MIC45205 Evaluation Board 26V/6A DC-to-DC Power Module General Description Getting Started Micrels MIC45205 is a synchronous step-down regulator 1. VIN Supply module, featuring a unique adaptive ON-time control Connect a supply to the VIN and GND terminals, architecture. The module incorporates a DC-to-DC paying careful attention to the polarity and the supply controller, power MOSFETs, bootstrap diode, bootstrap range (4.5V < VIN < 26V). Monitor IIN with a current capacitor, and an inductor in a single package simplifying meter and monitor input voltage at VIN and GND the design and layout process for the end user. 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 6A 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 MIC45205-1 uses Micrels HyperLight Load (HLL) is monitored at the VOUT terminal. MIC45205-2 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 MIC45205 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 6A the output of the MIC45205 evaluation board. 600kHz Switching Frequency 4. Turn Power 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 MIC45205-1 and MIC45205-2 evaluation board requires only a single power supply with at least 10A MIC45205-1YMP EV MIC45205-1 Evaluation Board current capability. No external linear regulator is required MIC45205-2YMP EV MIC45205-2 Evaluation Board to power the internal biasing of the IC because the MIC45205 has an internal PVDD LDO. In the applications with 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 MIC45205 evaluation board does not have reverse polarity protection. Applying a negative voltage to the VIN and GND terminals may damage the device. The maximum VIN of the board is rated at 26V. Exceeding 30V on the VIN could damage the device. Hyper LightLoad 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. MIC45205 Evaluation Board Features Feedback Resistors The output voltage on the MIC45205 evaluation board, where V = 0.8V, and R is one of R3 thru R9. REF BOTTOM which is preset to 5.0V, is determined by the feedback Leaving the R open by removing all jumpers on the BOTTOM divider, as illustrated in Equation 1: feedback headers gives a 0.8V output voltage. All other voltages not listed above can be set by modifying R BOTTOM value according to Equation 2: R14 V = V 1 + Eq. 1 OUT REF R BOTTOM R1 V REF R = Eq. 2 BOTTOM V V OUT REF Note that the output voltage should not be set to exceed 5V. Table 1. Typical Values of Some Components R14 R C14 V VIN C OUT 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 20.0k 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 1.91k 2.2nF 100F/6.3V February 9, 2015 2 Revision 2.0