Datasheet MIC5250-3.0BMM, MIC5250-3.3BMM, MIC5250-2.7BMM, MIC5250-2.8BMM Datasheet (MICREL)

MIC5250 Micrel

MIC5250

Dual 150mA µCap CMOS LDO Regulator

Preliminary Information

General Description

The MIC5250 is an efficient, precise dual CMOS voltage
regulator optimized for ultra-low-noise applications. The
MIC5250 offers better than 1% initial accuracy, extremely low
dropout voltage (typically 150mV at 150mA) and constant
ground current over load (typically 100µA). The MIC5250
provides a very-low-noise output, ideal for RF applications
where quiet voltage sources are required. A noise bypass pin
is also available for further reduction of output noise.

Designed specifically for hand-held and battery-powered
devices, the MIC5250 provides TTL logic compatible enable
pins. When disabled, power consumption drops nearly to
zero.

The MIC5250 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in hand-held wireless devices.

Key features include current limit, thermal shutdown, push­pull outputs for faster transient response, and active clamps
to speed up device turnoff. Available in the 10-lead MSOP
(micro-shrink-outline package), the MIC5250 also offers a
range of fixed output voltages.

Features

• Ultralow dropout—100mV @ 100mA

• Ultralow noise—30µV(rms)

• Stability with ceramic, tantalum, or aluminum electrolytic
capacitors

• Load independent, ultralow ground current

• 150mA output current

• Current limiting

• Thermal Shutdown

• Tight load and line regulation

• “Zero” off-mode current

• Fast transient response

• TTL-Logic-controlled enable input

Applications

• Cellular phones and pagers

• Cellular accessories

• Battery-powered equipment

• Laptop, notebook, and palmtop computers

• PCMCIA VCC and VPP regulation/switching

• Consumer/personal electronics

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

• High-efficiency linear power supplies

Typical Application

Ordering Information

Part Number Voltage Junction Temp. Range Package

MIC5250-2.7BMM 2.7V –40°C to +125°C 10-lead MSOP
MIC5250-2.8BMM 2.8V –40°C to +125°C 10-lead MSOP
MIC5250-3.0BMM 3.0V –40°C to +125°C 10-lead MSOP
MIC5250-3.3BMM 3.3V –40°C to +125°C 10-lead MSOP

Other voltages available. Contact Micrel for details.

MIC5250-3.3BMM

9

V

ENABLE

SHUTDOWN

ENABLE

SHUTDOWN

ENA may be connected directly to INA.
ENB may be connected directly to INB.
GNDA and GND B may be connected to

isolated grounds or the same ground.

INA

V

INB

INA

2

ENA

7

INB

5

ENB

OUTA

BYPA

GNDA

OUTB

BYPB

GNDB

10

1

C

3

8
4
6

BYPA

(optional)

C

BYPB

(optional)

C

C

3.3V

OUTA

3.3V

OUTB

Dual Ultra-Low-Noise Regulator Circuit

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

March 2000 1 MIC5250

MIC5250 Micrel

Pin Configuration

ENA

GNDA

BYPB

ENB

Pin Description

Pin Number Pin Name Pin Function

9 / 7 INA / B Supply Input*
3 / 6 GNDA / B Ground*
2 / 4 ENA / B Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;

1 / 4 BYPA / B Reference Bypass: Connect external 0.01µF capacitor to GND to reduce

10 / 8 OUTA / B Regulator Output

* Supply inputs and grounds are fully isolated.

1BYPA
2
3
4
5

10 OUTA

INA

9

OUTB

8

INB

7

GNDB

6

MIC5250-x.xBMM

logic low = shutdown. Do not leave open.

output noise. May be left open.

