Datasheet MIC5205-2.5BM5, MIC5205-2.5YM5, MIC5205-2.7BM5, MIC5205-2.7YM5, MIC5205-2.85BM5 Datasheet (Micrel) [ru]

General Description

MIC5205

150mA Low-Noise LDO Regulator

Features

The MIC5205 is an efficient linear voltage regulator with
ultra low-noise output, very low dropout voltage (typically
17mV at light loads and 165mV at 150mA), and very low
ground current (600⎧A at 100mA output). The MIC5205
offers better than 1% initial accuracy.

Designed especially for hand-held, battery-powered
devices, the MIC5205 includes a CMOS or TTL compatible
enable/shutdown control input. When shut down, power
consumption drops nearly to zero. Regulator ground
current increases only slightly in dropout, further
prolonging battery life.

Key MIC5205 features include a reference bypass pin to
improve its already excellent low-noise performance,
reversed-battery protection, current limiting, and
overtemperature shutdown.

The MIC5205 is available in fixed and adjustable output
voltage versions in a small SOT-23-5 package.

For low-dropout regulators that are stable with ceramic
output capacitors, see the

Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.

___________________________________________________________________________________________________________

µ

Cap MIC5245/6/7 family.

• Ultra-low-noise output

• High output voltage accuracy

• Guaranteed 150mA output

• Low quiescent current

• Low dropout voltage

• Extremely tight load and line regulation

• Very low temperature coefficient

• Current and thermal limiting

• Reverse-battery protection

• “Zero” off-mode current

• Logic-controlled electronic enable

Applications

• Cellular telephones

• Laptop, notebook, and palmtop computers

• Battery-powered equipment

CC

and V

PP

• PCMCIA V

• Consumer/personal electronics

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

• High-efficiency linear power supplies

regulation/switching

Typical Application

Xxxxx is a trademark of Micrel, Inc
Xxxxx is a registered trademark of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

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Ultra-Low-Noise Regulator Application

408

) 944-0800 • fax + 1 [phone] • http://www.micrel.com

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Ordering Information

Part Number Marking

Standard Pb-Free Standard Pb-Free

MIC5205BM5 MIC5205YM5 LBAA KBAA 1% Adj –40°C to +125°C SOT-23-5

MIC5205-2.5BM5 MIC5205-2.5YM5 LB25 KB25 1% 2.5V –40°C to +125°C SOT-23-5

MIC5205-2.7BM5 MIC5205-2.7YM5 LB27 KB27 1% 2.7V –40°C to +125°C SOT-23-5

MIC5205-2.8BM5 MIC5205-2.8YM5 LB28 KB28 1% 2.8V –40°C to +125°C SOT-23-5

MIC5205-2.85BM5 MIC5205-2.85YM5 LB2J KB2J 1% 2.85V –40°C to +125°C SOT-23-5

MIC5205-2.9BM5 MIC5205-2.9YM5 LB29 KB29 1% 2.9V –40°C to +125°C SOT-23-5

MIC5205-3.0BM5 MIC5205-3.0YM5 LB30 KB30 1% 3.0V –40°C to +125°C SOT-23-5

MIC5205-3.1BM5 MIC5205-3.1YM5 LB31 KB31 1% 3.1V –40°C to +125°C SOT-23-5

MIC5205-3.2BM5 MIC5205-3.2YM5 LB32 KB32 1% 3.2V –40°C to +125°C SOT-23-5

MIC5205-3.3BM5 MIC5205-3.3YM5 LB33 KB33 1% 3.3V –40°C to +125°C SOT-23-5

MIC5205-3.6BM5 MIC5205-3.6YM5 LB36 KB36 1% 3.6V –40°C to +125°C SOT-23-5

MIC5205-3.8BM5 MIC5205-3.8YM5 LB38 KB38 1% 3.8V –40°C to +125°C SOT-23-5

MIC5205-4.0BM5 MIC5205-4.0YM5 LB40 KB40 1% 4.0V –40°C to +125°C SOT-23-5

MIC5205-5.0BM5 MIC5205-5.0YM5 LB50 KB50 1% 5.0V –40°C to +125°C SOT-23-5

Note:

1. Underbar (_) symbol may not be to scale.

Accuracy Voltage Temperature Package

(1)

Pin Configuration

MIC5205-x.xBM5/YM5 MIC5205BM5/YM5
Fixed Voltages Adjustable Voltages

Pin Description

MIC5205-x.x

(fixed)

1 1 IN Supply Input

2 2 GND Ground

3 3 EN

4 BYP

4 ADJ

5 5 OUT Regulator Ouput

MIC5205

(adjustable)

Pin Name Pin Function

Enable/Shudown (Input): CMOS compatible input. Logic high = enable, logic low
or open = shutdown

Reference Bypass: Connect external 470pF capacitor to GND to reduce output
noise. May be left open.

