The LD33290 (analog MC33290) is a serial link bus interface device designed to provide bidirectional half-duplex communication interfacing in automotive diagnostic applications. It is designed to interface between the vehicles on-board micro controller and systems off-board the vehicle via the special ISO K line. The LD33290 is designed to meet the Diagnostic Systems ISO9141 specification. The devices K line bus drivers output is fully protected against bus shorts and over temperature conditions.The LD33290 derives its robustness to temperature and voltage extremes by being built on a SMARTMOS process, incorporating CMOS logic, bipolar/MOS analog circuitry, and DMOS power FETs. Although the LD33290 was principally designed for automotive applications, it is suited for other serial communication applications. It is parametrically specified over an ambient temperature range of -40 TA 125 and 8.0V VBB18V supply. The economical SOP8 surface-mount plastic package makes the LD33290 very cost.