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MIC5239 Micrel MIC5239 Low Quiescent Current 500mA Cap LDO Regulator Advance Information General Description The MIC5239 is a low quiescent current, Cap low-dropout regulator. With a maximum operating input voltage of 30V and a quiescent current of 23A, it is ideal for supplying keepalive 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 Cap LDO, the MIC5239 is stable with either a ceramic or a tantalum output capacitor. It only requires a 3.3F 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, overvoltage shutdown, load-dump protection, reverse leakage protections, and reverse battery protection. Available in the thermally enhanced SOIC-8, MSOP-8 and SOT-223, the MIC5239 comes in fixed 3.0V and adjustable voltages. For other output voltages, contact Micrel. Features * * * * * * * * * * * * * Ultra-low quiescent current (IQ = 23A @IO = 100A) Continuious 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 40 VIN 30V MIC5239 IN OUT EN FLG GND GROUND CURRENT (A) 35 30 25 20 15 10 4 VOUT 3.0V/100A IGND = 23A IOUT = 1mA IOUT = 100A IOUT = 10A 9 14 19 24 INPUT VOLTAGE (V) 29 Regulator with Low IO and Low IQ Ground Current vs. Input Voltage Micrel, Inc. * 1849 Fortune Drive * San Jose, CA 95131 * USA * tel + 1 (408) 944-0800 * fax + 1 (408) 944-0970 * http://www.micrel.com January 2002 1 MIC5239 MIC5239 Micrel Ordering Information Part Number * MIC5239-3.0BMM MIC5239-3.0BS MIC5239-3.0BM MIC5239BMM MIC5239BM Voltage 3.0V 3.0V 3.0V ADJ ADJ Junction Temp. Range -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C Package 8-lead MSOP SOT-223 8-lead SOIC 8-lead MSOP 8-lead SOIC Pin Configuration EN 1 FLG 2 IN 3 OUT 4 8 GND 7 GND 6 GND 5 GND EN 1 ADJ 2 IN 3 OUT 4 8 GND 7 GND 6 GND 5 GND SOIC-8 (M) MSOP-8 (MM) (Fixed) GND TAB SOIC-8 (M) MSOP-8 (MM) (Adj.) 1 2 3 IN GND OUT SOT-223 (S) Pin Description Pin Number Pin Number MSOP-8/SOIC-8 SOT-223 2 (Fixed) Pin Name FLG Pin Function 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. Adjustable Feedback Input. Connect to voltage divider network. Power supply input. Regulated Output Enable (Input): Logic low = shutdown; logic high = enabled. Ground: Pins 5, 6, 7, and 8 are internally connected in common via the leadframe. 2 (Adj) 3 4 1 5-8 1 3 2 ADJ IN OUT EN GND MIC5239 2 January 2002 MIC5239 Micrel Absolute Maximum Ratings (Note 1) Supply Voltage (VIN) ..................................... -20V to +32V Enable Input Voltage (VEN) .......................... -0.3V to +32V Power Dissipation (PD), Note 3 ............... Internally Limited Junction Temperature (TJ) ....................... -40C to +125C Storage Temperature (TS) ....................... -65C to +150C Lead Temperature (soldering, 5 sec.) ....................... 260C ESD Rating, Note 4 Operating Ratings (Note 2) Supply Voltage (VIN) ........................................ 2.3V to 30V Enable Input Voltage (VEN) ................................. 0V to 30V Junction Temperature (TJ) ....................... -40C to +125C Package Thermal Resistance MSOP (JA) ......................................................... 80C/W SOT-223 (JA) ..................................................... 50C/W Electrical Characteristics VIN = VOUT + 1V; VEN 2.0V; IOUT = 100A; TJ = 25C, bold values indicate -40C TJ +125C; unless noted. Symbol VOUT Parameter Output Voltage Accuracy Conditions variation from nominal VOUT Min -1 -2 Typ Max 1 +2 Units % % VOUT/VOUT VOUT/VOUT V Line Regulation Load Regulation Dropout Voltage, Note 6 VIN = VOUT + 1V to 30V IOUT = 100A to 500mA, Note 5 IOUT = 100A IOUT = 150mA IOUT = 500mA 0.06 0.5 50 260 350 23 1.3 8.5 0.1 850 160 0.5 1 % % mV 350 400 mV mV mV A A mA mA A mA Vrms IGND Ground Pin Current VEN 2.0V, IOUT = 100A VEN 2.0V, IOUT = 150mA VEN 2.0V, IOUT = 500mA 40 45 5 15 1 1200 IGND(SHDN) ISC en FLAG Output VFLG