MIC5209YUTR - Micrel, Inc. - Datasheet.Directory

June 2006 1

M9999-060906

Typical Applications

1

3

2

0.1

µ

F

22

µ

F

tantalum

V

OUT

2.5V

±

1%

V

IN

≥

3.0V

MIC5209-2.5BS

3.3V Nominal-Input Slot-1

Power Supply

1

2

3

4

8

7

6

5

MIC5209-5.0BM

2.2

µ

F

tantalum

V

OUT

5V

470pF

(OPTIONAL)

V

IN

6V

ENABLE

SHUTDOWN

Ultra-Low-Noise 5V Regulator

MIC5209

500mA Low-Noise LDO Regulator

General Description

The MIC5209 is an efﬁ cient linear voltage regulator with very

low dropout voltage, typically 10mV at light loads and less

than 500mV at full load, with better than 1% output voltage

accuracy.

Designed especially for hand-held, battery-powered devices,

the MIC5209 features low ground current to help prolong

battery life. An enable/shutdown pin on SO-8 and TO-263-

5 versions can further improve battery life with near-zero

shutdown current.

Key features include reversed-battery protection, current

limiting, overtemperature shutdown, ultra-low-noise capability

(SO-8 and TO-263-5 versions), and availability in thermally

efﬁ cient packaging. The MIC5209 is available in adjustable

or ﬁ xed output voltages.

For space-critical applications where peak currents do not

exceed 500mA, see the MIC5219.

Features

• Meets Intel

®

Slot 1 and Slot 2 requirements

® Slot 1 and Slot 2 requirements

®

• Guaranteed 500mA output over the full operating

temperature range

• Low 500mV maximum dropout voltage at full load

• Extremely tight load and line regulation

• Thermally-efﬁ cient surface-mount package

• Low temperature coefﬁ cient

• Current and thermal limiting

• Reversed-battery protection

• No-load stability

• 1% output accuracy

• Ultra-low-noise capability in SO-8 and TO-263-5

• Ultra-small 3mm x 3mm MLF™ package

Applications

• Pentium II Slot 1 and Slot 2 support circuits

• Laptop, notebook, and palmtop computers

• Cellular telephones

• Consumer and personal electronics

• SMPS post-regulator/dc-to-dc modules

• High-efﬁ ciency linear power supplies

Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

MIC5209 Micrel, Inc.

M9999-060906

2 June 2006

Ordering Information

Part Number

Voltage

Junction Temp. Range

Package

Pb-Free

MIC5209-2.5BS

2.5V

-40°C to +125°C

SOT-223

MIC5209-2.5YS

2.5V

-40°C to +125°C

SOT-223

X

MIC5209-3.0BS

3.0V

-40°C to +125°C

SOT-223

MIC5209-3.0YS

3.0V

-40°C to +125°C

SOT-223

X

MIC5209-3.3BS

3.3V

-40°C to +125°C

SOT-223

MIC5209-3.3YS

3.3V

-40°C to +125°C

SOT-223

X

MIC5209-3.6BS

3.6V

-40°C to +125°C

SOT-223

MIC5209-3.6YS

3.6V

-40°C to +125°C

SOT-223

X

MIC5209-4.2BS

4.2V

-40°C to +125°C

SOT-223

MIC5209-4.2YS

4.2V

-40°C to +125°C

SOT-223

X

MIC5209-5.0BS

5.0V

-40°C to +125°C

SOT-223

MIC5209-5.0YS

5.0V

-40°C to +125°C

SOT-223

X

MIC5209-1.8BM*

1.8V

-0°C to +125°C

SOIC-8

MIC5209-1.8YM*

1.8V

-0°C to +125°C

SOIC-8

X

MIC5209-2.5BM

2.5V

-40°C to +125°C

SOIC-8

MIC5209-2.5YM

2.5V

-40°C to +125°C

SOIC-8

X

MIC5209-3.0BM

3.0V

-40°C to +125°C

SOIC-8

MIC5209-3.0YM

3.0V

-40°C to +125°C

SOIC-8

X

MIC5209-3.3BM

3.3V

-40°C to +125°C

SOIC-8

MIC5209-3.3YM

3.3V

-40°C to +125°C

SOIC-8

X

MIC5209-3.6BM

3.6V

-40°C to +125°C

SOIC-8

MIC5209-3.6YM

3.6V

-40°C to +125°C

SOIC-8

X

MIC5209-5.0BM

5.0V

-40°C to +125°C

SOIC-8

MIC5209-5.0YM

5.0V

-40°C to +125°C

SOIC-8

X

MIC5209BM

Adj.