Adjust (Input): Adjustable regulator feedback input. Connect to resistor voltage
divider.

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z

Absolute Maximum Ratings

(1)

Operating Ratings

(2)

Supply Input Voltage (VIN).............................. –20V to +20V

Enable Input Voltage (V
Power Dissipation (P

)............................. –20V to +20V

EN

) .................Internally Limited, Note 3

D

Lead Temperature (soldering, 5 sec.)........................ 260°C

Junction Temperature (T
Storage Temperature (T

) ........................–40°C to +125°C

J

)......................... –65°C to +150°C

S

Input Voltage (VIN)......................................... +2.5V to +16V

Enable Input Voltage (V

).....................................0V to V

EN

Junction Temperature (TJ) ........................–40°C to +125°C

Thermal Resistance, SOT-23-5 (θ

) ........................ Note 3

JA

Electrical Characteristics

V

= V

OUT

+ 1V; I

IN

Symbol Parameter Condition Min Typ Max Units

V

O

∆VO/∆T

∆VO/V

O

∆VO/V

O

VIN – V

O

I

GND

I

GND

PSRR Ripple Rejection Frequency = 100Hz, IL = 100µA 75 dB

I

LIMIT

∆VO/∆PDThermal Regulation Note 8 0.05 %/W

e

NO

ENABLE Input

V

IL

V

IH

I

IL

I

IH

= 100µA; C

L

Output Voltage Accuracy variations from specified V

Output Voltage Temperature
Coefficient

Line Regulation VIN = V

Load Regulation IL = 0.1mA to 150mA, Note 5 0.02

Dropout Voltage, Note 6

Quiescent Current

Ground Pin Current, Note 7

Current Limit V

Output Noise

Enable Input Logic-Low Voltage regulator shutdown

Enable Input Logic-High
Voltage

Enable Input Current

(4)

= 1.0µF; V

L

≥ 2.0V; T

EN

= 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.

J

OUT

Note 4

+ 1V to 16V 0.004

OUT

I

= 100µA

L

= 50mA

I

L

= 100mA

I

L

= 150mA

I

L

V

≤ 0.4V (shutdown)

EN

V

≤ 0.18V (shutdown)

EN

V

≥ 2.0V, IL = 100µA

EN

= 50mA

I

L

= 100mA

I

L

= 150mA

I

L

= 0V

OUT

I

= 50mA, CL = 2.2µF, 470pF from BYP to

L

GND

regulator enabled

V

≤ 0.4V

IL

V

≤ 0.18V

IL

= 2.0V

V

IL

VIL = 2.0V

–1

–2

40

1
2

0.012

0.05

0.2

0.5

10

110

140

165

50

70
150
230
250
300
275
350

0.01

1
5

80

350

600

1300

125
150
600
800

1000
1500
1900

2500

320

500 mA

260

0.4

0.18

2.0

2

V

0.01

5

–1

–2

20

25

%
%

ppm/°C

%/V
%/V

%
%

mV
mV
mV
mV
mV
mV
mV
mV

µA
µA

µA
µA
µA
µA
µA
µA
µA
µA

nV/

V
V

µA
µA
µA
µA

H

IN

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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

power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The ⎝
versions) is 220°C/W mounted on a PC board (see “Thermal Considerations” section for further details).

4. Output voltage temperature coefficient is defined as 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 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.

6. Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V
differential.

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, 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 150mA load pulse at V

A

(ambient temperature) is P

IN

= 16V for t = 10ms.

D(max)

= (T

J(max)

– TA) ⎟ ⎝JA. Exceeding the maximum allowable

JA

of the MIC5205-xxBM5 (all

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Typical Characteristics

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Typical Characteristics

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Block Diagrams

Ultra-Low-Noise Fixed Regulator

Ultra-Low-Noise Adjustable Regulator

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(

)

(

Application Information

0.33µF for currents below 1mA.

Enable/Shutdown

Forcing EN (enable/shutdown) high (> 2V) enables the
regulator. EN is compatible with CMOS logic gates.

If the enable/shutdown feature is not required, connect
EN (pin 3) to IN (supply input, pin 1). See Figure 1.

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 filter capacitor or if a battery is used as the
input.

Reference Bypass Capacitor

BYP (reference bypass) is connected to the internal
voltage reference. A 470pF capacitor (C

) connected

BYP

from BYP to GND quiets this reference, providing a

BYP

significant reduction in output noise. C
regulator phase margin; when using C

reduces the

, output

BYP

capacitors of 2.2µF or greater are generally required to
maintain stability.

The start-up speed of the MIC5205 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 a major concern, omit C

BYP

and

leave BYP open.

