MIC39100/1/2 1A, Low-Voltage, Low-Dropout Regulator General Description Features The MIC39100, MIC39101, and MIC39102 are 1A lowdropout linear voltage regulators that provide low-voltage, high-current output from an extremely small package. Utilizing Micrel’s proprietary Super βeta PNP® pass element, the MIC39100/1/2 offers extremely low dropout (typically 410mV at 1A) and low ground current (typically 11mA at 1A). • Fixed and adjustable output voltages to 1.24V • 410mV typical dropout at 1A − Ideal for 3.0V to 2.5V conversion − Ideal for 2.5V to 1.8V conversion • 1A minimum guaranteed output current • 1% initial accuracy • Low ground current • Current-limiting and thermal-shutdown protection • Reversed-battery and reversed-leakage protection • Fast transient response • Low-profile SOT-223 package • Power SO-8 package The MIC39100 is a fixed output regulator offered in the SOT-223 package. The MIC39101 and MIC39102 are fixed and adjustable regulators, respectively, in a thermally enhanced power 8-lead SOIC package. The MIC39100/1/2 is ideal for PC add-in cards that need to convert from standard 5V to 3.3V, 3.3V to 2.5V or 2.5V to 1.8V. A guaranteed maximum dropout voltage of 630mV over all operating conditions allows the MIC39100/1/2 to provide 2.5V from a supply as low as 3.13V and 1.8V from a supply as low as 2.43V. The MIC39100/1/2 is fully protected with overcurrent limiting, thermal-shutdown, and reverse-battery protection. Fixed voltages of 5.0V, 3.3V, 2.5V, and 1.8V are available on MIC39100/1 with adjustable output voltages to 1.24V on MIC39102. Applications • • • • • • LDO linear regulator for PC add-in cards High-efficiency linear power supplies SMPS post regulator Multimedia and PC processor supplies Battery chargers Low-voltage microcontrollers and digital logic Datasheets and support documentation are available on Micrel’s web site at: www.micrel.com. Typical Applications 2.5V/1A Regulator 2.5V/1A Regulator with Error Flag 1.5V/1A Adjustable Regulator Super βeta PNP is a registered trademark of Micrel, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com June 3, 2015 Revision 3.0 Micrel, Inc. MIC39100/1/2 Ordering Information Part Number Voltage MIC39100-1.8WS (1) MIC39100-2.5WS (1) MIC39100-3.3WS (1) MIC39100-5.0WS (1) EN Flag Adjustable Junction Temperature Range Package 1.8V –40°C to +125°C SOT-223 2.5V –40°C to +125°C SOT-223 3.3V –40°C to +125°C SOT-223 5.0V –40°C to +125°C SOT-223 MIC39101-1.8YM 1.8V √ √ –40°C to +125°C SOIC-8 MIC39101-2.5YM 2.5V √ √ –40°C to +125°C SOIC-8 MIC39101-3.3YM 3.3V √ √ –40°C to +125°C SOIC-8 MIC39101-5.0YM 5.0V √ √ –40°C to +125°C SOIC-8 Adjustable √ –40°C to +125°C SOIC-8 MIC39102YM √ Note: 1. RoHS-compliant with “high-melting solder” exemption. Pin Configuration MIC39100-xx Fixed SOT-223 (S) (Top View) MIC39101-xx Fixed SOIC-8 (M) (Top View) June 3, 2015 MIC39102 Adjustable SOIC-8 (M) (Top View) 2 Revision 3.0 Micrel, Inc. MIC39100/1/2 Pin Description Part Number MIC39100 Part Number MIC39101 Part Number MIC39102 Pin Name 1 1 EN Enable (Input): CMOS-compatible control input. Logic HIGH = enable; logic LOW or OPEN = shutdown. 1 2 2 IN Supply (Input) 3 3 3 OUT Regulator Output. FLG Flag (Output): Open-collector error flag output. Active LOW = output undervoltage. 4 ADJ Adjustable Input: Feedback input. Connect to resistive voltagedivider network. 5−8 GND Ground. 4 2, TAB June 3, 2015 5−8 3 Pin Function Revision 3.0 Micrel, Inc. MIC39100/1/2 Absolute Maximum Ratings(2) Operating Ratings(3) Supply Voltage (VIN) ....................................... −20V to +20V Enable Voltage (VEN) .................................................... +20V Lead Temperature (soldering, 5s) .............................. 