MIC47100YMMETR - Micrel, Inc.

MIC47100

1A High Speed Low VIN LDO

MicroLead Frame and MLF are registered trademark of Amkor Technology

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

September 2008 M9999-092908-B

General Description

The MIC47100 is a high speed, Low VIN LDO capable of

delivering up to 1A and designed to take advantage of

point of load applications that use multiple supply rails to

generate a low voltage, high current power supply. The

MIC47100 is stable with only a 1µF ceramic output

capacitor and is available in a thermally enhanced

2mm × 2mm MLF® package thus making it an optimal

solution for board-constrained applications.

The MIC47100 has an NMOS output stage offering very

low output impedance. The NMOS output stage offers a

unique ability to respond very quickly to sudden load

changes such as that required by a microprocessor, DSP

or FPGA. The MIC47100 consumes little quiescent

current and therefore can be used for driving the core

voltages of mobile processors, post regulating a core

DC/DC converter in any portable device.

The MIC47100 is available in fixed and adjustable output

voltages in the exposed pad MSOP-8 package and the tiny

2mm × 2mm MLF® package with an operating junction

temperature range of -40°C to +125°C.

Data sheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

Features

• Operating voltage range:

- Input Supply: 1.0V to 3.6V

- Bias Supply: 2.3V to 5.5V

• 0.8V to 2.0V output voltage range

• High bandwidth – very fast transient response

• PSRR >50dB at 100kHz

• Stable with a 1µF ceramic output capacitor

• Low dropout voltage of 80mV at 1A

• High output voltage accuracy:

- +/- 1.5% initial accuracy

- +/- 2% over temperature

• Logic level enable input

• UVLO on both supply voltages for easy turn-on

• ePad MSOP-8 – small form factor power package

• Thermally enhanced 2mm × 2mm MLF® – smallest

solution

Applications:

• Point of Load

• PDAs

• DSP, PLD and FPGA Power Supply

• Low Voltage Post Regulation

___________________________________________________________________________________________________________

Typical Application

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Ordering Information

Part Number Marking Code Nominal Output

Voltage(1) Package Lead Finish

MIC47100YML EAA ADJ

8-Pin 2mm × 2mm MLF®(2) Pb free

MIC47100-0.8YML E08 0.8V

8-Pin 2mm × 2mm MLF®(2) Pb free

MIC47100-1.0YML E10 1.0V

8-Pin 2mm × 2mm MLF®(2) Pb free

MIC47100-1.2YML E12 1.2V

8-Pin 2mm × 2mm MLF®(2) Pb free

MIC47100YMME ZEAAY ADJ 8-pin e-MSOP Pb free

MIC47100-08YMME ZE08Y 0.8V 8-pin e-MSOP Pb free

MIC47100-10YMME ZE10Y 1.0V 8-pin e-MSOP Pb free

MIC47100-12YMME ZE12Y 1.2V 8-pin e-MSOP Pb free

Note:

1. Other Voltage available. Contact Micrel for details.

2. MLF® is a Green RoHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen free

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Pin Configur ation

8-pin 2mm x 2mm MLF®

Fixed and Adjustable (ML) 8-pin Exposed Pad MSOP

Fixed and Adjustable (MME)

Pin Description

Pin Number

MLF Pin Number

MSOP

Pin Name Pin Name

1,2 1,2 IN

Input Supply. Drain of NMOS pass transistor which is the

power input voltage for regulator. The NMOS pass transistor

steps down this input voltage to create the output voltage.

3 3 GND

Ground. Ground pins and exposed pad must be connected

externally.

4 4 BIAS

Bias Supply. The bias supply is the power supply for the

internal circuitry of the regulator.

5 5 EN

Enable: TTL/CMOS compatible input. Logic high = enable,

logic low or open = shutdown

6 (Fixed) 6 (Fixed) FB Feedback Input. Connect to OUT. Optimum load regulation is

obtained when feedback is taken from the actual load point.

6 (Adj) 6 (Adj) ADJ Adjust Input. Connect external resistor divider to program

output voltage.

