UG169: Si8285/86-EVB User s Guide This document describes the operation of the Si8285 86-EVB. KEY POINTS The Si8285 86 Evaluation Kit contains the following items: Discusses hardware overview and setup, Si8285 86-EVB including: Si8285CD-IS and Si8286CD-IS installed on the evaluation board. Si8285/86 low voltage side connections. Si8285/86 isolated gate drive connections. Offers alternative configurations. Demonstrates driver functionality. Shows Si8285/86-EVB schematics and silkscreen/copper layout. Includes a bill of materials and ordering guide. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 Rev. 0.1 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice December 20, 2021 1UG169: Si8285/86-EVB User s Guide Overview and Setup 1. Overview and Setup 1.1 Hardware Si8285/86-EVB can be used to demonstrate the isolated gate drive capabilities of the installed Si8285CD-IS and Si8286CD-IS, as well as their features specific to driving MOSFETs and IGBTs. The EVB is split into two halves that operate independentlyone for Si8285 and the other for Si8286. Si8285 Low Voltage Side Connections Supply power to the input side of Si8285 by applying 3 to 5.5 V to VDDA at terminal block J1. LED D1 above terminal block J1 DC illuminates to show power applied. J7J11 single pin headers provide access to the IN+, IN, RSTb inputs, and FLTb and RDY outputs of the Si8285. These signals can be brought out to an external microcontroller using a ribbon cable (not supplied). FLTb output signal has a pull-up resistor to VDDA and is open drain output. This allows multiple gate drivers FLTb outputs to share the same microcontroller input. Driver functionality can be exercised without a microcontroller by applying a GNDA referenced PWM signal from a function generator to the IN+ and IN inputs. Maximum input voltage is VDDA. Si8285 Isolated Gate Drive Connections Supply power to the output side of the Si8285 by applying VDDB, VMID, and VSSB at terminal block J3. In typical MOSFET driver applications, VMID = VSSB. When driving IGBTs, typical values for VDDB and VSSB IGBTs are +15 V and 9 V, with respect to VMID. LED D2 above terminal block J3 illuminates to show power applied. There are four different load options for the Si8285 gate driver: 1. Through holes for a MOSFET or an IGBT in a TO-247 package (not supplied) at Q1. 2. Through holes for a MOSFET or an IGBT in a TO-220 package (not supplied) at Q2. 3. Through holes for a capacitor (not supplied) at C8. 4. Pads for a 1206-size surface mount capacitor (not supplied) at C9. From top to bottom, the through holes for the transistor leads are Source, Drain, and Gate. Load transistors are biased by applying voltage across VPWR and VMID terminals of J2. This voltage should not exceed the rated VDS of the transistor or the 300 V blocking voltage rating of installed D3. Supply voltage constraints are summarized in Table 1.1 Supply Voltage Constraints on page 3. Note: Si8285 can drive the gate of either high-side or low-side MOSFET or IGBT in a bridge configuration. When used as a high-side gate driver, VMID is connected to the load. When used as a low-side gate driver, VMID is the return for the load. For capacitive loads, capacitor value should be chosen to match the gate capacitance of the desired transistor. Si8286 Low Voltage Side Connections Supply power to the input side of Si8286 by applying 3 to 5.5 V to VDDA at terminal block J4. LED D4 above terminal block J4 DC illuminates to show power applied. J14-J17 single pin headers provide access to the IN+, IN, RSTb input, and the FLTb output of the Si8286. These signals can be brought out to an external microcontroller using a ribbon cable (not supplied). FLTb output signal has a pull-up resistor to VDDA and is an open drain output. This allows multiple gate drivers FLTb outputs to share the same microcontroller input. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 Rev. 0.1 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice December 20, 2021 2