VOL ILEAK Enable Input VIL VIH IIN Ground Pin in Shutdown Short Circuit Current Output Noise VEN 0.6V, VIN = 30V VOUT = 0V 10Hz to 100kHz, VOUT = 3.0V, CL = 3.3F % of VOUT % of VOUT VIN = VOUT(nom) - 0.12VOUT, IOL = 200A VOH = 30V regulator off regulator on VEN = 0.6V, regulator off VEN = 2.0V, regulator on VEN = 30V, regulator on 2.0 -1.0 -2.0 Low Threshold High Threshold FLAG Output Low Voltage FLAG Output Leakage 94 95 150 0.1 % % mV A Input Low Voltage Input High Voltage Enable Input Current 0.6 V V A A A A A A 0.01 0.15 0.5 1.0 2.0 1.0 2.0 2.5 5.0 Note 1. Note 2. Note 3: Exceeding the absolute maximum rating may damage the device. The device is not guaranteed to function outside its operating rating. The maximum allowable power dissipation of any TA (ambient temperature) is PD(max) = (TJ(max) - TA) / JA. Exceeding the maximum allowable power dissipation will result in excessive die termperature, and the regulator will go into thermal shutdown. The JA of the MIC5239x.xBMM (all versions) is 80C/W, the MIC5239-x.xBM (all versions) is 63C/W, and the MIC5239-x.xBS (all versions) is 50C/W mounted on a PC board (see "Thermal Characteristics" for further details). January 2002 3 MIC5239 MIC5239 Note 4. Note 5: Note 6: Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. Micrel Regulation is measured at constant junction temperature using pulse testing with a low duty-cycle. Changes in output voltage due to heating effects are covered by the specification for thermal regulation. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1.0V differential. MIC5239 4 January 2002 MIC5239 Micrel Typical Characteristics (VO = 3V) Power Supply Rejection Ratio 60 50 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) ILOAD = 500mA 450 400 350 300 250 200 150 100 50 0 0 Dropout Voltage vs. Output Current 600 500 400 300 200 100 Dropout Voltage vs. Temperature IOUT = 500mA PSRR (dB) 40 30 20 10 0 0.01 0.1 1 10 100 FREQUENCY (Hz) 1000 100 200 300 400 500 OUTPUT CURRENT (mA) 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) Dropout Characteristics 3.5 9000 ILOAD = 100A GROUND CURRENT (A) Ground Pin Current vs. Output Current GROUND CURRENT (A) 8000 7000 6000 5000 4000 3000 2000 1000 0 0 100 200 300 400 500 OUTPUT CURRENT (mA) VIN = 4V 30 28 26 24 22 20 18 16 14 12 10 0 Ground Pin Current vs. Output Current VIN = 30V VIN = 24V OUTPUT VOLTAGE (V) 3 2.5 I LOAD = 250mA 2 1.5 1 0.5 0 0 0.5 1 1.5 2 2.5 3 3.5 4 INPUT VOLTAGE (V) ILOAD = 500mA VIN = 4V VIN = 12V 100 200 300 400 500 OUTPUT CURRENT (A) 80 Ground Pin Current vs. Temperature GROUND CURRENT (mA) 3 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2 Ground Pin Current vs. Temperature GROUND CURRENT (mA) ILOAD = 250mA 10.5 10 9.5 9 8.5 8 Ground Pin Current vs. Temperature ILOAD = 500mA GROUND CURRENT (A) 75 70 65 60 55 ILOAD = 10mA 50 -40 -20 0 20 40 60 80 100 120 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) TEMPERATURE (C) 7.5 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) Ground Pin Current vs. Input Voltage GROUND CURRENT (mA) GROUND CURRENT (A) Ground Pin Current vs. Input Voltage 14.4 12.4 10.4 8.4 6.4 4.4 2.4 0.4 1.5 2 2.5 3 3.5 INPUT VOLTAGE (V) 4 IOUT = 250mA IOUT=500mA GROUND CURRENT (A) 40 35 30 25 20 15 10 4 Ground Pin Current vs. Input Voltage 100 90 80 70 IOUT = 10mA IOUT = 1mA IOUT = 100A 60 50 IOUT = 1mA 40 30 20 10 0 1.5 IOUT = 100A IOUT = 10A 9 14 19 24 INPUT VOLTAGE (V) 29 IOUT = 10A 2 2.5 3 3.5 INPUT VOLTAGE (V) 4 January 2002 5 MIC5239 MIC5239 Micrel Input Current 120 INPUT CURRENT (mA) OUTPUT VOLTAGE (V) 3.05 3.04 3.03 3.02 3.01 3 2.99 2.98 2.97 2.96 Output Voltage vs. Temperature ILOAD = 100A SHORT CIRCUIT CURRENT (mA) 900 800 700 600 500 400 300 200 100 Short Circuit Current 100 80 60 40 20 0 -20 VEN = 5V RLOAD = 30 -10 0 SUPPLY VOLTAGE (V) 10 VIN = 4V 2.95 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (C) Load