MIC2039 Evaluation Board High-Accuracy, High-Side, Adjustable Current Limit Power Switch General Description Getting Started The MIC2039 is a high-side MOSFET power distribution switch providing increased system reliability by using 5% current limit accuracy. The MIC2039 has an operating input voltage range from 2.5V to 5.5V, is internally current limited, and has thermal shutdown to protect the device and system. The MIC2039 is offered with either active-high or active-low logic level enable input controls. It has an open drain fault status output flag with a built-in 32ms delay that asserts low during overcurrent or thermal shutdown conditions. The MIC2039 switch features an adjustable output current limit that is resistor programmable from 0.2A to 2.5A. The MIC2039 switch also offers a unique Kickstart feature, which allows momentary high-current surges up to the secondary current limit (ILIMIT_2nd) during startup or while operating in steady state. This is useful for charging loads with high inrush currents, such as capacitors. After an overcurrent condition is established, these switches enter into a constant current limit mode unless the die temperature exceeds the thermal shutdown specification. The MIC2039 is offered in both 6-pin SOT-23 and 6-pin 2mm x 2mm thin DFN packages. It has an operating junction temperature range of −40°C to +125°C. Requirements The MIC2039 evaluation board requires a single power supply to provide VIN. The VIN power supply must be able to deliver a minimum of 2.5V and more than 1.5A capability. The output load can either be active or passive. Precautions The evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN terminal can damage the device. In addition, the maximum VIN operating voltage of the MIC2039 evaluation board is 5.5V. Exceeding 5.5V on VIN can permanently damage the device. 1. Connect an external supply to VIN terminal. Apply the desired input voltage to the VIN and ground terminals of the evaluation board, paying careful attention to polarity and supply voltage. The user can place an ammeter between the input supply and the VIN terminal to the evaluation board. Make sure 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. Connect the load to the VOUT and ground terminals. The load can be either passive (resistive) or active (as in an electronic load). The user can place an ammeter between the load and the VOUT terminal. Make sure that the output voltage is monitored at the VOUT terminal. 3. Enable the switch. The MIC2039 evaluation boards are configured for default enable using a 10kΩ pull-up resistor from the ENABLE pin to VIN. To disable the switch, place a jumper short across the jumper pins at TP2. 4. Fault detection The MIC2039 is equipped with an error flag pin, FAULT/. TP3 is provided to monitor the FAULT/ pin. Ordering Information Part Number Description MIC2039-05AYM6 EV Evaluation board featuring the MIC2039AYM6 Power Switch Current limit is set for 500mA MIC2039-1AYM6 EV Evaluation board featuring the MIC2039AYM6 Power Switch Current limit is set for 1A MIC2039-05AYMT EV Evaluation board featuring the MIC2039AYMT Power Switch Current limit is set for 500mA MIC2039-1AYMT EV Evaluation board featuring the MIC2039AYMT Power Switch Current limit is set for 1A Ramp Control is a trademark of Micrel, 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 October 2012 M9999-100112-A Micrel, Inc. MIC2039 Evaluation Board Application Information where ILIMIT is the typical current limit from the electrical table. If the output current exceeds the set current limit, the MIC2039 switch enters constant current limit mode. The maximum allowable current limit may be less than the full specified and/or expected current if the MIC2039 is not mounted on a circuit board with sufficiently low thermal resistance. Resistor values (1%) for select current limit settings are shown in Table 1. Adjustable Current Limit The factory sets the MIC2039-xYMx evaluation boards for either a 500mA or 1A current limit. However, connecting a resistor (R3) from the ILIMIT pin to GND allows the current limit to be adjusted from 0.2A to 2.5A. For the MIC2039-xYMT evaluation board, jumper TP4 must be shorted for R3 to connect to the ILIMIT pin of the IC. The following equation determines the value of R3: R3 ≅ 289/ILIMIT Eq. 1 ILIMIT 0.2A 0.5A 1.0A 2A 2.5A R3 1.43kΩ 576Ω 287Ω 143Ω 115Ω Table 1. Resistor Selection for Adjustable Current Limit October 2012 2 M9999-100112-A Micrel, Inc. MIC2039 Evaluation Board Evaluation Board Schematics MIC2039xYMT Evaluation Board MIC2039xYM6 Evaluation Board October 2012 3 M9999-100112-A Micrel, Inc. MIC2039 Evaluation Board Bill of Materials Item C1, C2 R1, R2 R3 U1 Part Number Manufacturer C1608X5R0J105K TDK 06036D105KAT2A AVX(2) CRCW060310K0FKEA CRCW06032870FKEA CRCW06031430FKEA MIC2039xYMT MIC2039xYM6 Description Qty. (1) Vishay/Dale(3) Vishay/Dale Micrel(4) 1µF/6.3V ceramic capacitor, X5R, 0603 2 10kΩ, film resistor, 0603, 1% 2 287Ω film resistor, 0603, 1% or 1 143Ω film resistor, 0603, 1% High-accuracy, high-side, adjustable current limit power switch 1 Notes: 1. TDK: www.tdk.com. 2. AVX: www.avx.com. 3. Vishay: www.vishay.com. 4. Micrel, Inc.: www.micrel.com. October 2012 4 M9999-100112-A Micrel, Inc. MIC2039 Evaluation Board Evaluation Board PCB Layout MIC2039xYMT Evaluation Board – Top Layer MIC2039xYMT Evaluation Board – Bottom Layer October 2012 5 M9999-100112-A Micrel, Inc. MIC2039 Evaluation Board Evaluation Board PCB Layout (Continued) MIC2039xYM6 Evaluation Board – Top Layer MIC2039xYM6 Evaluation Board – Bottom Layer October 2012 6 M9999-100112-A Micrel, Inc. MIC2039 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 makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. 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. © 2012 Micrel, Incorporated. October 2012 7 M9999-100112-A