-40°C to +125°C

SOIC-8

MIC5209YM

Adj.

-40°C to +125°C

SOIC-8

X

MIC5209-1.8YU*

1.8V

-0°C to +125°C

TO-263-5

X

MIC5209-2.5BU

2.5V

-40°C to +125°C

TO-263-5

MIC5209-2.5YU

2.5V

-40°C to +125°C

TO-263-5

X

MIC5209-3.0BU

3.0V

-40°C to +125°C

TO-263-5

MIC5209-3.0YU

3.0V

-40°C to +125°C

TO-263-5

X

MIC5209-3.3BU

3.3V

-40°C to +125°C

TO-263-5

MIC5209-3.3YU

3.3V

-40°C to +125°C

TO-263-5

X

MIC5209-3.6BU

3.6V

-40°C to +125°C

TO-263-5

MIC5209-3.6YU

3.6V

-40°C to +125°C

TO-263-5

X

MIC5209-5.0BU

5.0V

-40°C to +125°C

TO-263-5

MIC5209-5.0YU

5.0V

-40°C to +125°C

TO-263-5

X

MIC5209BU

Adj.

-40°C to +125°C

TO-263-5

MIC5209YU

Adj.

-40°C to +125°C

TO-263-5

X

MIC5209YML

Adj.

-40°C to +125°C

8-pin MLF™

X

* Contact marketing for availability.

June 2006 3

M9999-060906

MIC5209 Micrel, Inc.

1

2

3

4

8

7

6

5

GND

EN

IN

OUT

BYP

MIC5209-x.xBM

SO-8

Fixed Voltages

1

2

3

4

8

7

6

5

GND

EN

IN

OUT

ADJ

MIC5209BM

SO-8

Adjustable Voltage

Pin Description

Pin No.

8-pin MLF

Pin No.

SOT-223

Pin No.

SO-8

Pin No.

TO-263-5

Pin Name

Pin Function

1, 2

1

2

IN

Supply Input.

7

2, TAB

5–8

3

GND

Ground: SOT-223 pin 2 and TAB are internally connected. SO-8

pins 5 through 8 are internally connected.

3, 4

3

4

OUT

Regulator Output. Pins 3 and 4 must be tied together.

8

1

EN

Enable (Input): CMOS compatible control input. Logic high =

enable; logic low = shutdown.

4 (ﬁ xed)

5 (ﬁ xed)

BYP

Reference Bypass: Connect external 470pF capacitor to GND to

reduce output noise. May be left open. For 1.8V or 2.5V operation,

see “Applications Information.”

6

4 (adj.)

5 (adj.)

ADJ

Adjust (Input): Feedback input. Connect to resistive voltage-divider

network.

5 BYP

4 OUT

3 GND

2 IN

1 EN

DNG

BAT

MIC5209-x.xBU

TO-263-5

Fixed Voltages

5

ADJ

4

OUT

3

GND

2

IN

1

EN

D

N

G

B

A

T

ATA

MIC5209BU

TO-263-5

Adjustable Voltage

Pin Conﬁ guration

I

N

OUT

GND

1

3

2

TAB

GND

MIC5209-x.xBS

SOT-223

Fixed Voltages

1

VIN

VOUT

8

EN

GND

ADJ

NC

7

6

5

2

3

4

5209

YWW

Y

Part

Identification

MIC5209YML

8-Pin 3x3 MLF

Adjustable Voltages

MIC5209 Micrel, Inc.

M9999-060906

4 June 2006

Electrical Characteristics

(Note 11)

V

IN

= V

OUT

+ 1.0V; C

OUT

= 4.7µF, I

OUT

= 100µA; T

J

= 25°C,

bold

values indicate –40°C ≤ T

J

≤ +125°C except 0°C ≤ T

J

≤ +125°C

for 1.8V version; unless noted.

Symbol Parameter Conditions Min Typical Max Units

V

OUT

Output Voltage Accuracy variation from nominal V

OUT

–1 1 %

–2 2

%

ΔV

OUT

/ΔT Output Voltage

Note 4

40

ppm/°C

Temperature Coefﬁ cient

ΔV

OUT

/V

OUT

Line Regulation V

IN

= V

OUT

+ 1V to 16V 0.009 0.05 %/V

0.1

%/V

ΔV

OUT

/V

OUT

Load Regulation I

OUT

= 100µA to 500mA

(5)

0.05 0.5 %

0.7 %

V

IN

– V

OUT

Dropout Voltage

(6)

I

OUT

= 100µA 10 60 mV

80

mV

I

OUT

= 50mA 115 175 mV

250

mV

I

OUT

= 150mA 165 300 mV

400

mV

I

OUT

= 500mA 350 500 mV

600

mV

I

GND

Ground Pin Current

(7, 8)