Transient Response OUTPUT CURRENT OUTPUT VOLTAGE (500mA/div.) (500mV/div.) 500mA 0mA VIN = 4V VOUT = 3V COUT = 4.7F ceramic TIME (400s/div.) MIC5239 6 January 2002 MIC5239 Micrel Functional Diagram IN OUT EN ENABLE FLAG VREF GND Block Diagram - Fixed Voltages IN R1 OUT EN ENABLE ADJ R2 GND Block Diagram - Adjustable Voltages January 2002 7 MIC5239 MIC5239 Micrel Error Detection Comparator Output The FLAG pin is an open collector output which goes low when the output voltage drops 5% below it's internally programmed level. It senses conditions such as excessive load (current limit), low input voltage, and over temperature conditions. Once the part is disabled via the enable input, the error flag output is not valid. Overvoltage conditions are not reflected in the error flag output. The error flag output is also not valid for input voltages less than 2.3V. The error output has a low voltage of 400mV at a current of 200A. In order to minimize the drain on the source used for the pull-up, a value of 200k to 1M is suggested for the error flag pull-up. This will guarantee a maximum low voltage of 0.4V for a 30V pull-up potential. An unused error flag can be left unconnected. 4.75V Application Information The MIC5239 provides all of the advantages of the MIC2950: wide input voltage range, load dump (positive transients up to 60V), and reversed-battery protection, with the added advantages of reduced quiescent current and smaller package. Additionally, when disabled, quiescent current is reduced to 0.1A. Enable A low on the enable pin disables the part, forcing the quiescent current to less than 0.1A. Thermal shutdown and the error flag are not functional while the device is disabled. The maximum enable bias current is 2A for a 2.0V input. An open collector pull-up resistor tied to the input voltage should be set low enough to maintain 2V on the enable input. Figure 1 shows an open collector output driving the enable pin through a 200k pull-up resistor tied to the input voltage. In order to avoid output oscillations, slow transitions from low to high should be avoided. 200k VIN 5V MIC5239 IN OUT 200k EN SHUTDOWN ENABLE Output Voltage Error FLAG Output 0V VALID ERROR NOT VALID NOT VALID VERR VOUT COUT Input Voltage 5V 1.3V 0V FLG GND Figure 3. Error FLAG Output Timing Thermal Shutdown The MIC5239 has integrated thermal protection. This feature is only for protection purposes. The device should never be intentionally operated near this temperature as this may have detrimental effects on the life of the device. The thermal shutdown may become inactive while the enable input is transitioning a high to a low. When disabling the device via the enable pin, transition from a high to low quickly. This will insure that the output remains disabled in the event of a thermal shutdown. 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 4.7F capacitor tied to the enable pin. The off time is set by the 200K resistor as it recharges the 4.7F 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. 1N4148 200k VIN 5V MIC5239 IN OUT 200k EN FLG GND COUT VERR VOUT Figure 1. Remote Enable Input Capacitor An input capacitor may be required when the device is not near the source power supply or when supplied by a battery. Small, surface mount, ceramic capacitors can be used for bypassing. Larger values may be required if the source supply has high ripple. Output Capacitor The MIC5239 has been designed to minimize the effect of the output capacitor ESR on the closed loop stability. As a result, ceramic or film capacitors can be used at the output. Figure 2 displays a range of ESR values for a 10F capacitor. Virtually any 10F capacitor with an ESR less than 3.4 is sufficient for stability over the entire input voltage range. Stability can also be maintained throughout the specified load and line