July 2005 1 MIC5236
MIC5236 Micrel, Inc.
MIC5236
Low Quiescent Current µCap LDO Regulator
General Description
The MIC5236 is a low quiescent current, µCap low-dropout
regulator. With a maximum operating input voltage of 30V and
a quiescent current of 20µA, it is ideal for supplying keep-alive
power in systems with high-voltage batteries.
Capable of 150mA output, the MIC5236 has a dropout volt-
age of only 300mV. It can also survive an input transient of
–20V to +60V.
As a µCap LDO, the MIC5236 is stable with either a ceramic
or a tantalum output capacitor. It only requires a 1.0µF output
capacitor for stability.
The MIC5236 includes a logic compatible enable input and
an undervoltage error flag indicator. Other features of the
MIC5236 include thermal shutdown, current-limit, overvoltage
shutdown, load-dump protection, reverse leakage protections,
and reverse battery protection.
Available in the thermally enhanced SOIC-8 and MSOP-8, the
MIC5236 comes in fixed 2.5V, 3.0V, 3.3V, 5.0V, and adjustable
voltages. For other output voltages, contact Micrel.
Typical Application
IGND = 20µA
VOUT
3.0V/100µA
VIN
30V
IN
MIC5236
EN
OUT
GND
ERR
Regulator with Low IO and Low IQ
Features
• Ultra-low quiescent current (IQ = 20µA @IO = 100µA)
• Wide input range: 2.3V to 30V
• Low dropout:
230mV @50mA;
300mV @150mA
• Fixed 2.5V, 3.0V, 3.3V, 5.0V, and Adjustable outputs
• ±1.0% initial output accuracy
• Stable with ceramic or tantalum output capacitor
• Load dump protection: –20V to +60V input transient
survivability
• Logic compatible enable input
• Low output flag indicator
• Overcurrent protection
• Thermal shutdown
• Reverse-leakage protection
• Reverse-battery protection
• High-power SOIC-8 and MSOP-8
Applications
• Keep-alive supply in notebook and
portable personal computers
• Logic supply from high-voltage batteries
• Automotive electronics
• Battery-powered systems
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
COUT
VOUT
3.0V/150mA
VIN
5V
VERR
IN
MIC5236
EN
47k
OUT
GND
ERR
Regulator with Error Output
VOUT
3.0V/150mA
VIN
5V
IN
R1
R2
MIC5236
EN
OUT
GND
ADJ
Regulator with Adjustable Output
MIC5236 Micrel, Inc.
MIC5236 2 July 2005
Pin Description
Pin Number Pin Number Pin Name Pin Function
1 /ERR Error (Output): Open-collector output is active low when the output is out
of regulation due to insufficient input voltage or excessive load. An external
pull-up resistor is required.
1 ADJ Adjustable Feedback Input. Connect to voltage divider network.
2 2 IN Power supply input.
3 3 OUT Regulated Output
4 4 EN Enable (Input): Logic low = shutdown; logic high = enabled.
5–8 5–8 GND Ground: Pins 5, 6, 7, and 8 are internally connected in common via the lead-
frame.
Pin Configuration
1
IN
OUT
EN
8 GND
GND
GND
GND
7
6
5
2
3
4
ERR
8-Pin SOIC (M)
8-Pin MSOP (MM)
1
IN
OUT
EN
8 GND
GND
GND
GND
7
6
5
2
3
4
ADJ
8-Pin SOIC (M)
8-Pin MSOP (MM)
Ordering Information
Part Number* Voltage Junction Temp. Range Package
Standard Pb-Free
MIC5236BM MIC5236YM ADJ -40°C to +125°C 8-Pin SOIC
MIC5236BMM MIC5236YMM ADJ -40°C to +125°C 8-Pin MSOP
MIC5236-2.5BM MIC5236-2.5YM 2.5V -40°C to +125°C 8-Pin SOIC
MIC5236-2.5BMM MIC5236-2.5YMM 2.5V -40°C to +125°C 8-Pin MSOP
MIC5236-3.0BM MIC5236-3.0YM 3.0V -40°C to +125°C 8-Pin SOIC
MIC5236-3.0BMM MIC5236-3.0YMM 3.0V -40°C to +125°C 8-Pin MSOP
MIC5236-3.3BM MIC5236-3.3YM 3.3V -40°C to +125°C 8-Pin SOIC
MIC5236-3.3BMM MIC5236-3.3YMM 3.3V -40°C to +125°C 8-Pin MSOP
MIC5236-5.0BM MIC5236-5.0YM 5.0V -40°C to +125°C 8-Pin SOIC
MIC5236-5.0BMM MIC5236-5.0YMM 5.0V -40°C to +125°C 8-Pin MSOP
* Contact factory regarding availability for voltages not listed
July 2005 3 MIC5236
MIC5236 Micrel, Inc.