V

EN

≥ 3.0V, I

OUT

= 100µA 80 130 µA

170

µA

V

EN

≥ 3.0V, I

OUT

= 50mA 350 650 µA

900

µA

V

EN

≥ 3.0V, I

OUT

= 150mA 1.8 2.5 mA

3.0

mA

V

EN

≥ 3.0V, I

OUT

= 500mA 8 20 mA

25

mA

I

GND

Ground Pin Quiescent Current

(8)

V

EN

≤ 0.4V (shutdown) 0.05

3

µA

V

EN

≤ 0.18V (shutdown) 0.10

8

µA

PSRR Ripple Rejection f = 120Hz 75 dB

I

LIMIT

Current Limit V

OUT

= 0V 700

900 mA

1000

mA

ΔV

OUT

/ΔP

D

Thermal Regulation

Note 9

0.05 %/W

e

no

Output Noise

(10)

V

OUT

= 2.5V, I

OUT

= 50mA, 500 nV √Hz

C

OUT

= 2.2µF, C

BYP

= 0

I

OUT

= 50mA, C

OUT

= 2.2µF, C

BYP

= 470pF 300 nV √Hz

Symbol Parameter Conditions Min Typical Max Units

/ΔT Output Voltage

Temperature Coefﬁ cient

Line Regulation V

Load Regulation I

I

Ground Pin Current

V

Ground Pin Quiescent Current

V

PSRR Ripple Rejection f = 120Hz 75 dB

Current Limit V

Thermal Regulation

Output Noise

C

I

Symbol Parameter Conditions Min Typical Max Units

Output Voltage Accuracy variation from nominal V

Temperature Coefﬁ cient

Line Regulation V

Load Regulation I

I

600

V

PSRR Ripple Rejection f = 120Hz 75 dB

Current Limit V

V

C

I

Symbol Parameter Conditions Min Typical Max Units

–1 1 %

Temperature Coefﬁ cient

+ 1V to 16V 0.009 0.05 %/V

0.05 0.5 %

= 100µA 10 60 mV

= 50mA 115 175 mV

= 150mA 165 300 mV

= 500mA 350 500 mV

600

= 100µA 80 130 µA

= 50mA 350 650 µA

= 150mA 1.8 2.5 mA

= 500mA 8 20 mA

≤ 0.4V (shutdown) 0.05

≤ 0.18V (shutdown) 0.10

PSRR Ripple Rejection f = 120Hz 75 dB

= 0V 700

Note 9

= 50mA, 500 nV √Hz

= 470pF 300 nV √Hz

Symbol Parameter Conditions Min Typical Max Units

–1 1 %

–2 2

40

Temperature Coefﬁ cient

+ 1V to 16V 0.009 0.05 %/V

0.05 0.5 %

= 100µA 10 60 mV

= 50mA 115 175 mV

= 150mA 165 300 mV

= 500mA 350 500 mV

600

= 100µA 80 130 µA

= 50mA 350 650 µA

= 150mA 1.8 2.5 mA

= 500mA 8 20 mA

≤ 0.4V (shutdown) 0.05

≤ 0.18V (shutdown) 0.10

PSRR Ripple Rejection f = 120Hz 75 dB

= 0V 700

= 50mA, 500 nV √Hz

= 470pF 300 nV √Hz

Symbol Parameter Conditions Min Typical Max Units

–1 1 %

–2 2

ppm/°C

+ 1V to 16V 0.009 0.05 %/V

0.05 0.5 %

= 100µA 10 60 mV

= 50mA 115 175 mV

= 150mA 165 300 mV

= 500mA 350 500 mV

600

= 100µA 80 130 µA

= 50mA 350 650 µA

= 150mA 1.8 2.5 mA

= 500mA 8 20 mA

PSRR Ripple Rejection f = 120Hz 75 dB

0.05 %/W

= 50mA, 500 nV √Hz

= 470pF 300 nV √Hz

Symbol Parameter Conditions Min Typical Max Units

–1 1 %

ppm/°C

+ 1V to 16V 0.009 0.05 %/V

0.05 0.5 %

0.7 %

= 100µA 10 60 mV

= 50mA 115 175 mV

= 150mA 165 300 mV

= 500mA 350 500 mV

= 100µA 80 130 µA

= 50mA 350 650 µA

= 150mA 1.8 2.5 mA

= 500mA 8 20 mA

PSRR Ripple Rejection f = 120Hz 75 dB

900 mA

0.05 %/W

= 50mA, 500 nV √Hz

= 470pF 300 nV √Hz

Absolute Maximum Ratings

(1)

Supply Input Voltage (V

IN

)

..............................