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. 1.0µF minimum is recommended
when C
recommended when C

is not used (see Figure 2). 2.2µF minimum is

BYP

is 470pF (see Figure 1).

BYP

Larger values improve the regulator’s transient
response. The output capacitor value may be increased
without limit.

The output capacitor should have an ESR (effective
series resistance) of about 5Ω or less and a resonant
frequency above 1MHz. Ultra-low-ESR capacitors can
cause a low amplitude oscillation on the output and/or
underdamped transient response. Most tantalum or
aluminum electrolytic capacitors are adequate; film 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 required for output stability. The capacitor
can be reduced to 0.47⎧F for current below 10mA or

February 2006

No-Load Stability

The MIC5205 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.

Thermal Considerations

The MIC5205 is designed to provide 150mA of
continuous current in a very small package. Maximum
power dissipation can be calculated based on the output
current and the voltage drop across the part. To
determine the maximum power dissipation of the
package, use the junction-to-ambient thermal resistance
of the device and the following basic equation:

TT

−

JA

AJ(max)

JA

P

D(max)

T

J(max)

is the maximum junction temperature of the die,

125°C, and T

=

θ

A

is the ambient operating temperature. θ

is layout dependent; Table 1 shows examples of
junction-toambient thermal resistance for the MIC5205.

Package θJA

Recommended

Minimum
Footprint

SOT-23-5(M5) 220°C/W 170°C/W 130°C/W

Table 1. SOT-23-5 Thermal Resistance

θJA Square

Copper Clad

θJC

The actual power dissipation of the regulator circuit can
be determined using the equation:

= (VIN – V

P

D

Substituting P

) I

OUT

D(max)

+ VIN I

OUT

GND

for PD and solving for the operating
conditions that are critical to the application will give the
maximum operating conditions for the regulator circuit.
For example, when operating the MIC5205-3.3BM5 at
room temperature with a minimum footprint layout, the
maximum input voltage for a set output current can be
determined as follows:

)

C25C125

P

D(max)

D(max)

=

455mWP

=

°−°

C/W220

°

The junction-to-ambient thermal resistance for the
minimum footprint is 220°C/W, from Table 1. The
maximum power dissipation must not be exceeded for
proper operation. Using the output voltage of 3.3V and
an output current of 150mA, the maximum input voltage
can be determined. From the Electrical Characteristics
table, the maximum ground current for 150mA output
current is 2500µA or 2.5mA.

455mW = (V

455mW = V

950mW = V

8

– 3.3V) 150mA + VIN·2.5mA

IN

×150mA – 495mW + VIN·2.5mA

IN

×152.5mA

IN

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V

= 6.23V

IN(max)

Therefore, a 3.3V application at 150mA of output current
can accept a maximum input voltage of 6.2V in a SOT­23-5 package. For a full discussion of heat sinking and
thermal effects on voltage regulators, refer to the
Regulator Thermals section of Micrel’s

Low-Dropout Voltage Regulators

handbook.

Fixed Regulator Applications

Figure 1. Ultra-Low-Noise Fixed Voltage Application

Figure 1 includes a 470pF capacitor for low-noise
operation and shows EN (pin 3) connected to IN (pin 1)
for an application where enable/shutdown is not
required. C

OUT

= 2.2µF minimum.

Figure 2. Low-Noise Fixed Voltage Application

Figure 2 is an example of a low-noise configuration
where C

is not required. C

BYP

OUT

= 1µF minimum.

Adjustable Regulator Applications

The MIC5205BM5 can be adjusted to a specific output
voltage by using two external resistors (Figure 3). The

Designing with

MIC5205

resistors set the output voltage based on the following
equation:

R2

OUT

1.242VV

⎛
⎜

⎝

R1

+×= 1

⎞
⎟

⎠

This equation is correct due to the configuration of the
bandgap reference. The bandgap voltage is relative to
the output, as seen in the block diagram. Traditional
regulators normally have the reference voltage relative
to ground and have a different V

OUT

equation.

Resistor values are not critical because ADJ (adjust) has
a high input impedance, but for best results use resistors
of 470kΩ or less. A capacitor from ADJ to ground
provides greatly improved noise performance.

Figure 3. Ultra-Low-Noise

Adjustable Voltage Application

Figure 3 includes the optional 470pF noise bypass
capacitor from ADJ to GND to reduce output noise.

Dual-Supply Operation

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.

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Package Information

SOT-23-5 (M5)

MIC5205

MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA

TEL [phone] FAX [phone] WEB http:/www.micrel.com

The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its

Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product

reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical impla

can nt

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

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use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.

indemnify Micrel for any damages resulting from such use or sale.

© 2004 Micrel, Incorporated.

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