MIC61150 Evaluation Board Low Input Voltage, Single-Supply High-Current LDO General Description Getting Started Micrel’s MIC61150 is a 1.5A output, low input voltage, single-supply regulator. This regulator operates over an input voltage range of 1.1V to 3.6V and offers an ultra-low dropout of less than 200mV over the entire operating temperature range. The MIC61150 is designed to drive digital circuits requiring low voltages at high currents such as DSPs, FPGAs, and microcontrollers. The regulator is available as a 1.0V fixedoutput voltage option or an adjustable-output voltage option. The MIC61150 is stable with a 22µF, low-ESR ceramic output capacitor, and includes protection features such as thermal shutdown, current limiting, and logic enable. The MIC61150 is offered in two different packages: a lowprofile, leadless 10-pin 3mm x 3mm MLF® and a 10-pin ePad MSOP. The MIC61150 has 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. 1. Connect an external supply to VIN terminal. Apply desired input voltage to the VIN and ground terminals of the evaluation board, paying careful attention to polarity and supply voltage. An ammeter may be placed between the input supply and the VIN terminal to the evaluation board. Ensure that the supply voltage is monitored at the VIN terminal. The ammeter and/or power lead resistance can reduce the voltage supplied to the input. 2. Connect the load to the VOUT and ground terminals. The load can be either passive (resistive) or active (as in an electronic load). An ammeter can be placed between the load and the VOUT terminal. Ensure that the output voltage is monitored at the VOUT terminal. The VOUT can be adjusted by changing the feedback resistors. See Adjustable Regulator Design section. 3. Enable the MIC61150. The EN pin is provided on the evaluation board with a 10k pull-up resistor. The output of the MIC61150 may be turned off by shorting the EN pin to ground. An external connection on the board provides easy access to the enable pin. Removing the pull-up resistor and leaving the EN pin floating will cause the regulator to operate in an indeterminate state. 4. Soft-Start. The CP pin is the output of the internal charge pump. The soft-start rise time is controlled by the external capacitor connected from CP pin to GND(J5). During soft-start, the charge pump feeds a current to CCP. The output voltage rise time is dependent upon the value of CCP, the input voltage, output voltage and the current limit. The value of the charge pump external capacitor selected is recommended in the range of 0.1µF to 1µF. Requirements The MIC61150 evaluation board requires a single power supply to provide VIN. The VIN power supply must be able to deliver greater than 1.1V with more than 1.5A capability. The output load can either be an active or passive load. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN terminal may damage the device. In addition, the maximum VIN operating voltage of the MIC61150 evaluation board is 3.6V. Exceeding 3.6V on VIN could damage the device. Ordering Information Part Number Description MIC61150YML EV Evaluation Board MIC61150YMME EV Evaluation Board MLF and MicroLeadFrame are registered trademarks of Amkor Technology, 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 October 2010 M9999-102910-A Micrel, Inc. MIC61150 Adjustable Regulator Design Output Capacitor The MIC61150 adjustable version allows programming the output voltage from 0.5V to 3.0V by placing a resistor divider network (R1, R2) from VOUT to GND (see Application Circuit). The high side of R1 should be connected at the point-of-load for high-accuracy Kelvin sensing. VOUT is determined by the following equation: As part of the frequency compensation, the MIC61150 requires a 22µF ceramic output capacitor. However, any other type of capacitor can be placed in parallel as long as the 22µF ceramic output capacitor is placed next to the MIC61150. Output voltages below 0.8V require either a 47µF or 2x 22µF output capacitance for large output transients. The increased output capacitance