7,8 7,8 OUT Output. Output Voltage of Regulator

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Absolute Maximum Ratings(1)

Input Supply Voltage (VIN).................................... 0V to +4V

Bias Supply Voltage (VBIAS).................................. 0V to +6V

Enable Voltage (VEN)............................................ 0V to +6V

Power Dissipation, Internally Limited (3)

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

Storage Temperature (Ts) ..........................-65°C to +150°C

ESD Rating (4)................................................................. 2kV

Operating Ratings(2)

Input Supply Voltage (VIN).............................. 1.0V to +3.6V

Bias Supply Voltage (VBIAS)............................ 2.3V to +5.5V

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

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

Junction Thermal Resistance

ePad MSOP-8 (θJA) ...........................................64°C/W

2mm x 2mm MLF® (θJA).....................................90°C/W

Electrical Characteristics(5)

VIN = VOUT+0.5V; VBIAS = VOUT + 2.1V, IOUT = 100µA; TA = 25°C, bold values indicate –40°C< TA < +125°C, unless noted.

Parameter Condition Min Typ Max Units

UVLO Thresholds (6) Bias Supply

Input Supply

1.9

0.7 2.1

0.85

2.3

1.0 V

UVLO Hysteresis VBIAS

VIN 70

25 mV

Variation from nominal VOUT -1.5 +1.5 % Output Voltage

Accuracy Variation from nominal VOUT; -40°C to +125°C -2.0 +2.0 %

Output Voltage Line

Regulation (Bias

Supply)

VBIAS = VOUT + 2.1V to 5.5V

-0.1 0.015 0.1 %/V

Output Voltage Line

Regulation

(Input Supply)

VIN = VOUT + 0.5V to 3.6V

-0.05 0.005 0.05 %/V

Load Regulation IOUT = 10mA to 1A 0.2 0.5 %

Input Supply Dropout

Voltage

IOUT = 100mA;

IOUT = 500mA;

IOUT = 1A;

8.5

250

Bias Supply Dropout

Voltage

IOUT = 100mA;

IOUT = 500mA;

IOUT = 1A

1.15

1.25

1.35

2.1

Ground current from

VBIAS

IOUT = 1mA

IOUT = 1A

350

350 500

500 µA

µA

Shutdown current

from VBIAS

EN < 0.2V 0.1 1.0 µA

Ground current from

VIN

IOUT = 1A 6 µA

Shutdown current

from VIN

EN < 0.2V 0.1 1.0 µA

Ripple Rejection f = 1kHz; COUT = 1.0µF; IOUT = 100mA

f = 100kHz; COUT = 1.0µF; IOUT = 100mA

f = 500kHz; COUT = 1.0µF; IOUT = 100mA

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Parameter Condition Min Typ Max Units

Current Limit VIN = 2.7V; VOUT = 0V 1.1 1.6 2.5 A

Output Voltage Noise COUT=1μF; 10Hz to 100kHz; IOUT = 100mA 63 µVRMS

Over-temperature

Shutdown

160

°C

Over-temperature

Shutdown Hysteresis

°C

Enable Inputs

Logic Low 0.2 V Enable Voltage

Logic High 1.0 V

VIL < 0.2V 1 µA Enable Input Current

VIH = 1.2V 6 µA

Turn-on Time COUT = 1µF; 90% of typical VOUT 35 500 µs

Reference Voltage (Adjustable Op tio n Only)

Reference Voltage 0.69

0.686

0.7 0.71

0.714

ADJ pin Input current 20 nA

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 of any TA (ambient temperature) is PD(max) = TJ(max) – TA) / θJA. Exceeding the maximum allowable power

dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown.

4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.

5. Specification for packaged product only.

6. Both UVLO thresholds must be met for the output voltage to be allowed to turn-on. If either of the two input voltages are below the UVLO thresholds,

the output is kept off.

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Typical Characteristics

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Typical Characteristics (c ontinued)

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Functional Characteristics

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Functional Diagram

MIC47100 Block Diagram

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Applications Information

The MIC47100 is a high speed, dual supply NMOS LDO

designed to take advantage of point-of-load applications that

use multiple supply rails to generate a low voltage, high

current power supply. The MIC47100 can source 1A of

output current while only requiring a 1µF ceramic output

capacitor for stability.

The MIC47100 regulator is fully protected from damage due

to fault conditions, offering linear current limiting and thermal

shutdown.

Bias Supply Voltage

VBIAS, requiring relatively light current, provides power

to the control portion of the MIC47100. Bypassing on

the bias pin is recommended to improve performance

of the regulator during line and load transients. Small

ceramic capacitors from VBIAS-to-ground help reduce

high frequency noise from being injected into the

control circuitry from the bias rail and are good design

practice.

Input Supply Voltage

VIN provides the supply to power the LDO. The

minimum input voltage is 1V, allowing conversion from

low voltage supplies.

