XL555

XL555 and XD555 are precision timing circuits capable of producing accurate time delays or oscillations. In the time delay or monostable operating mode, the timing interval is controlled by a single external resistor and capacitor network. In the astable operating mode, frequency and duty cycle can be independently controlled by two external resistors and one external capacitor. The threshold and trigger levels are normally two-thirds and one-third of Vcc, respectively. These levels can be altered by using 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 overrides 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. Compared to the conventional bipolar NE555, the XL555 and XD555 provide lower supply current spikes during output transitions, which allows the use of smaller decoupling capacitors.

Applications

• Monostable timing
• Astable oscillation

Key features

• Ultra-low power consumption: 120μA typical at VDD = 5V
• Low supply current reduces spikes during output transitions
• Maximum astable frequency up to 1.8 MHz
• 2V to 16V single-supply operation
• Rail-to-rail swing CMOS output
• High output current capability: sink current 100mA max, source current 10mA typical
• Pin and function compatible with bipolar NE555
• ESD exceeds 1500V per MIL-STD-883C Method 3015.2
• Two package options available: SOP8 (XL555) and DIP8 (XD555)