1. General description
The 74HC193-Q100; 74HCT193-Q100 is a 4-bit synchronous binary up/down counter. Separate
up/down clocks, CPU and CPD respectively, simplify operation. The outputs change state
synchronously with the LOW-to-HIGH transition of either clock input. If the CPU clock is pulsed
while CPD is held HIGH, the device counts up. If the CPD clock is pulsed while CPU is held
HIGH, the device counts down. Only one clock input can be held HIGH at any time to guarantee
predictable behavior. The device can be cleared at any time by the asynchronous master reset
input (MR). It may also be loaded in parallel by activating the asynchronous parallel load input (PL).
The terminal count up (TCU) and terminal count down (TCD) outputs are normally HIGH. When
the circuit has reached the maximum count state of 15, the next HIGH-to-LOW transition of CPU
causes TCU to go LOW. TCU remains LOW until CPU goes HIGH again, duplicating the count up
clock. Likewise, the TCD output goes LOW when the circuit is in the zero state and the CPD goes
LOW. The terminal count outputs duplicate the clock waveforms and can be used as the clock input
signals to the next higher-order circuit in a multistage counter. Multistage counters are not fully
synchronous, since there is a slight delay time difference added for each stage that is added. The
counter may be preset by the asynchronous parallel load capability of the circuit. Information on the
parallel data inputs (D0 to D3), is loaded into the counter. This information appears on the outputs
(Q0 to Q3) regardless of the conditions of the clock inputs when the parallel load (PL) input is LOW.
A HIGH level on the master reset (MR) input disables the parallel load gates. It overrides both clock
inputs and sets all outputs (Q0 to Q3) LOW. If one of the clock inputs is LOW during and after a
reset or load operation, the next LOW-to-HIGH transition of that clock is interpreted as a legitimate
signal and it is counted. Inputs include clamp diodes that enable the use of current limiting resistors
to interface inputs to voltages in excess of VCC.
This product has been qualified to the Automotive Electronics Council (AEC) standard Q100
(Grade 1) and is suitable for use in automotive applications.
2. Features and benefits
• Automotive product qualification in accordance with AEC-Q100 (Grade 1)
• Specified from -40 °C to +85 °C and from -40 °C to +125 °C
• Wide supply voltage range from 2.0 to 6.0 V
• CMOS low power dissipation
• High noise immunity
• Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
• Input levels:
• For 74HC193-Q100: CMOS level
• For 74HCT193-Q100: TTL level
• Synchronous reversible 4-bit binary counting
• Asynchronous parallel load
• Asynchronous reset
• Expandable without external logic
• Complies with JEDEC standards:
• JESD8C (2.7 V to 3.6 V)
• JESD7A (2.0 V to 6.0 V)