MIC2811/21 Evaluation Board Four Output Power Management IC with 2MHz, 600mA DC/DC and Triple 300mA LDOs of the evaluation board. Ensure that the supply voltage is monitored at the input terminals. The ammeter and/or power lead resistance can reduce the voltage supplied to the input. 2. Enable/Disable the MIC2811 and MIC2821. The MIC2811 evaluation board has three separate enable pins for the four different outputs. The DC/DC buck converter and LDO3 are controlled from the EN terminal. LDO1 and LDO2 are enabled from EN1 and EN2, respectively. The enable pins are connected to the pin terminals and must not be left floating. Disable the regulators by pulling their respective EN terminal to GND. Enable the regulators by pulling their respective EN terminal above 1.2V (not to exceed DVIN). The MIC2821 differs from the MIC2811 in that LDO3 is enabled from a separate enable pin labeled EN3. 3. Connect loads to the output terminals (J10 for LDO3, J11 for LDO2, J12 for LDO1, J13 for the DC/DC converter) and GND pins (J5 and J14). The load can be either passive (resistor) or active (electronic load). Be sure to monitor the output voltage at the output terminals (J10, J11, J12, and J13). General Description The MIC2811 and MIC2821 are high performance four output power management ICs with single 600mA DC/DC buck converter for high efficiency and three 300mA LDOs for low noise supplies. The PWM DC/DC converter operates at 2MHz switching frequency to allow use of a small 2.2µH inductor. LDO1 and LDO2 support independent input supplies which are capable of operating at input voltages as low as 1.65V. This conveniently allows for post regulation of the DC/DC converter for efficient ultra-low noise supplies. The MIC2811 supports the use of a bypass cap for improved noise performance on LDO1 and LDO2 while the MIC2821 offers a separate enable pin for LDO3. Requirements The MIC2811/21 Evaluation board requires at least one input power supply able to provide greater than 2A at 3V. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage to any input supply or enable terminal may damage the device. The MIC2811 and MIC2821 input and enable voltages should never exceed DVIN (up to 5.5V). Getting Started 1. Connect external supplies to the VINs. Apply desired input voltage to the DVIN(J1) and ground(J2) terminals of the evaluation board, paying careful attention to polarity and supply voltage range (2.7V ≤ DVIN ≤ 5.5V). DVIN(J1) supplies chip VCC as well as power to the DC/DC converter and LDO3. Therefore, DVIN is required for any of the four regulators to operate properly. VIN1(J3) and VIN2(J4) provides power to LDO1 and LDO2, respectively. Both VIN1(J3) and VIN2(J4) should not exceed the DVIN(J1) supply and be kept within the supply range of 1.65V ≤ VIN1/VIN2 ≤ DVIN. An ammeter may be placed between the power supply and the input terminals Ordering Information Part Number MIC2811-4GJLYML EV MIC2811-4GMSYML EV MIC2821-4GJLYML EV MIC2821-4GMSYML EV Description Evaluation board with the MIC2811-4GJLYML 1.2V/1.8V/2.5V/2.7V device Evaluation board with the MIC2811-4GMSYML 1.2V/1.8V/2.8V/3.3V device Evaluation board with the MIC2821-4GJLYML 1.2V/1.8V/2.5V/2.7V device Evaluation board with the MIC2821-4GMSYML 1.2V/1.8V/2.8V/3.3V device 