Absolute Maximum Ratings (Note 1)

Supply Input Voltage (VIN) .................................. 0V to +7V

Enable Input Voltage (VEN) ................................. 0V to +7V

Junction Temperature (TJ) ...................................... +150°C

Storage Temperature ............................... –65°C to +150°C

Operating Ratings (Note 2)

Input Voltage (VIN) ......................................... +2.7V to +6V

Enable Input Voltage (VEN) .................................. 0V to V

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

Thermal Resistance (θJA)......................................200°C/W

IN

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

ESD, Note 3

MIC5250 2 March 2000

MIC5250 Micrel

Electrical Characteristics

Each regulator: VIN = V

Symbol Parameter Conditions Min Typical Max Units

V

O

∆V

LNR

∆V

LDR

VIN – V

I

Q

I

GND

OUT

Output Voltage Accuracy I

Line Regulation VIN = V
Load Regulation I
Dropout Voltage, Note 5 I

Quiescent Current VEN ≤ 0.4V (shutdown) 0.2 1 µA
Ground Pin Current, Note 6 I

PSRR Power Supply Rejection f = 120Hz, C
I
e

LIM

n

Current Limit V
Output Voltage Noise C

Enable Input

V

IL

V

IH

I

EN

Enable Input Logic-Low Voltage VIN = 2.7V to 5.5V, regulator shutdown 0.8 0.4 V
Enable Input Logic-High Voltage VIN = 2.7V to 5.5V, regulator enabled 2.0 1V
Enable Input Current VIL ≤ 0.4V 0.17 µA

Shutdown Resistance Discharge 500 Ω

Thermal Protection

Thermal Shutdown Temperature 150 °C
Thermal Shutdown Hysteresis 10 °C

+ 1V, VEN = V

OUT

= 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.

IN; IOUT

= 0mA –11%

OUT

–2 2 %

+ 0.1V to 6V –0.3 0 0.3 %/V

OUT

= 0.1mA to 150mA, Note 4 2.0 3.0 %

OUT

= 100µA 1.5 5 mV

OUT

I

= 50mA 50 85 mV

OUT

I

= 100mA 100 150 mV

OUT

I

= 150mA 150 200 mV

OUT

= 0mA 100 150 µA

OUT

I

= 150mA 100 µA

OUT

= 10µF, C

OUT

= 0V 160 300 mA

OUT

= 10µF, C

OUT

f = 10Hz to 100kHz

= 0.01µF, 30

BYP

= 0.01µF50dB

BYP

VIH ≥ 2.0V 1.5 µA

250 mV

µV(rms)

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. Devices are ESD sensitive. Handling precautions recommended.
Note 4. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load

Note 5. Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V

Note 6. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground

range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.

differential.

pin current.

March 2000 3 MIC5250

MIC5250 Micrel

Typical Characteristics

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

10k

VIN = 4V
V

OUT

100k

= 3V

1M

I

= 100µA

OUT

C

= 1µF tant

OUT

0

1E+11E+21E+31E+41E+5 1E+6 1E+7

10

1k

100

FREQUENCY (Hz)

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

10k

VIN = 4V
V

OUT

100k

= 3V

1M

I

= 150mA

OUT

C

= 1µF tant

OUT

0

1E+11E+21E+31E+41E+5 1E+6 1E+7

10

1k

100

FREQUENCY (Hz)

10M

10M

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

I

= 10mA

OUT

C

= 1µF tant

OUT

0

1E+11E+21E+31E+41E+5 1E+6 1E+7

10

1k

100

FREQUENCY (Hz)

10k

VIN = 4V
V

OUT

100k

= 3V

1M

Power Supply

100

PSRR (dB)

Rejection Ratio

80

60

40

I

= 100µA

20

VIN = 4V
V

OUT

0

1E+11E+21E+31E+41E+5 1E+6 1E+7

100 1k 10k 100k 1M 10M

10

OUT

C

= 10µF cer.