conditions with 4.7F film or ceramic capacitors. OUTPUT CAPACITOR ESR () 5 4 3 Stable Region 2 1 0 TJ = 25C VOUT = 10F 5 10 15 20 25 30 SHUTDOWN ENABLE 4.7F INPUT VOLTAGE (V) Figure 2. Output Capacitor ESR Figure 4. Remote Enable with Short-Circuit Current Foldback MIC5239 8 January 2002 MIC5239 Thermal Characteristics The MIC5239 is a high input voltage device, intended to provide 500mA of continuous output current in two very small profile packages. The power MSOP-8 allow the device to dissipate about 50% more power than their standard equivalents. Power MSOP-8 Thermal Characteristics 900 COPPER AREA (mm2) Micrel 40C 50C 55C 65C 75C 85C 800 700 600 500 400 300 200 100 0 0 0.25 0.50 0.75 1.00 1.25 1.50 POWER DISSIPATION (W) One of the secrets of the MIC5239's performance is its power MSOP-8 package featuring half the thermal resistance of a standard MSOP-8 package. Lower thermal resistance means more output current or higher input voltage for a given package size. Lower thermal resistance is achieved by joining the four ground leads with the die attach paddle to create a singlepiece electrical and thermal conductor. This concept has been used by MOSFET manufacturers for years, proving very reliable and cost effective for the user. Thermal resistance consists of two main elements, JC (junction-to-case thermal resistance) and CA (case-to-ambient thermal resistance). See Figure 5. JC is the resistance from the die to the leads of the package. CA is the resistance from the leads to the ambient air and it includes CS (case-tosink thermal resistance) and SA (sink-to-ambient thermal resistance). Figure 6. Copper Area vs. Power-MSOP Power Dissipation ( JA) (T Figure 6 shows copper area versus power dissipation with each trace corresponding to a different temperature rise above ambient. From these curves, the minimum area of copper necessary for the part to operate safely can be determined. The maximum allowable temperature rise must be calculated to determine operation along which curve. T = TJ(max) - TA(max) TJ(max) = 125C TA(max) = maximum ambient operating temperature For example, the maximum ambient temperature is 50C, the T is determined as follows: T = 125C - 50C T = 75C 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: PD = (VIN - VOUT) IOUT + VIN * IGND If we use a 3V output device and a 28V input at moderate output current of 25mA, then our power dissipation is as follows: PD = (28V - 3V) x 25mA + 28V x 250A PD = 625mW + 7mW PD = 632mW From Figure 6, the minimum amount of copper required to operate this application at a T of 75C is 110mm2. Quick Method Determine the power dissipation requirements for the design along with the maximum ambient temperature at which the device will be operated. Refer to Figure 7, which shows safe operating curves for three different ambient temperatures: 25C, 50C and 85C. From these curves, the minimum amount of copper can be determined by knowing the maximum power dissipation required. If the maximum ambient temperature is 50C and the power dissipation is as above, 639mW, the curve in Figure 7 shows that the required area of copper is 110mm2. The JA of this package is ideally 80C/W, but it will vary depending upon the availability of copper ground plane to which it is attached. MSOP-8 JA JC CA AMBIENT ground plane heat sink area printed circuit board Figure 5. Thermal Resistance Using the power MSOP-8 reduces the JC dramatically and allows the user to reduce CA. The total thermal resistance, JA (junction-to-ambient thermal resistance) is the limitingfactor in calculating the maximum power dissipation capability of the device. Typically, the power MSOP-8 has a JC of 80C/W, this is significantly lower than the standard MSOP-8 which is typically 200C/W. CA is reduced because pins 5 through 8 can now be soldered directly to a ground plane which