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 June 2008 M9999-060608-A Micrel, Inc. MIC2811/21 Evaluation Board Evaluation Board Schematic J1 DVIN U1 MIC2811/2821-YML DVIN 6 C1 4.7µF/6.3V J2 GND DVIN VO-LDO2 LDO2 10 VIN 12 VIN1 C2 4.7µF/6.3V J4 VIN2 VIN1 C3 4.7µF/6.3V C4 VIN2 4.7µF/6.3V LDO1 J9 EN3 R3 SGND EN2 PGND EN1 J11 VO_LDO2 J12 VO_LDO1 J5 GND VO BIAS J14 GND 13 2 C6 0.1µF/10V 10K (FOR MIC2821 ONLY) C5 0.1µF (FOR MIC2811 ONLY) June 2008 2 J13 VOUT C10 4.7µF/6.3V R2 OPTION 3 1 16 BYP/EN3 J7 EN1 J10 VO_LDO3 2.2µH EN 4 R4 10K 15 L1 R1 OPTION FB J6 EN 5 VIN2 14 J8 EN2 R5 10K 11 C7 2.2µF/6.3V SW 7 8 C8 2.2µF/6.3V VIN1 VIN2 9 C9 2.2µF/6.3V DVIN J3 VIN1 VO-LDO3 LDO3 M9999-060608-A Micrel, Inc. MIC2811/21 Evaluation Board Bill of Materials Item Part Number 06036D475KAT2A C1, C2, C3, C4, C10 C5, C6 C1608X5R0J475K TDK(3) AVX(1) R1 ME3220-222-ML CRCW06030000Z0TA 2.2µF, 6.3V, 0603, X5R Ceramic Capacitor 3 0.1µF, 10V, 0603, X5R Ceramic Capacitor (C5 for MIC2811 EV Board only) 2 (4) TDK CDRH2D11HPNP L1 5 (3) C1608X5R0J225K GRM21BR71H104KA01L 4.7µF, 6.3V, 0603, X5R Ceramic Capacitor Murata 06036D225KAT2A C1005X7R1C104KT Qty. AVX Taiyo Yuden(2) GRM188R60J225KE19D Description (1) JMK107BJ475MA-T GRM188R60J475KE19D C7, C8, C9 Manufacturer (4) Murata TDK(3) Murata (4) Sumida(5) Coilcraft 2.2µH, 1.1A, 3.2x3.2x1.2mm Inductor (6) 1 2.2µH, 1.1A, 2.5x3.2x2mm Inductor Vishay(7) R2 0Ω, 0603, 1% resistor 1 Open 0 R3, R4, R5 CRCW06031002FRT1 Vishay(7) 10kΩ, 0603, 1% resistor (R3 for MIC2821 EV Board only) 3 U1 MIC2811 Micrel, Inc.(8) Four Output Power Management IC with 2MHz, 600mA DC/DC and Triple 300mA LDOs (MIC2811 Evaluation Board Only) 1 U1 MIC2821 Micrel, Inc.(8) Four Output Power Management IC with 2MHz, 600mA DC/DC and Triple 300mA LDOs (MIC2821 Evaluation Board Only) 1 Notes: 1. AVX: www.avx.com 2. Taiyo Yuden: www.t-yuden.com 3. TDK: www.tdk.com 4. Murata: www.murata.com 5. Sumida: www.sumida.com 6. Coilcraft: www.coilcraft.com 7. Vishay: www.vishay.com 8. Micrel, Inc.: www.micrel.com June 2008 3 M9999-060608-A Micrel, Inc. MIC2811/21 Evaluation Board PCB Layout Recommendations Top Layer Bottom Layer June 2008 4 M9999-060608-A Micrel, Inc. MIC2811/21 Evaluation Board Ripple Measurements To properly measure voltage ripple on either the input or output of any regulator with a switching regulator near by, a proper ring in tip measurement is required. Standard oscilliscope probes come with a grounding clip, or a long wire with an alligator clip. Unfortunately, for high frequency measurements, this ground clip can pick up high frequency noise and erroneously inject it into the measured output ripple. The MIC2811 and MIC2821 evaluation boards accommodate a home made ring in tip measurement by probing across input and output capacitors. This requires the removing of the oscilloscope probe sheath and ground clip from a standard oscilloscope probe and wrapping a nonshielded bus wire around the oscilloscope probe (as shown on the left). If there does not happen to be any non-shielded bus wire immediately available, the leads from axial resistors will work. By maintaining the shortest possible ground lengths on the oscilloscope probe, true ripple measurements can be obtained. 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. June 2008 5 M9999-060608-A