OUT

= 3V

C

= 0.01µF

BYP

FREQUENCY (Hz)

10M

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

I

= 100mA

OUT

C

= 1µF tant

OUT

0

1E+11E+21E+31E+41E+5 1E+61E+7

10

1k

100

FREQUENCY (Hz)

10k

VIN = 4V
V

OUT

100k

= 3V

1M

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

VIN = 4V
V

= 3V

OUT

I

= 10mA

OUT

C

= 10µF cer.

OUT

C

= 0.01µF

0

1E+11E+21E+31E+41E+5 1E+61E+7

100 1k 10k 100k 1M 10M

10

BYP

FREQUENCY (Hz)

10M

Power Supply

100

80

60

40

PSRR (dB)

20

Rejection Ratio

VIN = 4V
V

= 3V

OUT

I

= 100mA

OUT

C

= 10µF cer.

OUT

C

= 0.01µF

0

1E+11E+21E+31E+41E+5 1E+6 1E+7

100 1k 10k 100k 1M 10M

10

BYP

FREQUENCY (Hz)

Power Supply Ripple Rejection

vs. Voltage Drop

80
70
60
50
40
30
20

RIPPLE REJECTION (dB)

10

0

0 200 400 600 800 1000

I

= 100mA

OUT

100mA

10mA

C
C

VOLTAGE DROP (mV)

100µA

= 10µF cer.

OUT

= 0.01µF

BYP

Power Supply

100

80

60

40

PSRR (dB)

20

NOISE (µV/√Hz)

Rejection Ratio

VIN = 4V
V

= 3V

OUT

I

= 150mA

OUT

C

= 10µF cer.

OUT

C

= 0.01

BYP

0

1E+11E+21E+31E+41E+5 1E+61E+7

100 1k 10k 100k 1M 10M

10

FREQUENCY (Hz)

Noise Performance

10

IL = 100µA

1

VIN = 4V

0.1

V

= 3V

OUT

C

= 1µF cer.

OUT

C

= 0.01µF

BYP

0.01
10 100 1k 10k 100k 1M

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6

FREQUENCY (Hz)

Power Supply Ripple Rejection

vs. Voltage Drop

80
70
60
50
40
30
20

RIPPLE REJECTION (dB)

10

0

0 200 400 600 800 1000

10

1

VIN = 4V

0.1

V

NOISE (µV/√Hz)

0.01
10

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6

10mA100µA

I

= 100mA

OUT

C

VOLTAGE DROP (mV)

Noise Performance

= 3V

OUT

C

= 10µF cer.

OUT

C

= 0.01µF

BYP

1k

100

FREQUENCY (Hz)

10k

150mA

= 1µF

OUT

IL = 100µA

100k

1M

MIC5250 4 March 2000

MIC5250 Micrel

0

25

50

75

100

012345

QUIESCENT CURRENT (µA)

INPUT VOLTAGE (V)

0

100

200

300

400

500

600

-40-20 0 20 40 60 80 100120140

OUTPUT CURRENT (mA)

TEMPERATURE (°C)

Ground Pin Current

150

VIN = 4V
V

= 3V

OUT

125

100

75

I

QUIESCENT CURRENT (µA)

50

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

OUT

= 150mA

Ground Pin Current

95

VIN = 4V
V

= 3V

OUT

90

QUIESCENT CURRENT (µA)

85

0.1 1 10 100 500

LOAD CURRENT (mA)

Ground Pin Current

V

= 3V

OUT

I

OUT

Ground Pin Current

200

VIN = 4V
V

= 3V

OUT

150

100

50

QUIESCENT CURRENT (µA)

0

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

I

OUT

= 100µA

= 100µA

Ground Pin Current

100

V

= 3V

OUT

75

50

25

I

OUT

= 150mA

QUIESCENT CURRENT (µA)

0

012345

INPUT VOLTAGE (V)

Dropout Characteristics

3.5
V

OUT

3.0

RL = 30kΩ

2.5

2.0

1.5

1.0

OUTPUT VOLTAGE (V)

