MIC5253 Micrel MIC5253 100mA Low Noise µCap Teeny™ LDO General Description Features The MIC5253 is an efficient, CMOS voltage regulator optimized for ultra-low-noise applications. It offers 1.5% initial accuracy, extremely low dropout voltage (165mV at 100mA), and low ground current (typically 95µA at full load). The MIC5253 provides a very low noise output, ideal for RF applications where a clean voltage source is required. A noise bypass pin is also available for further reduction of output noise. • • • • • • • Designed specifically for handheld and battery-powered devices, the MIC5253 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops nearly to zero. Input voltage range: 2.7V to 5.5V Teeny™ SC-70-5 package Ultra-low output noise: 30µV(rms) 100mA continuous output current, 150mA peak current Stability with ceramic output capacitors Ultralow dropout: 165mV @ 100mA High output accuracy: 1.5% initial accuracy 3.0% over temperature Low ground current: 95µA TTL-Logic-controlled enable input “Zero” off-mode current Thermal shutdown and current limit protection • • • • The MIC5253 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in handheld wireless devices. Applications Available in the Teeny™ SC-70-5 package, the MIC5253 offers a wide range of output voltages. Key features include current limit, thermal shutdown, faster transient response, and an active clamp to speed up device turn-off. • • • • • 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 MIC5253-x.xBC5 1 5 VOUT 2 3 4 COUT = 1.0µF Ceramic EN EN (pin 3) may be connected directly to IN (pin 1). CBYP = 0.01µF Ultra-Low-Noise Regulator Application Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com November 2005 1 M9999-112305 MIC5253 Micrel Ordering Information Part Number Voltage* Marking Pb-Free Marking** 1.5V 715 MIC5253-1.5YC5 715 1.8V 718 MIC5253-1.8YC5 718 1.85V 71J MIC5253-1.85YC5 71J 2.5V 725 MIC5253-2.5YC5 725 2.6V 726 MIC5253-2.6YC5 726 2.7V 727 MIC5253-2.7YC5 727 2.8V 728 MIC5253-2.8YC5 728 2.9V 729 MIC5253-2.9YC5 729 3.0V 730 MIC5253-3.0YC5 730 3.1V 731 MIC5253-3.1YC5 731 3.2V 732 MIC5253-3.2YC5 732 3.3V 733 MIC5253-3.3YC5 733 Standard MIC5253-1.5BC5 MIC5253-1.8BC5 MIC5253-1.85BC5 MIC5253-2.5BC5 MIC5253-2.6BC5 MIC5253-2.7BC5 MIC5253-2.8BC5 MIC5253-2.9BC5 MIC5253-3.0BC5 MIC5253-3.1BC5 MIC5253-3.2BC5 MIC5253-3.3BC5 Junction Temp. Range –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C –40°C to +125°C Package SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 SC-70-5 * Other voltage options available. Contact Micrel Marketing for details. ** Under bar symbol ( _ ) may not be to scale. Pin Configuration EN GND 3 22 IN 1 7xx 4 5 BYP OUT SC-70-5 (C5) Pin Description Pin Number Pin Name Pin Function 1 IN Supply Input. 2 GND 3 EN 4 BYP Reference Bypass: Connect external 0.01µF ≤ CBYP ≤ 1.0µF capacitor to GND to reduce output noise. May be left open. 5 OUT Regulator Output. M9999-112305 Ground. Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. 2 November 2005 MIC5253 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 Rating(4) ................................................................................ 2kV Input Voltage (VIN) ...................................... +2.7V to +5.5V Enable Input Voltage (VEN) .................................. 0V to VIN Junction Temperature (TJ) ....................... –40°C to +125°C Thermal Resistance SC-70-5 (θJA) .................................................... 400°C/W Electrical Characteristics(5) VIN = VOUT + 1V, VEN = VIN; IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless otherwise noted. Symbol Parameter Conditions Min VO Output Voltage Accuracy IOUT = 100µA –1.5 –3 ∆VLNR Line Regulation VIN = VOUT + 1V to 6V ∆VLDR Load Regulation VIN – VOUT Dropout Voltage(7) Typical Max Units 1.5 3 % % 0.035 0.05 %/V IOUT = 0.1mA to 100mA, Note 6 1.5 2.5 % IOUT = 50mA 80 150 mV IOUT = 100mA 165 300 mV IQ Quiescent Current VEN ≤ 0.4V (shutdown) 0.2 1 µA IGND Ground Pin Current(8) IOUT = 0mA 75 100 µA IOUT = 100mA 90 150 µA f = 100Hz, COUT = 1.0µF, CBYP = 0.1µF 66 dB f = 1kHz, VIN = VOUT +1, CBYP = 0.1µF 70 dB f = 10kHz, VIN = VOUT +1, CBYP = 0.1µF 65 dB PSRR Ripple Rejection 30 150 µs 250 450 mA tON Turn-On Time 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 µA VIH ≥ 1.6V, regulator enabled 0.01 µA Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C 150 µV(rms) 30 Enable Input 0.4 1.6 V V Thermal Protection Notes: 1. Exceeding the absolute maximum ratings may damage the device. 2. The device is not guaranteed to function outside its operating ratings. 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 MIC5253-x.xBC5 (all versions) is 400°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 100mA. 