MIC39300-2.5WU-TR - MICROCHIP TECHNOLOGY

MIC39300/39301/39302

3A, Low-Voltage Low-Dropout Regulator

**See Thermal Load Current Section

Super eta PNP is a registered trademark of Micrel, Inc.

StrongARM is a trademark of Advanced RISC Machines, Ltd

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

October 2009 M9999-102309-A

General Description

The MIC39300, MIC39301 and MIC39302 are 3.0A low-

dropout linear voltage regulators that provide a low

voltage, high-current output with a minimum of external

components. Utilizing Micrel’s proprietary Super eta

PNP® pass element, the MIC39300/1/2 offers extremely

low dropout (typically 385mV at 3.0A) and low ground

current (typically 36mA at 3.0A).

The MIC39300/1/2 is ideal for PC add-in cards that need

to convert from standard 3.3V to 2.5V or 2.5V to 1.8V. A

guaranteed maximum dropout voltage of 500mV over all

operating conditions allows the MIC39300/1/2 to provide

2.5V from a supply as low as 3V, and 1.8V from a supply

as low as 2.5V. The MIC39300/1/2 also has fast transient

response for heavy switching applications. The device

requires only 47µF of output capacitance to maintain

stability and achieve fast transient response.

The MIC39300/1/2 is fully protected with overcurrent

limiting, thermal shutdown, reversed-battery protection,

reversed-leakage protection, and reversed-lead insertion.

The MIC39301 offers a TTL-logic compatible enable pin

and an error flag that indicates under voltage and over

current conditions. Offered in fixed voltages, the

MIC39300/1 comes in the TO-220 and TO-263 (D2Pak)

packages and is an ideal upgrade to older, NPN-based

linear voltage regulators. The MIC39302 adjustable option

allows programming the output voltage anywhere between

1.24V and 15.5V and is offered in a 5-Pin, TO-263 (D2Pak)

package.

Features

• 3.0A minimum guaranteed output current

• 550mV maximum dropout voltage over temperature

• Ideal for 3.0V to 2.5V conversion

• Ideal for 2.5V to 1.8V conversion

• 1% initial accuracy

• Low ground current

• Current limiting and Thermal shutdown

• Reversed-battery protection

• Reversed-leakage protection

• Fast transient response

• TO-263 (D2Pak) and TO-220 packaging

• TTL/CMOS compatible enable pin (MIC39301/2 only)

• Error flag output (MIC39301 only)

• Adjustable output (MIC39302 only)

Applications

• LDO linear regulator for PC add-in cards

• High-efficiency linear power supplies

• SMPS post regulator

• Multimedia and PC processor supplies

• Low-voltage microcontrollers

• StrongARM™ processor supply

_________________________________________________________________________________________________________________________

Typical Application

MIC39300

MIC39301

MIC39302 Adjustable Output Application

(*See Minimum Load Current Section)

Micrel, Inc. MIC39300/39301/39302

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Ordering Information

Part Number

Standard RoHS Compliant*

Voltage Junction Temp

Range Package

MIC39300-1.8BT MIC39300-1.8WT 1.8V –40°C to +125°C 3-Pin TO-220

MIC39300-1.8BU MIC39300-1.8WU 1.8V –40°C to +125°C 3-Pin TO-263

MIC39300-2.5BT MIC39300-2.5WT 2.5V –40°C to +125°C 3-Pin TO-220

MIC39300-2.5BU MIC39300-2.5WU 2.5V –40°C to +125°C 3-Pin TO-263

MIC39301-1.8BT MIC39301-1.8WT 1.8V –40°C to +125°C 5-Pin TO-220

MIC39301-1.8BU MIC39301-1.8WU 1.8V –40°C to +125°C 5-Pin TO-263

MIC39301-2.5BT MIC39301-2.5WT 2.5V –40°C to +125°C 5-Pin TO-220

MIC39301-2.5BU MIC39301-2.5WU 2.5V –40°C to +125°C 5-Pin TO-263

— MIC39302WU Adjustable –40°C to +125°C 5-Pin TO-263

Note:

* RoHS compliant with ‘high-melting solder’ exemption.