Absolute Maximum Ratings (Note 1)
Supply Voltage (VIN), Note 3 .........................–20V to +60V
Power Dissipation (PD), Note 4 ............... Internally Limited
Junction Temperature (TJ) ....................................... +150°C
Storage Temperature (TS) ........................ –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ........................ 260°C
ESD Rating, Note 5
Operating Ratings (Note 2)
Supply Voltage (VIN) .................................... + 2.3V to +30V
Junction Temperature (TJ) ........................ –40°C to +125°C
Package Thermal Resistance
MSOP (θJA) ........................................................................ 80°C/W
SOIC (θJA) .......................................................... 63°C/W
Electrical Characteristics
VIN = 6.0V; VEN = 2.0V; COUT = 4.7µF, IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.
Symbol Parameter Conditions Min Typ Max Units
VOUT Output Voltage Accuracy variation from nominal VOUT –1 1 %
–2 +2 %
ΔVOUT/ΔT Output Voltage Note 6 50
ppm/°C
Temperature Coefficient
ΔVOUT/VOUT Line Regulation VIN = VOUT + 1V to 30V 0.2 0.5 %
1.0 %
ΔVOUT/VOUT Load Regulation IOUT = 100µA to 50mA, Note 7 0.15 0.3 %
0.5 %
IOUT = 100µA to 150mA, Note 7 0.3 0.6 %
1.0 %
ΔV Dropout Voltage, Note 8 IOUT = 100µA 50 100 mV
IOUT = 50mA 230 400 mV
IOUT = 100mA 270 mV
IOUT = 150mA 300 500 mV
IGND Ground Pin Current VEN ≥ 2.0V, IOUT = 100µA 20 30 µA
VEN ≥ 2.0V, IOUT = 50mA 0.5 0.8 mA
VEN ≥ 2.0V, IOUT = 100mA 1.5 mA
VEN ≥ 2.0V, IOUT = 150mA 2.8 4.0 mA
5.0 mA
IGND(SHDN) Ground Pin in Shutdown VEN ≤ 0.6V, VIN = 30V 0.1 1 µA
ISC Short Circuit Current VOUT = 0V 260 350 mA
en Output Noise 10Hz to 100kHz, VOUT = 3.0V, CL = 1.0µF 160 µVrms
/ERR Output
V/ERR Low Threshold % of VOUT 90 94 %
High Threshold % of VOUT 95 98 %
VOL /ERR Output Low Voltage VIN = VOUT(nom) – 0.12VOUT, IOL = 200µA 150 250 mV
400 mV
ILEAK /ERR Output Leakage VOH = 30V 0.1 1 µA
2 µA
Enable Input
VIL Input Low Voltage regulator off 0.6 V
VIH Input High Voltage regulator on 2.0 V
MIC5236 Micrel, Inc.
MIC5236 4 July 2005
Symbol Parameter Conditions Min Typ Max Units
IIN Enable Input Current VEN = 0.6V, regulator off 0.01 1.0 µA
2.0 µA
VEN = 2.0V, regulator on 0.15 1.0 µA
2.0 µA
VEN = 30V, regulator on 0.5 2.5 µA
5.0 µA
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3: The absolute maximum positive supply voltage (60V) must be of limited duration (≤100ms) and duty cycle (≤1%). The maximum continuous
supply voltage is 30V.
