USA - OnChip ( http://www.onchip.com ) introduced a family of electromagnetic interference (EMI) low-pass RC Pi filter arrays with on-board diodes for electrostatic discharge (ESD) protection. Offered in Flip Chip style Chip Scale Packages (CSP), these devices are specifically designed for high-speed data LCD and memory card interfaces in mobile phones, PDAs and MP3 players. They provide superior electrical performance across a wide frequency range as well as significant board space savings.
The OC1425 is a 4-channel EMI filter while the EMF4020 and the OC1442 are 8-channel EMI filter arrays. All three devices are designed to reject rerouted and retransmitted radiation frequencies on the lines between the graphics controller and the LCD.
Designed with line capacitances that support up to 30MHz frequencies and minimize impact on the rise and fall times of video signals, these devices are capable of attenuating unwanted signals over the RF band between 800MHz and 3GHz. Additionally, they have built-in Zener diodes that protect the LCD controller and the I/O ports against damage from ESD of up to 15kV rated to meet IEC61000-4-2 standard level 4 ESD requirements.
These filters are offered in a flip-chip package, reducing board space and also minimizing the package parasitics thereby delivering excellent S21 characteristics with extremely low parasitic inductance (10 pH). They have a very low profile of 0.65 mm or less than 0.03 inches.
OnChip has also introduced EMF1402 for SIM (Subscriber Identity Module) Card I/O port and EMF1423 for Secure Digital (SD) Card I/O port EMI Filtering and ESD protection used in moblie devices. These devices are also offered in the same low-profile CSP format.