MIC5258 Micrel, Inc. MIC5258 150mA µCap CMOS LDO Regulator w/Power Good General Description Features The MIC5258 is an efficient, precise CMOS voltage regulator with power good output. The MIC5258 offers better than 3% initial accuracy, and constant ground current (typically 100µA)over load . • • • • • • • • • • The MIC5258 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices. Key features include current limit, thermal shutdown, a pushpull output for faster transient response, and an active clamp to speed up device turnoff. Available in the IttyBitty™ SOT-23-5 package, the MIC5258 is a fixed 1.2V regulator. Power Good indicator Load independent, ultralow ground current: 100µA 150mA output current Current limiting Thermal shutdown Tight load and line regulation “Zero” off-mode current Stability with low-ESR capacitors Fast transient response TTL-Logic-controlled enable input Applications • Processor power-up sequencing • Laptop, notebook, and palmtop computers • PCMCIA VCC and VPP regulation/switching Typical Application Part Number Standard Marking Pb-Free Marking MIC5258-1.2BM5 LN12 MIC5258-1.2YM5 KN12 Voltage Junction Temp. Range* Package 1.2V –40ºC to +125ºC SOT-23-5 * Other voltages available. Contact Micrel marketing for information. Typical Application 47k VIN MIC5258-x.xBM5 1 5 COUT 2 Enable Shutdown VOUT 3 4 PG EN EN (pin 3) may be connected directly to IN (pin 1). Low-Noise Regulator Application IttyBitty is a 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 April 2006 1 MIC5258 MIC5258 Micrel, Inc. Pin Configuration EN GND IN 2 3 1 LNxx KNxx 4 5 PG OUT MIC5258-x.xBM5/YM5 Pin Description Pin Number MIC5258 Pin Name Pin Function 1 IN 2 GND Supply Input 3 EN Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. 4 PG Power Good Output 5 OUT Ground Regulator Output 2 April 2006 MIC5258 Micrel, Inc. Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Input Voltage (VIN) ....................................0V to +7V Enable Input Voltage (VEN) ...................................0V to VIN Flag Output Voltage (VPG) .....................................0V to VIN Junction Temperature (TJ) ....................................... +150°C Storage Temperature ................................ –65°C to +150°C Lead Temperature (soldering, 5 sec.) ........................ 260°C ESD, Note 3 Input Voltage (VIN) .......................................... +2.7V to +6V Enable Input Voltage (VEN) ...................................0V to VIN Flag Output Voltage (VPG) .....................................0V to VIN Junction Temperature (TJ) ........................ –40°C to +125°C Thermal Resistance SOT-23(θJA).......................................................235°C/W Electrical Characteristics VIN = 2.7V, 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 = 2.7V to 6V IQ Quiescent Current ΔVLDR Load Regulation IGND Ground Pin Current, Note 5 Min –0.3 0.3 %/V 3.5 4 % 1 µA 110 150 µA IOUT = 150mA; VIN = 6.0V 110 150 µA IOUT = 0mA; VIN = 6.0V f = 120Hz, COUT = 4.7µF, IOUT = 150mA Power Supply Rejection Current Limit VOUT = 0V VIL Enable Input Logic-Low Voltage VIN = 5.5V, regulator shutdown IEN Enable Input Current Enable Input Logic-High Voltage % % 0.45 PSRR VIH Units 3 4 IOUT = 0.1mA to 150mA, Note 4 Typical VEN ≤ 0.4V (shutdown) PG = NC ILIM Enable Input Max –3 –4 VIN = 5.5V, regulator enabled 160 tbd dB 350 mA 0.4 1.6 V 0.01 µA 0.01 µA Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C Thermal Protection VIL ≤ 0.4V; VIN = 5.5V V VIH ≥ 1.6V; VIN = 5.5V Power Good , Note 6 VPG Low Threshold High Threshold VOL PG Output Logic-Low Voltage IPG Power Good Leakage Current VPG Delay Delay time to Power Good % of VOUT (PG ON) % of VOUT (PG OFF) 89 IL = 100µA, fault condition power good off, VPG = 5.5V See Timing Diagram 97 0.02 0.1 0.01 1 % % V µA 5 ms Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Devices are ESD sensitive. Handling precautions recommended. Note 4. 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. 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. The power good is a function of the output voltage being 5% low and the detection of one of the following: overcurrent, overtemperature or dropout. See “Applications Information” section for additional information. Note 5. Note 6. April 2006 3 MIC5258 MIC5258 Micrel, Inc. Block Diagram IN EN Reference Voltage Startup/ Shutdown Control Quickstart PULL UP Thermal Sensor FAULT Error Amplifier Undervoltage Lockout Current Amplifier ACTIVE SHUTDOWN OUT PULL DOWN Out of Regulation Detection PG Overcurrent Dropout Detection Delay GND Timing Diagram VOUT 97% 89% 97% Fault Condition VEN VPG MIC5258 Min - Max 1-5ms 1-5ms 4 April 2006 MIC5258 Micrel, Inc. Typical Characteristics IOUT = 100µA 109 99.4 99.2 107 IOUT = 150mA 101 2.0 VIN = 3.3V 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 -40 -20 0 20 40 60 80 100120140 TEMPERATURE(°C) Output Voltage vs. Output Current 1.190 1.185 Short Circuit Current vs. Temperature 400 VIN = 3.3V 380 360 340 320 300 280 260 240 220 200 -40 -20 0 20 40 60 80 100120140 TEMPERATURE(°C) Power Good Pull-up Resistor vs. Power Good 3.5 3.0 P ower Good 1.5 1.195 1.175 P ower F ail 0.5 PULL-UP RESISTOR (k Ω) Output Voltage vs. Temperature 1.4 1.175 1.190 0.9 April 