High-Performance, Multi-Mode, Step-Down Controller MIC2111B Evaluation Board General Description The MIC2111B is a programmable-frequency, valleycurrent/voltage-mode PWM controller that provides the control and protection features necessary for power devices and drivers that use current-sensing across the inductor. The MIC2111B provides a single tri-state PWM logic signal to DrMOS modules to realize low output voltage, high current power supply. The device has precision enable and power good (PG) functions for the sequencing of multiple power supplies. In addition, the solution is compatible with intelligent power stages in a high-current, step-down DC/DC converter. The MIC2111B evaluation board operates over an input supply range of 5.5V to 16V and provides a regulated output at up to 20A of load current. The output voltage is adjustable down to 0.6V with a typical accuracy of ±1%. The evaluation board operates at a switching frequency of 500kHz, in valley current mode. The MIC2111B utilizes a programmable control architecture. The MIC2111B evaluation board is configured for valley current mode control. An undervoltage lockout feature is provided to ensure proper operation under power sag conditions. An adjustable softstart feature is provided to reduce inrush current. An adjustable current-limit is provided. “Hiccup” mode shortcircuit protection and thermal shutdown ensures protection of the IC during fault conditions. The basic parameters of the evaluation board are: • VIN supply: 5.5V to 16V • Output: 1.2V at 20A • 500kHz switching frequency (Adjustable from 200kHz to 2MHz) • Control mode: Valley current mode (Adjustable to voltage mode) The customer can configure the MIC2111B evaluation board to operate in voltage mode through the following jumper selections. Control Mode P1 P2 Valley Current Mode Pins 1-2 Pins 1-2 Voltage Mode Pins 2-3 OPEN For information about compensation component selection, see the MIC2111 datasheet on Micrel’s website at: www.micrel.com. Requirements The MIC2111B evaluation board requires only a single power supply with at least 10A current capability. The MIC2111B has an on-board 5V LDO to power the internal biasing of the MIC2111B IC and DrMOS gate drive supply. Power-up 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 MIC2111B evaluation board is 16V. Ordering Information Part Number Description MIC2111BYMT MIC2111B Evaluation Board 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 14, 2015 Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board Oscillator Frequency The MIC2111 has an internal oscillator by which the frequency can be set through an external resistor at the FREQ pin. The switching frequency can be programmed from 200kHz to 2MHz by using the following equation. Getting Started 1. Connect a supply to the VIN and GND terminals. Pay careful attention to the polarity and the supply range (5.5V < VIN < 16V). 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. Do not apply power until Step 4. RFREQ = 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. Soft-Start/Soft-Stop (SS) The MIC2111 has digital soft-start/soft-stop (SS) to avoid high inrush current in the input supply lines. The soft-start time can be programmed with an external resistor connected from the SS pin to GND. Table 1 illustrates resistor values and soft-start times. Soft-stop time is the same as the programmed soft-start time (contact the factory for instructions on disabling soft-stop). Table 1. Soft-Start Programming 4. Turn on the power. Turn on the VIN power supply and verify that the output voltage is regulated to 1.2V. Evaluation Board Description Output Voltage The output voltage on the MIC2111B evaluation board is adjustable. It is set by adjusting the feedback resistors and using the following equation. 𝑽𝑽𝑽𝑽𝑽𝑽𝑽𝑽 = 𝑽𝑽𝑭𝑭𝑭𝑭 𝒙𝒙 �𝟏𝟏 + 𝑹𝑹𝑹𝑹𝑹𝑹 � Eq. 1 where VFB = 0.6V and R11 is 4.99kΩ for a 1.2V output voltage. Leaving R11 open gives a 0.6V output voltage. The output can be adjusted from 0.6V to 3.46V by changing the value of R11 according to the equation above. The output voltage should not be set in excess of 3.46V due to the need for headroom for the current sense amplifier of MIC2111B. Please refer to the Application Information section of the MIC2111 datasheet for setting the output voltage. October 14, 2015 Eq. 2 where FSW = the desired switching frequency in Hz. 3. Enable input. An EN connector is provided on the evaluation board for users to easily access the enable feature. The output of the MIC2111B turns on when VCC exceeds the UVLO threshold. The output of the MIC2111B evaluation board may be turned off by shorting the EN pin to ground. 