The TLC555 is a monolithic timing circuit
fabricated using the TI LinCMOS™ technology. The timer is fully compatible
with CMOS, TTL, and MOS logic and operates at frequencies up to 2 MHz. Because of a
high input impedance, this device supports smaller timing capacitors than those
supported by the NE555 or LM555. As a result, more accurate time delays and
oscillations are possible. Power consumption is low across the full range of
power-supply voltage.Like the NE555, the
TLC555 has a trigger level equal to approximately one-third of the supply voltage
and a threshold level equal to approximately two-thirds of the supply voltage. These
levels can be altered by use of the control voltage terminal (CONT). When the
trigger input (TRIG) falls below the trigger level, the flip-flop is set and the
output goes high. If TRIG is above the trigger level and the threshold input (THRES)
is above the threshold level, the flip-flop is reset and the output is low. The
reset input (RESET) can override all other inputs and can be used to initiate a new
timing cycle. If RESET is low, the flip-flop is reset and the output is low.
Whenever the output is low, a low-impedance path is provided between the discharge
terminal (DISCH) and GND. All unused inputs must be tied to an appropriate logic
level to prevent false triggering.
