SLLSFN5A June 2023 – February 2024 ISO1228
PRODUCTION DATA
The board layout for ISO1228 can be completed in two layers. On the field side, place RTHR, CIN, RPAR, RILIM, CFIL, RSURGE, and CSURGE on the top layer. Use the bottom layer as the field ground (FGND) plane. TI recommends using RPAR and CIN in 0603 footprints for a compact layout, although larger sizes (0805) can also be used. The CIN capacitor is a 50V capacitor and is available in the 0603 footprint. Keep CIN as close to the ISO1228 device as possible. TI recommends using RTHR, RSURGE, RILIM in MELF 0204 footprint surge-proof resistors and 0805 footprint 50V capacitors for CSURGE and CFIL. The placement of the RTHR resistor is flexible, although the resistor pin connected to external high voltage should not be placed within 4mm of the ISO1228 device pins or the CIN and RPAR pins to avoid flashover during EMC tests. The placement of LEDs is flexible to display the channel status on the field side.
Only a decoupling capacitor is required on side 1. Place this capacitor on the top-layer, with the bottom layer for GND1.
Layout Example shows the example layout.