0.5

0

012345

300

250

200

150

100

50

DROPOUT VOLTAGE (mV)

0

0 25 50 75 100 125 150

OUTPUT CURRENT (mA)

March 2000 5 MIC5250

= 3V

RL = 30Ω

INPUT VOLTAGE (V)

Dropout Voltage

TA = 125°C

TA = 25°C

TA = -40°C

Dropout Voltage

8

I

= 100µA

LOAD

6

4

2

DROPOUT VOLTAGE (mV)

0

-40-20 0 20 40 60 80 100120140

TEMPERATURE (°C)

Short Circuit Current

VIN = 3.5V
V

= 3V

EN

300

Dropout Voltage

IL = 150mA

250

200

150

100

50

DROPOUT VOLTAGE (mV)

0

-40-20 0 20 40 60 80 100120140

TEMPERATURE (°C)

Output Voltage

3.05

3.00

2.95

2.90

OUTPUT VOLTAGE (V)

2.85

vs. Temperature

VIN = 4V

TYPICAL 3V DEVICE

I

= 100µA

LOAD

-50 0 50 100 150

TEMPERATURE (°C)

MIC5250 Micrel

Enable Pin Bias Current

2.0

1.5

1.0

0.5

ENABLE PIN CURRENT (µA)

0

-40-20 0 20 40 60 80 100120140

TEMPERATURE (°C)

Functional Characteristics

Line Transient Response

(50mV/div.)

∆ OUTPUT VOLTAGE

VIN = 4.0V

VEN = 100mV

Enable Threshold Voltage

4

3

2

VIN = 4.0V

1

THRESHOLD VOLTAGE (V)

0

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

Load Transient Response

(100mV/div.)

∆ OUTPUT VOLTAGE

6V

V

= 3V

(2V/div.)

INPUT VOL TAGE

C

C

BYP

I

OUT

OUT

= 10µF

OUT

= 0.01µF
= 100µA

4V

OUTPUT CURRENT

TIME (10ms/div.)

Enable Pin Delay

(1V/div.)

ENABLE VOL TAGE

VIN = 4V

= 3V

V

(1V/div.)

OUTPUT VOL TAGE

C
C
I

OUT
OUT
BYP

OUT

= 10µF

= 0.01µF

= no load

TIME (20µs/div.)

(2V/div.)

ENABLE VOL TAGE

V

= 3V

(1V/div.)

OUTPUT VOL TAGE

OUT

C

OUT

C

BYP

I

OUT

= 10µF
= 0.01µF

= no load

VIN = 4V

= 3V

V

OUT

= 10µF cer.

C

OUT

= 0.01µF

C

BYP

TIME (100µs/div.)

Shutdown Delay

TIME (1ms/div.)

150mA

100µA

MIC5250 6 March 2000

MIC5250 Micrel

= 3.3V

V

OUTB

= 10µF

C

OUTB

C

= 0

(20mV/div.)

I

LOAD

BYPB

= 100µA

OUTPUT VOL TAGE B

V

= 4.3V

IN

separate supplies

(100mV/div.)

I

= 100µA

OUTPUT VOL TAGE A

LOAD

Block Diagrams

Crosstalk

Characteristics

I

LOAD

TIME (25µs/div.)

INA

V

= 3.3V

OUTA

= 10µF

C

OUTA

= 0

C

BYPA

= 150mA

Reference

Voltage

Startup/

Shutdown

Control

(20mV/div.)

OUTPUT VOL TAGE B

(100mV/div.)

OUTPUT VOL TAGE A

Quickstart/

Noise

Cancellation

V

OUTB

C

OUTB

C

BYPB

= 100µA

I

LOAD

V

= 4.3V

IN

common supply

I

= 100µA

LOAD

Crosstalk

Characteristics

= 3.3V

= 10µF

= 0

TIME (25µs/div.)