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. November 2005 3 M9999-112305 MIC5253 Micrel Typical Characteristics Power Supply Rejection Ratio 70 70 60 60 1mA 30 10mA 100mA VOUT = 1.8V COUT = 1µF 10 V = 2.8V CBYP = 0.1µF IN 0 1k 10k 100k 100 FREQUENCY (Hz) 20 1M 100µA 1mA 30 10mA 100mA 20 V = 1.8V COUT = 1µF 10 OUT CBYP = 0.01µF VIN = 2.8V 0 10k 100k 1k 100 FREQUENCY (Hz) 40 Ground Pin Current GROUND CURRENT (µA) GROUND CURRENT (µA) 88 86 84 82 80 78 76 74 72 I = 100mA LOAD 70 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) OUTPUT VOLTAGE (mV) GROUND CURRENT (µA) 60 50 40 30 20 = 100mA 5 250 –40°C 25°C 100 125°C 50 VIN = 3.6V VOUT = 2.6V 0 0 M9999-112305 25 50 75 100 125 150 OUTPUT CURRENT (mA) 25 50 75 100 125 150 OUTPUT CURRENT (mA) 78 76 74 72 I = 100µA LOAD 70 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 60 50 40 30 20 10 0 0 ILOAD = 100µA 1 2 3 4 INPUT VOLTAGE (V) 5 Dropout Voltage 250 ILOAD = 100mA 1.4 ILOAD = 100µA 1.2 1 0.8 0.6 0.4 0.2 V = 1.85V OUT 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 200 150 100 50 VIN = 3.6V VOUT = 2.6V ILOAD = 100mA 0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) Output Voltage vs. Temperature Short Circuit Current SHORT CIRCUIT CURRENT (mA) DROPOUT VOLTAGE (mV) 300 VOUT =1.8V VIN = VOUT + 1V Ground Pin Current 80 Dropout Voltage 350 150 81 0 1M 70 1.8 1.6 70 200 82 82 80 LOAD 83 80 2 I 84 Dropout Characteristics Ground Pin Current 1 2 3 4 INPUT VOLTAGE (V) 85 84 90 0 0 86 Ground Pin Current 90 10 87 GROUND CURRENT (µA) 40 50 DROPOUT VOLTAGE (mV) 100µA 2.7 290 OUTPUT VOLTAGE (V) 50 Ground Pin Current 88 GROUND CURRENT (µA) 80 PSRR (dB) PSRR (dB) Power Supply Rejection Ratio 80 270 250 230 210 190 170 150 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 INPUT VOLTAGE (V) 4 2.65 2.6 2.55 ILOAD = 100µA VOUT = 2.6V VIN = 3.6V 2.5 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) November 2005 MIC5253 Micrel Functional Characteristics Load Transient Response Output Voltage (20mV/div) Input Voltage (1V/div) Line Transient Response 5V 4V CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF IOUT = 100µA Output Current (50mA/div) Output Voltage (50mV/div) 100mA Enable Pin Delay Shutdown Delay Enable Voltage (1V/div) TIME (5µs/div) Enable Voltage (1V/div) TIME (500µs/div) CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF VIN = 4V Output Voltage (500mV/div) Output Voltage (500mV/div) CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF IOUT = 100µA TIME (500µs/div) TIME (5µs/div) November 2005 100µA CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF VIN = 4V 5 M9999-112305 MIC5253 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 M9999-112305 6 November 2005 MIC5253 Micrel No-Load Stability The MIC5253 will remain stable and in regulation with no load unlike many other voltage regulators. This is especially important in CMOS RAM keep-alive applications. Thermal Considerations The MIC5253 is designed to provide 100mA of continuous current in a very small package. Maximum ambient operating temperature can be calculated based on the output current and the voltage drop across the part. Given that the input voltage is 5.0V, the output voltage is 2.9V, and the output current = 100mA. The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT) IOUT + VIN IGND Applications Information Enable/Shutdown The MIC5253 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 The MIC5253 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. Output Capacitor The MIC5253 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. Bypass Capacitor A capacitor can be placed 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 MIC5253 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 The MIC5253 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. November 2005 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. PD = (5.0V – 2.9V) × 100mA PD = 0.21W To determine the maximum ambient operating temperature 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 TJ(max) = 125°C, the max. junction temperture of the die θJA thermal resistance = 400°C/W Table 1 shows junction-to-ambient thermal resistance for the MIC5253 in the SC-70 package. Package SC-70-5 (C5) θJA Recommended Minimum Footprint θJA 1" Sq. Copper Clad θJC 400°C/W 325°C 250°C/W Table 1. Thermal Resistance Substituting PD for PD(max) and solving for the ambient operating temperature will give the maximum operating conditions for the regulator circuit. The junction-to-ambient thermal resistance for the minimum footprint is 400°C/W, from Table 1. The maximum power dissipation must not be exceeded for proper operation. For example, when operating the MIC5253-2.9BC5 at an input voltage of 5.0V and 100mA load with a minimum footprint layout, the maximum ambient operating temperature TA can be determined as follows: 0.21W = 125°C − TA 400°C/W TA = 41°C 7 M9999-112305 MIC5253 Micrel Therefore, a 2.9V application at 100mA of output current can accept an ambient operating temperature of 41°C in a SC-70 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. This information can be found on Micrel's website at: http://www.micrel.com/_PDF/other/LDOBk_ds.pdf M9999-112305 8 November 2005 MIC5253 Micrel Package Information 0.65 (0.0256) BSC 1.35 (0.053) 2.40 (0.094) 1.15 (0.045) 1.80 (0.071) 2.20 (0.087) 1.80 (0.071) DIMENSIONS: MM (INCH) 1.00 (0.039) 1.10 (0.043) 0.80 (0.032) 0.80 (0.032) 0.10 (0.004) 0.00 (0.000) 0.30 (0.012) 0.15 (0.006) 0.18 (0.007) 0.10 (0.004) 0.30 (0.012) 0.10 (0.004) 5-Pin SC-70-5 (C5) MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB USA 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. © 2004 Micrel, Incorporated. November 2005 9 M9999-112305