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Pin Configur ation

MIC39300-x.xBT

TO-220-3 (T) MIC39300-x.xBU

TO-263-3 (U)

MIC39301-x.xBT

TO-220-5 (T) MIC39301-x.xBU

TO-263-5 (D2Pak) (U)

MIC39302WU

TO-263-5 (D2Pak) (U)

Pin Description

Number

MIC39300

Number

MIC39301

Number

MIC39302 Pin Name Pin Function

— 1 1 EN

Enable (Input): TTL/CMOS compatible input. Logic high = enable; logic low

or open = shutdown.

1 2 2 IN Unregulated Input: +16V maximum supply.

2, TAB 3, TAB 3, TAB GND Ground: Ground pin and TAB are internally connected.

3 4 4 OUT Regulator Output

— 5

—

FLG Error Flag (Ouput): Open-collector indicates an output fault condition.

Active low.

— —

ADJ Adjustable Regulator Feedback Input: Connect to the resistor voltage

divider that is placed from OUT to GND in order to set the output voltage.

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Absolute Maximum Ratings(1)

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

Enable Voltage (VEN)....................................................+20V

Storage Temperature (TS)................–65°C to +150°C Lead

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

ESD Rating................................................................ Not e 3

Operating Ratings(2)

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

Enable Voltage (VEN)....................................................+16V

Maximum Power Dissipation (PD(max)) ....................... Note 4

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

Package Thermal Resistance

TO-263 (θJC) ........................................................2°C/W

TO-220 (θJC) ........................................................2°C/W

Electrical Characteristics(5)

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

Symbol Parameter Condition Min Typ Max Units

VOUT Output Voltage 10mA

10mA  IOUT  3A, VOUT + 1V  VIN  8V

–1

–2

Line Regulation IOUT = 10mA, VOUT + 1V  VIN  8V 0.06 0.5 %

Load Regulation VIN = VOUT + 1V, 10mA  IOUT  3A 0.2 1 %

VOUT/T

Output Voltage Temp.

Coefficient

Note 6

20 100 ppm/°C

IOUT = 100mA, VOUT = –1% 65 200 mV

IOUT = 750mA, VOUT = –1% 185 mV

IOUT = 1.5A, VOUT = –1% 250 mV

VDO Dropout Voltage

Note 7, Note 10

IOUT = 3A, VOUT = –1% 385 550 mV

IOUT = 750mA, VIN = VOUT + 1V 10 20 mA

IOUT = 1.5A, VIN = VOUT + 1V 17 mA

IGND Ground Current

Note 8

IOUT = 3A, VIN = VOUT + 1V 45 mA

IGND(do) Dropout Ground Pin Current VIN  VOUT(nominal) – 0.5V, IOUT = 10mA 6 mA

IOUT(lim) Current Limit VOUT = 0V, VIN = VOUT + 1V 4.5 A

Enable Input (MIC39301)

VEN Enable Input Voltage logic low (off) 0.8 V

logic high (on) 2.5 V

IIN Enable Input Current VEN = 2.5V 15 30

µA

EN = 0.8V 2 µA

4 µA

IOUT(shdn) Shutdown Output Current Note 9 10

20 µA

Flag Output (MIC39301)

IFLG(leak) Output Leakage Current VOH = 16V 0.01 1

µA

VFLG(do) Output Low Voltage VIN = 2.50V, IOL, = 250µA, Note 10 220 300

400

VFLG Low Threshold % of VOUT 93 %

High Threshold % of VOUT 99.2 %

Hysteresis 1 %

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Symbol Parameter Condition Min Typ Max Units

Reference (Adju st Pin) – MIC39302 only

1.228 1.240 1.252 V VADJ Reference Voltage 1.215

1.265 V

VTC Reference Voltage Temp.

