CD40110BE | Texas Instruments

Counter, CD40110BE, Texas Instruments

The CD40110B is a dual-clocked up/down counter with a special preconditioning circuit that allows the counter to be clocked, via a positive-going input, up or down regardless of the state or timing (within 100 ns typ.) of the other clock line. The clock signal is fed into the control logic and Johnson counter after it is preconditioned. The output of the Johnson counter (which includes anti-lock gating to avoid being locked at an illegal state) is fed into a latch. This data can be fed directly to the decoder through the latch or can be strobed to hold a particular count while the Johnson counter continues to be clocked.

The decoder feeds a seven-segment bipolar output driver which can source up to 25 mA to drive an LED or other display such as a low-voltage fluorescent or incandescent lamp. A short-duration negative-going pulse appears on the BORROW output when the count changes from 0 to 9 or the CARRY output when the count changes from 9 to 0. At other times the BORROW and CARRY outputs are at logic 1.

Features

• Separate clock-up and clock-down lines
• Capable of driving common cathode LEDs and other displays directly
• Allows cascading without any external circuitry

Applications

• Rate comparators
• General counting applications where display is desired
• Up-down counting applications where input pulses are random in nature