PRESETTABLE BCD/DECADE UP/DOWN COUNTERS
PRESETTABLE BCD/DECADE UP/DOWN COUNTERS
PRESETTABLE 4-BIT BINARY UP/DOWN COUNTERS
The SN54 / 74LS190 is a synchronous UP...
Description
PRESETTABLE BCD/DECADE UP/DOWN COUNTERS
PRESETTABLE 4-BIT BINARY UP/DOWN COUNTERS
The SN54 / 74LS190 is a synchronous UP/ DOWN BCD Decade (8421) Counter and the SN54/ 74LS191 is a synchronous UP / DOWN Modulo-16 Binary Counter. State changes of the counters are synchronous with the LOW-to-HIGH transition of the Clock Pulse input.
An asynchronous Parallel Load (PL) input overrides counting and loads the data present on the Pn inputs into the flip-flops, which makes it possible to use the circuits as programmable counters. A Count Enable (CE) input serves as the carry / borrow input in multi-stage counters. An Up / Down Count Control (U/D) input determines whether a circuit counts up or down. A Terminal Count (TC) output and a Ripple Clock (RC) output provide overflow/underflow indication and make possible a variety of methods for generating carry / borrow signals in multistage counter applications.
Low Power . . . 90 mW Typical Dissipation High Speed . . . 25 MHz Typical Count Frequency Synchronous Counting Asynchronous Parallel Load Individual Preset Inputs Count Enable and Up/ Down Control Inputs Cascadable Input Clamp Diodes Limit High Speed Termination Effects
CONNECTION DIAGRAM DIP (TOP VIEW)
VCC 16
P0 15
CP 14
RC 13
TC 12
PL 11
P2 10
P3 9
NOTE: The Flatpak version has the same pinouts (Connection Diagram) as the Dual In-Line Package.
1 P1
2 Q1
3 Q0
4 CE
5 U/D
6 Q2
7 Q3
8 GND
PIN NAMES
LOADING (Note a)
HIGH
LOW
CE Count Enable (Activ...
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