Coefficient

Note 11 20 ppm/°C

40 80 nA IADJ Adjust Pin Bias Current

120 nA

ITC Adjust Pin Bias Current Temp.

Coefficient

0.1 nA/°C

Notes:

1. Exceeding the absolute maximum ratings may damage the device.

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

3. Devices are ESD sensitive. Handling precautions recommended.

4. PD(max) = (TJ(max) – TA) ÷ JA, where JA depends upon the printed circuit layout. See “Applications Information.”

5. Specification for packaged product only.

6. Output voltage temperature coefficient is VOUT(worst case) ÷ (TJ(max) – TJ(min)) where TJ(max) is +125°C and TJ(min) is –40°C.

7. VDO = VIN – VOUT when VOUT decreases to 99% of its nominal output voltage with VIN = VOUT + 1V. For output voltages below 2.5V, dropout voltage

is the input-to-output voltage differential with the minimum input voltage being 2.5V. Minimum input operating voltage is 2.5V.

8. IGND is the quiescent current. IIN = IGND + IOUT.

9. VEN  0.8V, VIN  8V, and VOUT = 0V

10. For a 1.8V device, VIN = 2.5V.

11. 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 200mA load pulse at VIN = 8V for t = 10ms.

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Typical Characteristics

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Typical Characteristics (cont)

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Functional Characteristics

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Functional Diagram

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Application Information

The MIC39300/1/2 are high-performance, low-dropout

voltage regulators suitable for moderate to high-current

voltage regulator applications. Its 550mV dropout

voltage at full load makes it especially valuable in

battery-powered systems and as a high-efficiency noise

filter in post-regulator applications. Unlike older NPN-

pass transistor designs, where the minimum dropout

voltage is limited by the base-to-emitter voltage drop and

collector-to-emitter saturation voltage, dropout

performance of the PNP output of these devices is

limited only by the low VCE saturation voltage.

A trade-off for the low dropout voltage is a varying base

drive requirement. Micrel’s Super eta PNP® process

reduces this drive requirement to only 2% to 5% of the

load current.

The MIC39300/1/2 regulators are fully protected from

damage due to fault conditions. Current limiting is

provided. This limiting is linear; output current during

overload conditions is constant. Thermal shutdown

disables the device when the die temperature exceeds

the maximum safe operating temperature. Transient

protection allows device (and load) survival even when

the input voltage spikes above and below nominal. The

output structure of these regulators allows voltages in

excess of the desired output voltage to be applied

without reverse current flow.

Thermal Design

Linear regulators are simple to use. The most

complicated design parameters to consider are thermal

characteristics. Thermal design requires four application-

specific parameters:

• Maximum ambient temperature (TA)

• Output Current (IOUT)

• Output Voltage (VOUT)

• Input Voltage (VIN)

• Ground Current (IGND)

Calculate the power dissipation of the regulator from

these numbers and the device parameters from this

datasheet, where the ground current is taken from the

data sheet.

D = (VIN – VOUT) IOUT + VIN × IGND

The heat sink thermal resistance is determined by:

()

CSJC

A(max)J

SA P

TT θ+θ−

−

=θ

where TJ(max)  125°C and CS is between 0° and 2°C/W.

The heat sink may be significantly reduced in

applications where the minimum input voltage is known

and is large compared with the dropout voltage. Use a

series input resistor to drop excessive voltage and

distribute the heat between this resistor and the

regulator. The low dropout properties of Micrel Super

eta PNP® regulators allow significant reductions in

regulator power dissipation and the associated heat sink

without compromising performance. When this technique

is employed, a capacitor of at least 1.0F is needed

directly between the input and regulator ground.

Refer to “Application Note 9” for further details and

examples on thermal design and heat sink specification.

