器件名称: NE555PWRE4
功能描述: PRECISION TIMERS
文件大小: 559.59KB 共27页
简 介:NA555, NE555, SA555, SE555 PRECISION TIMERS
www.ti.com
SLFS022F – SEPTEMBER 1973 – REVISED JUNE 2006
FEATURES
Timing From Microseconds to Hours Astable or Monostable Operation Adjustable Duty Cycle TTL-Compatible Output Can Sink or Source up to 200 mA
DESCRIPTION/ORDERING INFORMATION
These devices are precision timing circuits 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 200 mA. Operation is specified for supplies of 5 V to 15 V. With a 5……