I

LOAD

V

= 3.3V

OUTA

= 10µF

C

OUTA

= 0

C

BYPA

= 150mA

ENA

GNDA

INB

ENB

GNDB

Thermal

Sensor

Under-

voltage

Lockout

Reference

Voltage

Thermal

Sensor

Under-

voltage

Lockout

FAULT

Startup/

Shutdown

Control

FAULT

Error

Amplifier

Quickstart/

Cancellation

Error

Amplifier

Current

Amplifier

ACTIVE SHUTDOWN

Noise

Current

Amplifier

ACTIVE SHUTDOWN

PULL

PULL

DOWN

PULL

PULL

DOWN

BYPA

UP

OUTA

BYPB

UP

OUTB

March 2000 7 MIC5250

MIC5250 Micrel

P

TT

D

JA

JA

(max

max)()

=

−











θ

P

D(max)

=

°− °

°











125 C 6 C

C/W

0

200

Applications Information

Enable/Shutdown

The MIC5250 comes with active-high enable pins that allows
either regulator to be disabled. Forcing an enable pin low
disables the respective regulator and places it into a “zero”
off-mode-current state. In this state, current consumed by the
regulator goes nearly to zero. Forcing an enable pin high
enables the output voltage. This part is CMOS therefore the
enable pin cannot be left floating; a floating enable pin may
cause an indeterminate state on the output.

Input Capacitor

Input capacitors are not required for stability. A 1µF input
capacitor is recommended for either regulator when the bulk
ac supply capacitance is more than 10 inches away from the
device, or when the supply is a battery.

Output Capacitor

The MIC5250 requires output capacitors for stability. The
design requires 1µF or greater on each output to maintain
stability. Capacitors can be low-ESR ceramic chip capaci­tors. The MIC5250 has been designed to work specifically
with low-cost, small chip capacitors. Tantalum capacitors can
also be used for improved capacitance over the operating
temperature range. The value of the capacitor can be in­creased without bounds.

Bypass Capacitor

Capacitors can be placed from each noise bypass pin to their
respective ground to reduce output voltage noise. These
capacitors bypass the internal references. A 0.01µF capaci­tor is recommended for applications that require low-noise
outputs.

Transient Response

The MIC5250 implements a unique output stage design
which dramatically improves transient response recovery
time. The output is a totem-pole configuration with a P­channel MOSFET pass device and an N-channel MOSFET
clamp. The N-channel clamp is a significantly smaller device
that prevents the output voltage from overshooting when a
heavy load is removed. This feature helps to speed up the
transient response by significantly decreasing transient re­sponse recovery time during the transition from heavy load
(100mA) to light load (100µA).

Active Shutdown

Each regulator also features an active shutdown clamp,
which is an N-channel MOSFET that turns on when the
device is disabled. This allows the output capacitor and load
to discharge, de-energizing the load.

Cross Talk

When a load transient occurs on one output of the MIC5250,
the second output may couple a small amount of ripple to its
output. This typically comes from a common input source or
from poor grounding. Using proper grounding techniques
such as star grounding as well as good bypassing directly at
the inputs of each regulator will help to reduce the magnitude
of the cross talk. See “Functional Characteristics” for an
example of cross talk performance.

Thermal Considerations

The MIC5250 is a dual LDO voltage regulator designed to
provide two output voltages from one package. Both regula­tor outputs are capable of sourcing 150mA of output current.
Proper thermal evaluation needs to be done to ensure that
the junction temperature does not exceed it’s maximum
value, 125°C. Maximum power dissipation can be calculated
based on the output current and the voltage drop across each
regulator. The sum of the power dissipation of each regulator
determines the total power dissipation. The maximum power
dissipation that this package is capable of handling can be
determined using thermal resistance, junction to ambient,
and the following basic equation:

T

125°C and

is the maximum junction temperature of the die,

J(max)

T

is the ambient operating temperature of the die.