2006 Enable Voltage vs. Input Voltage 1.2 1.1 VIN = 3.3V 1.160 0 20 40 60 80 100120 140160 OUTPUT CURRENT (mA) IOUT = 150mA 1.3 1.200 1.195 1.165 IOUT = 100µA 1.170 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) 1.180 1.170 Output Voltage vs. Input Voltage 1.180 1.0 1.205 2.0 IOUT = 100µA 1.9 1.8 1.7 1.6 1.5 1.4 1.3 1.2 1.1 1.0 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) 1.185 2.0 0.0 Power Good Delay vs. Input Voltage 1.190 2.5 10000 Power Good Delay vs. Temperature 85 -40 -20 02 04 06 08 0 100120140 TEMPERATURE (°C) 1000 360 350 340 330 320 310 300 290 280 270 260 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) 98.2 02 04 06 08 0 100120140160 OUTPUT CURRENT (mA) 10 Short Circuit Current vs. Input Voltage IOUT = 150mA 90 100 95 2.5 3 3.5 4 4.5 5 5.5 6 6.5 INPUT VOLTAGE (V) IOUT = 100µA 98.4 1 97 1.195 95 98.6 99 Ground Current vs. Temperature 100 98.8 0 .0 0 1 103 105 99 SHORT CIRCUIT CURRENT (mA) 105 110 VIN = 3.3V 0 .1 111 Ground Current vs. Output Current 0 .0 1 113 Ground Current vs. Input Voltage 1.0 0.8 1.185 IOUT = 100µA 1.180 -40 -20 0 20 40 60 80 100120140 TEMPERATURE(°C) 5 0.7 IOUT = 100µA 0.6 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) MIC5258 MIC5258 Micrel, Inc. 1.20 Enable Voltage vs. Temperature VIN = 3.3V 1.15 1.10 1.05 1.00 0.95 0.90 0.85 0.80 -40 -20 0 20 40 60 80 100120140 TEMPERATURE(°C) Power Good Characteristic TIME (250µs/div) MIC5258 6 April 2006 MIC5258 Micrel, Inc. Applications Information Transient Response The MIC5258 implements a unique output stage to dramatically improve transient response recovery time. The output is a totem-pole configuration with a P-channel MOSFET pass device and an N-channel MOSFET clamp. The N-channel clamp is a significantly smaller device that prevents the output voltage from overshooting when a heavy load is removed. This feature helps to speed up the transient response by significantly decreasing transient response recovery time during the transition from heavy load (100mA) to light load (100µA). Enable/Shutdown The MIC5258 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. Input Capacitor Active Shutdown An input capacitor is not required for stability. A 1µF input capacitor is recommended when the bulk ac supply capacitance is more than 10 inches away from the device, or when the supply is a battery. The MIC5258 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. Output Capacitor Thermal Considerations The MIC5258 requires an output capacitor for stability. The design requires 1µF or greater on the output to maintain stability. The capacitor can be a low-ESR ceramic chip capacitor. The MIC5258 has been designed to work specifically with the low-cost, small chip capacitors. Tantalum capacitors can also be used for improved capacitance over temperature. The value of the capacitor can be increased without bound. The MIC5258 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: X7R dielectric 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 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 or a tantalum capacitor to ensure the same minimum capacitance value over the operating temperature range. Tantalum capacitors have a very stable dielectric (10% over their operating temperature range) and can also be used with this device. PD(max) = 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-to-ambient thermal resistance for the MIC5258. Package θJA Recommended Minimum Footprint θJA 1” Square Copper Clad θJC 235°C/W 185°C/W 145°C/W SOT-23-5 (M5) Table 1. SOT-23-5 Thermal Resistance The actual power dissipation of the regulator circuit can be determined using the equation: Power Good The power good output is an open-drain output. It is designed essentially to work as a power-on reset generator once the regulated voltage was up and/or a fault condition. The output of the power good drives low when a fault condition AND an undervoltage detection occurs. The power good output comes back up once the output has reached 97% of its nominal value and a 1ms to 5ms delay has passed. See Timing Diagram. 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 MIC5258-1.2BM5 at 50°C with a minimum footprint layout, the maximum input voltage for a set output current can be determined as follows: The MIC5258’s internal circuit intelligently monitors overcurrent, overtemperature and dropout conditions and ORs thes outputs together ti indicate some fault condition. this output is fed into an on-board delay circuitry that drives the open drain transistor to indicate a fault. April 2006 TJ(max) - TA θJA PD (max) = 125°C - 50°C 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 1.2V 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. 7 MIC5258 MIC5258 Micrel, Inc. 315mW = (VIN – 1.2V) 150mA 315mW = VIN ·150mA – 195mW 510mW = VIN·150mA VIN(max) = 3.4V Therefore, a 1.2V application at 150mA of output current can accept a maximum input voltage of 3.4V 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. Dual-Supply Operation When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground. MIC5258 8 April 2006 MIC5258 Micrel, Inc. Package Information SOT-23-5 (M) 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. © 2001 Micrel Incorporated April 2006 9 MIC5258