MIC5236-3.0YMMTR - Micrel, Inc.

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

MIC5236

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

VERR

MIC5236

47k

OUT

GND

ERR

Regulator with Error Output

VOUT

3.0V/150mA

VIN

MIC5236

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

OUT

8 GND

GND

ERR

8-Pin SOIC (M)

8-Pin MSOP (MM)

OUT

8 GND

GND

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

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

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 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

0 100 200 300 400 500

GROUND PIN CURRENT (µA)

OUTPUT CURRENT (µA)

Ground Pin Current

vs. Output Current

VIN = 10V

VIN = 4V

MIC5236-3.0

012345678

GROUND CURRENT (mA)

SUPPLY VOLTAGE (V)

Ground Current

vs. Supply Voltage

ILOAD = 100µA

VOUT = 3V

MIC5236-3.0

ILOAD = 150mA

100

012345678

GROUND PIN CURRENT (µA)

SUPPLY VOLTAGE (V)

Ground Current

vs. Supply Voltage

ILOAD = 10mA

MIC5236-3.0

1mA 100

10µA

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

0.2

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

-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

-40 -20 0 20 40 60 80 100 120

INPUT VOLTAGE (V)

TEMPERATURE (°C)

Overvoltage Threshold

vs. Temperature

MIC5236-3.0

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

100

120

-30 -20 -10 0 10

INPUT CURRENT (mA)

INPUT VOLTAGE (V)

Input Current

VE N = 5V

RL= 30Ω

MIC5236-3.0

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

0.25

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 5 10 15 20

REVERSE CURRENT (µA)

EXTERNAL VOLTAGE (V)

Reverse Current

(Grounded Input)

-40°C

+25°C

+85°C

Note 11

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

MIC5236

OUT

GND

Reverse�

Current

MIC5236

OUT

GND

Reverse�

Current

July 2005 7 MIC5236

MIC5236 Micrel, Inc.

Functional Characteristics

Enable

Transient Response

TIME (250µs/div.)

).vi

/V5(

TUO

).vi

/V2(

= 5V

= 10mA

Load

Transient Response

TIME (250µs/div.)

).v

/Am001(

TUO

).vid/Vm001(

= 4V

OUT

= 3V

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

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

VERR

MIC5236

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.

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

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

VERR

MIC5236

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.

100

200

300

400

500

600

700

800

900

0 0.25 0.50 0.75 1.00 1.25 1.50

(AERA

REP

)

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.

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)

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.

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

GND

OUTIN

VIN

4 1

5-8

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 +

)

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.