MIC2937A/29371/29372
Micrel, Inc.
MICMIC2937A/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
INPUT
GROUND OUTPUT
TO-263 Package
(MIC2937A-xxBU)
1 2 3 4 5
TO-263-5 Package
(MIC29371/29372BU)
Five Lead Package Pin Functions:
MIC29371 MIC29372
1) Error
Adjust
2) Input
Shutdown
3) Ground
Ground
4) Output
Input
5) Shutdown Output
2 3 OUTPUT
INPUT 1
GROUND
TO-220 Package
(MIC2937A-xxBT)
1 2 3 4 5
TO-220-5 Package
(MIC29371/29372BT)
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
April 2005
1
M9999-041205
MIC2937A/29371/29372
Micrel, Inc.
Ordering Information
Standard
Part Number
Pb-Free**
Voltage
Temperature
Range*
Package
MIC2937A-3.3BU
MIC2937A-3.3WU
3.3V
–40°C to +125°C
TO-263-3
MIC2937A-3.3BT
MIC2937A-3.3WT
3.3V
–40°C to +125°C
TO-220-3
MIC2937A-5.0BU
MIC2937A-5.0WU
5.0V
–40°C to +125°C
TO-263-3
MIC2937A-5.0BT
MIC2937A-5.0WT
5.0V
–40°C to +125°C
TO-220-3
MIC2937A-12BU
MIC2937A-12WU
12V
–40°C to +125°C
TO-263-3
MIC2937A-12BT
MIC2937A-12WT
12V
–40°C to +125°C
TO-220-3
MIC29371-3.3BU
MIC29371-3.3WU
3.3V
–40°C to +125°C
TO-263-5
MIC29371-3.3BT
MIC29371-3.3WT
3.3V
–40°C to +125°C
TO-220-5
MIC29371-5.0BU
MIC29371-5.0WU
5.0V
–40°C to +125°C
TO-263-5
MIC29371-5.0BT
MIC29371-5.0WT
5.0V
–40°C to +125°C
TO-220-5
MIC29371-12BU
MIC29371-12WU
12V
–40°C to +125°C
TO-263-5
MIC29371-12BT
MIC29371-12WT
12V
–40°C to +125°C
TO-220-5
MIC29372BU
MIC29372WU
ADJ
–40°C to +125°C
TO-263-5
MIC29372BT
MIC29372WT
ADJ
–40°C to +125°C
TO-220-5
* Junction Temperature Range
** Pb-Free RoHS compliant with "hot-melting solder" exemption.
Absolute Maximum Ratings
If Military/Aerospace specified devices are required, contact your local Micrel representative/distributor for availability and specifications.
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
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.
M9999-041205
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April 2005
MIC2937A/29371/29372
Micrel, Inc.
Electrical Characteristics(Note 13)
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:
5mA ≤ IL ≤ 500mA
(Note 2)
Output voltage > 10V
VIN = VOUT + 1V to 26V
∆VO
∆T
∆VO
VO
∆VO
VO
Output Voltage
Temperature Coef.
Line Regulation
Load Regulation
IL = 5 to 500mA
(Note 3)
VIN – VO
Dropout Voltage
(Note 4)
IL = 5mA
IL = 750mA
200
240
300
420
370
IL = 5mA
160
IL = 500mA
Output voltage > 10V
IGNDDO
ILIMIT
∆VO
∆PD
en
April 2005
Max
1
2
2.5
1.5
3
4
100
350
0.10
0.40
0.16
0.30
150
180
Units
%
ppm/°C
%
%
mV
600
750
IL = 100mA
1
IL = 500mA
8
IL = 750mA
15
250
300
2.5
3
13
16
25
200
500
µA
1.1
1.5
2
0.2
A
Ground Pin
Current at Dropout
(Note 5)
Current Limit
VIN = 0.5V less than designed VOUT
(VOUT ≥ 3.3V)
IO = 5mA
VOUT = 0V
(Note 6)
Thermal Regulation (Note 7)
Output Noise
Voltage
(10Hz to 100kHz)
IL = 100mA
20
80
0.03
80
Output voltage > 10V
Ground Pin Current
(Note 5)
Typical
0.04
IL = 100mA
IGND
Min
–1
–2
–2.5
–1.5
–3
–4
0.05
CL = 10µF
400
CL = 100µF
260
3
µA
mA
%/W
µV RMS
M9999-041205
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
perature
Coefficient
20
(Note 7)
20
Adjust Pin Bias
Current Temperature
Coefficient
Error Comparator
Units
ppm/°C Tem-
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
40
25
M9999-041205
95
140
mV
mV
1.3
V
0.7
High (OFF)
Regulator Output
Current in Shutdown
mV
MIC29371/MIC29372
Input Logic Voltage
Low (ON)
Shutdown Pin
Input Current
60
2.0
VSHUTDOWN = 2.4V
30
50
100
µA
VSHUTDOWN = 26V
450
600
750
µA
3
10
20
µA
(Note 10)
4
April 2005
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.
Note 13: Specification for packaged product only.
