ML6518 Datasheet | Micro Linear

DESCRIPTION The ML6518 Bi CMOS 18 line SCSI terminator provides active termination in SCSI systems using single-ended drivers and receivers. Active SCSI termination helps to effectively control analog transmission line effects such as ringing, noise, crosstalk, and ground bounce. In addition, the ML6518 provides support for hot insertability on the SCSI bus. The ML6518 provides a V-I characteristic optimized to minimize transmission line effects during both signal negation and assertion using a MOSFET-based architecture. The desired V-I characteristic is achieved by trimming one resistor in the control block. Internal clamping controls signal assertion transients and provides current sink capability to handle active negation driver overshoots above 2.85V. It provides a 2.85V reference through an internal low dropout (1V) linear regulator. The ML6518 also provides a disconnect function which effectively removes the terminator from the SCSI bus. The disconnect mode capacitance is typically less than 5p F per line. Current limiting and thermal shutdown protection are also included. FEATURES s s s s s s s s s Fully monolithic IC solution providing active termination for 18 lines of the SCSI bus Provides onboard support for hot-insertability on the SCSI bus Low dropout voltage (1V) linear regulator, trimmed for accurate termination current Low disconnect capacitance (typically < 5p F) Logic pin with active pull-up to disconnect terminator from the SCSI bus Current sinking capability in excess of 8.3m A per line to handle active negation driver overshoots above 2.85V Negative clamping on all lines to handle signal assertion transients Regulator can source 400m A and sink 150m A while maintaining regulation Current limit and thermal shutdown protection - This Part Is End Of Life As Of August 1, 2000 BLOCK DIAGRAM TERMPWR VREF DISCNKT 2.85V LINEAR REGULATOR 1V DROPOUT 2.85V RTRIM VREF CONTROL BLOCK MOSFETs WITH IMAX = 24m A ... NCLAMP ... ... ... NCLAMP NCLAMP L1...