–20V to +20V

Power Dissipation (P

D

)

..........................

Internally Limited

(3)

Junction Temperature (T

J

)

all except 1.8V

......................................

–40°C to +125°C

1.8V only

...................................................

0°C to +125°C

Lead Temperature (soldering, 5 sec.)

........................

260°C

Storage Temperature (T

S

)

........................

–65°C to +150°C

Operating Ratings

(2)

Supply Input Voltage (V

IN

)

............................

+2.5V to +16V

Enable Input Voltage (V

EN

)

...................................

0V to V

IN

Junction Temperature (T

J

)

all except 1.8V

......................................

–40°C to +125°C

1.8V only

...................................................

0°C to +125°C

Package Thermal Resistance

...................................

Note 3

June 2006 5

M9999-060906

MIC5209 Micrel, Inc.

ENABLE Input

V

ENL

Enable Input Logic-Low Voltage V

ENL Enable Input Logic-Low Voltage V

ENL

EN

= logic low (regulator shutdown) 0.4 V

0.18

V

EN

= logic high (regulator enabled) 2.0 V

I

ENL

Enable Input Current V

ENL Enable Input Current V

ENL

≤ 0.4V 0.01 –1 µA

ENL ≤ 0.4V 0.01 –1 µA

ENL

V

ENL

≤ 0.18V

ENL ≤ 0.18V

ENL

0.01

–2

µA

I

ENH

V

ENH

= 2.0V 5 20 µA

25

µA

V

ENH

= 16V 30 µA

50

µA

Notes:

1.

Exceeding the absolute maximum rating may damage the device.

2. The device is not guaranteed to function outside its operating rating.

3. The maximum allowable power dissipation at any T

A

3. The maximum allowable power dissipation at any TA

3. The maximum allowable power dissipation at any T

(ambient temperature) is calculated using: P

A (ambient temperature) is calculated using: P

A

D

(max) = (T

J

(max) – T

A

(max) – TA

(max) – T

)

÷

θ

JA

. Exceeding the

maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. See Table 1 and the

“Thermal Considerations”

section for details.

“Thermal Considerations” section for details.“Thermal Considerations”

4. Output voltage temperature coefﬁ cient is the worst case voltage change divided by the total temperature range.

5. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range

from 100µA to 500mA. Changes in output voltage due to heating effects are covered by the thermal regulation speciﬁ cation.

6. Dropout voltage is deﬁ ned as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V differen-

tial.

7. Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load

current plus the ground pin current.

8. V

EN

is the voltage externally applied to devices with the EN (enable) input pin. [SO-8 (M) and TO-263-5 (U) packages only.]

9. Thermal regulation is the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation ef-

fects. Speciﬁ cations are for a 500mA load pulse at V

IN

= 16V for t = 10ms.

10. C

BYP

is an optional, external bypass capacitor connected to devices with a BYP (bypass) or ADJ (adjust) pin. [SO-8 (M) and TO-263-5 (U) packages

only].

Enable Input Logic-Low Voltage V

V

Enable Input Current V

V

25

V

Enable Input Logic-Low Voltage V

V

Enable Input Current V

V

25

V

= logic low (regulator shutdown) 0.4 V

= logic high (regulator enabled) 2.0 V

≤ 0.4V 0.01 –1 µA

≤ 0.18V

= 2.0V 5 20 µA

25

= 16V 30 µA

= logic low (regulator shutdown) 0.4 V

= logic high (regulator enabled) 2.0 V

≤ 0.4V 0.01 –1 µA

= 2.0V 5 20 µA

25

= 16V 30 µA

= logic low (regulator shutdown) 0.4 V

= logic high (regulator enabled) 2.0 V

≤ 0.4V 0.01 –1 µA

= 2.0V 5 20 µA

25

= 16V 30 µA

= logic low (regulator shutdown) 0.4 V

= logic high (regulator enabled) 2.0 V

≤ 0.4V 0.01 –1 µA

= 2.0V 5 20 µA

= 16V 30 µA

µA

MIC5209 Micrel, Inc.

M9999-060906

6 June 2006

Block Diagrams

Current Limit

Thermal Shutdown

IN

OUT

GND

Bandgap

Ref.

C

OUT

V

OUT

V

IN

MIC5209-x.xBS

Low-Noise Fixed Regulator (SOT-223 version only)

IN

EN

OUT

BYP

C

BYP

(optional)

GND

V

REF

Bandgap

Ref.

V

Ref.

V

REF

Ref.