Schematic Diagram
FEEDBACK
IN
R18
20kΩ
Q15A
Q15B
Q24
Q26
Q25
OUT
Q9
Q3
R11
18
kΩ
Q4
Q7
Q6
R11
20.6
kΩ
Q1
10
R2
50 kΩ
Q16
Q17
R27
R17
12 kΩ
Q14
V TAP
R28
Q2
Q20
R1
20 kΩ
Q42
SENSE
Q8
Q5
C1
20
pF
R5
180
kΩ
Q40
R6
140
kΩ
Q13
Q22
R10
150
kΩ
R8
31.4 kΩ
Q21
R12
110
kΩ
Q12
Q41
Q23
C2
40 pF
R9
27.8 kΩ
R13
100
kΩ
R15
100 kΩ
R14
350
kΩ
R16
30 kΩ
Q11
R17
10 Ω
Q29
R30
30
kΩ
Q18
Q19
Q28
R3
50 kΩ
R4
13 kΩ
R21 8 Ω
50 kΩ
Q30 Q31
Q37
10 kΩ
R22
150 kΩ
Q36
R23 60 kΩ
ERROR
Q38
Q34
R26
60 kΩ
DENOTES CONNECTION ON
MIC2937A-xx AND MIC29371-xx
VERSIONS ONLY
R25
2.8 kΩ
GND
Q39
April 2005
SHDN
R24
50 kΩ
5
M9999-041205
MIC2937A/29371/29372
Micrel, Inc.
Typical Characteristics
1
0.1
1
100
100
0
10
100
1000
OUTPUT CURRENT (mA)
0.20
0.15
0.10
ILOAD = 5mA
0.05
0
1
2
3
4
5
INPUT VOLTAGE (V)
Ground Current
vs. Supply Voltage
25
20
15
10
FIXED 5V
ILOAD = 750mA
5
0
2
4
6
8
INPUT VOLTAGE (V)
ILOAD = 100mA
1.0
0.8
0.6
0.4
0.2
0.0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
1.2
ILOAD = 750mA
25
20
15
10
5
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
Ground Current
vs. Input Voltage
500
VOUT = VNOMINAL – 0.5V
1.0
0.8
0.6
10
30
1.6
1.4
1.2
6
Ground Current
vs. Temperature
1.4
CURRENT (A)
OUTPUT VOLTAGE (V)
ILOAD = 750mA
1
0
8
VOUT = 0V
0.4
3.24
3.22
0.2
3.20
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
0.0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
M9999-041205
2
Short Circuit and Maximum
Current vs. Temperature
3.40
3.38
3.28
3.26
2 3 4 5 6 7
SUPPLY VOLTAGE (V)
2.0
1.8
Fixed 3.3V Output Voltage
vs. Temperature
3.32
3.30
1
3
Ground Current
vs. Temperature
0.00
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
3.36
3.34
FIXED 5V VERSION
ILOAD = 5mA
0
ILOAD = 5mA
30
150
50
Dropout
Characteristics
4
0
Ground Current
vs. Supply Voltage
200
Ground Current
vs. Temperature
0.25
GROUND CURRENT (mA)
200
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
GROUND CURRENT (µA)
GROUND CURRENT (mA)
10
ILOAD = 750mA
300
200
400
600
800
OUTPUT CURRENT (mA)
Ground Current
vs. Output Current
30
400
GROUND CURRENT (mA)
0
5
500
GROUND CURRENT (mA)
100
600
FIXED 5V
VERSION
6
GROUND CURRENT (µA)
200
6
OUTPUT VOLTAGE (V)
DROPOUT VOLTAGE (mV)
300
700
GROUND CURRENT (mA)
DROPOUT VOLTAGE (mV)
400
0
Dropout Voltage
vs. Temperature
Dropout Voltage
vs. Output Current
500
400
RLOAD = 100Ω
300
200
100
0
-100
-30
-20 -10 0
10 20
INPUT VOLTAGE (V)
30
April 2005
MIC2937A/29371/29372
Micrel, Inc.
VEN = 5V
75
150
C
OUT
= 10 µF
0
-150
-250
-5
MIC29372/3 Adjust Pin
Current vs. Temperature
10
ILOAD = 1mA
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
20
0
-20
-40
10
8
6
4
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
TIME (ms)
OUTPUT IMPEDANCE (Ω)
10
-100
1000
-200
750
500
250
0
-250
-5
Line Transient
COUT = 10 µF
IL = 5mA
COUT = 100 µF
0
INPUT (V)
20
10
100
Load Transeint
20
10
5mA
0
5
TIME (ms)
10
Line Transient
COUT = 100 µF
IL = 5mA
0
-10
10
8
6
4
-0.2 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
TIME (ms)
Output Impedance
vs. Frequency
1
0.1
ILOAD = 10mA
1x100
0.01
1x106
30
40
0
5
TIME (ms)
100x103
40
INPUT (V)
∆ OUTPUT (mV)
50
5mA
200
∆ OUTPUT (mV)
250
0
10x103
25
750
500
1x103
VEN = 2V
100x100
50
OUTPUT (mA)
1000
-300
0
-60 -30 0 30 60 90 120 150
TEMPERATURE (°C)
ADJUST PIN CURRENT (nA)
Load Transient
∆ OUTPUT (mV)
100
300
10x100
ENABLE CURRENT (µA)
125
OUTPUT (mA) ∆ OUTPUT (mV)
MIC29371/2 Shutdown Current
vs. Temperaure
FREQUENCY (Hz)
April 2005
7
M9999-041205
MIC2937A/29371/29372
Micrel, Inc.