reduces the output voltage drop caused by load transients, which increases as a percentage of the output voltage as the output voltage is lowered. The output capacitor type and placement criteria are the same as the input capacitor. See the Input Capacitor section in the MIC61150 datasheet for a detailed description. ⎛ R1 ⎞ VOUT = 0.5 × ⎜ + 1⎟ ⎝ R2 ⎠ Eq. 1 where VOUT is the desired output voltage. The resistor (R2) value between the FB pin and GND is selected to maintain a minimum 10mA load on the output. The resistor values are calculated from the previous equation, resulting in the following: Minimum Load Current The MIC61150 requires a minimum load of 10mA to maintain output voltage regulation. ⎛V ⎞ R1 = R2 × ⎜⎜ OUT − 1⎟⎟ ⎝ 0.5 ⎠ Eq. 2 Table 1 is a list of resistor combinations to set the output voltage. A 1% tolerance is recommended for both R1 and R2. For a unity gain, 0.5V output voltage, connect the FB pin directly to the output. VOUT R1 R2 0.5V − 49.9Ω 0.6V 10.0Ω 49.9Ω 0.7V 20.0Ω 49.9Ω 0.8V 30.1Ω 49.9Ω 0.9V 40.2Ω 49.9Ω 1.0 49.9Ω 49.9Ω 1.1V 60.4Ω 49.9Ω 1.2V 69.8Ω 49.9Ω 1.5V 100Ω 49.9Ω 1.8V 130Ω 49.9Ω 2.2V 169Ω 49.9Ω Table 1. Resistor Selection for Specific VOUT October 2010 2 M9999-102910-A Micrel, Inc. MIC61150 MIC61150YML Evaluation Board Schematic (3mm × 3mm 10-Pin ePad MLF®) MIC61150YML Evaluation Board (J1, J2, J5, R4 are for Testing Purposes) Bill of Materials Item C1 Part Number C0805C106K8PACTU C3216X5ROJ476M C2 GRM31Cr60J476ME19L 12066D476MAT2A Manufacturer Kemet (1) Description Qty. 10µF/10V Ceramic Capacitor, X5R,Size 0805 TDK(2) 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 or Murata(3) 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 or (4) AVX (1) 1 1 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 C3 C0603C104K8RACTU Kemet 0.1µF/10V Ceramic Capacitor, X7R, Size 0603 1 R1 CRCW080569R8F Vishay(5) 69.8Ω Film Resistor, Size 0805, 1% 1 CRCW080549R9F (5) 49.9Ω Film Resistor, Size 0805, 1% 1 (5) R2 Vishay R3 CRCW08051002F Vishay 10kΩ Film Resistor, Size 0805, 1% 1 R4 CRCW080500R0F Vishay(5) 0Ω Film Resistor, Size 0805, 1% 1 U1 MIC61150YML 1.5A Low-Voltage, Single-Supply LDO 1 Micrel, Inc.(6) Notes: 1. Kemet: www.kemet.com. 2. TDK: www.tdk.com. 3. Murata: www.murata.com. 4. AVX: www.avx.com. 5. Vishay: www.vishay.com. 6. Micrel, Inc.: www.micrel.com. October 2010 3 M9999-102910-A Micrel, Inc. MIC61150 MIC61150YML PCB Layout Recommendations MIC61150YML Evaluation Board – Top Layer MIC61150YML Evaluation Board – Bottom Layer October 2010 4 M9999-102910-A Micrel, Inc. MIC61150 MIC61150YMME Evaluation Board Schematic (10-Pin ePad MSOP) MIC61150YMME Evaluation Board (J1, J2, J5, R4 Are for Testing Purposes) Bill of Materials Item C1 Part Number C0805C106K8PACTU C3216X5ROJ476M C2 GRM31Cr60J476ME19L 12066D476MAT2A C3 C0603C104K8RACTU Manufacturer Kemet (1) (2) TDK (3) Murata (4) AVX Kemet Description Qty. 10µF/10V Ceramic Capacitor, X5R,Size 0805 1 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 or 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 or 1 22µF/6.3V Ceramic Capacitor, X5R, Size 1206 (1) 0.1µF/10V Ceramic Capacitor, X7R, Size 0603 1 (5) R1 CRCW080569R8F Vishay 69.8Ω Film Resistor, Size 0805, 1% 1 R2 CRCW080549R9F Vishay(5) 49.9Ω Film Resistor, Size 0805, 1% 1 CRCW08051002F (5) 10kΩ Film Resistor, Size 0805, 1% 1 R3 R4 CRCW080500R0F U1 MIC61150YMME Vishay (5) Vishay Micrel, Inc.(6) 0Ω Film Resistor, Size 0805, 1% 1 1.5A Low-Voltage, Single-Supply LDO 1 Notes: 1. Kemet: www.kemet.com. 2. TDK: www.tdk.com. 3. Murata: www.murata.com. 4. AVX: www.avx.com. 5. Vishay: www.vishay.com. 6. Micrel, Inc.: www.micrel.com. October 2010 5 M9999-102910-A Micrel, Inc. MIC61150 MIC61150YMME PCB Layout Recommendations MIC61150YMME Evaluation Board – Top Layer MIC61150YMME Evaluation Board – Bottom Layer October 2010 6 M9999-102910-A Micrel, Inc. MIC61150 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 Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right 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. © 2010 Micrel, Incorporated. October 2010 7 M9999-102910-A