REF

Current Limit

Thermal Shutdown

C

OUT

V

OUT

V

IN

MIC5209-x.xBM/U

Ultra-Low-Noise Fixed Regulator

IN

EN

OUT

C

BYP

(optional)

GND

V

REF

Bandgap

Ref.

V

Ref.

V

REF

Ref.

REF

Current Limit

Thermal Shutdown

C

OUT

V

OUT

V

IN

R1

R2

MIC5209BM/U [adj.]

ADJ

Ultra-Low-Noise Adjustable Regulator

June 2006 7

M9999-060906

MIC5209 Micrel, Inc.

Typical Characteristics

-100

-80

-60

-40

-20

0

1E+1 1E+21E+31E+41E+51E+61E+7

)B

d(

RR

S

P

FREQUENCY (Hz)

Power Supply

Rejection Ratio

IOUT = 100µA

COUT = 1µF

VIN = 6V

VOUT = 5V

10 100 1k 10k 100k 1M 10M

-100

-80

-60

-40

-20

0

1E+11E+21E+31E+41E+51E+61E+7

)B

d(

RR

S

P

FREQUENCY (Hz)

Power Supply

Rejection Ratio

I

OUT

= 1mA

C

OUT

= 1µF

V

IN

= 6V

V

OUT

= 5V

10 100 1k 10k 100k 1M 10M -100

-80

-60

-40

-20

0

1E+11E+21E+31E+41E+51E+61E+7

)Bd(RRSP

FREQUENCY (Hz)

Power Supply

Rejection Ratio

I

OUT

= 100mA

C

OUT

= 1µF

V

IN

= 6V

V

OUT

= 5V

10 100 1k 10k 100k 1M 10M

-100

-80

-60

-40

-20

0

1E+1 1E+21E+31E+41E+51E+61E+7

)B

d(

RR

S

P

FREQUENCY (Hz)

Power Supply

Rejection Ratio

IOUT = 100µA

COUT = 2.2µF

CBYP = 0.01µF

VIN = 6V

VOUT = 5V

10 100 1k 10k 100k 1M 10M

-100

-80

-60

-40

-20

0

1E+11E+21E+31E+41E+51E+61E+7

)B

d(

RR

S

P

FREQUENCY (Hz)

Power Supply

Rejection Ratio

I

OUT

= 1mA

C

OUT

= 2.2µF

C

BYP

= 0.01µF

V

IN

= 6V

V

OUT

= 5V

10 100 1k 10k 100k 1M 10M -100

-80

-60

-40

-20

0

1E+11E+21E+31E+41E+51E+61E+7

)Bd(RRSP

FREQUENCY (Hz)

Power Supply

Rejection Ratio

I

OUT

= 100mA

C

OUT

= 2.2µF

C

BYP

= 0.01µF

V

IN

= 6V

V

OUT

= 5V

10 100 1k 10k 100k 1M 10M

0

10

20

30

40

50

60

0 0.1 0.2 0.3 0.4

)Bd(N

OI

T

CE

JE

RELPPI

R

VOLTAGE DROP (V)

Power Supply Ripple Rejection

vs. Voltage Drop

I

OUT

= 100mA

10mA

1mA

C

OUT

= 1µF

0

10

20

30

40

50

60

70

80

90

100

0 0.1 0.2 0.3 0.4

)Bd(NOITCE

J

E

R

EL

PP

I

R

VOLTAGE DROP (V)

Power Supply Ripple Rejection

vs. Voltage Drop

IOUT = 100mA

10mA

1mA

COUT = 2.2µF

CBYP = 0.01µF

0.0001

0.001

0.01

0.1

1

10

1E+11E+21E+31E+41E+51E+61E+7

(ESION µ/V √)zH

FREQUENCY (Hz)

Noise Performance

10 100 1k 10k 100k 1M 10M

10mA, C

OUT = 1µF

VOUT = 5V

0.0001

0.001

0.01

0.1

1

10

1E+11E+21E+31E+41E+51E+61E+7

(ESION µ/V

√

)zH

FREQUENCY (Hz)

Noise Performance

10mA

1mA

100mA

10 100 1k 10k 100k 1M 10M

V

OUT

= 5V

C

OUT

= 10µF

electrolytic

0.0001

0.001

0.01

0.1

1

10

1E+11E+21E+31E+41E+51E+61E+7

(ESION µ/V

√

)zH

FREQUENCY (Hz)

Noise Performance

10mA

1mA

100mA

10 100 1k 10k 100k 1M 10M

VOUT = 5V

COUT = 10µF

electrolytic

CBYP = 100pF

0

100

200

300

400

0 100 200 300 400 500

)Vm(

E

GATLOVTUOPORD

OUTPUT CURRENT (mA)

Dropout Voltage

vs. Output Current

MIC5209 Micrel, Inc.