260°C Storage Temperature (TS) ......................... −65°C to +150°C ESD Rating.................................................................Note 5 Supply Voltage (VIN) .................................... +2.25V to +16V Enable Voltage (VEN) .................................................... +16V Maximum Power Dissipation (PD(MAX)) ....................... Note 4 Junction Temperature (TJ) ........................ −40°C to +125°C Package Thermal Resistance SOT-223 (θJC) .................................................. +15°C/W SOIC-8 (θJC)..................................................... +20°C/W Electrical Characteristics(6) VIN = VOUT + 1V; VEN = 2.25V; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Symbol Parameter VOUT Output Voltage ∆VOUT/∆T VDO IGND IOUT(LIM) Condition Min. Typ. Max. 10mA −1 +1 10mA ≤ IOUT ≤ 1A, VOUT +1V ≤ VIN ≤ 8V −2 +2 Units % Line Regulation IOUT = 10mA, VOUT + 1V ≤ VIN ≤ 16V 0.06 0.5 % Load Regulation VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 1A 0.2 1 % 40 100 ppm/°C Output Voltage Temperature Coefficient(7) Dropout Voltage(8) Ground Current(9) Current Limit 200 IOUT = 100mA, ∆VOUT = −1% 140 IOUT = 500mA, ∆VOUT = −1% 275 IOUT = 750mA, ∆VOUT = −1% 300 IOUT = 1A, ∆VOUT = −1% 410 IOUT = 100mA, VIN = VOUT + 1V 400 IOUT = 500mA, VIN = VOUT + 1V 4 IOUT = 750mA, VIN = VOUT + 1V 6.5 IOUT = 1A, VIN = VOUT + 1V 11 20 VOUT = 0V, VIN = VOUT + 1V 1.8 2.5 250 500 mV 550 630 µA mA A Notes: 2. Exceeding the absolute maximum ratings may damage the device. 3. The device is not guaranteed to function outside its operating ratings. 4. PD(MAX) = (TJ(MAX) − TA) ÷ θJA, where θJA depends upon the printed circuit layout (see Applications Information). 5. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF. 6. Specification for packaged product only. 7. Output voltage temperature coefficient is ∆VOUT(WORST CASE) ÷ (TJ(MAX) − TJ(MIN)), where TJ(MAX) = +125°C and TJ(MIN) = −40°C. 8. VDO = VIN – VOUT when VOUT decreases to 99% of its nominal output voltage with VIN = VOUT + 1V. For output voltages below 2.25V, dropout voltage is the input-to-output voltage differential with the minimum input voltage being 2.25V. Minimum input operating voltage is 2.25V. 9. IGND is the quiescent current (IIN = IGND + IOUT). June 3, 2015 4 Revision 3.0 Micrel, Inc. MIC39100/1/2 Electrical Characteristics(6) VIN = VOUT + 1V; VEN = 2.25V; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Symbol Parameter Condition Min. Typ. Max. Units Enable Input VEN Enable Input Voltage 0.8 Logic LOW (Off) 2.25 Logic HIGH (On) 1 VEN = 2.25V IEN 15 30 75 Enable Input Current 2 VEN = 0.8V V µA 4 Flag Output IFLG(LEAK) Output Leakage Voltage VOH = 16V 0.01 VFLG(DO) Output Low Voltage VIN = 2.250V, IOL = 250µA(10) 210 Low Threshold % of VOUT High Threshold % of VOUT VFLG 1 2 300 400 µA mV 93 99.2 Hysteresis % 1 MIC39102 Only Reference Voltage 1.228 IOUT = 10mA 1.215 1.240 1.203 Note 11 1.252 1.265 V 1.277 80 Adjust Pin Bias Current 40 Reference Voltage Temperature Coefficient 20 ppm/°C Adjust Pin Bias Current Temperature Coefficient 0.1 nA/°C 120 nA Notes: 10. For a 2.5V device, VIN = 2.250V (device is in dropout). 11. VREF ≤ VOUT ≤ (VIN – 1V), 2.25V ≤ VIN ≤ 16V, 10mA ≤ IL ≤ 1A, TJ = TMAX. June 3, 2015 5 Revision 3.0 Micrel, Inc. MIC39100/1/2 Typical Characteristics June 3, 2015 6 Revision 3.0 Micrel, Inc. MIC39100/1/2 Typical Characteristics (Continued) June 3, 2015 7 Revision 3.0 Micrel, Inc. MIC39100/1/2 Typical Characteristics (Continued) June 3, 2015 8 Revision 3.0 Micrel, Inc. MIC39100/1/2 Functional Characteristics June 3, 2015 9 Revision 3.0 Micrel, Inc. MIC39100/1/2 Functional Diagrams MIC39100 Fixed Regulator Block Diagram MIC39101 Fixed Regulator with Flag and Enable Block Diagram MIC39102 Adjustable Regulator Block Diagram June 3, 2015 10 Revision 3.0 Micrel, Inc. MIC39100/1/2 Applications Information The MIC39100/1/2 is a high-performance low-dropout voltage regulator suitable for moderate to high-current voltage regulator applications. Its 630mV dropout voltage at full load and overtemperature makes it especially valuable in battery-powered systems and as highefficiency noise filters 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 βeta PNP process reduces this drive requirement to only 2% of the load current. The MIC39100/1/2 regulator is fully protected from damage due to fault conditions. Linear current limiting is provided. 