MIC5248 Micrel MIC5248 150mA µCap CMOS LDO Regulator w/Power Good Final Information General Description Features The MIC5248 is an efficient, precise CMOS voltage regulator with power good output. The MIC5248 offers better than 3% initial accuracy, and constant ground current (typically 100µA) over load. • • • • • • • • • • The MIC5248 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in handheld 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 MIC5248 is a fixed 1.2V regulator. Power Good indicator Load independent, ultra-low 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 Ordering Information Part Number Marking Voltage Junction Temp. Range* Package MIC5248-1.2BM5 LV12 1.2 –40°C to +125°C SOT-23-5 MIC5248-1.2YM5 KV12 1.2 –40°C to +125°C, Lead-free SOT-23-5 Other voltages available. Contact Micrel for details. Typical Application 47k VIN MIC5248-x.xBM5 1 5 2 COUT 3 Enable Shutdown VOUT 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. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com November 2002 1 MIC5248 MIC5248 Micrel Pin Configuration EN GND IN 3 2 EN GND IN 1 3 LVxx 4 PG 2 1 KVxx 5 4 PG OUT MIC5248-x.xBM5 5 OUT MIC5248-x.xYM5 Pin Description Pin Number Pin Name Pin Function 1 IN Supply Input 2 GND 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 MIC5248 Ground Regulator Output 2 November 2002 MIC5248 Micrel 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 Min VO Output Voltage Accuracy IOUT = 100µA ∆VLNR Line Regulation VIN = 2.7V to 6V ∆VLDR Load Regulation IQ IGND Typical Max Units 3 4 % % 0 0.3 %/V IOUT = 0.1mA to 150mA, Note 4 4.0 5.0 % Quiescent Current VEN ≤ 0.4V (shutdown) 0.45 1 µA Ground Pin Current, Note 5 IOUT = 0mA; VIN = 6.0V 100 150 µA IOUT = 150mA; VIN = 6.0V 100 150 µA 60 dB 350 mA –3 –4 –0.3 PSRR Power Supply Rejection f = 120Hz, COUT = 4.7µF, IOUT = 150mA ILIM Current Limit VOUT = 0V VIL Enable Input Logic-Low Voltage VIN = 5.5V, regulator shutdown VIH Enable Input Logic-High Voltage VIN = 5.5V, regulator enabled IEN Enable Input Current VIL ≤ 0.4V; VIN = 5.5V 0.01 µA VIH ≥ 1.6V; VIN = 5.5V 0.01 µA Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C 160 Enable Input 0.4 1.6 V V Thermal Protection Power Good, Note 6 VPG Low Threshold High Threshold % of VOUT (PG ON) % of VOUT (PG OFF) 89.5 VOL PG Output Logic-Low Voltage IL = 100µA, fault condition 0.02 IPG Power Good Leakage Current power good off, VPG = 5.5V 0.01 VPG Delay Delay Time to Power Good See “Timing Diagram” 1 96.5 % % 0.1 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, over-temperature or dropout. See “Applications Information” section for additional information. Note 5. Note 6. November 2002 3 MIC5248 MIC5248 Micrel Block Diagrams 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 89.5% 96.5% 96.5% Fault Condition VEN Min - Max 1-5ms 1-5ms VPG Indeterminable when VEN low MIC5248 4 November 2002 MIC5248 Micrel Typical Characteristics Ground Current vs. Input Voltage Ground Current vs. Output Current 99.4 107 105 IOUT = 150mA 103 101 99 97 95 2.5 3 3.5 4 4.5 5 5.5 6 6.5 INPUT VOLTAGE (V) 99.2 99 98.8 98.6 98.4 98.2 0 340 330 320 310 300 290 280 270 260 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) 90 300 290 280 270 260 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (°C) 2 1.9 1.6 1.5 1.4 1.3 1.2 1.1 1 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) Output Voltage vs. Input Voltage 1.195 3.5 2.5 2 1.5 1 10000 1000 1 0.1 0.001 0 0.01 1.1 1 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (°C) 10 Power Fail 0.5 100 1.4 1.3 1.2 OUTPUT VOLTAGE (V) Power Good 3 1.6 1.5 IOUT = 100µA 1.8 1.7 Power Good Pull-up Resistor vs. Power Good 1.8 1.7 IOUT = 150mA Power Good Delay vs. Input Voltage 310 POWER