SL74LS164 8-Bit Serial-Input/Parallel-Output Shift Register This 8-bit shift register features gated serial inputs and an asynchronous reset. The gated serial inputs (A and B) permit complete control over incoming data as a low at either (or both) input(s) inhibits entry of the new data and resets the first flip flop to the low level at the next clock pulse. A high level input enables the other input which will then determine the state of the first flip-flop. Data at the serial inputs may be changed while the clock is high or low, but only information meeting the setup requirements will be entered clocking occurs or the low-to-high level transition of the clock input. All inputs are diodeclamped to minimize transmission-line effects. • Gated (Enable/Disable) Serial Inputs • Fully Buffered Clock and Serial Inputs • Asynchronous Clear ORDERING INFORMATION SL74LS164N Plastic SL74LS164D SOIC TA =0° to 70°C for all packages PIN ASSIGNMENT LOGIC DIAGRAM FUNCTION TABLE Inputs PIN 14 =VCC PIN 7 = GND Outputs Reset Clock A1 A2 L X X X QA QB ... QH L L ... L H X X no change H H D D QAn ... QGn H D H D QAn ... QGn H L L L QAn ... QGn D = data input X = don’t care QAn - QGn = data shifted from the previous stage on a rising edge at the clock input. SLS System Logic Semiconductor SL74LS164 MAXIMUM RATINGS * Symbol Parameter Value Unit VCC Supply Voltage 7.0 V VIN Input Voltage 7.0 V VOUT Output Voltage 5.5 V Tstg Storage Temperature Range -65 to +150 °C * Maximum Ratings are those values beyond which damage to the device may occur. Functional operation should be restricted to the Recommended Operating Conditions. RECOMMENDED OPERATING CONDITIONS Symbol Parameter Min Max Unit 5.25 V VCC Supply Voltage 4.75 VIH High Level Input Voltage 2.0 VIL Low Level Input Voltage 0.8 V IOH High Level Output Current -0.4 mA IOL Low Level Output Current 8.0 mA TA Ambient Temperature Range 0 +70 °C Clock Frequency 0 25 MHz tsu Setup Time, A1 or A2 to Clock 15 ns th Hold Time, Clock to A1 or A2 5 ns tw Pulse Width, Clock 20 ns tw Pulse Width, Reset 20 ns trec Recovery Time 5 ns fclock V DC ELECTRICAL CHARACTERISTICS over full operating conditions Guaranteed Limit Symbol Parameter Test Conditions Min Max Unit -1.5 V VIK Input Clamp Voltage VCC = min, IIN = -18 mA VOH High Level Output Voltage VCC = min, IOH = -0.4 mA VOL Low Level Output Voltage VCC = min, IOL = 4 mA 0.4 VCC = min, IOL = 8 mA 0.5 VCC = max, VIN = 2.7 V 20 mA VCC = max, VIN = 7.0 V 0.1 mA -0.4 mA -100 mA 27 mA IIH High Level Input Current IIL Low Level Input Current VCC = max, VIN = 0.4 V IO Output Short Circuit Current VCC = max, VO = 0 V (Noote 1) ICC Supply Current VCC = max (Note 2) 2.7 -20 V V Note 1: Not more than one output should be shorted at a time, and duration should not exceed one second. SLS System Logic Semiconductor SL74LS164 Note 2: ICC is measured with outputs open, serial inputs grouned, the clock input at 2.4 V, and a momentary ground, then 4.5 V applied. AC ELECTRICAL CHARACTERISTICS (TA=25°C, VCC = 5.0 V, CL = 15 pF, RL = 2 kΩ, t r =15 ns, tf = 6.0 ns) Symbol Parameter Min Max Unit tPLH Propagation Delay Time, Clock to Q 27 ns tPHL Propagation Delay Time, Clock to Q 32 ns tPHL Propagation Delay Time, Reset to Q 36 ns tsu Setup Time, A1 or A2 to Clock 15 ns th Hold Time, Clock to A1 or A2 5 ns tw Pulse Width, Clock 20 ns tw Pulse Width, Reset 20 ns Figure 1. Switching Waveforms Figure 2. Switching Waveforms NOTES A. CL includes probe and jig capacitance. B. All diodes are 1N916 or 1N3064. Figure 3. Switching Waveform SLS System Logic Semiconductor Figure 4. Test Circuit SL74LS164 TIMING DIAGRAM SLS System Logic Semiconductor