M9999-060906

8 June 2006

0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 1 2 3 4 5 6 7 8 9

)V(E

G

ATL

O

VTU

P

TUO

INPUT VOLTAGE (V)

Dropout Characteristics

IL =100µA

IL=100mA

IL=500mA

0

2

4

6

8

10

12

0 100 200 300 400 500

)Am(TNERRUCDNUORG

OUTPUT CURRENT (mA)

Ground Current

vs. Output Current

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9

)A

m

(TN

ER

RUCD

NU

ORG

INPUT VOLTAGE (V)

Ground Current

vs. Supply Voltage

IL=500mA

0

0.5

1.0

1.5

2.0

2.5

3.0

0 2 4 6 8

)Am(TNERRUCDNUORG

INPUT VOLTAGE (V)

Ground Current

vs. Supply Voltage

IL=100 mA

IL=100µ

A

June 2006 9

M9999-060906

MIC5209 Micrel, Inc.

Applications Information

Enable/Shutdown

Enable is available only on devices in the SO-8 (M) and

TO-263-5 (U) packages.

Forcing EN (enable/shutdown) high (> 2V) enables the regula-

tor. EN is compatible with CMOS logic. If the enable/shutdown

feature is not required, connect EN to IN (supply input).

Input Capacitor

A 1µF capacitor should be placed from IN to GND if there is

more than 10 inches of wire between the input and the ac

ﬁ lter capacitor or if a battery is used as the input.

Output Capacitor

An output capacitor is required between OUT and GND to

prevent oscillation. The minimum size of the output capacitor

is dependent upon whether a reference bypass capacitor is

used. 1µF minimum is recommended when C

BYP

is not used

(see Figure 1). 2.2µF minimum is recommended when C

BYP

is 470pF (see Figure 2). Larger values improve the regulator’s

transient response.

The output capacitor should have an ESR (equivalent series

resistance) of about 1Ω and a resonant frequency above

1MHz. Ultra-low-ESR capacitors can cause a low amplitude

oscillation on the output and/or underdamped transient re-

sponse. Most tantalum or aluminum electrolytic capacitors

are adequate; ﬁ lm types will work, but are more expensive.

Since many aluminum electrolytics have electrolytes that

freeze at about –30°C, solid tantalums are recommended

for operation below –25°C.

At lower values of output current, less output capacitance

is needed for output stability. The capacitor can be reduced

to 0.47µF for current below 10mA or 0.33µF for currents

below 1mA.

No-Load Stability

The MIC5209 will remain stable and in regulation with no load

(other than the internal voltage divider) unlike many other

voltage regulators. This is especially important in CMOS

RAM keep-alive applications.

Reference Bypass Capacitor

BYP (reference bypass) is available only on devices in SO-8

and TO-263-5 packages.

BYP is connected to the internal voltage reference. A 470pF

capacitor (C

BYP

) connected from BYP to GND quiets this

reference, providing a signiﬁ cant reduction in output noise

(ultra-low-noise performance). Because C

BYP

reduces the

phase margin, the output capacitor should be increased to

at least 2.2µF to maintain stability.

The start-up speed of the MIC5209 is inversely proportional

to the size of the reference bypass capacitor. Applications

requiring a slow ramp-up of output voltage should consider

larger values of C

BYP

. Likewise, if rapid turn-on is necessary,

consider omitting C

BYP

.

If output noise is not critical, omit C

BYP

and leave BYP

open.

Thermal Considerations

The SOT-223 has a ground tab which allows it to dissipate

more power than the SO-8. Refer to “Slot-1 Power Supply”

for details. At 25°C ambient, it will operate reliably at 2W

dissipation with “worst-case” mounting (no ground plane,

minimum trace widths, and FR4 printed circuit board).

Thermal resistance values for the SO-8 represent typical

mounting on a 1”-square, copper-clad, FR4 circuit board.

For greater power dissipation, SO-8 versions of the MIC5209

feature a fused internal lead frame and die bonding arrange-

ment that reduces thermal resistance when compared to

standard SO-8 packages.

Package

θ

JA

θ

JC

SOT-223 (S) 50°C/W 8°C/W

SO-8 (M) 50°C/W 20°C/W

TO-263-5 (U) — 2°C/W

3x3 MLF (ML) 63°C/W 2°C/W

Table 1. MIC5209 Thermal Resistance

Multilayer boards with a ground plane, wide traces near the

pads, and large supply-bus lines will have better thermal con-

ductivity and will also allow additional power dissipation.

