MIC5316 Evaluation Board Low Voltage Dual 300mA LDO with Power On Reset and Voltage Select General Description The MIC5316 is a dual low input voltage, low dropout regulator with Power on Reset (POR) and voltage select for the second output. The /VSC2 pin is used to select the output of the second LDO between two preset voltages. The MIC5316 provides two high-performance 300mA LDOs, a POR generator, and Voltage select for the LDO2 output into a 2.5mm x 2.5mm Thin MLF® package. Requirements The MIC5316 evaluation board requires two power supplies. The first supply must be able to provide a minimum of 600mA with a voltage range of 1.7V to 5.5V to the VIN1 and VIN2 terminals. The second supply is required to provide the VBIAS current. Although typical VBIAS current is 40µA, in dropout conditions, VBIAS currents can reach as high as a few mA. The VBIAS supply should be able to provide a voltage range of 2.5V to 5.5V. Alternatively, a single power supply may be used to power both VIN and VBIAS. The output load can be either an active or passive load. Circuit Description The MIC5316 dual linear regulator is easy to use. A minimum output capacitance of 1µF for each of the outputs is required. The MIC5316 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. The evaluation board includes the footprint for two 10µF ceramic capacitors (C1 and C7) connected to the VIN1 and VIN2 pins. Although this is much larger than required for the device, this was designed to allow for the long inductive test leads that will be attached to the evaluation board. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN or VBIAS terminals may damage the device. Getting Started 1. Connect an external supply to VBIAS. Apply desired input voltage to the VBIAS (J3) and ground (J2) terminals of the evaluation board, paying careful attention to polarity and supply voltage (2.5V ≤ VBIAS ≤ 5.5V). 2. Connect an external supply to 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 (1.7V ≤ VIN ≤ VBIAS). 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. 3. Enable/Disable the MIC5316. The evaluation board is provided with 100k pull up resistors on both of the enable pins (EN1 and EN2) to VIN. To disable an output, simply jumper the EN terminal (J4 for LDO1, J5 for LDO2) to the GND terminal (J2). The enable pins must be either pulled high or low. Removing the pull up resistors and leaving the pins floating will cause the regulators to operate in an indeterminate state. 4. Connect the loads to the VOUT terminals (J7 for LDO1, J8 for LDO2) and ground terminal (J9). The load can be either a passive (resistor) or active (electronic load). Be sure to monitor the output voltage at the VOUT (J7 and J8) terminals. 5. Power on Reset. Connect an oscilloscope to the POR2 terminal (J6) and ground terminal (J2 or J9). The evaluation board has a 0.1µF capacitor connected from the CSET2 pin-to-GND. This corresponds to a delay of 100ms on the POR2 output. The POR2 delay time can be modified by changing the value of C4 with a rate of 1s/µF, or removing C4 for zero delay. 6. Voltage Scaling. The evaluation board has a 100k pull down resistor-to-GND. By leaving the VSC terminal floating, the /VSC2 pin is pulled low, setting the output voltage on LDO2 to the lower voltage. To switch LDO2’s output voltage to the higher voltage use a jumper wire to connect the VSC terminal (J10) to the VIN terminal (J1). 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 September 2008 M9999-091208-A Micrel, Inc. MIC5316 Evaluation Board Ordering Information Part Number(1) Description MIC5316-GW3YMT EV Evaluation board with the 300mA Dual LDO with POR and voltage scaling. (VOUT1 = 1.8V, VOUT2 = 1.6V/1.1V) 1. For other output voltage options contact Micrel Marketing. Evaluation Board Schematic U1 MIC5316-xxyYMT VIN J1 VIN R1 100k J3 VBIAS J4 EN1 J5 EN2 1 VIN1 2 VIN2 3 VBIAS 4 EN1 5 EN2 7 POR2 9 C1 1µF C2 1µF VOUT1 CBYP C4 10nF GND 8 J2 GND J7 VO1 12 VOUT2 11 J8 VO2 /VSC2 10 J10 VSC CSET2 6 C3 0.01µF C6 1µF C5 1µF J9 GND Bill of Materials Item Part Number Manufacturer Description (1) C1, C2, C5, C6 C1608X5R1A105K Capacitor, 1µF Ceramic, 10V, X5R, Size 0603 4 C3 VJ0603Y104KXACW1BC Vishay(2) Capacitor, 0.1µF, 50V, X7R, Size 0603 1 C4 VJ0603Y103KXACW1BC Vishay(2) Capacitor, 0.01µF, 50V, X7R, Size 0603 1 R1 CRCW0603100KFKEA U1 MIC5316-xxyYMT TDK Qty (2) Vishay Micrel(3) Resistor, 100kΩ, 1%, 1/16W, Size 0603 1 Low Voltage Dual 300mA LDO with POR and V Select 1 Notes: 1. TDK: www.tdk.com 2. Vishay: www.vishay.com 3. Micrel, Inc.: www.micrel.com September 2008 2 M9999-091208-A Micrel, Inc. MIC5316 Evaluation Board PCB Layout Recommendations Top Layer Bottom Layer September 2008 3 M9999-091208-A Micrel, Inc. MIC5316 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. © 2007 Micrel, Incorporated. September 2008 4 M9999-091208-A