MIC5259 Micrel, Inc. MIC5259 300mA High PSRR, Low Noise µCap CMOS LDO General Description Features The MIC5259 is an efficient CMOS voltage regulator optimized for low-noise applications. It offers 1.5% initial accuracy, low dropout voltage (300mV at 300mA) and low ground current (typically 105µA at light load). The MIC5259 provides a verylow-noise output, ideal for RF applications where a clean voltage source is required. The MIC5259 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 = 70dB @ 1kHz Low output noise: 30µV(rms) Stability with ceramic output capacitors Low-dropout: 300mV @ 300mA High-output accuracy: 1.5% initial accuracy 3.0% over temperature Low quiescent current: 105µA 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 MIC5259 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops to nearly zero. The MIC5259 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications; critical issue 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 MIC5259 is available in the 6-pin 2mm × 2mm MLF™ package and the ThinSOT™-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 Industrial portable electronics PC peripherals Typical Application CIN = 1.0µF Ceramic Enable Shutdown VIN MIC5259-x.xBD5 1 5 2 3 EN EN (pin 3) may be connected directly to IN (pin 1). 4 VOUT VIN ENABLE SHUTDOWN COUT = 1.0µF Ceramic EN CIN = 1.0µF VOUT MIC5259-x.xBML 1 6 2 5 3 4 CBYP COUT = 1.0µF (optional) 0.01µF CBYP = 0.01µF Ultra-Low-Noise Regulator Application MicroLeadFrame and MLF are trademarks of Amkor Technology. ThinSOT is a trademark of Linear Technology Corporation. Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com May 2005 1 M9999-051305 MIC5259 Micrel, Inc. Ordering Information Part Number Marking Standard Pb-Free MIC5259-2.5BD5 MIC5259-2.5YD5 Standard Pb-Free NY25 NY25 MIC5259-2.8BD5 MIC5259-2.8YD5 NY28 MIC5259-2.85BD5 MIC5259-2.85YD5 NY2J MIC5259-3.0BD5 MIC5259-3.0YD5 MIC5259-3.3BD5 MIC5259-3.3YD5 MIC5259-2.5BML Voltage Junction Temp. Range Package 2.5V –40°C to +125°C ThinSOT™-23-5 NY28 2.8V –40°C to +125°C ThinSOT™-23-5 NY2J 2.85V –40°C to +125°C ThinSOT™-23-5 NY30 NY30 3.0V –40°C to +125°C ThinSOT™-23-5 NY33 NY33 3.3V –40°C to +125°C ThinSOT™-23-5 MIC5259-2.5YML Y25 Y25 2.5V –40°C to +125°C 2mm × 2mm MLF™ MIC5259-2.8BML MIC5259-2.8YML Y28 Y28 2.8V –40°C to +125°C 2mm × 2mm MLF™ MIC5259-2.85BML MIC5259-2.85YML Y2J Y2J 2.85V –40°C to +125°C 2mm × 2mm MLF™ MIC5259-3.0BML MIC5259-3.0YML Y30 Y30 3.0V –40°C to +125°C 2mm × 2mm MLF™ MIC5259-3.3BML MIC5259-3.3YML Y33 Y33 3.3V –40°C to +125°C 2mm × 2mm MLF™ Other voltages available. Contact Micrel for details. Pin Configuration EN GND IN 2 3 1 EN 1 NYxx GND 2 4 5 BYP OUT IN 3 MIC5259-x.xBD5 ThinSOT™-23-5 (D5) (Top View) 6 BYP 5 NC 4 OUT MIC5259-x.xBML 6-Pin 2mm × 2mm MLF™ (ML) (Top View) Pin Description Pin Number ThinSOT™-23-5 Pin Number MLF™-6 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. M9999-051305 Pin Name Pin Function Supply Input. Ground. 2 May 2005 MIC5259 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(TS) ......................... –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 ThinSOT™-23 (θJA) ...........................................235°C/W 2mm × 2mm 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 –1.5 –3 ΔVLNR Line Regulation VIN = VOUT + 1V to 6V –0.3 ΔVLDR VIN – VOUT IQ Load Regulation Dropout Voltage(7) Quiescent Current Ground Pin Current(8) PSRR Ripple Rejection; IOUT = 150mA en µV(rms) IOUT = 150mA Current Limit Output Voltage Noise Max Units 1.5 3 % % 0.02 0.3 %/V 0.6 3.0 % 150 IOUT = 300mA IGND ILIM IOUT = 0.1mA to 300mA(6) Typical 300 mV 500 550 mV mV 0.2 1 µA IOUT = 0mA 105 150 µA IOUT = 300mA 120 250 f = 10Hz, COUT = 1.0µF, CBYP = 0.01µF 65 dB f = 10Hz, VIN = VOUT + 0.3V 53 dB 53 dB 475 mA VEN ≤ 0.4V (shutdown) f = 10kHz, VIN = VOUT + 0.3V VOUT = 0V 350 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 = 2.7 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 MIC5259-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 300mA. 