For additional heat sink characteristics, please refer to Mi-

crel Application Hint 17, “Designing P.C. Board Heat Sinks”,

included in Micrel’s

Databook

. For a full discussion of heat

sinking and thermal effects on voltage regulators, refer to

Regulator Thermals section of Micrel’s

Designing with Low-

Dropout Voltage Regulators

handbook.

Low-Voltage Operation

The MIC5209-1.8 and MIC5209-2.5 require special con-

sideration when used in voltage-sensitive systems. They

may momentarily overshoot their nominal output voltages

unless appropriate output and bypass capacitor values are

chosen.

During regulator power up, the pass transistor is fully satu-

rated for a short time, while the error ampliﬁ er and voltage

reference are being powered up more slowly from the output

(see “Block Diagram”). Selecting larger output and bypass

capacitors allows additional time for the error ampliﬁ er and

reference to turn on and prevent overshoot.

To ensure that no overshoot is present when starting up into

a light load (100µA), use a 4.7µF output capacitance and

470pF bypass capacitance. This slows the turn-on enough

to allow the regulator to react and keep the output voltage

from exceeding its nominal value. At heavier loads, use a

10µF output capacitance and 470pF bypass capacitance.

Lower values of output and bypass capacitance can be used,

depending on the sensitivity of the system.

Applications that can withstand some overshoot on the output

of the regulator can reduce the output capacitor and/or reduce

or eliminate the bypass capacitor. Applications that are not

sensitive to overshoot due to power-on reset delays can use

normal output and bypass capacitor conﬁ gurations.

Please note the junction temperature range of the regulator

at 1.8V output (ﬁ xed and adjustable) is 0˚C to +125˚C.

SOT-223 (S) 50°C/W 8°C/W

SO-8 (M) 50°C/W 20°C/W

TO-263-5 (U) — 2°C/W

3x3 MLF (ML) 63°C/W 2°C/W

Package

SO-8 (M) 50°C/W 20°C/W

3x3 MLF (ML) 63°C/W 2°C/W

MIC5209 Micrel, Inc.

M9999-060906

10

June 2006

Fixed Regulator Circuits

MIC5209-x.xBM

I

N

OUT

GND

1

µ

F

V

IN

V

OUT

E

N

BYP

1

2

5

–

8

3

4

Figure 1. Low-Noise Fixed Voltage Regulator

Figure 1 shows a basic MIC5209-x.xBM (SO-8) ﬁ xed-voltage

regulator circuit. See Figure 5 for a similar conﬁ guration us-

ing the more thermally-efﬁ cient MIC5209-x.xBS (SOT-223).

A 1µF minimum output capacitor is required for basic ﬁ xed-

voltage applications.

MIC5209-x.xBM

I

N

OUT

GND

470pF

V

IN

E

N

BYP

1

2

5

–

8

3

4

2.2

µ

F

V

OUT

Figure 2. Ultra-Low-Noise Fixed Voltage Regulator

Figure 2 includes the optional 470pF noise bypass capacitor

between BYP and GND to reduce output noise. Note that the

minimum value of C

OUT

must be increased when the bypass

capacitor is used.

Adjustable Regulator Circuits

MIC5209BM

I

N

OUT

GND

V

IN

E

N

ADJ

1

2

5

–

8

3

4

1

µ

F

V

OUT

R1

R2

Figure 3. Low-Noise Adjustable Voltage Regulator

The MIC5209BM/U can be adjusted to a speciﬁ c output volt-

age by using two external resistors (Figure 3). The resistors

set the output voltage based on the equation:

V

=

1.242V

+

R2

R1

OUT

VOUT

V

1





































This equation is correct due to the conﬁ guration of the

bandgap reference. The bandgap voltage is relative to the

output, as seen in the block diagram. Traditional regula-

tors normally have the reference voltage relative to ground;

therefore, their equations are different from the equation for

the MIC5209BM/U.

Although ADJ is a high-impedance input, for best performance,

R2 should not exceed 470kΩ.

MIC5209BM

IN OUT

GND

V

IN

EN ADJ

1

2

5–8

3

4

2.2µF

V

OUT

R1

R2

470pF

Figure 4. Ultra-Low-Noise Adjustable Application.

Figure 4 includes the optional 470pF bypass capacitor from

ADJ to GND to reduce output noise.

Slot-1 Power Supply

Intel’s Pentium II processors have a requirement for a 2.5V

±5% power supply for a clock synthesizer and its associated

loads. The current requirement for the 2.5V supply is depen-

dant upon the clock synthesizer used, the number of clock

outputs, and the type of level shifter (from core logic levels to

2.5V levels). Intel estimates a worst-case load of 320mA.