Figure 1. Capacitor Requirements

Output Capacitor

The MIC39300/1/2 requires an output capacitor to

maintain stability and improve transient response.

Proper capacitor selection is important to ensure proper

operation. The MIC39300/1/2 output capacitor selection

is dependent upon the ESR (equivalent series

resistance) of the output capacitor to maintain stability.

When the output capacitor is 47F or greater, the output

capacitor should have less than 1 of ESR. This will

improve transient response as well as promote stability.

Ultralow ESR capacitors, such as ceramic chip

capacitors may promote instability. These very low ESR

levels may cause an oscillation and/or underdamped

transient response. A low-ESR solid tantalum capacitor

works extremely well and provides good transient

response and stability over temperature. Aluminum

electrolytics can also be used, as long as the ESR of the

capacitor is < 1.

The value of the output capacitor can be increased

without limit. Higher capacitance values help to improve

transient response and ripple rejection and reduce

output noise.

Input Capacitor

An input capacitor of 1F or greater is recommended

when the device is more than 4 inches away from the

bulk ac supply capacitance, or when the supply is a

battery. Small, surface mount, ceramic chip capacitors

can be used for the bypassing. Larger values will help to

improve ripple rejection by bypassing the input to the

regulator, further improving the integrity of the output

voltage.

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Transient Response and 3.3V to 2.5V and 2.5V to

1.8V Conversions

The MIC39300/1/2 has excellent transient response to

variations in input voltage and load current. The device

has been designed to respond quickly to load current

variations and input voltage variations. Large output

capacitors are not required to obtain this performance. A

standard 47F output capacitor, preferably tantalum, is

all that is required. Larger values help to improve

performance even further.

By virtue of its low-dropout voltage, this device does not

saturate into dropout as readily as similar NPN-based

designs. When converting from 3.3V to 2.5V or 2.5V to

1.8V, the NPN-based regulators are already operating in

dropout, with typical dropout requirements of 1.2V or

greater. To convert down to 2.5V without operating in

dropout, NPN-based regulators require an input voltage

of 3.7V at the very least. The MIC39300/1 regulator will

provide excellent performance with an input as low as

3.0V or 2.5V. This gives the PNP-based regulators a

distinct advantage over older, NPN-based linear

regulators.

Minimum Load Current

The MIC39300/1/2 regulators are specified between

finite loads. If the output current is too small, leakage

currents dominate and the output voltage rises. A 10mA

minimum load current is necessary for proper regulation.

Error Flag

The MIC39301 version features an error flag circuit

which monitors the output voltage and signals an error

condition when the voltage drops 5% below the nominal

output voltage. The error flag is an open-collector output

that can sink 10mA during a fault condition.

Low output voltage can be caused by a number of

problems, including an overcurrent fault (device in

current limit) or low input voltage. The flag is inoperative

during overtemperature shutdown.

When the error flag is not used, it is best to leave it

open. A pull-up resistor from FLG to either VIN or VOUT is

required for proper operation.

Enable Input

The MIC39301/2 features an enable input for on/off

control of the device. The enable input’s shutdown state

draws “zero” current (only microamperes of leakage).

The enable input is TTL/CMOS compatible for simple

logic interface, but can be connected to up to 20V. When

enabled, it draws approximately 15A.

Adjustable Regulator Design

Figure 2. Adjustable Regulator with Resistors

The MIC39302 allows programming the output voltage

anywhere between 1.24V and 15.5V. Two resistors are

used. The resistor values are calculated by:

⎟

⎠

⎞

⎜

⎝

⎛−×= 1

1.240

R2R1 OUT

Where VOUT is the desired output voltage. Figure 2

shows component deﬁnition. Applications with widely

varying load currents may scale the resistors to draw the

minimum load current required for proper operation (see

Minimum Load Current section).

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Package Information

3-Pin TO-220 (T)

5-Pin TO-220 (T)

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3-Pin TO-263 (U)

5-Pin TO-263 (U)

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.