ML6509 Datasheet | Micro Linear

DESCRIPTION The ML6509 Bi CMOS SCSI terminator provides active termination in a SCSI system with single ended drivers and receivers, in full pliance with the SCSI-1, SCSI-2 and SCSI-3 remendations. It provides a 2.85V reference through an internal 1V dropout linear regulator. Active SCSI termination helps the system designer to effectively control analog transmission line effects like ringing, noise, crosstalk, ground bounce, etc. In addition it provides greater immunity to voltage drops on the TERMPWR line of the SCSI bus. The desired V-I characteristics for signal negation requires that the terminator source 0- 24m A while maintaining 2.85V and for signal assertion preferably follow a linear slope of 110W . The ML6509 attempts to provide a V-I characteristic optimized to minimize the transmission line effects during both signal assertion and negation, using a MOSFET based architecture. The desired V-I characteristic is achieved by trimming one resistor in the control block. It provides negative clamping for signal assertion transients and current sink capability, to handle active negation driver overshoots above 2.85V, which is currently acplished with external ponents in SCSI subsystems today. It provides a disconnect mode, where the terminator is pletely disconnected from the SCSI bus and the output capacitance is < 5p F, typically. FEATURES s s Fully monolithic IC solution providing active termination for 9 lines of the SCSI bus Low dropout voltage (1V) linear regulator, trimmed for accurate termination current, with 300m A current source capability Output capacitance typically <5p F Disconnect mode - logic pin to disconnect terminator from the SCSI bus, <100µA Lowpower mode - for power conscious, portable system & peripheral applications, using less than 6" cables. (Equivalent to a 1m A current drive with a 2.5k W termination) Current sinking - can sink current >10m A per line to handle active negation driver overshoots above 2.85V Negative clamping on all lines to...