Datasheet

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MIC5239

Low Quiescent Current 500mA µCap

LDO Regulator

MLF and MicroLeadFrame is a registered trademark of Amkor Technologies

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

408

) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

December 2007

M9999-121007

General Description

The MIC5239 is a low quiescent current, µCap low-dropout

regulator. With a maximum operating input voltage of 30V

and a quiescent current of 23µA, it is ideal for supplying

keep-alive power in systems with high voltage batteries.

Capable of 500mA output, the MIC5239 has a dropout

voltage of only 350mV. It can provide high output current

for applications such as USB.

As a µCap LDO, the MIC5239 is stable with either a

ceramic or a tantalum output capacitor. It only requires a

3.3µF output capacitor for stability.

The MIC5239 includes a logic compatible enable input and

an undervoltage error flag indicator. Other features of the

MIC5239 include thermal shutdown, current limit, overvolt-

age shutdown, reverse-leakage protection, and reverse-

battery protection.

Available in the thermally enhanced SOIC-8, MSOP-8 and

SOT-223, the MIC5239 comes in fixed 1.5V, 1.8V, 2.5V,

3.0V, 3.3V and 5.0V, and adjustable voltages. For other

output voltages, contact Micrel.

All support documentation can be found on Micrel’s web

site at: www.micrel.com.

Features

• Ultra-low quiescent current (I

= 23µA @I

= 100µA)

• Continuous 500mA output current

• Wide input range: 2.3V to 30V

• Low dropout voltage: 350mV @500mA

• ±1.0% initial output accuracy

• Stable with ceramic or tantalum output capacitor

• Logic compatible enable input

• Low output voltage error flag indicator

• Overcurrent protection

• Thermal shutdown

• Reverse-leakage protection

• Reverse-battery protection

• High-power SOIC-8, MSOP-8 and SOT-223 packages

Applications

• USB power supply

• Keep-alive supply in notebook and portable personal

computers

• Logic supply from high voltage batteries

• Automotive electronics

• Battery-powered systems

___________________________________________________________________________________________________________

Typical Application

GND

= 23µA

OUT

3.0V/100µA

30V

MIC5239

OUT

GND

FLG

Regulator with Low I

and Low I

914

OUT

= 1mA

OUT

= 10µA

OUT

= 100µA

Ground Current vs. Input Voltage

Summary of content (14 pages)

PAGE 1
MIC5239 Low Quiescent Current 500mA µCap LDO Regulator General Description Features The MIC5239 is a low quiescent current, µCap low-dropout regulator. With a maximum operating input voltage of 30V and a quiescent current of 23µA, it is ideal for supplying keep-alive power in systems with high voltage batteries. Capable of 500mA output, the MIC5239 has a dropout voltage of only 350mV. It can provide high output current for applications such as USB.
PAGE 2
Micrel MIC5239 Ordering Information Part Number Standard Pb-Free Voltage(1) Junction Temp. Range Package MIC5239-1.5BM MIC5239-1.5YM 1.5V –40°C to +125°C 8-pin SOIC MIC5239-1.5BMM MIC5239-1.5YMM 1.5V –40°C to +125°C 8-pin MSOP MIC5239-1.5BS MIC5239-1.5YS 1.5V –40°C to +125°C SOT-223 MIC5239-1.8BM MIC5239-1.8YM 1.8V –40°C to +125°C 8-pin SOIC MIC5239-1.8BMM MIC5239-1.8YMM 1.8V –40°C to +125°C 8-pin MSOP MIC5239-1.8BS MIC5239-1.8YS 1.8V –40°C to +125°C SOT-223 MIC5239-2.
PAGE 3
Micrel MIC5239 Pin Configuration SOIC-8 (M) MSOP-8(MM) (Fixed) SOT-223 (S) SOIC-8 (M) MSOP-8(MM) (Adj) Pin Description Pin Number MSOP/SOIC Pin Number SOT-223 Pin Name 2 (fixed) — FLG Error FLAG (Output): Open-collector output is active low when the output is out of regulation due to insufficient input voltage or excessive load. An external pull-up resistor is required. 2 (adj) — ADJ Adjustable Feedback Input: Connect to voltage divider network.
PAGE 4
Micrel MIC5239 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN) ...................................... –20V to +32V Enable Input Voltage (VEN)............................ –0.3V to +32V Power Dissipation (PD)(3) ...........................Internally Limited Junction Temperature (TJ) ........................–40°C to +125°C Storage Temperature (TS).........................–65°C to +150°C Lead Temperature (soldering, 5 sec.)........................ 260°C ESD Rating(4) SOT-23-3L ........
PAGE 5
Micrel MIC5239 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. The θJA of the MIC5239x.xBMM (all versions) is 80°C/W, the MIC5239-x.
PAGE 6
Micrel MIC5239 Typical Characteristics (VOUT = 3V) December 2007 6 M9999-121007
PAGE 7
Micrel MIC5239 Typical Characteristics (continued) (VOUT = 3V) Input Current INPUT CURRENT (mA) 120 100 80 60 40 20 0 -20 VEN = 5V RLOAD = 30 -10 0 SUPPLY VOLTAGE (V) 10 Functional Characteristics December 2007 7 M9999-121007
PAGE 8
Micrel MIC5239 Functional Diagram Block Diagram — Fixed Voltages Block Diagram — Adjustable Voltages December 2007 8 M9999-121007
PAGE 9
Micrel MIC5239 Application Information The MIC5239 provides all of the advantages of the MIC2950: wide input voltage range, and reversedbattery protection, with the added advantages of reduced quiescent current and smaller package. Additionally, when disabled, quiescent current is reduced to 0.1µA. Enable A low on the enable pin disables the part, forcing the quiescent current to less than 0.1µA. Thermal shutdown and the error flag are not functional while the device is disabled.
PAGE 10
Micrel MIC5239 Current Limit Figure 4 displays a method for reducing the steady state short-circuit current. The duration that the supply delivers current is set by the time required for the error flag output to discharge the 4.7µF capacitor tied to the enable pin. The off time is set by the 200kΩ resistor as it recharges the 4.7µF capacitor, enabling the regulator. This circuit reduces the short-circuit current from 800mA to 40mA while allowing for regulator restart once the short is removed.
PAGE 11
Micrel MIC5239 ∆T = TJ(max) – TA(max) TJ(max) = 125°C TA(max) = maximum ambient operating temperature For example, the maximum ambient temperature is 50°C, the ∆T is determined as follows: ∆T = 125°C – 50°C ∆T = 75°C Using Figure 6, the minimum amount of required copper can be determined based on the required power dissipation. Power dissipation in a linear regulator is calculated as follows: Figure 8. Copper Area vs.
PAGE 12
Micrel MIC5239 The MIC5239YM can be adjusted from 1.24V to 20V by using two external resistors (Figure 10). The resistors set the output voltage based on the following equation: Adjustable Regulator Application R1 ⎞ ⎛ VOUT = VREF ⎜1 + ⎟ R2 ⎝ ⎠ Where VREF = 1.23V. Feedback resistor R2 should be no larger than 300kΩ. Figure 10.
PAGE 13
Micrel MIC5239 Package Information 8-Pin MSOP (MM) SOT-223 (S) December 2007 13 M9999-121007
PAGE 14
Micrel MIC5239 8-Pin SOIC (M) 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.