MIC45208 Evaluation Board 26V/10A DC-to-DC Power Module General Description Getting Started Micrels MIC45208 is a synchronous step-down regulator 1. VIN Supply module, featuring a unique adaptive ON-time control Connect a power supply to the VIN and GND architecture. The module incorporates a DC-to-DC terminals, paying careful attention to the polarity and controller, power MOSFETs, bootstrap diode, bootstrap the supply range (4.5V < VIN < 26V). Monitor IIN with capacitor, and an inductor in a single package simplifying a current meter and monitor input voltage at VIN and the design and layout process for the end user. GND terminals with a voltmeter. Do not apply power until Step 4. This highly-integrated solution expedites system design and improves product time-to-market. The internal 2. Connect Load and Monitor Output MOSFETs and inductor are optimized to achieve high Connect a load to the VOUT and GND terminals. The efficiency at a low output voltage. The fully optimized load can be either a passive (resistive) or an active (as design can deliver up to 10A current under a wide input in an electronic load) type. A current meter may be voltage range of 4.5V to 26V, without requiring additional placed between the VOUT terminal and load to cooling. monitor the output current. Ensure the output voltage The MIC45208-1 uses Micrels HyperLight Load (HLL) is monitored at the VOUT terminal. MIC45208-2 uses Micrels Hyper Speed Control 3. Enable Input architecture which enables ultra-fast load transient The EN pin has an on-board 100k pull-up resistor response, allowing for a reduction of output capacitance. (R10) to VIN, which allows the output to be turned on The MIC45208 offers 1% output accuracy that can be when PVDD exceeds its UVLO threshold. An EN adjusted from 0.8V to 5.5V with two external resistors. connector is provided on the evaluation board for The basic parameters of the evaluation board are: users to easily access the enable feature. Applying an external logic signal on the EN pin to pull it low or Input: 4.5V to 26V using a jumper to short the EN pin to GND will shut off Output: 0.8V to 5V at 10A the output of the MIC45208 evaluation board. 600kHz Switching Frequency 4. Turn Power On (Adjustable 200kHz to 600kHz) Turn on the VIN supply and verify that the output voltage is regulated to 5V. Datasheets and support documentation are available on Micrels web site at: www.micrel.com. Ordering Information Requirements Part Number Description The MIC45208-1 and MIC45208-2 evaluation board only MIC45208-1YMP EV MIC45208-1 Evaluation Board requires a single power supply with at least 10A current capability. No external linear regulator is required to power MIC45208-2YMP EV MIC45208-2 Evaluation Board the internal biasing of the IC because the MIC45208 has an internal PVDD LDO. In applications where VIN < +5.5V, PVDD should be tied to VIN to bypass the internal linear regulator. The output load can either be a passive or an active load. Precautions The MIC45208 evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN and GND terminals can damage the device. The maximum VIN of the board is rated at 30V. Exceeding 30V on the VIN could damage the device. HyperLight Load is a registered trademark and Hyper Speed 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 Micrel, Inc. MIC45208 Evaluation Board Features Feedback Resistors The output voltage on the MIC45208 evaluation board, All other voltages not listed above can be set by modifying which is preset to 5.0V, is determined by the feedback R value according to: BOTTOM divider: R1 V REF R14 R = Eq. 2 BOTTOM V = V 1 + Eq. 1 V V OUT REF OUT REF R BOTTOM Note that the output voltage should not be set to exceed where V = 0.8V, and R is one of R3 thru R9. REF BOTTOM 5V. Leaving the R open by removing all jumpers on the BOTTOM feedback headers gives a 0.8V output voltage. Table 1. Typical Values of Some Components R14 R C12 V V C OUT IN OUT (C ) (Top Feedback Resistor) (Bottom Feedback Resistor) ff 1.0V 5V to 26V 10k 40.2k 2.2nF 100F/6.3V 1.2V 5V to 26V 10k 20k 2.2nF 100F/6.3V 1.5V 5V to 26V 10k 11.5k 2.2nF 100F/6.3V 1.8V 5V to 26V 10k 8.06k 2.2nF 100F/6.3V 2.5V 5V to 26V 10k 4.75k 2.2nF 100F/6.3V 3.3V 5V to 26V 10k 3.24k 2.2nF 100F/6.3V 5V 7V to 26V 10k 1.9k 2.2nF 100F/6.3V August 19, 2015 2 Revision 2.0