MIC5252 Micrel, Inc. MIC5252 150mA High PSRR, Low Noise µCap CMOS LDO General Description Features The MIC5252 is an efficient, precise CMOS voltage regulator optimized for ultra-low-noise applications. It offers 1% initial accuracy, extremely-low dropout voltage (135mV at 150mA) and low ground current (typically 90µA). The MIC5252 provides a very-low-noise output, ideal for RF applications where a clean voltage source is required. The MIC5252 has a high PSRR even at low supply voltages, critical for battery operated electronics. A noise bypass pin is also available for further reduction of output noise. • • • • • • • • • • • Designed specifically for handheld and battery-powered devices, the MIC5252 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops nearly to zero. The MIC5252 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in handheld wireless devices. Input voltage range: 2.7V to 6.0V PSRR = 50dB @ VO + 0.3V Ultra-low output noise: 30µV(rms) Stability with ceramic output capacitors Ultra-low dropout: 135mV @ 150mA High output accuracy: 1.0% initial accuracy 2.0% over temperature Low quiescent current: 90µA Tight load and line regulation TTL-Logic-controlled enable input “Zero” off-mode current Thermal shutdown and current limit protection Applications • • • • • Key features include current limit, thermal shutdown, faster transient response, and an active clamp to speed up device turn-off. The MIC5252 is available in the 6-pin 2mm × 2mm MLF™ package and the IttyBitty® SOT-23-5 package in a wide range of output voltages. Cellular phones and pagers Cellular accessories Battery-powered equipment Laptop, notebook, and palmtop computers Consumer/personal electronics Typical Application C IN = 1.0µF Ceramic Enable Shutdown V IN MIC5252-x.xBM5 1 5 2 3 EN EN (pin 3) may be connected directly to IN (pin 1). 4 V OUT VIN ENABLE SHUTDOWN C OUT = 1.0µF Ceramic C BYP = 0.01µF EN VOUT MIC5252-x.xBML 1 6 2 5 3 4 CBYP COUT (optional) Ultra-Low-Noise Regulator Application IttyBitty is a registered trademark of Micrel, Inc. MicroLeadFrame and MLF are trademarks 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 February 2005 1 M9999-020305 MIC5252 Micrel, Inc. Ordering Information Part Number Marking Standard Pb-Free Voltage Junction Temp. Range Package MIC5252-1.8YM5 L618 L618 1.8V -40°C to +125°C SOT-23-5 MIC5252-2.5BM5 MIC5252-2.5YM5 L625 L625 2.5V -40°C to +125°C SOT-23-5 MIC5252-2.8BM5 MIC5252-2.8YM5 L628 L628 2.8V -40°C to +125°C SOT-23-5 MIC5252-2.85BM5 MIC5252-2.85YM5 L62J L62J 2.85V -40°C to +125°C SOT-23-5 MIC5252-3.0BM5 MIC5252-3.0YM5 L630 L630 3.0V -40°C to +125°C SOT-23-5 MIC5252-4.75BM5 MIC5252-4.75YM5 L64H L64H 4.75V -40°C to +125°C SOT-23-5 MIC5252-2.8BML MIC5252-2.8YML 628 628 2.8V -40°C to +125°C 6-Pin 2x2 MLF™ MIC5252-2.85BML MIC5252-2.85YML 62J 62J 2.85V -40°C to +125°C 6-Pin 2x2 MLF™ MIC5252-3.0BML MIC5252-3.0YML 630 630 3.0V -40°C to +125°C 6-Pin 2x2 MLF™ Standard Pb-Free MIC5252-1.8BM5 Other voltages available. Contact Micrel for details. Pin Configuration EN GND 2 3 IN 1 EN 1 L6xx 4 BYP GND 2 6 BYP 5 NC 5 IN 3 OUT MIC5252-x.xBM5 SOT-23-5 (M5) (Top View) 4 OUT MIC5252-x.xBML 6-Pin 2mm × 2mm MLF™ (ML) (Top View) Pin Description Pin Number SOT-23-5 Pin Number 6-MLF™ 1 3 IN 2 2 GND 3 1 EN Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. 