Note 4: The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max) – TA) ÷ θJA. Exceeding the maximum allow-
able power dissipation will result in excessive die termperature, and the regulator will go into thermal shutdown. The θJA of the MIC5236-x.
xBM (all versions) is 63°C/W, and the MIC5236-x.xBMM (all versions) is 80°C/W, mounted on a PC board (see “Thermal Characteristics” for
further details).
Note 5. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
Note 6: Output voltage temperature coefficient is defined as the worst-case voltage change divided by the total temperature range.
Note 7: Regulation is measured at constant junction temperature using pulse testing with a low duty-cycle. Changes in output voltage due to heating
effects are covered by the specification for thermal regulation.
Note 8: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1.0V
differential.
July 2005 5 MIC5236
MIC5236 Micrel, Inc.
Typical Characteristics
0
100
200
300
400
0 40 80 120 160 200
DROPOUT VOLTAGE (mV)
OUTPUT CURRENT (mA)
Dropout Voltage
vs. Output Current
MIC5236-3.0
VOUT = 98% of Nominal VOUT
1.0
1.5
2.0
2.5
3.0
3.5
1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT VOLTAGE (V)
SUPPLY VOLTAGE (V)
Dropout Characteristics
ILOAD = 10mA
ILOAD = 50mA
ILOAD = 100mA
ILOAD = 150mA
MIC5236-3.0
0
100
200
300
400
500
600
-40 -20 0 20 40 60 80 100 120
DROPOUT VOLTAGE (mV)
TEMPERATURE (°C)
Dropout Voltage
vs. Temperature
ILOAD = 150mA
MIC5236-3.0
0
1
2
3
4
0 20 40 60 80 100 120 140 160
GROUND PIN CURRENT (mA)
OUTPUT CURRENT (mA)
Ground Current
vs. Output Current
VIN = 4V
VIN = 10V
MIC5236-3.0
0
1
2
3
4
5
012345678
GROUND CURRENT (mA)
SUPPLY VOLTAGE (V)
Ground Current
vs. Supply Voltage
ILOAD = 100µA
VOUT = 3V
MIC5236-3.0
ILOAD = 150mA
0
10
20
30
40
50
60
70
80
90
100
012345678
GROUND PIN CURRENT (µA)
SUPPLY VOLTAGE (V)
Ground Current
vs. Supply Voltage
ILOAD = 10mA
MIC5236-3.0
1mA 100
µ
A
10µA
0
0.02
0.04
0.06
0.08
0.10
-40 -20 0 20 40 60 80 100 120
GROUND CURRENT (mA)
TEMPERATURE (°C)
Ground Current
vs. Temperature
VIN = 4V
ILOAD = 10mA
MIC5236-3.0
0
0.2
0.4
0.6
0.8
1.0
1.2
-40 -20 0 20 40 60 80 100 120
GROUND CURRENT (mA)
TEMPERATURE (°C)
Ground Current
vs. Temperature
VIN = 4V
ILOAD = 75mA
MIC5236-3.0
0
1
2
3
4
-40 -20 0 20 40 60 80 100 120
GROUND CURRENT (mA)
TEMPERATURE (°C)
Ground Current
vs. Temperature
VIN = 4V
ILOAD = 150mA
MIC5236-3.0
2.985
2.990
2.995
3.000
3.005
3.010
3.015
-40 -20 0 20 40 60 80 100 120
VOLTAGE OUTPUT (V)
TEMPERATURE (°C)
Output Voltage
vs. Temperature
VIN = 4V
ILOAD = 150mA
MIC5236-3.0
255
260
265
270
275
280
285
-40 -20 0 20 40 60 80 100 120
SHORT CIRCUIT CURRENT (mA)
TEMPERATURE (°C)
Short Circuit Current
vs. Temperature
VOUT = 0V
MIC5236-3.0
MIC5236 Micrel, Inc.
