MC14557B

2. Maximum Ratings are those values beyond which damage to the device may occur.
3. Temperature Derating: Plastic "P and D/DW" Packages: 7.0 mW/°C From 65°C To 125°C

This device contains protection circuitry to guard against damage due to high static voltages or electric fields. However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltages to this highimpedance circuit. For proper operation, V_in and V_out should be constrained to the range V_SS (V_in or Vout) V_DD.  Unused inputs must always be tied to an appropriate logic voltage level (e.g., either V_SS or V_DD). Unused outputs must be left open.

The MC14557B is a static clocked serial shift register whose length may be programmed to be any number of bits between 1 and 64. The number of bits selected is equal to the sum of the subscripts of the enabled Length Control inputs (L1, L2, L4, L8, L16, and L32) plus one. Serial data may be selected from the A or B data inputs with the A/B select input. MC14557B feature is useful for recirculation purposes. A Clock Enable (CE) input is provided to allow gating of the clock or negative edge clocking capability.

The MC14557B can be effectively used for variable digital delay lines or simply to implement odd length shift registers.
• 164 Bit Programmable Length
• Q and Q Serial Buffered Outputs
• Asynchronous Master Reset
• All Inputs Buffered
• No Limit On Clock Rise and Fall Times
• Supply Voltage Range = 3.0 V_dc to 18 V_dc
• Capable of Driving Two Lowpower TTL Loads or one Lowpower Schottky TTL Load Over the Rated Temperature Range