MIC4478/79/80 Evaluation Board 32V Low-Side Dual MOSFET Drivers General Description Requirements The MIC4478, MIC4479, and MIC4480 are low-side dual The evaluation board requires: MOSFET drivers. They are designed to switch N-channel A V power supply with an output between 4.5V enhancement type MOSFETs from TTL-compatible control DD and 32V to power the driver. While the driver can signals for low-side switching applications. The MIC4478 is operate up to 32V, do not exceed 18V when using dual non-inverting, the MIC4479 is dual inverting, and the the MOSFETs that come with this evaluation MIC4480 has complimentary non-inverting and inverting board. drivers. Short propagation delays and high peak currents produce precise edges and rapid rise and fall times. The An external V supply voltage for powering the IN MIC4478/4479/4480 are powered from a +4.5V to +32V MOSFET drains. Do not exceed the 100V V DS supply voltage. The on-state gate drive output voltage is rating of the MOSFETs. approximately equal to the supply voltage (no internal regulators or clamps). In a low-side configuration, the Precautions drivers can control a MOSFET that switches any voltage Ensure the V supply does not exceed the DD up to the rating of the MOSFET. The MIC4478/4479/4480 maximum V of the MOSFETs being used. GS are available in an 8-lead SOIC (ePAD and non-ePAD) V for the MOSFETs that come with the GS(ABS MAX) package and rated for 40C to +125C ambient evaluation board is 20V. 18V maximum is temperature range. recommended. Data sheets and support documentation are available on The evaluation board does not have reverse Micrels web site at: www.micrel.com. polarity protection. Applying a negative voltage to V or V may damage the device. Do not exceed DD IN Evaluation Board Description 32V on the input, nor exceed the MOSFETs Control IC ............................... MIC4478/MIC4479/MIC4480 V to prevent damage to the driver and GS(MAX) Topology ......... Dual Low-Side MOSFET Driver with Enable MOSFETs. Do not exceed 100V on either of the (1) V Supply Voltage Range ............................. 4.5V to 32V two DRAIN A or DRAIN B terminals. DD Maximum Input Pin Voltage ........................................... V DD Ordering Information Maximum Enable Pin Voltage ........................................ V DD Maximum External FET Supply Voltage (V ) .............. 100V IN Part Number Description Note: MIC4478YML EV MIC4478YML Evaluation Board 1. V must be less than 18V so as not to exceed the maximum FET DD V rating. GS MIC4479YML EV MIC4479YML Evaluation Board MIC4480YML EV MIC4480YML Evaluation Board Features External MOSFETs on the board to simplify testing. Resistor and capacitor component locations on the driver outputs for ease of testing. Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC4478/79/80 Evaluation Board Getting Started External MOSFETs 1. Connect the V and GND terminals to an external A pair of 100V MOSFETs are included with the board to DD supply voltage. The input voltage range is from 4.5V to facilitate testing of the driver. Terminals are provided for an 18V. The 18V maximum is limited by the V of the external supply. A 1k resistor is connected in series GS MOSFETs. between each of the supply inputs and MOSFET drains. This limits the current flowing through the MOSFETs and 2. Apply a square wave or pulse to the INA and/or INB allows the switching waveform to be observed. These terminals. The logic 0 level is less than 0.8V and the resistors may be changed or removed, depending on the logic 1 level is greater than 2.4V. Do not exceed V DD application. A 4.7F capacitor, from the supply terminal to on the inputs. Headers TP1 and TP4 may be used to ground, is provided for decoupling the high frequency apply or monitor the input signal. switching currents. The capacitors and MOSFETs are 3. The output signal can be monitored with a scope rated to 100V. probe at the OUT A and OUT-B pins. Headers TP3 and TP6 may also be used to monitor the output signals. ENA and ENB Inputs The ENA and ENB inputs are each accessible through a 3- pin header. The EN pins are internally pulled up and do not need a jumper or external signal for the outputs to be enabled. The outputs can be individually disabled with a low signal or a shorting jumper connected from EN to ground. Headers JP2 and JP3 can be used to apply or monitor the enable signals. INA and INB Inputs The output drivers are controlled by the INA and INB signal. Table 1 to shows the output state based on the input for each of the three drivers. Do not leave the inputs floating when V is applied. DD Table 1. Input Configuration INA INB OUTA OUTB Device (Pin 2) (Pin 4) (Pin 7) (Pin 5) MIC4478 L/H L/H L/H L/H MIC4479 L/H L/H H/L H/L MIC4480 L/H L/H H/L L/H OUTA and OUTB Outputs The evaluation board allows the option of driving a MOSFET or capacitance. The board is populated with a 100V N-channel MOSFET to show real world operation. The MOSFET may be removed and a capacitor used if standardized testing is needed. Capacitor locations C3 (OUT A) and C6 (OUT B) may be used for capacitive testing. Resistor locations R4 and R9 allow a resistor to be placed in series with the driver output. The board comes with the resistor pads shorted with etch. The etch between the pads of the resistor must be cut before a resistor is added. 2 Revision 1.0 September 9, 2015