MIC5236 6 July 2005
3.002
3.004
3.006
3.008
3.010
3.012
3.014
3.016
3.018
0 5 10 15 20 25 30 35
VOLTAGE OUTPUT (V)
INPUT VOLTAGE (V)
Line Regulation
ILOAD = 10mA
MIC5236-3.0
36
37
38
39
40
41
-40 -20 0 20 40 60 80 100 120
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Overvoltage Threshold
vs. Temperature
MIC5236-3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0 100 200 300 400
OUTPUT VOLTAGE (V)
CURRENT LIMIT (mA)
Current Limit
vs. Output Voltage
MIC5236-3.0
0
20
40
60
80
100
120
-30 -20 -10 0 10
INPUT CURRENT (mA)
INPUT VOLTAGE (V)
Input Current
VE N = 5V
RL= 30Ω
MIC5236-3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
0 0.5 1.0 1.5 2.0
OUTPUT-LOW VOLTAGE (V)
SINK CURRENT (mA)
Dropout Induced
Error Flag
VIN = 2.7V
VOUT =2.62V
No Load
MIC5236-3.0
0
0.25
0.50
0.75
1.00
1.25
0 0.5 1.0 1.5 2.0 2.5 3.0
OUTPUT-LOW VOLTAGE (V)
SINK CURRENT (mA)
Current Limit Induced
Error Flag
VIN = 6V
VOUT = 2.03V
RL= 6Ω
MIC5236-3.0
0
10
20
30
40
50
60
70
0 5 10 15 20
REVERSE CURRENT (µA)
EXTERNAL VOLTAGE (V)
Reverse Current
(Grounded Input)
-40°C
+25°C
+85°C
Note 11
0
10
20
30
40
50
60
0 5 10 15 20
REVERSE CURRENT (µA)
EXTERNAL VOLTAGE (V)
Reverse Current
(Open Input)
-40°C
+25°C
+85°C
Note 10
Note 10 Note 11
IN
MIC5236
OUT
GND
Reverse�
Current
EN
IN
MIC5236
OUT
GND
Reverse�
Current
EN
July 2005 7 MIC5236
MIC5236 Micrel, Inc.
Functional Characteristics
Enable
Transient Response
TIME (250µs/div.)
V
NE
).vi
d
/V5(
V
TUO
).vi
d
/V2(
V
IN
= 5V
I
L
= 10mA
Load
Transient Response
TIME (250µs/div.)
I
T
UO
).v
id
/Am001(
V
TUO
).vid/Vm001(
V
IN
= 4V
V
OUT
= 3V
C
OUT
= 15µF
ESR = 200mΩ
MIC5236 Micrel, Inc.
MIC5236 8 July 2005
Functional Diagram
RFB1
Error
Amplifier
Error
Comparator
VREF
1.23V
RFB2
RFB3
OUT
ERR
GND
MIC5236-x.x
IN
EN
July 2005 9 MIC5236
MIC5236 Micrel, Inc.
Application Information
The MIC5236 provides all of the advantages of the MIC2950:
wide input voltage range, load dump (positive transients up
to 60V), and reversed-battery protection, with the added ad-
vantages of reduced quiescent current and smaller package.
Additionally, when disabled, quiescent current is reduced to
0.1µA.
Enable
A low on the enable pin disables the part, forcing the quies-
cent current to less than 0.1µA. Thermal shutdown and the
error flag are not functional while the device is disabled. The
maximum enable bias current is 2µA for a 2.0V input. An open
collector pull-up resistor tied to the input voltage should be
set low enough to maintain 2V on the enable input. Figure 1
shows an open collector output driving the enable pin through
a 200k pull-up resistor tied to the input voltage.
In order to avoid output oscillations, slow transitions from low
to high should be avoided.
COUT
VOUT
VIN
5V
VERR
IN
MIC5236
EN
200k
200k
OUT
GND
SHUTDOWN
ENABLE
ERR
Figure 1. Remote Enable
Input Capacitor
An input capacitor may be required when the device is not
near the source power supply or when supplied by a bat-
tery. Small, surface mount, ceramic capacitors can be used
for bypassing. Larger values may be required if the source
supply has high ripple.