A

θJA is layout dependent. Table 1 shows the typical thermal

resistance for a minimum footprint layout for the MIC5250.

θθθθθ

egakcaP

01-POSMW/C°002

AJ

dednemmoceRta

tnirptooFmuminiM

Table 1. Thermal Resistance

The actual power dissipation of each regulator output can be
calculated using the following simple equation:

PVV I VI

=−

()

DIN

OUT OUT

+

IN

GND

Each regulator contributes power dissipation to the overall
power dissipation of the package.

PPP

=+

D total D reg D reg()

() ( )12

Each output is rated for 150mA of output current, but the
application may limit the amount of output current based on
the total power dissipation and the ambient temperature.

A typical application may call for two 3.0V outputs from a
single Li-ion battery input. This input can be as high as 4.2V.
When operating at high ambient temperatures, the output
current may be limited. When operating at an ambient of
60°C, the maximum power dissipation of the package is
calculated as follows:

P

D(max)

= 325mW

For the application mentioned above, if regulator 1 is sourcing
150mA, it contributes the following to the overall power
dissipation:

PVVIVI

DIN

P

D(reg1)

P

D(reg1)

=−

(reg1)

()

=−

()

=180.4mW

OUT OUT

+

IN

GND

+×µ4.2V 3.0V 150mA 4.2V 100 A

MIC5250 8 March 2000

MIC5250 Micrel

Since the total power dissipation allowable is 325mW, the
maximum power dissipation of the second regulator is limited
to:

PPP

DDD(max) (reg1) (reg2)

325mW 180.4mW=+P

P

D reg()2

=+

D reg()2

=144.6mW

The maximum output current of the second regulator can be
calculated using the same equations but solving for the
output current (ground current is constant over load and
simplifies the equation):

PVVIVI

D reg IN

144.6mW 4.2V 3.0V 4.2V 100 A=−

I

OUT

=−

()2

=120.5mA

OUT

+

IN

GND

+×µI

()

OUT OUT

()

The second output is limited to 120mA due to the total power
dissipation of the system when operating at 60°C ambient
temperature.

Fixed Regulator Applications

MIC5250-3.3BMM

9

V

INA

V

INB

INA

2

ENA

7

INB

5

ENB

OUTA

BYPA

GNDA

OUTB

BYPB

GNDB

10

1
3

0.01µF

8
4
6

0.01µF

3.3V

1µF

3.3V

1µF

Figure 1. Ultra-Low-Noise Dual 3.3V Application

Figure 1 includes 0.01µF capacitors for low-noise operation
and shows EN (pin 3) connected to IN (pin 1) for an applica­tions where enable/shutdown is not required. C

OUT

= 1µF

minimum.

MIC5250-3.3BMM

9

V

INA

V

INB

INA

2

ENA

7

INB

5

ENB

OUTA
BYPA

GNDA

OUTB

BYPB

GNDB

10

1
3

8
4
6

3.3V

1µF

3.3V

1µF

Figure 2. Low-Noise Fixed Voltage Application

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

is not required. C

BYP

= 1µF minimum.

OUT

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.

March 2000 9 MIC5250

MIC5250 Micrel

Package Information

3.15 (0.122)

2.85 (0.114)

0.30 (0.012)

0.15 (0.006)

0.50 BSC (0.020)

4.90 BSC (0.193)

3.10 (0.122)

2.90 (0.114)

1.10 (0.043)

0.94 (0.037)

0.15 (0.006)

0.05 (0.002)

10-Lead MSOP (MM)

6° MAX

0° MIN

DIMENSIONS:

MM (INCH)

0.26 (0.010)

0.10 (0.004)

0.70 (0.028)

0.40 (0.016)

MIC5250 10 March 2000

MIC5250 Micrel

March 2000 11 MIC5250

MIC5250 Micrel

MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA

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other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.

© 2000 Micrel Incorporated

MIC5250 12 March 2000