GOOD (V) POWER GOOD DELAY (ms) 95 85 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (°C) 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) VIN = 3.3V VIN = 3.3V IOUT = 100µA 100 320 Power Good Delay vs. Temperature 2 1.9 105 Short Circuit Current vs. Temperature SHORT CIRCUIT CURRENT (mA) SHORT CIRCUIT CURRENT (mA) Short Circuit Current vs. Input Voltage 360 350 GROUND CURRENT (µA) 109 110 VIN = 3.3V POWER GOOD DELAY (ms) IOUT = 100µA 111 GROUND CURRENT (µA) GROUND CURRENT (µA) 113 Ground Current vs. Temperature 1.19 IOUT = 100µA 1.185 1.18 1.175 IOUT = 150mA 1.17 2.6 3.1 3.6 4.1 4.6 5.1 5.6 6.1 INPUT VOLTAGE (V) PULL-UP RESISTOR (kΩ) Output Voltage vs. Output Current 1.18 1.175 1.17 1.165 VIN = 3.3V 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) November 2002 ENABLE VOLTAGE (V) 1.185 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.4 1.205 1.19 1.16 0 Enable Voltage vs. Input Voltage Output Voltage vs. Temperature 1.195 1.2 1.195 1.19 1.185 IOUT = 100µA 1.18 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (°C) 5 1.3 1.2 1.1 1 0.9 0.8 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) MIC5248 MIC5248 Micrel Enable Voltage vs. Temperature ENABLE VOLTAGE (V) 1.2 VIN = 3.3V 1.15 1.1 1.05 1 0.95 0.9 0.85 0.8 -40 -20 0 20 40 60 80 100120140 TEMPERATURE (°C) Power Good (2V/div) Output (1V/div) Enable (2V/div) Power Good Characteristic VIN = 12V VOUT = 5V TIME (250µs/div) MIC5248 6 November 2002 MIC5248 Micrel Transient Response The MIC5248 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). Applications Information Enable/Shutdown The MIC5248 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 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. Active Shutdown The MIC5248 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. Thermal Considerations Output Capacitor The MIC5248 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 MIC5248 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 MIC5248 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: TJ(max) − TA PD(max) = θ JA 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. 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 come back up once the output has reached 96.5% of its nominal value and a 1ms to 5ms delay has passed. See “Timing Diagram.” 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 MIC5248. Package SOT-23-5 (M5) 235°C/W θJC 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 MIC5248-1.2BM5 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 The MIC5248’s internal circuit intelligently monitors overcurrent, over-temperature and dropout conditions and ORs these outputs together to indicate some fault condition. This output is fed into an on-board delay circuitry that drives the open drain transistor to indicate a fault. November 2002 θJA Recommended θJA 1" Square Minimum Footprint Copper Clad 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 7 MIC5248 MIC5248 Micrel 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. ground current is < 1% and can be ignored for this calculation. 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. MIC5248 8 November 2002 MIC5248 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) 3.02 (0.119) 2.80 (0.110) 0.50 (0.020) 0.35 (0.014) 1.30 (0.051) 0.90 (0.035) 0.20 (0.008) 0.09 (0.004) 10° 0° 0.15 (0.006) 0.00 (0.000) 0.60 (0.024) 0.10 (0.004) SOT-23-5 (M) November 2002 9 MIC5248 MIC5248 MIC5248 Micrel 10 November 2002 MIC5248 November 2002 Micrel 11 MIC5248 MIC5248 Micrel MICREL INC. TEL 1849 FORTUNE DRIVE SAN JOSE, CA 95131 + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB USA http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2001 Micrel Incorporated MIC5248 12 November 2002