𝑹𝑹𝑹𝑹𝑹𝑹 𝟏𝟏𝟏𝟏𝟏𝟏𝟏𝟏 𝑭𝑭𝑺𝑺𝑺𝑺[Ω] 2 E96 Range Resistance Soft-Start 6.19kΩ 64µs 19.1kΩ 128µs 30.9kΩ 256µs 44.2kΩ 512µs 56.2kΩ 768µs 68.1kΩ 1024µs 80.6kΩ 1536µs 93.1kΩ 2048µs 105kΩ 3072µs 118kΩ 4096µs 130kΩ 6144µs 143kΩ 8192µs 154kΩ 16384µs 169kΩ 24576µs 182kΩ 32768µs Open 2048µs Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board Evaluation Board Performance October 14, 2015 3 Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board Evaluation Board Schematic October 14, 2015 4 Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board Bill of Materials Item Part Number C1 C1608X7R1C684K080AC C2, C21, C24, C30 C1608C0G1H100D C3, C7, C16, C17, C23,C31, R2, R6, R13, R15, R16, R17, R22, R26 OPEN C4, C9, C18, C19, C27,C32,C33,C34 Manufacturer (1) Qty. 0.68µF Ceramic Capacitor, X7R, 0603 Size, 16V 1 TDK 10pF Ceramic Capacitor, COG, 0603 Size, 50V 4 C1608X5R1E105K TDK 1µF Ceramic Capacitor, X5R, 0603 Size, 25V 6 C5 C1608C0G1H820J TDK 82pF Ceramic Capacitor, COG, 0603 Size, 50V 1 C6, C22 C1608C0G1H102J TDK 1nF Ceramic Capacitor, COG, 0603 Size, 50V 2 C8, C10 C3225X5R0J226M/1.60 TDK 22µF Ceramic Capacitor, X5R, 1210 Size, 6.3V 2 C11, C13 C3225X5R0J107M TDK 100µF Ceramic Capacitor, X5R, 1210 Size, 6.3V 2 C12, C20 C1608X7R1E104K 100nF Ceramic Capacitor, X7R, 0603 Size, 25V 2 C15 6SVP470MX 470µF OS-CON Capacitor, 6.3V 1 C25, C28, C29 C3225X5R1E106M 10µF Ceramic Capacitor, X5R, 1210 Size, 25V 2 C26 EEEFP1E471AP 470µF Alluminium Capacitor, 25V 1 0.4µH inductor, 37A saturation current 1 10Ω Resistor,0603 Size, 1% 4 L1 744325040 TDK Description TDK Panasonic (2) TDK Panasonic (3) Wurth Electric Vishay Dale (4) R1, R2, R3, R10 CRCW060310R0FKEA R4, R5, R7, R9, R29, R30 CRCW060310K0FKEA Vishay Dale 10kΩ Resistor,0603 Size, 1% 4 R8 CRCW0603866RFKEA Vishay Dale 866Ω Resistor,0603 Size, 1% 1 R11, R14 CRCW06034K99FKEA Vishay Dale 4.99kΩ Resistor,0603 Size, 1% 2 R11, R14 CRCW06034K99FKEA Vishay Dale 4.99kΩ Resistor,0603 Size, 1% 2 R12, R31, RSW CRCW06030000Z0EA Vishay Dale 0Ω Resistor,0603 Size, 1% 3 R18, R23 CRCW06031R21FKEA Vishay Dale 1.21Ω Resistor,0603 Size, 1% 2 R19 CRCW060311K0FKEA Vishay Dale 11kΩ Resistor,0603 Size, 1% 1 R20 CRCW06031K00FKEA Vishay Dale 1kΩ Resistor,0603 Size, 1% 1 R21 CRCW0603147KFKEA Vishay Dale 147kΩ Resistor,0603 Size, 1% 1 R24 CRCW06035K49FKEA Vishay Dale 5.5kΩ Resistor,0603 Size, 1% 1 R25 CRCW0603200KFKEA Vishay Dale 200kΩ Resistor,0603 Size, 1% 1 R27 CRCW0603118KFKEA Vishay Dale 118kΩ Resistor,0603 Size, 1% 1 R28 CRCW0603188KFKEA Vishay Dale 188kΩ Resistor,0603 Size, 1% 1 U1 MIC2111B High-Performance, Multi-Mode, Step-Down Controller 1 U2 SiC780ACD Integrated DrMOS power stage 1 U3 MIC5209-5.0YS 500mA Low Noise LDO Regulator 1 (5) Micrel, Inc. Vishay Micrel, Inc. Notes: 1. TDK: www.tdk.com. 2. Panasonic: www.industrial.panasonic.com. 3. Wurth Electronic: www.we-online.com. 4. Vishay Dale: www.vishay.com. 5. Micrel, Inc.: www.micrel.com. October 14, 2015 5 Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board PCB Layout Recommendations Top Layer Mid Layer 1 October 14, 2015 6 Revision 1.1 Micrel, Inc. MIC2111B Evaluation Board PCB Layout Recommendations (Continued) Mid Layer 2 Bottom Layer October 14, 2015 7 Revision 1.1 Micrel, Inc. MIC2111B 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 Micrel, Inc. is a leading global manufacturer of IC solutions for the worldwide high-performance linear and power, LAN, and timing & communications markets. The Company’s products include advanced mixed-signal, analog & power semiconductors; high-performance communication, clock management, MEMs-based clock oscillators & crystal-less clock generators, Ethernet switches, and physical layer transceiver ICs. Company customers include leading manufacturers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and computer products. Corporation headquarters and state-of-the-art wafer fabrication facilities are located in San Jose, CA, with regional sales and support offices and advanced technology design centers situated throughout the Americas, Europe, and Asia. Additionally, the Company maintains an extensive network of distributors and reps worldwide. Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this datasheet. 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. © 2015 Micrel, Incorporated. October 14, 2015 8 Revision 1.1