Exar is a global broadband communications IC manufacturer. It is specialized in providing high-performance analog and mixed signal IC products for the global communication market, as well as video and image IC products. Its main users include Alcatel, Cisco, HP, Lucent, Nokia and Tellabs. The company is headquartered in California, USA. The existing communication system is designed for the transmission of voice signals, which is not suitable for the simultaneous transmission of voice signals and data signals. In order to achieve the simultaneous transmission of voice signals and data signals, the existing system must be modified to increase the transmission bandwidth. For the T / E carrier transmission mode on copper wire, the transmission rate will transition from low-speed T1 / E1 (1.5mbps / 2.0mbps) to high-speed T3 / E3 (45mbps / 34mbps). For backbone optical fiber transmission network, SONET / SDH protocol will be upgraded from OC-3 (155mbps) and oc-12 (622Mbps) to OC-48 (2.5Gbps) and OC-192 (10Gbps). Because of its experience in high-speed analog and mixed signal fields and its understanding of the system, Exar can provide physical interface and access control scheme for high-speed broadband communication market. In addition, it also provides IC products for digital video image devices such as digital cameras that need high-speed and high-precision data acquisition operations. Exar's products are all produced by commissioned service providers. In terms of technology, it has a variety of processes such as bipolar, CMOS and BiCMOS, but the vast majority of products are produced by CMOS process.