MIC47100 1A High Speed Low VIN LDO General Description Features The MIC47100 is a high speed, Low VIN LDO capable of delivering up to 1A and designed to take advantage of point of load applications that use multiple supply rails to generate a low voltage, high current power supply. The MIC47100 is stable with only a 1µF ceramic output capacitor and is available in a thermally enhanced 2mm × 2mm MLF® package thus making it an optimal solution for board-constrained applications. The MIC47100 has an NMOS output stage offering very low output impedance. The NMOS output stage offers a unique ability to respond very quickly to sudden load changes such as that required by a microprocessor, DSP or FPGA. The MIC47100 consumes little quiescent current and therefore can be used for driving the core voltages of mobile processors, post regulating a core DC/DC converter in any portable device. The MIC47100 is available in fixed and adjustable output voltages in the exposed pad MSOP-8 package and the tiny 2mm × 2mm MLF® package with an operating junction temperature range of -40°C to +125°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. • Operating voltage range: - Input Supply: 1.0V to 3.6V - Bias Supply: 2.3V to 5.5V • 0.8V to 2.0V output voltage range • High bandwidth – very fast transient response • PSRR >50dB at 100kHz • Stable with a 1µF ceramic output capacitor • Low dropout voltage of 80mV at 1A • High output voltage accuracy: - +/- 1.5% initial accuracy - +/- 2% over temperature • Logic level enable input • UVLO on both supply voltages for easy turn-on • ePad MSOP-8 – small form factor power package • Thermally enhanced 2mm × 2mm MLF® – smallest solution Applications: • • • • Point of Load PDAs DSP, PLD and FPGA Power Supply Low Voltage Post Regulation ___________________________________________________________________________________________________________ Typical Application MicroLead Frame and MLF are registered trademark of Amkor Technology Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com February 2008 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Ordering Information Part Number MIC47100YML Nominal Output (1) Voltage Marking Code Lead Finish Package ADJ EAA Pb free 2x2 MLF8 MIC47100-0.8YML 0.8V E08 Pb free 2x2 MLF8 MIC47100-1.0YML 1.0V+ E10 Pb free 2x2 MLF8 MIC47100-1.2YML 1.2V+ E12 Pb free 2x2 MLF8 MIC47100YMME ADJ ZEAAY Pb free MSOP-8 w/ ePad MIC47100-0.8YMME 0.8V ZE08Y Pb free MSOP-8 w/ ePad MIC47100-1.0YMME 1.0V+ ZE10Y Pb free MSOP-8 w/ ePad MIC47100-1.2YMME 1.2V+ ZE12Y Pb free MSOP-8 w/ ePad Note: 1. Other Voltage available. Contact Micrel for details. February 2008 2 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Pin Configuration ® 8-pin Exposed Pad MSOP Fixed and Adjustable (MME) 8-pin 2mm x 2mm MLF Fixed and Adjustable (ML) Pin Description Pin Number MLF Pin Number 1,2 1,2 IN 3 3 GND Ground. Ground pins and exposed pad must be connected externally. 4 4 BIAS Bias Supply. The bias supply is the power supply for the internal circuitry of the regulator. 5 5 EN Enable: TTL/CMOS compatible input. Logic high = enable, logic low or open = shutdown 6 (Fixed) 6 (Fixed) FB Feedback Input. Connect to OUT. Optimum load regulation is obtained when feedback is taken from the actual load point. 6 (Adj) 6 (Adj) ADJ Adjust Input. Connect external resistor divider to program output voltage. 7,8 7,8 OUT Output. Output Voltage of Regulator February 2008 Pin Name Pin Name MSOP Input Supply. Drain of NMOS pass transistor which is the power input voltage for regulator. The NMOS pass transistor steps down this input voltage to create the output voltage. 3 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Absolute Maximum Ratings(1) Operating Ratings(2) Input Supply Voltage (VIN).................................... 0V to +4V Bias Supply Voltage (VBIAS).................................. 