The MIC5209 was designed to provide the 2.5V power

requirement for Slot-1 applications. Its guaranteed perfor-

mance of 2.5V ±3% at 500mA allows adequate margin for

all systems, and its dropout voltage of 500mV means that it

operates from a worst-case 3.3V supply where the voltage

can be as low as 3.0V.

MIC5209-x.xBS

I

N

OUT

GND

C

OUT

22

µ

F

V

IN

V

OUT

1

2,TAB

3

C

IN

0.1

µ

F

Figure 5. Slot-1 Power Supply

A Slot-1 power supply (Figure 5) is easy to implement. Only

two capacitors are necessary, and their values are not criti-

cal. C

IN

bypasses the internal circuitry and should be at least

0.1µF. C

OUT

provides output ﬁ ltering, improves transient

response, and compensates the internal regulator control

loop. Its value should be at least 22µF. C

IN

and C

OUT

may

be increased as much as desired.

Slot-1 Power Supply Power Dissipation

Powered from a 3.3V supply, the Slot-1 power supply of

Figure 5 has a nominal efﬁ ciency of 75%. At the maximum

anticipated Slot 1 load (320mA), the nominal power dissipa-

tion is only 256mW.

The SOT-223 package has sufﬁ cient thermal characteristics

for wide design margins when mounted on a single layer

copper-clad printed circuit board. The power dissipation of

the MIC5209 is calculated using the voltage drop across the

device

×

output current plus supply voltage

×

ground current.

June 2006 11

M9999-060906

MIC5209 Micrel, Inc.

Considering worst case tolerances, the power dissipation

could be as high as:

(V

IN(max)

– V

OUT(max)

)

×

I

OUT

+ V

IN(max)

×

I

GND

[(3.6V – 2.375V)

×

320mA] + (3.6V

×

4mA)

P

D

= 407mW

Using the maximum junction temperature of 125°C and a

θ

JC

of 8°C/W for the SOT-223, 25°C/W for the SO-8, or 2°C/W

for the TO-263 package, the following worst-case heat-sink

thermal resistance (

θ

SA

) requirements are:

θ

JA

J(max

)

A

D

T

J(max

TJ(max

T

A

TA

P

D

P

D

=

−

θ

SA

= θ

SA = θ

SA

JA

= θ

JA = θ

JA

JC

T

A

TA

T

40°C 50°C 60°C 75°C

A 40°C 50°C 60°C 75°C

A

θ

JA

(limit) 209°C/W 184°C/W 160°C/W 123°C/W

θ

SA

SOT-223 201°C/W 176°C/W 152°C/W 115°C/W

SA SOT-223 201°C/W 176°C/W 152°C/W 115°C/W

SA

θ

SA

SO-8 184°C/W 159°C/W 135°C/W 98°C/W

SA SO-8 184°C/W 159°C/W 135°C/W 98°C/W

SA

θ

SA

TO-263-5 207°C/W 182°C/W 158°C/W 121°C/W

SA TO-263-5 207°C/W 182°C/W 158°C/W 121°C/W

SA

Table 2. Maximum Allowable Thermal Resistance

Table 2 and Figure 6 show that the Slot-1 power supply ap-

plication can be implemented with a minimum footprint layout.

T

40°C 50°C 60°C 75°C

(limit) 209°C/W 184°C/W 160°C/W 123°C/W

SOT-223 201°C/W 176°C/W 152°C/W 115°C/W

SO-8 184°C/W 159°C/W 135°C/W 98°C/W

TO-263-5 207°C/W 182°C/W 158°C/W 121°C/W

Figure 6 shows the necessary copper pad area to obtain

speciﬁ c heat sink thermal resistance (

θ

SA

) values. The

θ

SA

values in Table 2 require much less than 500mm

2

of copper,

according to Figure 6, and can easily be accomplished with

the minimum footprint.

0

10

20

30

40

50

60

70

0

200

0

400

0

6000

COPPER HEAT SINK AREA (mm

2

COPPER HEAT SINK AREA (mm

2

COPPER HEAT SINK AREA (mm

)

Figure 6. PCB Heat Sink Thermal Resistance

MIC5209 Micrel, Inc.

M9999-060906

12

June 2006

Package Information

SOT-223 (S)

8-Pin SOIC (M)

June 2006 13

M9999-060906

MIC5209 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 speciﬁ cations at any time without notiﬁ cation 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 signiﬁ cant 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.

1

θ

θ1

3

θ

4θ

1

θ

2

θ

3

θ4θ

2θ1θ

TO-263-5 (U)

8-Pin 3mm x 3mm MLF (ML)