InterChip USB (IC-USB) is an addendum to the USB Forum's USB 2.0 specification. IC-USB is intended as a low power variant of the standard physical USB interface, and is made possible by intending its use for direct chip to chip communications and by restricting the length of the IC-USB bus to no more than 10 cm in length. This results in a lower inductance and capacitance, and therefore lower power requirements.
IC-USB is being used primarily in embedded systems and standards. One of the most relevant areas of application is in mobile phones, where for instance ETSI, in specification TS 102 600 has standardized on IC-USB as the official high speed interface for connections between the phone's main chipset and the SIM, or UICC, card.
The USB Forum's Inter-Chip USB Supplement was released in March 2006. ETSI TS 102 600, which is ETSI's USB implementation requirements specification, was first released in December 2007. IC-USB is sometimes also referred to as USB-IC or Inter-chip USB.