74F8961

Features:

• Octal latched transceiver
• Drives heavily loaded backplanes with equivalent load impedances down to 10W
• High drive (100mA) open collector drivers on B port
• Reduced voltage swing (1 volt) produces less noise and reduces power consumption
• High speed operation enhances performance of backplane buses and facilitates incident wave switching
• Compatible with IEEE futurebus standards
• Built-in precision band-gap reference provides accurate receiver thresholds and improved noise immunity
• Controlled output ramp and multiple GND pins minimize ground bounce
• Glitch-free power up/down operation


Pinout

Specifications

SYMBOL	PARAMETER		RATING	UNIT
VCC	Supply voltage		0.5 to +7.0	V
VX	Threshold control		0.5 to +7.0	V
VIN	Input voltage	OEB, OEA, LE	0.5 to +7.0	V
		A0 A7, B0 B7	0.5 to +5.5	V
IIN	Input current		40 to +5	mA
VOUT	Voltage applied to output in high output state		0.5 to VCC	V
IOUT	Current applied to output in low output state	A0 A7	48	mA
		B0 B7	200	mA
Tamb	Operating free air temperature range		0 to +70
Tstg	Storage temperature range		65 to +150

Description

The 74F8960 and 74F8961 are octal bidirectional latched transceivers and are intended to provide the electrical interface to a high performance wiredOR bus. The B port inverting drivers are lowcapacitance open collector with controlled ramp and are designed to sink 100mA from 2 volts. The B port inverting receivers have a 100 mV threshold region and a 4ns glitch filter.

The B port interfaces to 'Backplane Transceiver Logic' (BTL). BTL features a reduced (1V to 2V) voltage swing for lower power consumption and a series diode on  the drivers to reduce capacitive loading.

Incident switching of the 74F8961 is employed, therefore BTL propagation delays are short. Although the voltage swing is much less for BTL, so is its receiver threshold region, therefore noise margins are excellent.

BTL offers low power consumption, low ground bounce, EMI and crosstalk, low capacitive loading, superior noise margin and low propagation delays. This results in a high bandwidth, reliable backplane.

The 74F8961 ports have TTL 3state drivers and TTL receivers with a latch function. A separate Highlevel control input (VX) is provided to limit the A side output level to a given voltage level (such as 3.3V). For 5.0V systems, VX is simply tied to VCC.

The 74F8961 is the noninverting version of 74F8960.