4 6 BYP Reference Bypass: Connect external 0.01µF ≤ CBYP ≤ 1.0µF capacitor to GND to reduce output noise. May be left open. 5 4 OUT Regulator Output. – 5 NC – EP GND M9999-020305 Pin Name Pin Function Supply Input. Ground. No internal connection. Ground: Internally connected to the exposed pad. Connect externally to GND pin. 2 February 2005 MIC5252 Micrel, Inc. Absolute Maximum Ratings(1) Operating Ratings(2) Supply Input Voltage (VIN) ....................................0V to +7V Enable Input Voltage (VEN) ..................................0V to +7V Power Dissipation (PD) ..........................Internally Limited(3) Junction Temperature (TJ) ........................ –40°C to +125°C Storage Temperature ................................ –65°C to +150°C Lead Temperature (soldering, 5 sec.) ........................ 260°C ESD(4)............................................................................ 2kV Input Voltage (VIN) .......................................... +2.7V to +6V Enable Input Voltage (VEN) ...................................0V to VIN Junction Temperature (TJ) ........................ –40°C to +125°C Thermal Resistance SOT-23 (θJA) ......................................................235°C/W 2x2 MLF™ (θJA) ..................................................90°C/W Electrical Characteristics(5) VIN = VOUT + 1V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Conditions VO Output Voltage Accuracy IOUT = 100µA ΔVLNR Line Regulation VIN = VOUT + 1V to 6V VIN – VOUT Dropout Voltage(7) IOUT = 100µA IOUT = 150mA VEN ≤ 0.4V (shutdown) 0.2 1 µA 90 150 µA IOUT = 150mA 117 200 63 dB f = 10Hz, VIN = VOUT + 0.3V 48 dB 48 dB 425 mA ΔVLDR IQ Load Regulation Quiescent Current Ground Pin Current(8) PSRR Ripple Rejection; IOUT = 150mA en µV(rms) IOUT = 0.1mA to Current Limit Output Voltage Noise Typical Max Units 1 3 % % 0.02 0.2 % 0.6 1.5 % 0.1 5 mV 90 150 mV 135 200 250 mV mV –1 –3 150mA(6) IOUT = 100mA IGND ILIM Min IOUT = 0mA f = 10Hz, COUT = 1.0µF, CBYP = 0.01µF f = 10kHz, VIN = VOUT + 0.3V VOUT = 0V 250 COUT = 1.0µF, CBYP = 0.01µF, µA 30 f = 10Hz to 100kHz Enable Input VIL Enable Input Logic-Low Voltage IEN Enable Input Current VIH Enable Input Logic-High Voltage Shutdown Resistance Discharge VIN = 2.7V to 5.5V, regulator shutdown VIN = 2.7V to 5.5V, regulator enabled VIL ≤ 0.4V, regulator shutdown VIH ≥ 1.6V, regulator enabled 0.4 1.6 V V 0.01 1 µA 0.01 1 µA 500 Ω Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C Thermal Protection 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 MIC5252-x.xBM5 (all versions) is 235°C/W on a PC board. See ”Thermal Considerations” section for further details. 4. Devices are ESD sensitive. Handling precautions recommended. 5. Specification for packaged product only. 6. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. 7. Dropout Voltage is defined as the input-to-output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. For outputs below 2.7V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.7V. Minimum input operating voltage is 2.7V. 8. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground pin current. February 2005 3 M9999-020305 MIC5252 Micrel, Inc. Typical Characteristics P S R R with B ypas s V ariation (V IN = V OUT + 0.3V ) 90 90 80 80 70 70 20 10 0 10 C OUT = 1µF C eramic 10 10k 100k 1k 100 FREQUENCY (Hz) PSRR (dB) 60 50 150mA 40 30 C OUT = 1µF C B Y P = 10nF V OUT 2.8V 20 10 OUTPUT VOLTAGE (V) 100µA 70 0 100 200 300 400 500 600 700 800 900 1000 0 50 10 10 1M 150mA 40 20 10k 100k 1k 100 FREQUENCY (Hz) 2.85 2.83 2.81 2.79 2.77 2.75 2.73 2.71 2.69 