significantly reduces the case-to-sink thermal resistance and sink to ambient thermal resistance. Low-dropout linear regulators from Micrel are rated to a maximum junction temperature of 125C. It is important not to exceed this maximum junction temperature during operation of the device. To prevent this maximum junction temperature from being exceeded, the appropriate ground plane heat sink must be used. January 2002 9 100C MIC5239 MIC5239 900 800 COPPER AREA (mm2) Micrel Power SOIC-8 Thermal Characteristics T = 125C J 85C 50C 25C 700 600 500 400 300 200 100 0 0 0.25 0.50 0.75 1.00 1.25 1.50 POWER DISSIPATION (W) Figure 7. Copper Area vs. Power-MSOP Power Dissipation (TA) 900 TJA = COPPER AREA (mm2) 700 600 500 400 300 200 100 0 0 40C 50C 55C 65C 75C 85C 800 The power-SOIC-8 package follows the same idea as the power-MSOP-8 package, using four ground leads with the die attach paddle to create a single-piece electrical and thermal conductor, reducing thermal resistance and increasing power dissipation capability. Quick Method Determine the power dissipation requirements for the design along with the maximum ambient temperature at which the device will be operated. Refer to Figure 9, which shows safe operating curves for three different ambient temperatures, 25C, 50C, and 85C. From these curves, the minimum amount of copper can be determined by knowing the maximum power dissipation required. If the maximum ambient temperature is 50C, and the power dissipation is 632mW, the curve in Figure 9 shows that the required area of copper is less than 100mm2,when using the power SOIC-8. Adjustable Regulator Application MIC5239BM/MM VIN 2 4 3 100C IN EN OUT ADJ GND 5-8 1 VOUT R1 1F R2 0.25 0.50 0.75 1.00 1.25 1.50 POWER DISSIPATION (W) Figure 8. Copper Area vs. Power-SOIC Power Dissipation (TJA) 900 800 TJ = 125C 85C 50C 25C Figure 10. Adjustable Voltage Application The MIC5239BM 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: R1 ) R2 Where VREF = 1.23V. Feeback resistor R2 should be no larger than 300k. VOUT = VREF (1 + COPPER AREA (mm2) 700 600 500 400 300 200 100 0 0 0.25 0.50 0.75 1.00 1.25 1.50 POWER DISSIPATION (W) Figure 9. Copper Area vs. Power-SOIC Power Dissipation (TA) The same method of determining the heat sink area used for the power-MSOP-8 can be applied directly to the powerSOIC-8. The same two curves showing power dissipation versus copper area are reproduced for the power-SOIC-8 and they can be applied identically. MIC5239 10 January 2002 MIC5239 Micrel Package Information 3.15 (0.124) 2.90 (0.114) C L C L 3.71 (0.146) 7.49 (0.295) 3.30 (0.130) 6.71 (0.264) 2.41 (0.095) 2.21 (0.087) 4.7 (0.185) 4.5 (0.177) 6.70 (0.264) 6.30 (0.248) 1.04 (0.041) 0.85 (0.033) DIMENSIONS: MM (INCH) 1.70 (0.067) 16 1.52 (0.060) 10 10 MAX 0.10 (0.004) 0.02 (0.0008) 0.38 (0.015) 0.25 (0.010) 0.84 (0.033) 0.64 (0.025) 0.91 (0.036) MIN SOT-223 (S) 0.122 (3.10) 0.112 (2.84) 0.199 (5.05) 0.187 (4.74) DIMENSIONS: INCH (MM) 0.120 (3.05) 0.116 (2.95) 0.036 (0.90) 0.032 (0.81) 0.043 (1.09) 0.038 (0.97) 0.012 (0.30) R 0.007 (0.18) 0.005 (0.13) 0.012 (0.03) 0.0256 (0.65) TYP 0.008 (0.20) 0.004 (0.10) 5 MAX 0 MIN 0.012 (0.03) R 0.039 (0.99) 0.035 (0.89) 0.021 (0.53) 8-Lead MSOP (MM) January 2002 11 MIC5239 MIC5239 Micrel 0.026 (0.65) MAX) PIN 1 0.157 (3.99) 0.150 (3.81) DIMENSIONS: INCHES (MM) 0.050 (1.27) TYP 0.020 (0.51) 0.013 (0.33) 0.0098 (0.249) 0.0040 (0.102) 0-8 SEATING PLANE 45 0.010 (0.25) 0.007 (0.18) 0.064 (1.63) 0.045 (1.14) 0.197 (5.0) 0.189 (4.8) 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79) 8-Lead SOIC (M) MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL USA + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or 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. (c) 2002 Micrel Incorporated MIC5239 12 January 2002 |
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