CD74HC93

Features:

• Can Be Configured to Divide By 2, 8, and 16
• Asynchronous Master Reset
• Fanout (Over Temperature Range)
- Standard Outputs . . . . . . . . . . . . . . . 10 LSTTL Loads
- Bus Driver Outputs . . . . . . . . . . . . . 15 LSTTL Loads
• Wide Operating Temperature Range . . . -55oC to 125oC
• Balanced Propagation Delay and Transition Times
• Significant Power Reduction Compared to LSTTL Logic ICs
• HC Types
- 2V to 6V Operation
- High Noise Immunity: NIL = 30%, NIH = 30% of VCC at VCC = 5V
• HCT Types
- 4.5V to 5.5V Operation
- Direct LSTTL Input Logic Compatibility, VIL= 0.8V (Max), VIH = 2V (Min)
- CMOS Input Compatibility, Il £ 1mA at VOL, VOH


Pinout




Specifications

DC Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . .  -0.5V to 7V
DC Input Diode Current, IIK
For VI < -0.5V or VI > VCC + 0.5V . . . . . . . . . . . . . . . . . . . . . . ±20mA
DC Output Diode Current, IOK
For VO < -0.5V or VO > VCC + 0.5V . . . . . . . . . . . . . . . . . . . .  ±20mA
DC Output Source or Sink Current per Output Pin, IO
For VO > -0.5V or VO < VCC + 0.5V . . . . . . . . . . . . . . . . . . . .  ±25mA
DC VCC or Ground Current, ICC or IGND . . . . . . . . . . . . . . . . . . ±50mA


Description

The Harris CD74HC93 and CD74HCT93 are high speed silicon-gate CMOS devices and are pin-compatible with low power Schottky TTL (LSTTL). These 4-bit binary ripple counters consist of four master-slave flip-flops internally connected to provide a divide-by-two-section and a divid- byeight- section. Each section has a separate clock input (CP0 and CP1) to innate state changes of the counter on the HIGH to LOW clock transition. Sate changes of the Qn outputs do not occur simultaneously because of internal ripple delays. Therefore, decoded output signals are subject to decoding spikes and should not be used for clocks or strobes.

A gated AND asynchronous master reset (MR1 and MR2 is provided. CD74HC93 overrides both clocks and resets (clears) all flip-flops.

Because CD74HC93 output from the divide by two section is not internally connected to the succeeding stages, the device may be operated in various counting modes.

In a 4-bit ripple counter the output Q0 must be connected externally to input CP1. The CD74HC93 input count pulses are applied to clock input CP0. Simultaneous frequency divisions of 2, 4, 8, and 16 are performed at the Q0, Q1, Q2, and Q3 outputs as shown in the function table. As a 3-bit ripple counter the input count pulses are applied to input CP1.

CD74HC93 Simultaneous frequency divisions of 2, 4, and 8 are available at the Q1, Q2, Q3 outputs. Independent use of the first flipflop is available if the reset function coincides with the reset of the 3-bit ripple-through counter.