2.67 2.65 0 60 30 V IN = V OUT + 1V V OUT = 2.8V Load = 150mA C OUT = 1µF C eramic C B Y P = 10nF V IN = V OUT + 1V V OUT = 2.8V 10k 100k 1k 100 FREQUENCY (Hz) 1M Output V oltage vs . T emperature Output V oltage vs . L oad C urrent PSR R at 100Hz 90 80 C OUT = 1µF C eramic 0 10 1M 0nF 40 20 V IN = V OUT + 0.3V V OUT = 2.8V Load = 150mA 100nF 50 30 100µA 70 PSRR (dB) 0nF 10nF 30 80 1µF 60 1µF 50 40 90 10nF 2.84 2.82 OUTPUT VOLTAGE (V) 100nF PSRR (dB) PSRR (dB) 60 P S R R with L oad V ariation P S R R with B ypas s C ap V ariation (V IN = V OUT + 1V ) 2.8V OUT 2.8 2.78 2.76 2.74 2.72 100µA 2.7 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 20 40 60 80 100 120 140 OUTPUT CURRENT (mA) VOLTAGE DROP (mV) G round C urrent vs . T emperature 160 120 140 80 60 40 20 0 0 2.8V OUT 80 0mA Load 60 40 20 2.5 10mA Load 150mA Load 60 40 20 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 SUPPLY VOLTAGE (V) M9999-020305 100 150mA 1.5 1 0.5 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 SUPPLY VOLTAGE (V) 4 0µA Load 60 40 20 Dropout vs . T emperature 100 µA 2 80 1µA Load 100µA Load 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 SUPPLY VOLTAGE (V) 3 OUTPUT VOLTAGE (V) GROUND CURRENT (µA) 80 150mA Load Dropout C harac teris tic s G round C urrent vs . S uppl y V oltage 100 100 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) 140 120 120 120 DROPOUT VOLTAGE (mV) 100 G round C urrent vs . S uppl y V oltage GROUND CURRENT (µA) 140 GROUND CURRENT (µA) GROUND CURRENT (µA) G round C urrent vs . Output C urrent 200 180 160 140 120 100 80 60 40 2.8V OUT 20 I L = 150mA 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) February 2005 MIC5252 Micrel, Inc. 2.8V OUT 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) 1.4 1.4 1.3 1.3 1.2 E nable On 1.1 1 E nable Off 0.9 0.8 0.7 0.6 2.7 3.2 3.7 4.2 4.7 5.2 5.7 6.2 SUPPLY VOLTAGE (V) ENABLE THRESHOLD (V) 200 180 160 140 120 100 80 60 40 20 0 0 E nable T hres hold vs . T emperature E nable T hres hold vs . S uppl y V oltage ENABLE THRESHOLD (V) DROPOUT (mV) Dropout vs . Output C urrent V IN = 5V 1.2 1.1 1 0.9 V IN = 3.8V 0.8 0.7 0.6 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) SHORT CIRCUIT CURRENT (mA) S hort C irc uit C urrent vs . Input S uppl y V oltage 500 450 400 350 300 250 200 150 100 50 0 2.7 2.8V OUT 3.2 3.7 4.2 4.7 SUPPLY VOLTAGE (V) February 2005 5.2 5 M9999-020305 MIC5252 Micrel, Inc. Functional Characteristics EnablePin Delay OutputCurrent (100mA/div) OutputVoltage (1V/div) EnableVoltage (1V/div) OutputVoltage (50mV/div) Load Transient Response VOUT = 2.85V VIN = 3.6V COUT = 1µF Ceramic 150mA 100µA TIME (40µs/div) TIME (10µs/div) OutputVoltage (200mV/div) Line Transient Response InputVoltage (1V/div) 5V 3.3V 50mALoad TIME (10µs/div) M9999-020305 6 February 2005 MIC5252 Micrel, Inc. Block Diagram IN Reference Voltage Startup/ Shutdown Control Quickstart/ Noise Cancellation EN BYP Thermal Sensor FAU LT Error Amplifier Undervoltage Lockout Current Amplifier OU T ACTIV E SHU TDO W N GND February 2005 7 M9999-020305 MIC5252 Micrel, Inc. Applications Information No-Load Stability The MIC5252 will remain stable and in regulation with no load unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. Enable/Shutdown The MIC5252 comes with an 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. This part is CMOS and the enable pin cannot be left floating; a floating enable pin may cause an indeterminate state on the output. Thermal Considerations The MIC5252 is designed to provide 150mA of continuous current in a very small package. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. To determine the maximum power dissipation of the package, use the junction-to-ambient thermal resistance of the device and the following basic equation: T (max) − T A PD (max) = J θ JA Input Capacitor The MIC5252 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. TJ(max) is the maximum junction temperature of the die, 125°C, and TA is the ambient operating temperature. θJA is layout dependent; Table 1 shows examples of junction-toambient thermal resistance for the MIC5252. Package Output Capacitor SOT-23-5 (M5 or D5) The MIC5252 requires an output capacitor for stability. The design requires 1µF or greater on the output to maintain stability. The design is optimized for use with low-ESR ceramic chip capacitors. High ESR capacitors may cause high frequency oscillation. The maximum recommended ESR is 300mΩ. 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. θJA 1” Square Copper Clad θJC 235°C/W 185°C/W 145°C/W Table 1. SOT-23-5 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT) IOUT + VIN IGND Substituting PD(max) for PD and solving for the operating conditions that are critical to the application will give the maximum operating conditions for the regulator circuit. For example, when operating the MIC5252-2.8BM5 at 50°C with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: 125 °C − 50 °C PD (max) = 235 °C/W 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. PD(max) = 315mW The junction-to-ambient thermal resistance for the minimum footprint is 235°C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. Using the output voltage of 2.8V and an output current of 150mA, the maximum input voltage can be determined. Because this device is CMOS and the ground current is typically 100µA over the load range, the power dissipation contributed by the ground current is < 1% and can be ignored for this calculation. Bypass Capacitor A capacitor is required from the noise bypass pin to ground to reduce output voltage noise. The capacitor bypasses the internal reference. A 0.01µF capacitor is recommended for applications that require low-noise outputs. The bypass capacitor can be increased, further reducing noise and improving PSRR. Turn-on time increases slightly with respect to bypass capacitance. A unique quick-start circuit allows the MIC5252 to drive a large capacitor on the bypass pin without significantly slowing turn-on time. Refer to the “Typical Characteristics” section for performance with different bypass capacitors. 315mW = (VIN – 2.8V) 150mA 315mW = VIN × 150mA – 420mW 735mW = VIN × 150mA VIN(max) = 4.9V Therefore, a 2.8V application at 150mA of output current can accept a maximum input voltage of 4.9V in a SOT-23-5 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. Active Shutdown The MIC5252 also features an active shutdown clamp, which is an N-Channel MOSFET that turns on when the device is disabled. This allows the output capacitor and load to discharge, de-energizing the load. M9999-020305 θJA Recommended Minimum Footprint 8 February 2005 MIC5252 Micrel, Inc. Package Information SOT-23-5 (M5) 6-Pin MLF™ (ML) MICREL INC. TEL 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com This 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. © 2003 Micrel Incorporated February 2005 9 M9999-020305