MIC5252 Micrel 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. • • • • • • • • • • • 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 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. 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 CIN = 1.0µF Ceramic Enable Shutdown VIN MIC5252-x.xBM5 1 5 VIN VOUT ENABLE SHUTDOWN EN 2 3 4 COUT = 1.0µF Ceramic VOUT MIC5252-x.xBML 1 6 2 5 3 4 CBYP (optional) COUT EN EN (pin 3) may be connected directly to IN (pin 1). CBYP = 0.01µF Ultra-Low-Noise Regulator Application IttyBitty is a registered trademark of Micrel, Inc. MicroLeadFrame and MLF are trademarks of Amkor Technology. Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com December 2003 1 M0394-121003 MIC5252 Micrel Ordering Information Part Number Marking Voltage Junction Temp. Range Package MIC5252-1.8BM5 L618 1.8V –40°C to +125°C SOT-23-5 MIC5252-2.5BM5 L625 2.5V –40°C to +125°C SOT-23-5 MIC5252-2.8BM5 L628 2.8V –40°C to +125°C SOT-23-5 MIC5252-2.85BM5 L62J 2.85V –40°C to +125°C SOT-23-5 MIC5252-3.0BM5 L630 3.0V –40°C to +125°C SOT-23-5 MIC5252-4.75BM5 L64H 4.75V –40°C to +125°C SOT-23-5 MIC5252-2.8BML 628 2.8V –40°C to +125°C 6-Pin 2×2 MLF™ MIC5252-2.85BML 62J 2.85V –40°C to +125°C 6-Pin 2×2 MLF™ MIC5252-3.0BML 630 3.0V –40°C to +125°C 6-Pin 2×2 MLF™ Other voltages available. Contact Micrel for details. Pin Configuration EN GND IN 3 2 1 EN 1 L6xx GND 2 4 5 BYP OUT IN 3 6 BYP 5 NC 4 OUT MIC5252-x.xBML 6-Pin 2mm × 2mm MLF™ (ML) (Top View) MIC5252-x.xBM5 SOT-23-5 (M5) (Top View) Pin Description Pin Number SOT-23-5 Pin Number 6-MLF™ Pin Name Pin Function 1 3 IN Supply Input. 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 M0394-121003 Ground. No internal connection. Ground: Internally connected to the exposed pad. Connect externally to GND pin. 2 December 2003 MIC5252 Micrel 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 Electrical Characteristics(5) 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 VIN = VOUT + 1V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Conditions Min VO Output Voltage Accuracy IOUT = 100µA –1 –3 ∆VLNR Line Regulation VIN = VOUT + 1V to 6V ∆VLDR VIN – VOUT IQ IGND PSRR Load Regulation Dropout Voltage(7) Quiescent Current Ground Pin Current(8) Ripple Rejection; IOUT = 150mA Max Units 1 3 % % 0.02 0.05 %/V 0.6 1.5 % IOUT = 100µA 0.1 5 mV IOUT = 100mA 90 150 mV IOUT = 150mA 135 200 250 mV mV VEN ≤ 0.4V (shutdown) 0.2 1 µA IOUT = 0mA 90 150 µA IOUT = 150mA 117 200 µA f = 10Hz, COUT = 1.0µF, CBYP = 0.01µF 63 dB f = 10Hz, VIN = VOUT + 0.3V 48 dB f = 10kHz, VIN = VOUT + 0.3V 48 dB 425 mA 30 µV(rms) IOUT = 0.1mA to 150mA(6) 250 Typical ILIM Current Limit VOUT = 0V en Output Voltage Noise COUT = 1.0µF, CBYP = 0.01µF, f = 10Hz to 100kHz VIL Enable Input Logic-Low Voltage VIN = 2.7V to 5.5V, regulator shutdown VIH Enable Input Logic-High Voltage VIN = 2.7V to 5.5V, regulator enabled IEN Enable Input Current VIL ≤ 0.4V, regulator shutdown 0.01 1 µA VIH ≥ 1.6V, regulator enabled 0.01 1 µA Enable Input 0.4 1.6 V V 500 Ω Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C Shutdown Resistance Discharge 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. December 2003 3 M0394-121003 MIC5252 Micrel Typical Characteristics 90 90 80 80 70 70 40 0nF 10nF 30 20 10 COUT = 1µF Ceramic 0 10 1M OUTPUT VOLTAGE (V) 150mA 40 400 500 0 100 0 200 300 10 1000 20 800 900 COUT = 1µF CBYP = 10nF VOUT 2.8V 600 700 PSRR (dB) 60 30 C OUT = 1µF Ceramic 60 40 30 VIN = VOUT + 1V VOUT = 2.8V Load = 150mA C = 1µF Ceramic C = 10nF OUT BYP 20 10k 100k 100 1k FREQUENCY (Hz) 10 10 1M 2.84 2.83 2.81 2.82 2.79 2.77 2.75 2.73 2.71 2.69 VIN = VOUT + 1V VOUT = 2.8V 10k 100k 1k 100 FREQUENCY (Hz) 1M Output Voltage vs. Temperature 2.85 2.67 2.65 0 150mA 50 Output Voltage vs. Load Current 100µA 50 0nF 40 PSRR at 100Hz 70 100nF 0 10 90 80 70 50 30 100µA 80 1µF 60 10 10k 100k 1k 100 FREQUENCY (Hz) 90 10nF 20 VIN = VOUT + 0.3V VOUT = 2.8V Load = 150mA PSRR with Load Variation PSRR (dB) 100nF 1µF 50 PSRR with Bypass Cap Variation (VIN = VOUT + 1V) OUTPUT VOLTAGE (V) 60 PSRR (dB) PSRR (dB) PSRR with Bypass Variation (VIN = VOUT + 0.3V) 2.8 2.78 2.76 2.74 2.72 2.8VOUT 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) Ground Current vs. Temperature 160 120 140 100 80 60 40 20 80 0mA Load 60 40 20 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) Ground Current vs. Supply Voltage 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) M0394-121003 80 2.5 100µA 150mA 2 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 1µA Load 100µA Load 0µA Load 60 40 20 Dropout Characteristics OUTPUT VOLTAGE (V) GROUND CURRENT (µA) 10mA Load 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 SUPPLY VOLTAGE (V) Dropout vs. Temperature 3 100 80 150mA Load 100 140 120 120 DROPOUT VOLTAGE (mV) 0 0 2.8VOUT 120 Ground Current vs. Supply Voltage GROUND CURRENT (µA) 140 GROUND CURRENT (µA) GROUND CURRENT (µA) Ground Current vs. Output Current 200 180 160 140 120 100 80 60 40 20 2.8VOUT IL = 150mA 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) December 2003 MIC5252 Micrel Enable Threshold vs. Supply Voltage Enable Threshold vs. Temperature 1.4 1.4 180 160 1.3 1.3 140 120 100 80 60 40 20 0 0 2.8V OUT 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) 1.2 Enable On 1.1 1 Enable 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 ENABLE THRESHOLD (V) DROPOUT (mV) Dropout vs. Output Current 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) Short Circuit Current vs. Input Supply Voltage 500 450 400 350 300 250 200 150 100 50 0 2.7 2.8VOUT 3.2 3.7 4.2 4.7 5.2 SUPPLY VOLTAGE (V) December 2003 5 M0394-121003 MIC5252 Micrel Functional Characteristics Load Transient Response Output Voltage (1V/div) Output Current (100mA/div) Output Voltage (50mV/div) Enable Voltage (1V/div) Enable Pin Delay VOUT = 2.85V VIN = 3.6V COUT = 1µF Ceramic 150mA 100µA TIME (10µs/div) TIME (40µs/div) Output Voltage (200mV/div) Line Transient Response Input Voltage (1V/div) 5V 3.3V 50mA Load TIME (10µs/div) M0394-121003 6 December 2003 MIC5252 Micrel Block Diagram IN Reference Voltage Startup/ Shutdown Control Quickstart/ Noise Cancellation EN BYP Thermal Sensor FAULT Error Amplifier Undervoltage Lockout Current Amplifier OUT ACTIVE SHUTDOWN GND December 2003 7 M0394-121003 MIC5252 Micrel Applications Information No-Load Stability Enable/Shutdown 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. 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-modecurrent 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. Input Capacitor 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) − TA PD (max) = J θ JA 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 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. X7R/X5R dielectric-type ceramic capacitors are recommended because of their temperature performance. X7Rtype 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. SOT-23-5 (M5 or D5) 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 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. Active Shutdown 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. 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. M0394-121003 θJA Recommended Minimum Footprint 8 December 2003 MIC5252 Micrel Package Information 1.90 (0.075) REF 0.95 (0.037) REF 1.75 (0.069) 1.50 (0.059) 3.00 (0.118) 2.60 (0.102) DIMENSIONS: MM (INCH) 1.30 (0.051) 0.90 (0.035) 3.02 (0.119) 2.80 (0.110) 0.20 (0.008) 0.09 (0.004) 10° 0° 0.15 (0.006) 0.00 (0.000) 0.50 (0.020) 0.35 (0.014) 0.60 (0.024) 0.10 (0.004) SOT-23-5 (M5) TOP VIEW BOTTOM VIEW DIMENSIONS IN MILLIMETERS SIDE VIEW Rev. 02 6-Pin MLF™ (ML) MICREL, INC. TEL 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 FAX + 1 (408) 944-0970 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. December 2003 9 M0394-121003