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. Figure 1. Capacitor Requirements Output Capacitor The MIC39100/1/2 requires an output capacitor to maintain stability and improve transient response. Proper capacitor selection is important to ensure proper operation. The MIC39100/1/2 output capacitor selection is dependent upon the equivalent series resistance (ESR) of the output capacitor to maintain stability. When the output capacitor is 10µF or greater, the output capacitor should have an ESR less than 2Ω. This will improve transient response as well as promote stability. Ultra-low ESR capacitors (<100mΩ), 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 <2Ω. June 3, 2015 11 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 1µF or greater is recommended when the device is more than four 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 bypassing. Larger values will help to improve ripple rejection by bypassing the input to the regulator, further improving the integrity of the output voltage. Error Flag The MIC39101 features an error flag (FLG), which monitors the output voltage and signals an error condition when this voltage drops 5% below its expected value. The error flag is an open-collector output that pulls low under fault conditions and may sink up to 10mA. Low output voltage signifies a number of possible problems, including an overcurrent fault (the device is in current limit) or low input voltage. The flag output is inoperative during overtemperature conditions. A pull-up resistor from FLG to either VIN or VOUT is required for proper operation. For information regarding the minimum and maximum values of pull-up resistance, refer to the related graph in the Typical Characteristics section of the datasheet. Enable Input The MIC39101 and MIC39102 feature an active-HIGH enable input (EN) that allows on/off control of the regulator. Current drain reduces to zero when the device is shutdown, with only microamperes (µA) of leakage current. The EN input has TTL/CMOS-comparable thresholds for simple logic interfacing. EN can be directly tied to VIN and pulled-up to the maximum supply voltage. Transient Response and 3.3V to 2.5V or 2.5V to 1.8V Conversion The MIC39100/1/2 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 10µF 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 or 1.8V without operating in dropout, NPN-based regulators require an input voltage of 3.7V at the very least. Revision 3.0 Micrel, Inc. MIC39100/1/2 The MIC39100 regulator will provide excellent performance with an input as low as 3.0V or 2.5V respectively. This gives the PNP-based regulators a distinct advantage over older, NPN-based linear regulators. 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. Minimum Load Current The MIC39100/1/2 regulator is 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. Thermal resistance consists of two main elements, θJC (junction-to-case thermal resistance) and θCA (case-toambient thermal resistance, see Figure 3). θJC is the resistance from the die to the leads of the package. θCA is the resistance from the leads to the ambient air and it includes θCS (case- to-sink thermal resistance) and θSA (sink-to-ambient thermal resistance). Adjustable Regulator Design The MIC39102 allows programming the output voltage anywhere between 1.24V and the 16V maximum operating rating of the family. Two resistors are used. Resistors can be quite large, up to 1MΩ, because of the very high input