HCF4538B DUAL MONOSTABLE MULTIVIBRATOR RETRIGGERABLE/RESETTABLE CAPABILITY TRIGGER AND RESET PROPAGATION DELAYS INDEPENDENT OF R , C X X TRIGGERING FROM LEADING OR TRAILING EDGE DIP SOP Q AND Q BUFFERED OUTPUT AVAILABLE SEPARATE RESETS WIDE RANGE OF OUTPUT PULSE WIDTHS QUIESCENT CURRENT SPECIFIED UP TO ORDER CODES 20V PACKAGE TUBE T & R 5V, 10V AND 15V PARAMETRIC RATINGS DIP HCF4538BEY SCHMITT TRIGGER INPUT ALLOWS SOP HCF4538BM1 HCF4538M013TR UNLIMITED RISE AND FALL TIMES ON +TR AND -TR INPUTS INPUT LEAKAGE CURRENT I = 100nA (MAX) AT V = 18V T = 25C timing application. An external resistor (R ) and I DD A X an external capacitor (C ) control the timing and 100% TESTED FOR QUIESCENT CURRENT X accuracy for the circuit. Adjustment of R and C MEETS ALL REQUIREMENTS OF JEDEC X X provides a wide range of output pulse widths from JESD13B STANDARD SPECIFICATIONS the Q and Q terminals. The time delay from trigger FOR DESCRIPTION OF B SERIES CMOS input to output transition (trigger propagation DEVICE delay) and the time delay from reset input to output transition (reset propagation delay) and the DESCRIPTION time delay from reset input to output transition The HCF4538B is a monolithic integrated circuit (reset propagation delay) are independent of R X fabricated in Metal Oxide Semiconductor and C . Precision control of output pulse width is X technology available in DIP and SOP packages. achieved through linear CMOS techniques. The HCF4538B dual precision monostable Leading edge triggering (+TR) and trailing edge multivibrator provides stable retriggerable/ triggering (-TR) inputs are provided for triggering resettable one-shot operation for any fixed voltage PIN CONNECTION September 2001 1/10HCF4538B from either edge of an input pulse. An unused +TR pulse one period) on the application of each new input should be tied to V . An unused -TR input trigger pulse. For operation in the non-retiggerable SS should be tied to V . A RESET (on low level) is mode, Q is connected to -TR when leading edge DD provided for immediate termination of the output triggering (+TR) is used or Q is connected to +TR pulse or to prevent output pulses when power is when trailing edge triggering (-TR) is used. The turned on. An unused RESET input should be tied time period (T) for this multivibrator can be to V . However, if an entire section of the calculated by : T = R C . The min. value of DD X X HCF4538B is not used, its inputs must be tied to external resistance, R , is 4K. The max. and X either V or V (see table 1). In normal min. values of external capacitance, C , are 100 DD SS X operation the circuit triggers (extends the output F and 5nF, respectively. IINPUT EQUIVALENT CIRCUIT PIN DESCRIPTION PIN No SYMBOL NAME AND FUNCTION Trigger Inputs (Low to 4, 12 +TR High, Edge-Triggered) Trigger Inputs (High to 5, 11 -TR Low, Edge-Triggered) Direct Reset Inputs 3, 13 RESET (Active Low) External Capacitor Con- C 1, C 2 1, 15 X X nections R C 1 X X External Resistor/Capaci- 2, 14 R C 2 tor Connections X X 6, 10 Q1, Q2 Pulse Outputs Complementary Pulse 7, 9 Q1, Q2 Outputs V 8 Negative Supply Voltage SS V 16 Positive Supply Voltage DD Terminals 1, 8, 15 are electrically connected internally FUNCTIONAL DIAGRAM 2/10