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. May 2005 3 M9999-051305 MIC5259 Micrel, Inc. Typical Characteristics M9999-051305 4 May 2005 MIC5259 May 2005 Micrel, Inc. 5 M9999-051305 MIC5259 Micrel, Inc. Functional Characteristics Enable Turn-On CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF VIN = VOUT + 1V VOUT = 2.8V OutputVoltage (1V/div) OutputVoltage (2V/div) EnableVoltage (2V/div) EnableVoltage (1V/div) Enable Turn-Off CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF VIN = VOUT + 1V VOUT = 2.8V TIME (10µs/div) TIME (500µs/div) Load Transient Response Line Transient Response OutputVoltage (20mV/div) Input Voltage (1V/div) 5V 3.3V COUT = 1µF Ceramic CBYP = 0.01µF Load = 100µA VOUT = 3.0V Output Current (50mA/div) OutputVoltage (20mV/div) 150mA CIN = 1µF Ceramic COUT = 1µF Ceramic CBYP = 0.01µF VIN = VOUT + 1V VOUT = 3.0V TIME (100µs/div) TIME (500µs/div) M9999-051305 100µA 6 May 2005 MIC5259 Micrel, Inc. Block Diagram IN Reference Voltage Startup/ Shutdown Control Quickstart/ Noise Cancellation EN BYP Thermal Sensor Undervoltage Lockout FAULT Error Amplifier Current Amplifier OUT ACTIVE SHUTDOWN GND May 2005 7 M9999-051305 MIC5259 Micrel, Inc. Applications Information No-Load Stability The MIC5259 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 MIC5259 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 MIC5259 is designed to provide 300mA 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: TJ (max) −TA PD (max) = θJA Input Capacitor The MIC5259 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-toground 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 MIC5259. Package Output Capacitor The MIC5259 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 Recommended Minimum Footprint θJA 1” Square Copper Clad θJC SOT-23-5 (M5 or D5) 235°C/W 185°C/W 145°C/W MLF (ML) 90°C/W Table 1. Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT) IOUT + VIN IGND 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. 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 MIC5259-2.8BML at 70°C with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: 125°C − 70°C PD (max) = 90°C/W Bypass Capacitor The junction-to-ambient thermal resistance for the minimum footprint is 90°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 200mA, the maximum input voltage can be determined. Because this device is CMOS and the ground current is typically 110µA over the load range, the power dissipation contributed by the ground current is < 1% and can be ignored for this calculation. PD(max) = 611mW 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 MIC5259 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. 611mW = (VIN – 2.8V) 200mA 611mW = VIN × 200mA – 560mW 1171mW = VIN × 200mA VIN(max) = 5.85V Active Shutdown Therefore, a 2.8V application at 200mA of output current can accept a maximum input voltage of 5.85V in an MLF 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 MIC5259 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. M9999-051305 8 May 2005 MIC5259 Micrel, Inc. Package Information All Dimensions are in millimeters Thin SOT-23-5 (D5) TOP VIEW BOTTOM VIEW SIDE VIEW Rev. 01 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 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. May 2005 9 M9999-051305