Data sheet acquired from Harris Semiconductor SCHS185A
High Speed CMOS Logic Dual Decade Ripple Counter
Description
The CD74HC390 and 'HCT390 dual 4-bit decade ripple counters are high-speed silicon-gate CMOS devices and are pin compatible with low-power Schottky TTL (LSTTL). These devices are divided into four separately clocked sections. The counters have two divide-by-2 sections and two divideby-5 sections. These sections are normally used in a BCD decade or bi-quinary configuration, since they share a common master reset (nMR). If the two master reset inputs (1MR and 2MR) are used to simultaneously clear all 8 bits of the counter, a number of counting configurations are possible within one package. The separate clock inputs (nCP0 and nCP1) of each section allow ripple counter or frequency division applications or 100. Each section is triggered by the High-to-Low transition of the input pulses (nCP0 and nCP1). For BCD decade operation, the nQ0 output is connected to the nCP1 input of the divide-by-5 section. For bi-quinary decade operation, the nO3 output is connected to the nCP0 input and nQ0 becomes the decade output. The master reset inputs (1MR and 2MR) are active-High asynchronous inputs to each decade counter which operates on the portion of the counter identified by the "1" and "2" prefixes in the pin configuration. A High level on the nMR input overrides the clock and sets the four outputs Low.
Features
· Two BCD Decade or Bi-Quinary Counters· One Package Can Be Configured or 100· Two Master Reset Inputs to Clear Each Decade Counter Individually· Fanout (Over Temperature Range) - Standard Outputs. 10 LSTTL Loads - Bus Driver Outputs. 15 LSTTL Loads· Wide Operating Temperature Range. to 125oC· Balanced Propagation Delay and Transition Times· Significant Power Reduction Compared to LSTTL Logic ICs· HC Types to 6V Operation - High Noise Immunity: NIL = 30%, NIH 30% of VCC at VCC = 5V· HCT Types to 5.5V Operation - Direct LSTTL Input Logic Compatibility, VIL= 0.8V (Max), VIH = 2V (Min) - CMOS Input Compatibility, 1µA at VOL, VOH
PART NUMBER TEMP. RANGE (oC) to 125 PACKAGE 16 Ld PDIP 16 Ld SOIC 16 Ld CERDIP 16 Ld PDIP 16 Ld SOIC
1. When ordering, use the entire part number. Add the suffix 96 to obtain the variant in the tape and reel. 2. Wafer for this part number is available which meets all electrical specifications. Please contact your local TI sales office or customer service for ordering information.
CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright
TRUTH TABLE INPUTS L H ACTION No Change Count All Qs Low
NOTE: H = High Voltage Level, L = Low Voltage Level, X = Don't Care, = Transition from Low to High Level, = Transition from High to Low.
NOTE: Output nQ0 connected to nCP1 with counter input on nCP0.
NOTE: Output nQ3 connected to nCP0 with counter input on nCP1.
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