Output Capacitor
The MIC5236 has been designed to minimize the effect of the
output capacitor ESR on the closed loop stability. As a result,
ceramic or film capacitors can be used at the output. Figure 2
displays a range of ESR values for a 10µF capacitor. Virtually
any 10µF capacitor with an ESR less than 3.4Ω is sufficient
for stability over the entire input voltage range. Stability can
also be maintained throughout the specified load and line
conditions with 1µF film or ceramic capacitors.
0
1
2
3
4
5
5 10 15 20 25 30
OUTPUT CAPACITOR ESR (Ω)
INPUT VOLTAGE (V)
Stable Region
TJ= 25°C
VOUT = 10µF
Figure 2. Output Capacitor ESR
Error Detection Comparator Output
The ERR pin is an open collector output which goes low when
the output voltage drops 5% below it’s internally programmed
level. It senses conditions such as excessive load (current
limit), low input voltage, and over temperature conditions.
Once the part is disabled via the enable input, the error flag
output is not valid. Overvoltage conditions are not reflected
in the error flag output. The error flag output is also not valid
for input voltages less than 2.3V.
The error output has a low voltage of 400mV at a current of
200µA. In order to minimize the drain on the source used
for the pull-up, a value of 200k to 1MΩ is suggested for the
error flag pull-up. This will guarantee a maximum low voltage
of 0.4V for a 30V pull-up potential. An unused error flag can
be left unconnected.
NOT
VALID
NOT
VALID
VALID ERROR
Error
Output
Input
Voltage
Output
Voltage
4.75V
0V
0V
5V
1.3V
Figure 3. Error Output Timing
Reverse Current Protection
The MIC5236 is designed to limit the reverse current flow
from output to input in the event that the MIC5236 output
has been tied to the output of another power supply. See
the graphs detailing the reverse current flow with the input
grounded and open.
Thermal Shutdown
The MIC5236 has integrated thermal protection. This feature
is only for protection purposes. The device should never be
intentionally operated near this temperature as this may
have detrimental effects on the life of the device. The ther-
mal shutdown may become inactive while the enable input
is transitioning a high to a low. When disabling the device
via the enable pin, transition from a high to low quickly. This
will insure that the output remains disabled in the event of a
thermal shutdown.
Current Limit
Figure 4 displays a method for reducing the steady state
short circuit current. The duration that the supply delivers
current is set by the time required for the error flag output
to discharge the 4.7µF capacitor tied to the enable pin. The
off time is set by the 200K resistor as it recharges the 4.7µF
capacitor, enabling the regulator. This circuit reduces the
short circuit current from 280mA to 15mA while allowing for
regulator restart once the short is removed.
MIC5236 Micrel, Inc.
MIC5236 10 July 2005
COUT
VOUT
VIN
5V
VERR
IN
MIC5236
EN
200k
1N4148
200k
4.7µF
OUT
GND
SHUTDOWN
ENABLE
ERR
Figure 4. Remote Enable with Short-Circuit
Current Foldback
Thermal Characteristics
The MIC5236 is a high input voltage device, intended to
provide 150mA of continuous output current in two very small
profile packages. The power SOIC-8 and power MSOP-8 al-
low the device to dissipate about 50% more power than their
standard equivalents.
Power SOIC-8 Thermal Characteristics
One of the secrets of the MIC5236’s performance is its power
SO-8 package featuring half the thermal resistance of a
standard SO-8 package. Lower thermal resistance means
more output current or higher input voltage for a given pack-
age size.
Lower thermal resistance is achieved by joining the four
ground leads with the die attach paddle to create a single-
piece electrical and thermal conductor. This concept has
been used by MOSFET manufacturers for years, proving
very reliable and cost effective for the user.
