
Line Transient
COUT = 100 µF
IL = 5mA
0
8
6
4
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
TIME (ms)
1
0.1
1x106
100x103
1x100
0.01
10x103
ILOAD = 10mA
1x103
OUTPUT IMPEDANCE (Ω)
10
0
Output Impedance
vs. Frequency
100x100
ILOAD = 1mA
COUT = 100 µF
-10
10
10x100
10
Load Transeint
-100
INPUT (V)
-40
10
20
100
Line Transient
-20
30
200
∆ OUTPUT (mV)
75
300
INPUT (V)
ENABLE CURRENT (µA)
100
OUTPUT (mA) ∆ OUTPUT (mV)
MIC29371/2 Shutdown Current
vs. Temperaure
125
FREQUENCY (Hz)
May 2006
7
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
Applications Information
External Capacitors
A 10µF (or greater) capacitor is required between the MIC2937A
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 5Ω or
less and a resonant frequency above 500kHz. The value of
this capacitor may be increased without limit.
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
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.
At lower values of output current, less output capacitance is
required for output stability. The capacitor can be reduced to
0.5µF for current below 10mA or 0.15µF for currents below
1 mA. Adjusting the MIC29372 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 750mA load at
1.23V output (Output shorted to Adjust) a 22µF (or greater)
capacitor should be used.
The MIC29372 may programmed for any output voltage between its 1.235V reference and its 26V maximum rating. An
external pair of resistors is required, as shown in Figure 3.
Programming the Output Voltage (MIC29372)
The complete equation for the output voltage is
VOUT = VREF x { 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 recommended 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 MIC29372 typically
draws 100µA at no load with SHUTDOWN open-circuited,
this is a negligible addition.
The MIC2937A/29371 will remain in regulation with a minimum
load of 5mA. When setting the output voltage of the MIC29372
version 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 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 (MIC29371)
Reducing Output Noise
A logic low output will be produced by the comparator whenever the MIC29371 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 MIC29371. 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.
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 capacitor from 1µF to 220µF only decreases the noise from 430µV
to 160µVRMS for a 100kHz bandwidth at 5V output. Noise can
be reduced by a factor of four with the adjustable regulators
Figure 1 is a timing diagram depicting the ERROR signal
and the regulated output voltage as the MIC29371 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 MIC29371’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.
OUTPUT
VOLTAGE
4.75V
NOT*
VALID
ERROR NOT*
VALID
INPUT
VOLTAGE
5V
1.3V
* SEE APPLICATIONS INFORMATION
Figure 1. ERROR Output Timing
MIC2937A/29371/29372
8
May 2006
MIC2937A/29371/29372
Micrel, Inc.
Automotive Applications
with a bypass capacitor across R1, since it reduces the high
frequency gain from 4 to unity. Pick
CBYPASS ≅
The MIC2937A 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 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.
1
2 π R1 • 200 Hz
or about 0.01µF. When doing this, the output capacitor must
be increased to 10µF to maintain stability. These changes
reduce the output noise from 430µV to 100µVRMS for a 100
kHz 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.
Typical Applications
VIN
VIN
VOUT
+VIN
VOUT
VOUT = 5V
SHUTDOWN
INPUT
+
10µF
SHUTDOWN
OFF
GND ADJUST
ON
VOUT
1.2V
R1 .01
µF
26V
10µF
1.23V
GND
V REF
R
VOUT = VREF x (1 + 1 )
R2
Figure 2. MIC2937A-5.0 Fixed +5V Regulator
R2
Figure 3. MIC29372 Adjustable Regulator
+5V to +7V
+VIN
+V IN
VIN
VOUT
SHUTDOWN
INPUT
VOUT ≈ VIN
V CC OUT
VOUT
SHUTDOWN
OFF
ON
GND
GND
ADJUST
ADJUST
5V
470 k Ω
100pF
220k Ω
1%
300k Ω
1%
+
10µF
180k Ω
1%
2N2222
3.3V
Input
0
1
Output
3.3V
5.0V
*MINIMUM INPUT-OUTPUT VOLTAGE RANGES FROM 40mV TO 400mV,
DEPENDING ON LOAD CURRENT.
SHUTDOWN PIN LOW= ENABLE OUTPUT. Q1 ON = 3.3V, Q1 OFF = 5.0V.
Figure 4. MIC29372 Wide Input Voltage Range Current Limiter
Figure 5. MIC29372 5.0V or 3.3V Selectable Regulator with
Shutdown.
May 2006
9
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
Package Information
3-Pin TO-263 (U)
3-Pin TO-220 (T)
MIC2937A/29371/29372
10
May 2006
MIC2937A/29371/29372
Micrel, Inc.
θ4
θ1
θ2
θ1
θ1
θ2
θ3
θ4
θ1
θ3
5-Pin TO-263 (U)
5-Pin TO-220 (T)
May 2006
11
MIC2937A/29371/29372
MIC2937A/29371/29372
Micrel, Inc.
MICREL INC.
TEL
2180 FORTUNE DRIVE
+ 1 (408) 944-0800
FAX
SAN JOSE, CA 95131
+ 1 (408) 474-1000
WEB
USA
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.
© 1999 Micrel, Inc.
MIC2937A/29371/29372
12
May 2006