Applications Information
External Capacitors
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.
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.
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 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.
Programming the Output Voltage (MIC29372)
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.
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 opencircuited, this is a negligible addition.
Reducing Output Noise
Error Detection Comparator Output (MIC29371)
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
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.
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.
4.75V
OUTPUT
VOLTAGE
ERROR
NOT *
VALID
NOT*
VALID
INPUT
VOLTAGE
5V
1.3V
* SEE APPLICATIONS INFORMATION
Figure 1. ERROR Output Timing
M9999-041205
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April 2005
MIC2937A/29371/29372
Micrel, Inc.
regulators with a bypass capacitor across R1, since it reduces
the high frequency gain from 4 to unity. Pick
CBYPASS ≅
Automotive Applications
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
V IN
+VIN
VIN
*V OUT ≈5V
V
OUT
VOUT
VOUT = 5V
+
SHUTDOWN
10µF
INPUT
SHUTDOWN
26V
10µF
OFF
GND
VOUT
1.2V
GND ADJUST
R1 .01
µF
ON
1.23V
R1
VOUT = VREF x (1 +
)
R2
Figure 2. MIC2937A-5.0 Fixed +5V Regulator
V REF
R2
Figure 3. MIC29372 Adjustable Regulator
+5V to +7V
+VIN
+VIN
VIN
VOUT
VOUT ≈ VIN
VCC OUT
VOUT
SHUTDOWN
INPUT
SHUTDOWN
OFF
+
ON
100pF
GND
GND
ADJUST
300kΩ
1%
10µF
ADJUST
5V
470 kΩ
220kΩ
1%
180kΩ
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.
April 2005
9
M9999-041205
MIC2937A/29371/29372
Micrel, Inc.
Package Information
0.405±0.005
0.176 ±0.005
0.050±0.005
0.065 ±0.010
20°±2°
0.050 ±0.005
0.360±0.005
0.600±0.025
SEATING PLANE
0.004 +0.004
–0.008
0.100 BSC
0.100 ±0.01
8° MAX
0.050
0.015 ±0.002
DIM. = INCH
3-Lead TO-263 (U)
0.151 D ±0.005
(3.84 D ±0.13)
0.410 ±0.010
(10.41 ±0.25)
0.108 ±0.005
(2.74 ±0.13)
0.818 ±0.005
(20.78 ±0.13)
0.176 ±0.005
(4.47 ±0.13)
0.590 ±0.005
(14.99 ±0.13)
0.050 ±0.005
(1.27 ±0.13)
7°
0.356 ±0.005
(9.04 ±0.13)
7°
3°
1.140 ±0.010
(28.96 ±0.25)
0.050 ±0.003
(1.27 ±.08)
0.030 ±0.003
(0.76 ±0.08)
0.018 ±0.008
(0.46 ±0.020)
0.100 ±0.005
(2.54 ±0.13)
0.100 ±0.020
(2.54 ±0.51)
DIMENSIONS: INCH
(MM)
3-Lead TO-220 (T)
M9999-041205
10
April 2005
MIC2937A/29371/29372
Micrel, Inc.
0.405±0.005
0.176 ±0.005
0.050±0.005
0.065 ±0.010
20°±2°
0.060 ±0.005
0.360±0.005
0.600±0.025
SEATING PLANE
0.004 +0.004
–0.008
0.067±0.005
0.100 ±0.01
8° MAX
0.032 ±0.003
0.015 ±0.002
DIM. = INCH
5-Lead TO-263 (U)
0.150 D ±0.005
(3.81 D ±0.13)
0.177 ±0.008
(4.50 ±0.20)
0.400 ±0.015
(10.16 ±0.38)
0.108 ±0.005
(2.74 ±0.13)
0.050 ±0.005
(1.27 ±0.13)
0.241 ±0.017
(6.12 ±0.43)
0.578 ±0.018
(14.68 ±0.46)
SEATING
PLANE
7°
Typ.
0.550 ±0.010
(13.97 ±0.25)
0.067 ±0.005
(1.70 ±0.127)
0.032 ±0.005
(0.81 ±0.13)
0.268 REF
(6.81 REF)
0.018 ±0.008
(0.46 ±0.20)
0.103 ±0.013
(2.62±0.33)
Dimensions: inch
(mm)
5-Lead TO-220 (T)
April 2005
11
M9999-041205
MIC2937A/29371/29372
Micrel, Inc.
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.
© 1999 Micrel Incorporated
M9999-041205
12
April 2005