Thermal resistance consists of two main elements, θJC (junc-
tion-to-case thermal resistance) and θCA (case-to-ambient
thermal resistance). See Figure 5. θJC is the resistance from
the die to the leads of the package. θCA is the resistance
from the leads to the ambient air and it includes θCS (case-
to-sink thermal resistance) and θSA (sink-to-ambient thermal
resistance).
qJA
qJC
qCA
printed circuit board
ground plane
heat sink area
SOP-8
AMBIENT
Figure 5. Thermal Resistance
Using the power SOIC-8 reduces the θJC dramatically and
allows the user to reduce θCA. The total thermal resistance,
θJA (junction-to-ambient thermal resistance) is the limiting
factor in calculating the maximum power dissipation capabil-
ity of the device. Typically, the power SOIC-8 has a θJC of
20°C/W, this is significantly lower than the standard SOIC-8
which is typically 75°C/W. θCA is reduced because pins 5
through 8 can now be soldered directly to a ground plane
which significantly reduces the case-to-sink thermal resistance
and sink to ambient thermal resistance.
Low-dropout linear regulators from Micrel are rated to a
maximum junction temperature of 125°C. It is important not to
exceed this maximum junction temperature during operation
of the device. To prevent this maximum junction temperature
from being exceeded, the appropriate ground plane heat sink
must be used.
0
100
200
300
400
500
600
700
800
900
0 0.25 0.50 0.75 1.00 1.25 1.50
m
m
(AERA
REP
P
OC
2
)
POWER DISSIPATION (W)
04 °C
05 °C
55 °C
56 °C
57 °C
58 °C
001 °C
Figure 6. Copper Area vs. Power-SOIC
Power Dissipation (∆TJA)
Figure 6 shows copper area versus power dissipation with
each trace corresponding to a different temperature rise
above ambient.
From these curves, the minimum area of copper necessary for
the part to operate safely can be determined. The maximum
allowable temperature rise must be calculated to determine
operation along which curve.
ΔT = TJ(max) – TA(max)
TJ(max) = 125°C
TA(max) = maximum ambient operating temperature
For example, the maximum ambient temperature is 50°C,
the ΔT is determined as follows:
ΔT = 125°C – 50°C
ΔT = 75°C
Using Figure 6, the minimum amount of required copper can
be determined based on the required power dissipation. Power
dissipation in a linear regulator is calculated as follows:
PD = (VIN – VOUT) IOUT + VIN · IGND
If we use a 3V output device and a 28V input at moderate
output current of 25mA, then our power dissipation is as
follows:
PD = (28V – 3V) × 25mA + 28V × 250µA
PD = 625mW + 7mW
PD = 632mW
From Figure 6, the minimum amount of copper required to
operate this application at a ΔT of 75°C is 25mm2.
Quick Method
Determine the power dissipation requirements for the design
along with the maximum ambient temperature at which the
device will be operated. Refer to Figure 7, which shows safe
operating curves for three different ambient temperatures:
July 2005 11 MIC5236
MIC5236 Micrel, Inc.
25°C, 50°C and 85°C. From these curves, the minimum
amount of copper can be determined by knowing the maxi-
mum power dissipation required. If the maximum ambient
temperature is 50°C and the power dissipation is as above,
632mW, the curve in Figure 7 shows that the required area
of copper is 25mm2.
The θJA of this package is ideally 63°C/W, but it will vary
depending upon the availability of copper ground plane to
which it is attached.
0
100
200
300
400
500
600
700
800
900
0 0.25 0.50 0.75 1.00 1.25 1.50
COPPER AREA (mm2)
POWER DISSIPATION (W)
85°C
50°C
25°C
TJ= 125°C
Figure 7. Copper Area vs. Power-SOIC
Power Dissipation (TA)
0
100
200
300
400
500
600
700
0 0.25 0.50 0.75 1.00 1.25 1.50
COPPER AREA (mm2)
POWER DISSIPATION (W)
40°C
50°C
55°C
65°C
75°C
85°C
100°C
Figure 8. Copper Area vs. Power-MSOP
Power Dissipation (∆TJA)
The same method of determining the heat sink area used
for the power-SOIC-8 can be applied directly to the power-
MSOP-8. The same two curves showing power dissipation
versus copper area are reproduced for the power-MSOP-8
and they can be applied identically, see Figures 8 and 9.
