PDP11 PeripheralsHbk 1972 - Trailing-Edge

Table 2-1 Unibus Receiver and Transmitter Characteristics
Characteristics Specifications
Notes
Receiver (DEC 380A) Input high threshold VIH 2.5V min. 1
Input low threshold VIL 1.4V max. 1
Input current @ 2.5V IIH 160 uA max. 1,3
Input current @ OV IlL ±25 pA max. 1,3
Output high voltage VOH 3.5V min. 2
Output high current IOH ·2mA 2,3
Output low voltage VOL 0.6V max. 2
Output low current 10L Jl -12.5 MA 2,3
Propagation delay to TPDH 10 ns min. 4, 5
high state 45 ns max.
Propagation delay to TpDL 10 ns min. 4,5
low state 35 ns max.
Transmitter (DEC 8881) Input high voltage VIH 2.0V min. 6
Input low voltage V,L 0.8V max. 6
Input high current IIH 60JlA max. 6
Input low current IlL ·2.0 mA max. 6
Output low voltage VOL 0.8V max. 1
@ 50 mA sink
Output high leakage IOH 25 pA max. 1,3
current @ 3.SV
Propagation delay to TPDL 25 ns max. 5, 7
low state
Propagation delay to TPDH 35 ns max. 5, 8
high state
NOTES:
1. This is a critical parameter for use on the Unibus. All other parameters
are shown for reference oniy.
2. This is equivalent to being capable of driving seven unit loads of stan·
dard 7400 series TTL integrated circuits.
3. Current flow is defined as positive if into the terminal.
4. Conditions of load are 375Q to + 5V and 1.6KQ in parallel with 15 pf
to ground.
5. Times are measured from 1.5V level on input to 1.5V level on output.
6. This is equivalent to 1.25' standard TTL unit loading of input.
7. Conditions of 100S] to + 5V, 15 pf to ground on ouput.
8. Conditions of lKQ to ground on output. .
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