MIC5280 Evaluation Board 25mA, 120V, Low IQ, High PSRR LDO General Description The MIC5280 is a high performance low dropout regulator, offering a very low noise output with a very wide input voltage operating range, from 4.5V to 120V DC input voltage. Ideal for high input voltage applications such as industrial and telecom, the MIC5280 offers 2% initial accuracy, extremely high power supply rejection ratio (PSRR > 80dB) and low ground current (typically 30µA). The MIC5280 can also be put into a zero-off-mode current state, drawing minuscule amount of current when disabled. The MIC5280 has a very wide input voltage range, with DC rated from –24V to +120V. This wide input range of the MIC5280 makes it ideal for harsh environment applications. Requirements The MIC5280 evaluation board requires an input power source that is able to deliver greater than 0.1A at +120VDC. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage lower than –24V to the VIN (J1) terminal may damage the device. The MIC5280 evaluation board is tailored for a 4.5V to 120V input voltage range. The input voltage range should not exceed 120VDC on the input. Getting Started 1. Connect an external supply to the VIN. Apply desired input voltage to the VIN (J1) and ground (J2) terminals of the evaluation board, paying careful attention to polarity and supply voltage (4.5V ≤ VIN ≤ 120V). 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. Enabling the MIC5280. The MIC5280 has an enable pin EN for enable/disable functionality. EN: A logic high will turn on the linear regulator and a logic low will shut down the linear regulator reducing the quiescent current to less than 1μA (typical). Output Voltage The output voltage on the MIC5280 evaluation board is adjustable. The output voltage is controlled by the feedback resistors (R1 and R2) and can be calculated as follows: ⎛ R1 ⎞ VOUT = VREF ⋅ ⎜ + 1⎟ ⎝ R2 ⎠ VREF = 1.219V The evaluation board is initially adjusted to 5V, but can easily be modified by removing R1 and replacing it with the value that yields the desired output voltage. ⎛V ⎞ R1 = R2 ⋅ ⎜⎜ OUT − 1⎟⎟ ⎝ VREF ⎠ Ensure the output voltage selected does not exceed 5V. Ordering Information Part Number Description MIC5280YME EV Evaluation board for the MIC5280YME device Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com August 2009 M9999-081309-B Micrel, Inc. MIC5280 Evaluation Board Evaluation Board Schematic Bill of Materials Item Part Number NMC-P1210X7R184K200TRPLPF C1 C1812C184K2RAC VJ1812Y184KXC C2 U1 0.18µF, 200V, 1812, X7R Ceramic Capacitor Vishay AVX(5) VJ0603G105KXYPW1BC 0.18µF, 200V, 1210, X7R Ceramic Capacitor (3) 0603C225MAT GRM188R60J105KA01D R2 Kemet Qty. (2) TDK(4) C1608X5R0J105K R1 NIC Description (1) C1608X5R1A225K GRM188R60J225KE19D C3 Manufacturer 1 2.2µF, 6.3V, 0603, X5R Ceramic Capacitor 1 0.1µF, 6.3V, 0603, X5R Ceramic Capacitor 1 Murata(6) TDK(4) Vishay(3) (6) Murata CRCW060315R4FKEYE3 Vishay Dale(4) 15.4k, 0603, 1%, 1/16W Resistor 1 CRCW06034R87FKEYE3 (4) 4.87k, 0603, 1%, 1/16W Resistor 1 (7) 25mA, 120V, Low IQ, High PSRR LDO 1 MIC5280YME Vishay Dale Micrel, Inc. Notes: 1. NIC: www.niccomp.com 2. Kemet: www.kemet.com 3. Vishay: www.vishay.com 4. TDK: www.tdk.com 5. AVX: www.avx.com 6. Murata: www.murata.com 7. Micrel, Inc.: www.micrel.com August 2009 2 M9999-081309-B Micrel, Inc. MIC5280 Evaluation Board PCB Layout Recommendations Top Layer Bottom Layer August 2009 3 M9999-081309-B Micrel, Inc. MIC5280 Evaluation Board 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. August 2009 4 M9999-081309-B