Output Capacitor

The MIC47100 requires an output capacitor of 1µF or

greater to maintain stability. The design is optimized

for use with low-ESR ceramic chip capacitors. High

ESR capacitors may cause high frequency oscillation.

The output capacitor can be increased, but

performance has been optimized for a 1µF ceramic

output capacitor and does not improve significantly

with larger capacitance.

X7R/X5R dielectric-type ceramic capacitors are

recommended because of their temperature

performance. X7R-type capacitors change

capacitance by 15% over their operating temperature

range and are the most stable type of ceramic

capacitors. Z5U and Y5V dielectric capacitors change

value by as much as 50% and 60%, respectively, over

their operating temperature ranges. To use a ceramic

chip capacitor with Y5V dielectric, the value must be

much higher than an X7R ceramic capacitor to ensure

the same minimum capacitance over the equivalent

operating temperature range.

Input Capacitor

The MIC47100 is a high-performance, high bandwidth

device. Therefore, it requires a well-bypassed input

supply for optimal performance. A 1µF capacitor is

required from the input to ground to provide stability.

Low-ESR ceramic capacitors provide optimal

performance at a minimum of space. Additional high-

frequency capacitors, such as small-valued NPO

dielectric-type capacitors, help filter out high-

frequency noise and are good practice in any RF-

based circuit.

Minimum Load Current

The MIC47100, unlike most other regulators, does not

require a minimum load to maintain output voltage

regulation.

Adjustable Regulator Design

The MIC47100 adjustable version allows

programming the output voltage anywhere between

0.8V and 2.0V. Two resistors are used. The R1

resistor value between VOUT and the adjust pin should

not exceed 10kΩ. Larger values can cause instability.

R2 connects between the adjust pin and ground. The

resistor values are calculated by:

⎟

⎠

⎞

⎜

⎝

⎛−×= 1

0.7

R2R1 OUT

Where VOUT is the desired output voltage.

Enable/Shutdown

The MIC47100 comes with a single active-high enable

pin that allows the regulator to be disabled. Forcing

the enable pin low disables the regulator and sends it

into a “zero” off-mode-current state. In this state,

current consumed by the regulator goes nearly to

zero. Forcing the enable pin high enables the output

voltage. The active-high enable pin uses CMOS

technology and the enable pin cannot be left floating;

a floating enable pin may cause an indeterminate

state on the output.

Thermal Considerations

The MIC47100 is designed to provide 1A of

continuous current in a very small package. Maximum

ambient operating temperature can be calculated

based on the output current and the voltage drop

across the part. Given that the input voltage is 1.8V,

the output voltage is 1.2V and the output current is

1A. The actual power dissipation of the regulator

circuit can be determined using the equation:

D = (VIN – VOUT1) IOUT + VBIAS IGND

Because this device is CMOS, the ground current is

insignificant for power dissipation and can be ignored

for this calculation.

D = (1.8V – 1.2V) × 1A

D = 0.6W

To determine the maximum ambient operating

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temperature of the package, use the junction-to-

ambient thermal resistance of the device and the

following basic equation:

PD(MAX) =

TJ(MAX) - TA

⎝

⎛

TJ(max) = 125°C, the maximum junction temperature of

the die θJA thermal resistance = 90°C/W.

The table below shows junction-to-ambient thermal

resistance for the MIC47100 in the MLF® package.

Package

θJA

Recommended

Minimum

Footprint

θJC

8-pin 2mm x 2mm

MLF®

90°C/W 2°C/W

Thermal Resistance

Substituting PD for PD(max) and solving for the ambient

operating temperature will give the maximum

operating conditions for the regulator circuit. The

junction-to-ambient thermal resistance for the

minimum footprint is 90°C/W.

The maximum power dissipation must not be

exceeded for proper operation.

For example, when operating the MIC47100-1.2YML

at an input voltage of 1.8V and a 1A load with a

minimum footprint layout, the maximum ambient

operating temperature TA can be determined as

follows:

CT WC TC

°=

−°

)/90(

)125(

6.0

Therefore, a 1.2V application with 1A of output current

can accept an ambient operating temperature of 71°C

in a 2mm x 2mm MLF® package. For a full discussion

of heat sinking and thermal effects on voltage

regulators, refer to the “Regulator Thermals” section

of Micrel’s Designing with Low-Dropout Voltage

Regulators handbook. This information can be found

on Micrel's website at:

http://www.micrel.com/_PDF/other/LDOBk_ds.pdf

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Package Information

8-Pin 2mm×2mm MLF (ML)

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8-Pin e-MSOP (MME)

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

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

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.