Product details

Configuration Parallel-in, Serial-out Bits (#) 8 Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Input type Bipolar Output type Push-Pull Clock frequency (MHz) 25 IOL (max) (mA) 8 IOH (max) (mA) -0.4 Supply current (max) (µA) 32000 Features High speed (tpd 10-50ns) Operating temperature range (°C) -55 to 125 Rating Military
Configuration Parallel-in, Serial-out Bits (#) 8 Technology family LS Supply voltage (min) (V) 4.75 Supply voltage (max) (V) 5.25 Input type Bipolar Output type Push-Pull Clock frequency (MHz) 25 IOL (max) (mA) 8 IOH (max) (mA) -0.4 Supply current (max) (µA) 32000 Features High speed (tpd 10-50ns) Operating temperature range (°C) -55 to 125 Rating Military
CDIP (J) 16 135.3552 mm² 19.56 x 6.92 CFP (W) 16 69.319 mm² 10.3 x 6.73 LCCC (FK) 20 79.0321 mm² 8.89 x 8.89
  • Synchronous Load
  • Direct Overriding Clear
  • Parallel to Serial Conversion

 

  • Synchronous Load
  • Direct Overriding Clear
  • Parallel to Serial Conversion

 

The '166 and 'LS166A 8-bit shift registers are compatible with most other TTL logic families. All '166 and 'LS166A inputs are buffered to lower the drive requirements to one Series 54/74 or Series 54LS/74LS standard load, respectively. Input clamping diodes minimize switching transients and simplify system design.

These parallel-in or serial-in, serial-out shift registers have a complexity of 77 equivalent gates on a monolithic chip. They feature gated clock inputs and an overriding clear input. The parallel-in or serial-in modes are established by the shift/load input. When high, this input enables the serial data input and couples the eight flip-flops for serial shifting with each clock pulse. When low, the parallel (broadside) data inputs are enabled and synchronous loading occurs on the next clock pulse. During parallel loading, serial data flow is inhibited. Clocking is accomplished on the low-to-high-level edge of the clock pulse through a two-input positive NOR gate permitting one input to be used as a clock-enable or clock-inhibit function. Holding either of the clock inputs high inhibits clocking; holding either low enables the other clock input. This, of course, allows the system clock to be free-running and the register can be stopped on command with the other clock input. The clock inhibit input should be changed to the high level only while the clock input is high. A buffered, direct clear input overrides all other inputs, including the clock, and sets all flip-flops to zero.

 

The '166 and 'LS166A 8-bit shift registers are compatible with most other TTL logic families. All '166 and 'LS166A inputs are buffered to lower the drive requirements to one Series 54/74 or Series 54LS/74LS standard load, respectively. Input clamping diodes minimize switching transients and simplify system design.

These parallel-in or serial-in, serial-out shift registers have a complexity of 77 equivalent gates on a monolithic chip. They feature gated clock inputs and an overriding clear input. The parallel-in or serial-in modes are established by the shift/load input. When high, this input enables the serial data input and couples the eight flip-flops for serial shifting with each clock pulse. When low, the parallel (broadside) data inputs are enabled and synchronous loading occurs on the next clock pulse. During parallel loading, serial data flow is inhibited. Clocking is accomplished on the low-to-high-level edge of the clock pulse through a two-input positive NOR gate permitting one input to be used as a clock-enable or clock-inhibit function. Holding either of the clock inputs high inhibits clocking; holding either low enables the other clock input. This, of course, allows the system clock to be free-running and the register can be stopped on command with the other clock input. The clock inhibit input should be changed to the high level only while the clock input is high. A buffered, direct clear input overrides all other inputs, including the clock, and sets all flip-flops to zero.

 

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Technical documentation

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Type Title Date
* Data sheet Parallel-Load 8-Bit Shift Registers datasheet 01 Mar 1988
* SMD SN54LS166A SMD 8001701EA 21 Jun 2016
Application note Power-Up Behavior of Clocked Devices (Rev. B) PDF | HTML 15 Dec 2022
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
User guide LOGIC Pocket Data Book (Rev. B) 16 Jan 2007
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
Application note TI IBIS File Creation, Validation, and Distribution Processes 29 Aug 2002
Application note Designing With Logic (Rev. C) 01 Jun 1997
Application note Designing with the SN54/74LS123 (Rev. A) 01 Mar 1997
Application note Input and Output Characteristics of Digital Integrated Circuits 01 Oct 1996
Application note Live Insertion 01 Oct 1996

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CDIP (J) 16 Ultra Librarian
CFP (W) 16 Ultra Librarian
LCCC (FK) 20 Ultra Librarian

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