MIC5254 Dual 150mA µCap LDO with Error Flag Outputs General Description Features The MIC5254 is an efficient, precise, dual CMOS voltage regulator. It offers better than 1% initial accuracy, extremely low dropout voltage (typically 135mV at 150mA) and low ground current (typically 90µA) over load. The MIC5254 features two independent LDOs with error flags that indicate an output fault condition such as overcurrent, thermal shut-down and dropout. Designed specifically for handheld and battery-powered devices, the MIC5254 provides a TTL-logic-compatible enable pin. When disabled, power consumption drops nearly to zero. The MIC5254 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, faster transient response, and an active clamp to speed up device turnoff. The MIC5254 is available in the 10-pin MSOP package and is rated over a –40°C to +125°C junction temperature range. Data sheets and support documentation can be found on Micrel’s web site at www.micrel.com. • • • • • • • • • • • • Input voltage range: 2.7V to 6.0V Dual, independent 150mA LDOs Error flags indicate fault condition Stable with ceramic output capacitor Ultra-low dropout: 135mV @ 150mA High output accuracy: 1.0% initial accuracy 2.0% over temperature Low quiescent current: 90µA each LDO Tight load and line regulation Thermal shutdown and current limit protection “Zero” off-mode current TTL logic-controlled enable input 10-pin MSOP package Applications • • • • • Cellular phones and pagers Cellular accessories Battery-powered equipment Laptop, notebook, and palmtop computers Consumer/personal electronics ___________________________________________________________________________________________________________ Typical Application VINA 1µF VINB 1µF MIC5254 9 VINA OUTA 2 ENA FLGA 1 3 GNDA OUTB 8 6 VINA FLGB 4 GNDB 7 5 ENB VOUTA 10 FLGA 1µF Ceramic VOUTB FLGB 1µF Ceramic Dual Output LDO with Error Flag Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com December 2007 M9999-121107 Micrel, Inc. MIC5254 Ordering Information Part Number VOUTA VOUTB Temperature Range Package Lead Finish MIC5254-SJBMM 3.3V 2.5V –40° to +125°C 10-Pin MSOP Standard MIC5254-SJYMM 3.3V 2.5V –40° to +125°C 10-Pin MSOP Pb-Free Note: Other voltages available. Contact Micrel Marketing for details. Pin Configuration 10-Pin MSOP (MM) Pin Description Pin Number Pin Name Channel 1 FLGA A Error Flag (Output): Open-drain output. Active low indicates an output undervoltage condition. 2 ENA A Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. 3 GNDA A Ground 9 INA A Supply Input 10 OUTA A Regulator Output 4 FLGB B Error Flag (Output): Open-drain output. Active low indicates an output undervoltage condition. 5 ENB B Enable/Shutdown (Input): CMOS compatible input. Logic high = enable; logic low = shutdown. Do not leave open. 7 GNDB B Ground 6 INB B Supply Input 8 OUTB B Regulator Output December 2007 Pin Name 2 M9999-121107 Micrel, Inc. MIC5254 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Input Voltage (VIN).................................... 0V to +7V Enable Input Voltage (VEN)................................... 0V to +7V Power Dissipation (PD) ................... Internal Limited, Note 3 Junction Temperature (TJ) ........................–40°C to +125°C Lead Temperature (soldering, 5 sec.)........................ 260°C Storage Temperature (Ts) .........................–65°C to +150°C ESD Rating(4) .................................................................. 2kV Supply Input Voltage (VIN)............................... +2.7V to +6V Enable Input Voltage (VEN)..................................... 0V to VIN Junction Temperature (TJ) ........................ –40°C to +125°C Thermal Resistance MSOP-10 (θJA) .................................................200°C/W Electrical Characteristics(5) VIN = VOUT + 1V; VEN = VIN; IOUT = 100µ; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted. Symbol Parameter Condition Min VO Output Voltage Accuracy IOUT = 100µA ∆VLNR Line Regulation VIN = VOUT + 1V to 6V ∆VLDR Load Regulation VIN – VOUT Dropout Voltage, Note 7 Typ Max Units +1 +2 % % 0.02 0.075 %/V IOUT = 0.1mA to 150mA, Note 6 1.5 2.5 % IOUT = 100µA 0.1 IOUT = 100mA 90 150 mV IOUT = 150mA 135 200 250 mV mV –1 –2 mV IQ Quiescent Current VEN ≤ 0.4V (shutdown) 0.2 1 µA IGND Ground Pin Current, Note 8 IOUT = 0mA 90 150 µA IOUT = 150mA 117 µA PSRR Power Supply Rejection f = 10Hz, VIN = VOUT + 1V; COUT = 1µF 60 dB f = 100Hz, VIN = VOUT + 0.5V; COUT = 1µF 60 dB f = 10kHz, VIN = VOUT + 0.5V 45 dB ILIM Current Limit en Output Voltage Noise VOUT = 0V 160 425 mA 30 µVRMS Enable Input 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 500 Ω 0.4 Shutdown Resistance Discharge V V 1.6 Error Flag 96 % % 0.1 V VFLG Low Threshold High Threshold % of VOUT (Flag ON) % of VOUT (Flag OFF) VOL Output Logic-Low Voltage IL = 100µA, fault condition 0.02 IFL Flag Leakage Current Flag OFF, VFLG = 6V 0.01 µA Thermal Shutdown Temperature 150 °C Thermal Shutdown Hysteresis 10 °C 90 Thermal Protection December 2007 3 M9999-121107 Micrel, Inc. MIC5254 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 MIC5254-SJBMM is 200°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 1Vdifferential. 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. Test Circuit VINA 1µF VINB 1µF December 2007 MIC5254 9 VINA OUTA 2 ENA FLGA 1 3 GNDA OUTB 8 6 VINA FLGB 4 GNDB 7 5 ENB VOUTA 10 FLGA 0.01µF 1µF Ceramic VOUTB FLGB 0.01µF 4 1µF Ceramic M9999-121107 Micrel, Inc. MIC5254 Typical Characteristics For each LDO Channel Power Supply Rejection Ratio 70 60 PSRR (dB) 50 40 30 20 100µA* 50mA* 100mA* 150mA* *ILOAD 10 COUT = 1.0µF Ceramic 0 10 1M Ground Pin Current 125 120 115 110 105 VIN = VOUT + 1V 1 10 100 1000 OUTPUT CURRENT (mA) GROUND CURRENT (µA) 140 120 100 80 60 40 20 DROPOUT VOLTAGE (mV) 3.5 ILOAD = 150mA 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT VOLTAGE (V) 180 December 2007 Ground Pin Current OUTPUT VOLTAGE (V) 100 0.1 Dropout Voltage 160 140 120 100 80 60 40 20 ILOAD = 150mA 0 -40 -20 0 20 40 60 80 100120140 5 3 Dropout Characteristics 100µA 2.5 150mA 2 1.5 1 0.5 0 0 180 DROPOUT VOLTAGE (mV) GROUND CURRENT (µA) 130 100 1k 10k 100k FREQUENCY (Hz) 1 2 3 4 5 INPUT VOLTAGE (V) 6 Dropout Voltage T = –40°C 160 140 120 100 80 60 T = 25°C T = 125°C 40 20 0 0 20 40 60 80 100 120 140 160 OUTPUT CURRENT (mA) M9999-121107 Micrel, Inc. MIC5254 Typical Characteristics (continued) SHORT CIRCUIT CURRENT (mA) For each LDO Channel 600 Short Circuit Current 500 400 300 200 100 0 3 3.5 4 4.5 5 5.5 INPUT VOLTAGE (V) December 2007 6 6 M9999-121107 Micrel, Inc. MIC5254 Functional Characteristics For each LDO Channel December 2007 7 M9999-121107 Micrel, Inc. MIC5254 Functional Diagram INA ENA Reference Voltage Thermal Sensor Startup/ Shutdown Control Quickstart FAULT Error Amplifier Undervoltage Lockout Current Amplifier OUTA ACTIVE SHUTDOWN Out of Regulation Detection FLGA Overcurrent Dropout Detection GNDA INB ENB Reference Voltage Thermal Sensor Undervoltage Lockout Startup/ Shutdown Control Quickstart FAULT Error Amplifier Current Amplier OUTB ACTIVE SHUTDOWN Out of Regulation Detection FLGB Overcurrent Dropout Detection GNDB December 2007 8 M9999-121107 Micrel, Inc. MIC5254 chattering or inadvertent triggering of the error flag. The error flag must be pulled-up using a resistor from the flag pin to either the input or the output. The error flag circuit was designed essentially to work with a capacitor to ground to act as a power-on reset generator, signaling a power-good situation once the regulated voltage was up and/or out of a fault condition. This capacitor delays the error signal from pulling high, allowing the downstream circuits time to stabilize. When the error flag is pulled-up to the input without using a pull-down capacitor, there can be a glitch on the error flag upon start up of the device. This is due to the response time of the error flag circuit as the device starts up. When the device comes out of the “zero” off mode current state, all the various nodes of the circuit power up before the device begins supplying full current to the output capacitor. The error flag drives low immediately and then releases after a few microseconds. The intelligent circuit that triggers an error detects the output going into current limit AND the output being low while charging the output capacitor. The error output then pulls low for the duration of the turn-on time. A capacitor from the error flag to ground will filter out this glitch. The glitch does not occur if the error flag pulled up to the output. Application Information Enable/Shutdown The MIC5254 comes with an active-high enable pin for each regulator 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 The MIC5254 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 MIC5254 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. 