Service manual

EPSON Stylus PHOTO 870/1270 Revision B
PRODUCT DESCRIPTIONS Interface 22
* A low logic level on the Logic H signal is 2.0V or less when the printer
is powered off, and this signal is equal to or exceeding 3.0V when the
printer is powered on. The receiver shall provide an impedance
equivalent to 7.5K ohm to ground.
Table 1-12.
Signal Level: TTL Compatible (IEEE-1284 level 1 device)
Parameter Minimum Maximum Condition
VOH* - 5.5V
VOL* -0.5V -
IOH* - 0.32mA VOH = 2.4V
IOL* - 12mA VOL = 0.4V
CO - 50pF
VIH - 2.0V
VIL 0.8V -
IIH - 0.32mA VIH = 2.0V
IIL - 12mA VIL = 0.8V
CI - 50pF