0V to +6V Enable Voltage (VEN)............................................ 0V to +6V Power Dissipation, Internally Limited (3) Lead Temperature (soldering, #sec.)......................... 260°C Storage Temperature (Ts) ..........................-65°C to +150°C ESD Rating (4) ................................................................. 2kV Input Supply Voltage (VIN).............................. 1.0V to +3.6V Bias Supply Voltage (VBIAS)............................ 2.3V to +5.5V Enable Input Voltage (VEN).................................. 0V to VBIAS Junction Temperature (TJ) ........................ –40°C to +125°C Junction Thermal Resistance ePad MSOP-8 (θJA) ...........................................64°C/W 2mm x 2mm MLF® (θJA).....................................90°C/W Electrical Characteristics(5) VIN = VOUT+0.5V; VBIAS = VOUT + 2.1V, IOUT = 100µA; TA = 25°C, bold values indicate –40°C< TA < +125°C, unless noted. Parameter UVLO Thresholds (6) Condition Min Typ Max Units Bias Supply Input Supply 1.9 0.7 2.1 0.85 2.3 1.0 V UVLO Hysteresis VBIAS VIN Output Voltage Accuracy Variation from nominal VOUT -1.5 +1.5 % Variation from nominal VOUT; -40°C to +125°C -2.0 +2.0 % Output Voltage Line Regulation (Bias Supply) VBIAS = VOUT + 2.1V to 5.5V -0.1 0.015 0.1 %/V Output Voltage Line Regulation (Input Supply) VIN = VOUT + 0.5V to 3.6V -0.05 0.005 0.05 %/V Load Regulation IOUT = 10mA to 1A 0.2 0.5 % Input Supply Dropout Voltage IOUT = 100mA; IOUT = 500mA; IOUT = 1A; 8.5 37 80 50 250 mV mV mV IOUT = 100mA; IOUT = 500mA; IOUT = 1A 1.15 1.25 1.35 2.1 V V V Ground current from VBIAS IOUT = 1mA IOUT = 1A 350 350 500 500 µA µA Shutdown current from VBIAS EN < 0.2V 0.1 1.0 µA Ground current from VIN IOUT = 1A 6 Shutdown current from VIN EN < 0.2V 0.1 Bias Supply Dropout Voltage February 2008 70 25 4 mV µA 1.0 µA M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Ripple Rejection f = 1kHz; COUT = 1.0µF; IOUT = 100mA f = 100kHz; COUT = 1.0µF; IOUT = 100mA f = 500kHz; COUT = 1.0µF; IOUT = 100mA Current Limit VIN = 2.7V; VOUT = 0V Output Voltage Noise COUT=1µF; 10Hz to 100kHz; IOUT = 100mA 80 55 45 1.1 1.6 dB dB dB 2.5 A 63 µVRMS Over-temperature Shutdown 160 °C Over-temperature Shutdown Hysteresis 20 °C Enable Inputs Enable Voltage Logic Low 0.2 Logic High Enable Input Current Turn-on Time V V 1.0 VIL < 0.2V 1 µA VIH = 1.2V 6 µA COUT = 1µF; 90% of typical VOUT 35 500 µs 0.7 0.71 0.714 V V Reference Voltage (Adjustable Option Only) Reference Voltage 0.69 0.686 ADJ pin Input current 20 nA 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. 4. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF. 5. Specification for packaged product only. 6. Both UVLO thresholds must be met for the output voltage to be allowed to turn-on. If either of the two input voltages are below the UVLO thresholds, the output is kept off. February 2008 5 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Typical Characteristics February 2008 6 M9999-022108-A (408) 944-0800 Micrel, Inc. February 2008 MIC47100 7 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Functional Characteristics February 2008 8 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Functional Diagram MIC47100 Block Diagram February 2008 9 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 performance at a minimum of space. Additional highfrequency capacitors, such as small-valued NPO dielectric-type capacitors, help filter out highfrequency noise and are good practice in any RFbased circuit. Applications Information The MIC47100 is a high speed, dual supply NMOS LDO designed to take advantage of point-of-load applications that use multiple supply rails to generate a low voltage, high current power supply. The MIC47100 can source 1A of output current while only requiring a 1µF ceramic output capacitor for stability. The MIC47100 regulator is fully protected from damage due to fault conditions, offering linear current limiting