1FEATURES

• Timing From Microseconds to Hours

• Astable or Monostable Operation

• Adjustable Duty Cycle

• TTL-Compatible Output Can Sink or Source up

to 100 mA

• QML-V Qualified, SMD 5962-98555

• Military Temperature Range (-55°C to 125°C)

• Rad-Tolerant: 25 kRad (Si) TID (1)

(1) Radiation tolerance is a typical value based upon initial device

qualification with dose rate = 10 mrad/sec. Radiation Lot

Acceptance Testing is available - contact factory for details.

DESCRIPTION/ORDERING INFORMATION

The SE555 is a precision timing circuit capable of producing accurate time delays or oscillation. In the time-delay

or monostable mode of operation, the timed interval is controlled by a single external resistor and capacitor

network. In the astable mode of operation, the frequency and duty cycle can be controlled independently with two

external resistors and a single external capacitor.

The threshold and trigger levels normally are two-thirds and one-third, respectively, of VCC. These levels can be

altered by use of the control-voltage terminal. When the trigger input falls below the trigger level, the flip-flop is

set, and the output goes high. If the trigger input is above the trigger level and the threshold input is above the

threshold level, the flip-flop is reset and the output is low. The reset (RESET) input can override all other inputs

and can be used to initiate a new timing cycle. When RESET goes low, the flip-flop is reset, and the output goes

low. When the output is low, a low-impedance path is provided between discharge (DISCH) and ground.

The output circuit is capable of sinking or sourcing current up to 100 mA. Operation is specified for supplies of

4.5 V to 16.5 V. With a 5-V supply, output levels are compatible with TTL inputs.