impedance and low bias current of the sense comparator: The resistor values are calculated by Equation 1: V R1 = R 2 OUT − 1 1.240V Eq. 1 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 (Figure 2). Using the power SOIC-8 reduces the θJC dramatically and allows the user to reduce θCA. The total thermal resistance, θJA, (junction-to-ambient thermal resistance) is the limiting factor in calculating the maximum power dissipation capability of the device. Typically, the power SOIC-8 has a θJC of 20°C/W, which is significantly lower than the standard SOIC-8 (typically 75°C/W). θCA is reduced due to the capability of soldering Pins 5 − 8 directly to a ground plane. This significantly reduces the case-to-sink thermal resistance as well as the sink-to-ambient thermal resistance. R1 VOUT = 1.240V 1 + R2 Figure 2. Adjustable Regulator with Resistors Power SOIC-8 Thermal Characteristics One of the secrets of the MIC39101/2’s performance is its power SO-8 package. Lower thermal resistance means more output current or higher input voltage for a given package size. June 3, 2015 Figure 3. Thermal Resistance 12 Low-dropout linear regulators from Micrel are rated to a maximum junction temperature of 125°C. 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. Figure 4 shows copper area versus power dissipation with each trace corresponding to a different temperature rise above ambient. Revision 3.0 Micrel, Inc. MIC39100/1/2 From Figure 4, the minimum amount of copper required to operate this application at a ∆T of 75°C is 160mm2. 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 5, which shows safe operating curves for three different ambient temperatures: 25°C, 50°C, and 85°C. From these curves, the minimum amount of copper can be determined by knowing the maximum power dissipation required. If the maximum ambient temperature is 50°C and the power dissipation is as above, 836mW, the curve in Figure 5 shows that the required area of copper is 160mm2. Figure 4. Copper Area vs. Power SOIC Power Dissipation (∆TJA) 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. The θJA of this package is ideally 63°C/W, but it will vary depending upon the availability of copper ground plane to which it is attached. For example, the maximum ambient temperature is 50°C, the ∆T is determined as in Equation 2: ∆T = 125°C – 50°C ∆T = 75°C Eq. 2 Where: ∆T = TJ(MAX) − TA(MAX) Figure 5. Copper Area vs. Power SOIC Power Dissipation (TA) TJ(MAX) = 125°C TA(MAX) = Maximum ambient operating temperature Using Figure 4, the minimum amount of required copper can be determined based on the required power dissipation. Power dissipation in a linear regulator is calculated as in Equation 3: PD = (VIN – VOUT) IOUT + VIN × IGND Eq. 3 If we use a 2.5V output device and a 3.3V input at an output current of 1A, then our power dissipation is as in Equation 4: PD = (3.3V – 2.5V) × 1A + 3.3V × 11mA PD = 800mW + 36mW Eq. 4 PD = 836mW June 3, 2015 13 Revision 3.0 Micrel, Inc. MIC39100/1/2 Package Information and Recommended Landing Pattern(12) 8-Pin SOIC (M) Note: 12. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com. June 3, 2015 14 Revision 3.0 Micrel, Inc. MIC39100/1/2 Package Information and Recommended Landing Pattern(12) 3-Pin SOT-223 (S) June 3, 2015 15 Revision 3.0 Micrel, Inc. June 3, 2015 MIC39100/1/2 16 Revision 3.0 Micrel, Inc. MIC39100/1/2 Revision History Date Change Description/Edits by: 07/25/05 Initial release of datasheet. No editable file available on Marcom server. 1.0 08/25/05 “B” rev created; no listing of significant changes/edits made present. No editable file available on Marcom server. 2.0 06/03/15 (6) Complete overhaul of DS, including changes to Applications, Electrical Characteristics table and Notes, Applications Information, and Package Information and Recommended Landing Pattern(12). 3.0 June 3, 2015 Rev. 17 Revision 3.0