SN74LV221A-Q1

SN74LV221A-Q1 www.ti.com SCLS692A – OCTOBER 2005 – REVISED APRIL 2008 DUAL MONOSTABLE MULTIVIBRATOR WITH SCHMITT-TRIGGER INPUTS Check for Samples: SN74LV221A-Q1 FEATURES 1 Qualified for Automotive Applications 2-V to 5.5-V VCC Operation Supports Mixed-Mode Voltage Operation on All Ports Schmitt-Trigger Circuitry on A, B, and CLR Inputs for Slow Transition Rates Overriding Clear Terminates Output Pulse Glitch-Free Power-Up Reset on Outputs Ioff Supports Partial-Power-Down Mode Operation PW PACKAGE (TOP VIEW) 1A 1B 1CLR 1Q 2Q 2Cext 2Rext/Cext GND 1 2 3 4 5 6 7 8 16 VCC 15 1Rext/Cext 14 1Cext 13 1Q 12 2Q 11 2CLR 10 2B 9 2A DESCRIPTION/ORDERING INFORMATION The SN74LV221A is a dual multivibrator designed for 2-V to 5.5-V VCC operation. Each multivibrator has a negative-transition-triggered (A) input and a positive-transition-triggered (B) input, either of which can be used as an inhibit input. This edge-triggered multivibrator features output pulse-duration control by three methods. In the first method, the A input is low and the B input goes high. In the second method, the B input is high and the A input goes low. In the third method, the A input is low, the B input is high, and the clear (CLR) input goes high. The output pulse duration is programmable by selecting external resistance and capacitance values. The external timing capacitor must be connected between Cext and Rext/Cext(positive) and an external resistor connected between Rext/Cext and VCC. To ob...