LS7212N

LSI/CSI LS7211N-7212N U® L LSI Computer Systems, Inc. 1235 Walt Whitman Road, Melville, NY 11747 (631) 271-0400 FAX (631) 271-0405 A3800 PROGRAMMABLE DIGITAL DELAY TIMER July 2009 FEATURES: 8-bit programmable delay from microseconds to days On chip oscillator (RC or Crystal) or external clock time base Selectable prescaler for real time delay generation based on 50Hz/60Hz time base or 32,768Hz watch crystal Four operating modes Reset input for delay abort Low quiescent and operating current Direct relay drive +3V to +18V operation (VDD - VSS) LS7211N, LS7212N (DIP); LS7211N-S, LS7212N-S (SOIC) - See Figure 1 DESCRIPTION: The LS7211N and LS7212N are CMOS integrated circuits for generating digitally programmable delays. The delay is controlled by 8 binary weighted inputs, WB0 - WB7, in conjunction with an applied clock or oscillator frequency. The programmed time delay manifests itself in the Delay Output (OUT) as a function of the Operating Mode selected by the Mode Select inputs A and B: One-Shot, Delayed Operate, Delayed Release or Dual Delay. The time delay is initiated by a transition of the Trigger Input (TRIG). PIN ASSIGNMENT - TOP VIEW A1 B V DD (+V) 2 3 RC/CLOCK 4 RCS/CLKS PSCLS 5 6 RESET 7 V SS (-V) OUT 8 9 LS7211N LSI 18 TRIG 17 WB0 16 WB1 15 WB2 14 WB3 13 WB4 12 WB5 11 WB6 10 WB7 A1 B2 18 TRIG 17 WB0 LS7212N LSI I/O DESCRIPTION: MODE SELECT Inputs A & B (Pins 1 & 2) The 4 operating modes are selected by Inputs A and B accordin...