MIC59300 Evaluation Board 3.0A Low Voltage LDO Regulator General Description The demonstration board can be used to evaluate the MIC59300. The MIC59300, a 3.0A, ultra-high speed, low dropout linear regulator, utilizes a split supply input to regulate low output voltages. It is offered in fixed and adjustable outputs. The adjustable version allows the use of a resistor divider network to adjust the output voltage. An enable pin allows it to be placed in a zero-current off mode state. The evaluation board accommodates the adjustable version. Requirements The MIC59300 requires two power supplies. One to provide a minimum of 3.0A to the VIN and the other to provide Vbias current. Although typical Vbias current is 30mA, in dropout conditions Vbias currents can be very high. A 1A minimum power supply is recommended for Vbias. The Vbias should be able to deliver a minimum of 3v or 2.1V greater than Vout, whichever is greater. In cases where the Vin voltage satisfies the minimum Vbias voltage, one supply can be used. Circuit Description The MIC59300 ultra-high speed regulator is easy to use. It is extremely tolerable to a wide range and types of output capacitor. A minimum 1µF ceramic capacitor is recommended. An input capacitor is required when the power supply is more than 4 inches away from the device. The evaluation board has a 1µF ceramic on the VIN pin. For the adjustable version, the output can be selected by using the evaluation board jumper JP2. The available output options on the evaluation board are 1.0V, 1.2V, 1.5V and 1.8V. Also, a 0.5V output can be obtained by removing the jumper. Any of the four bottom feedback resistors can be substituted to obtain a different output voltage. The equation to set the output is as follows: VOUT = VREF ( R1 + 1) R2 Where VREF is 0.5V. R1 on the evaluation board is set to 1KΩ. Due to the high bandwidth of the MIC59300, larger values of R1 and the parasitic capacitance of the feedback pin introduce an additional pole. For R1 values greater than 1KΩ, a small feed forward capacitor (C4) across R1 will be required to maintain stability. Since R1 on the evaluation board is set to 1KΩ, the formula for adjusting the output to the desired level is as follows: R2 = R1× VREF VOUT − VREF R2 = 1kΩ × 0.5V VOUT − 0.5V A jumper at JP1 can turn on or turn off the device. JP1-2 is connected to the EN pin of MIC59300. If the jumper is shorting EN pin and VBIAS, the device is turned on. If the jumper is shorting GND and VBIAS, the device is turned off. Connecting EN pin to an external power supply can also control the device on and off. Minimal turn-on threshold voltage of EN pin is 1.6V. Maximum turn-off threshold voltage of EN pin is 0.3V. Getting Started 1. Connect external supplies to VIN terminal and VBIAS terminal. Apply desired input voltages to the VIN, VBIAS and ground terminals of the evaluation board, paying careful attention to polarity and supply voltage (1.0V<VIN<3.8V, 3.0V<VBIAS<5.5V). Ensure the supply voltages are monitored at the VIN and VBIAS terminals. Power lead resistances can reduce the voltages supplied to the inputs. 2. Connect the load to the VOUT and ground terminals. The load can be either passive (resistive) or active (as an electronic load). An ammeter can be placed between the load and the VOUT terminal. Ensure the output voltage is monitored at the VOUT terminal. The VOUT is set by the voltage selector. The output voltage can also be adjusted by changing the feedback resistors. See “Circuit Description”. 3. Enable the MIC59300. The output of the MIC59300 is turned on by shorting the enable pin to VBIAS or bringing the enable pin beyond the enable threshold. The output of the MIC59300 is turned off by shorting the enable pin to ground or bringing the enable pin below the enable threshold. See “Circuit Description”. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com April 2009 M9999-040109-A (408) 944-0800 Micrel, Inc. MIC59300 Evaluation Board Ordering Information Part Number Description Package MIC59300YME MIC59300YME EV IC Evaluation Board 8-Pin SOIC EPAD 8-Pin SOIC EPAD U1 MIC59300YME J1 VIN 1V to 3.8V C1 1uF/6.3V 3 6 VIN VIN C2 1uF/6.3V R1 1K C4 OPEN J2 GND 2 VBIAS 1 EN C3 1uF/6.3V J5 GND 7 ADJ Option for Fixed VOUT R1 = 0 Remove all Jumpers from JP2 1 J3 VBIAS 3V to 5.5V J4 VOUT 4 5 VOUT VOUT 9 C D 4 B 3 R5 383 2 JP2 R4 499 1 A R3 698 8 R2 1K 8 7 EP 6 GND 5 2 3 JP1 JP2 = Voltages Selector A VOUT = 1.0V B VOUT = 1.2V C VOUT = 1.5V D VOUT = 1.8V Bill of Materials Item Part Number Manufacturer Description Qty. 1uF Ceramic Capacitor X5R 0603 6.3V 3 C1,C2 C1608X5R0J105K TDK(1) C3 GRM188R60J105KA01D Murata(2) 0603D105KAT2A AVX(3) Open 1 R1,R2 CRCW06031K00FKXX Vishay(4) 1kΩ 1% 0603 Resistor 2 R3 CRCW0603698RFKXX Vishay(4) 698Ω 1% 0603 Resistor 1 R4 CRCW0603499RFKXX Vishay(4) 499Ω 1% 0603 Resistor 1 R5 CRCW0603383RFKXX Vishay(4) 383Ω 1% 0603 Resistor 1 U1 MIC59300YME Micrel, Inc.(5) Ultra High Speed 3.0A LDO 1 C4 Notes: 1. TDK: www.tdk.com 2. Murata Tel: www.murata.com 3. AVX Tel: www.avx.com 4. Vishay Tel: www.vishay.com 5. Micrel, Inc.: www.micrel.com April 2009 2 M9999-040109-A (408) 944-0800 Micrel, Inc. MIC59300 Evaluation Board Printed Circuit Board Layouts Figure 1a. Top Layer Figure 1b. Bottom Layer April 2009 3 M9999-040109-A (408) 944-0800 Micrel, Inc. MIC59300 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. © 2006 Micrel, Incorporated. April 2009 4 M9999-040109-A (408) 944-0800 Micrel, Inc. MIC59300 Evaluation Board Revision History Date April 2009 Edits by: Revision Number 5 M9999-040109-A (408) 944-0800