0
100
200
300
400
500
600
700
800
900
0 0.25 0.50 0.75 1.00 1.25 1.50
COPPER AREA (mm2)
POWER DISSIPATION (W)
85°C
50°C
25°C
TJ= 125°C
Figure 9. Copper Area vs. Power-MSOP
Power Dissipation (TA)
Power MSOP-8 Thermal Characteristics
The power-MSOP-8 package follows the same idea as the
power-SO-8 package, using four ground leads with the die
attach paddle to create a single-piece electrical and thermal
conductor, reducing thermal resistance and increasing power
dissipation capability.
Quick Method
Determine the power dissipation requirements for the design
along with the maximum ambient temperature at which the
device will be operated. Refer to Figure 9, which shows safe
operating curves for three different ambient temperatures,
25°C, 50°C, and 85°C. From these curves, the minimum
amount of copper can be determined by knowing the maxi-
mum power dissipation required. If the maximum ambient
temperature is 50°C, and the power dissipation is 639mW,
the curve in Figure 9 shows that the required area of copper
is 110mm2,when using the power MSOP-8.
Adjustable Regulator Application
MIC5236BM/MM
EN
GND
OUTIN
VIN
2
4 1
3
5-8
V
R1
R2
1µF
OUT
ADJ
Figure 10. Adjustable Voltage Application
The MIC5236BM/MM can be adjusted from 1.24V to 20V by
using two external resistors (Figure 10). The resistors set the
output voltage based on the following equation:
VOUT = VREF (1 +
R
R
1
2
)
Where VREF = 1.23V.
MIC5236 Micrel, Inc.
MIC5236 12 July 2005
Package Information
45°
0°–8°
0.244 (6.20)
0.228 (5.79)
0.197 (5.0)
0.189 (4.8) SEATING
PLANE
0.026 (0.65)
MAX)
0.010 (0.25)
0.007 (0.18)
0.064 (1.63)
0.045 (1.14)
0.0098 (0.249)
0.0040 (0.102)
0.020 (0.51)
0.013 (0.33)
0.157 (3.99)
0.150 (3.81)
0.050 (1.27)
TYP
PIN 1
DIMENSIONS:
INCHES (MM)
0.050 (1.27)
0.016 (0.40)
8-Pin SOIC (M)
0.008 (0.20)
0.004 (0.10)
0.039 (0.99)
0.035 (0.89)
0.021 (0.53)
0.012 (0.03) R
0.0256 (0.65) TYP
0.012 (0.30) R
5° MAX
0° MIN
0.122 (3.10)
0.112 (2.84)
0.120 (3.05)
0.116 (2.95)
0.012 (0.03)
0.007 (0.18)
0.005 (0.13)
0.043 (1.09)
0.038 (0.97)
0.036 (0.90)
0.032 (0.81)
DIMENSIONS:
INCH (MM)
0.199 (5.05)
0.187 (4.74)
8-Pin MSOP (MM)
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.
© 2005 Micrel, Inc.
Mouser Electronics
Authorized Distributor
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MIC5236-5.0YMM MIC5236-3.0YM MIC5236YM MIC5236-3.3YMM MIC5236-5.0YM MIC5236YMM MIC5236-
3.0YMM MIC5236-2.5YM MIC5236-3.3YM MIC5236-2.5YMM MIC5236-3.3YM TR MIC5236-5.0YMM TR MIC5236-
3.0YMM TR MIC5236-5.0YM TR MIC5236YM TR MIC5236YMM TR MIC5236-2.5YM TR MIC5236-3.0YM TR
MIC5236-3.3YMM TR MIC5236-2.5YMM TR MIC5236-3.3YM-TR MIC5236-5.0YM-TR MIC5236-2.5YM-TR
MIC5236-3.3YMM-TR MIC5236YM-TR MIC5236-3.0YM-TR MIC5236-5.0YMM-TR MIC5236YMM-TR MIC5236-
3.0YMM-TR MIC5236-2.5YMM-TR