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. Active Shutdown The MIC5254 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. No Load Stability The MIC5254 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 MIC5254 is a dual LDO voltage regulator designed to provide two output voltages from one package. Both regulator outputs are capable of sourcing 150mA of output current. Proper thermal evaluation needs to be done to ensure that the junction temperature does not exceed its maximum value, 125°C. Maximum power dissipation can be calculated based on the output current and the voltage drop across each regulator. The sum of the power dissipation of each regulator determines the total power dissipation. The maximum power dissipation that this package is capable of handling can be determined using thermal resistance, junction to ambient, and the following basic equation: Error Flag The error flag output is an active-low, open-drain output that drives low when a fault condition AND an undervoltage detection occurs. Internal circuitry intelligently monitors overcurrent, overtemperature and dropout conditions and ORs these outputs together to indicate some fault condition. The output of that OR gate is ANDed with an output voltage monitor that detects an undervoltage condition. That output drives the opendrain transistor to indicate a fault. This prevents December 2007 ⎛ TJ(max) − TA PD(max) = ⎜⎜ θ JA ⎝ ⎞ ⎟ ⎟ ⎠ TJ(max) is the maximum junction temperature of the die, 9 M9999-121107 Micrel, Inc. MIC5254 For the application mentioned above, if regulator 1 is sourcing 150mA, it contributes the following to the overall power dissipation: PD(reg2) = (VIN – VOUT) IOUT + VIN × IGND PD(reg1) = (4.2V – 3.3V)150mA + 4.2V × 100µA PD(reg1) = 135.5mW Since the total power dissipation allowable is 325mW, the maximum power dissipation of the second regulator is limited to: PD(max) = PD(reg1) + PD(reg2)) 325mW = 135.5mW + PD(reg2) PD(reg2) = 189.5mW The maximum output current of the second regulator can be calculated using the same equations but solving for the output current (ground current is constant over load and simplifies the equation): PD(reg2) = (VIN – VOUT) IOUT + VIN × IGND 189.5mW = (4.2V – 2.5V) IOUT + 4.2V × 100µA IOUT = 111.2mA The second output is limited to 110mA due to the total power dissipation of the system when operating at 60°C ambient temperature. 125°C and TA is the ambient operating temperature of the die. θJA is layout dependent. Table 1 shows the typical thermal resistance for a minimum footprint layout for the MIC5254. Package MSOP-10 θJA at Recommended Minimum Footprint 200°C Table 1. Thermal Resistance The actual power dissipation of each regulator output can be calculated using the following simple equation: PD = (VIN – VOUT) IOUT + VIN × IGND Each regulator contributes power dissipation to the overall power dissipation of the package. PD(total) = PD(reg1) + PD(reg2) Each output is rated for 150mA of output current, but the application may limit the amount of output current based on the total power dissipation and the ambient temperature. A typical application may call for one 3.3V output and one 2.5V output from a single Li-Ion battery input. This input can be as high as 4.2V. When operating at high ambient temperatures, the output current may be limited. When operating at an ambient of 60°C, the maximum power dissipation of the package is calculated as follows: ⎛ 125°C - 60°C ⎞ PD(max) = ⎜ ⎟ ⎝ 200°C/W ⎠ PD = 325mW December 2007 10 M9999-121107 Micrel, Inc. MIC5254 Package Information 10-Pin MSOP (MM) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +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 a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. December 2007 11 M9999-121107