and thermal shutdown. Minimum Load Current The MIC47100, unlike most other regulators, does not require a minimum load to maintain output voltage regulation. Adjustable Regulator Design The MIC47100 adjustable version allows programming the output voltage anywhere between 0.8V and 2.0V. Two resistors are used. The R1 resistor value between VOUT and the adjust pin should not exceed 10kΩ. Larger values can cause instability. R2 connects between the adjust pin and ground. The resistor values are calculated by: Bias Supply Voltage VBIAS, requiring relatively light current, provides power to the control portion of the MIC47100. Bypassing on the bias pin is recommended to improve performance of the regulator during line and load transients. Small ceramic capacitors from VBIAS-to-ground help reduce high frequency noise from being injected into the control circuitry from the bias rail and are good design practice. ⎞ ⎛V R1 = R2 × ⎜⎜ OUT − 1⎟⎟ ⎠ ⎝ 0.7 Input Supply Voltage VIN provides the supply to power the LDO. The minimum input voltage is 1V, allowing conversion from low voltage supplies. Where VOUT is the desired output voltage. Enable/Shutdown The MIC47100 comes with a single 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. The active-high enable pin uses CMOS technology and the enable pin cannot be left floating; a floating enable pin may cause an indeterminate state on the output. Output Capacitor The MIC47100 requires an output capacitor of 1µF or greater to maintain stability. The design is optimized for use with low-ESR ceramic chip capacitors. High ESR capacitors may cause high frequency oscillation. 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. Thermal Considerations The MIC47100 is designed to provide 1A 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 1.8V, the output voltage is 1.2V and the output current is 1A. The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT1) IOUT + VBIAS IGND Input Capacitor The MIC47100 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 February 2008 Because this device is CMOS, the ground current is insignificant for power dissipation and can be ignored for this calculation. PD = (1.8V – 1.2V) × 1A PD = 0.6W 10 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 To determine the maximum ambient operating temperature of the package, use the junction-toambient thermal resistance of the device and the following basic equation: PD(MAX) = ⎛ ⎝ The maximum power dissipation must not be exceeded for proper operation. For example, when operating the MIC47100-1.2YML at an input voltage of 1.8V and a 1A load with a minimum footprint layout, the maximum ambient operating temperature TA can be determined as follows: TJ(MAX) - TA JA (125°C − TA ) (90°C / W ) TA = 71°C TJ(max) = 125°C, the maximum junction temperature of the die θJA thermal resistance = 90°C/W. 0.6W = The table below shows junction-to-ambient thermal resistance for the MIC47100 in the MLF® package. Package θJA Recommended Minimum Footprint θJC 8-pin 2mm x 2mm 90°C/W 2°C/W MLF® Therefore, a 1.2V application with 1A of output current can accept an ambient operating temperature of 71°C in a 2mm x 2mm 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. This information can be found on Micrel's website at: http://www.micrel.com/_PDF/other/LDOBk_ds.pdf Thermal Resistance Substituting PD for PD(max) and operating temperature will operating conditions for the junction-to-ambient thermal minimum footprint is 90°C/W. February 2008 solving for the ambient give the maximum regulator circuit. The resistance for the 11 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 Package Information 8-Pin 2mm×2mm MLF (ML) February 2008 12 M9999-022108-A (408) 944-0800 Micrel, Inc. MIC47100 8-Pin e-Pad MSOP (MME) 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. © 2008 Micrel, Incorporated. February 2008 13 M9999-022108-A (408) 944-0800