| 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 |
| ICC (Max) (uA) | 30000 |
| Features | High speed (tpd 10-50ns) |
- Complementary Outputs
- Direct Overriding Load (Data) Inputs
- Gated Clock Inputs
- Parallel-to-Serial Data Conversion
The SN54165 and SN74165 devices are obsolete and are no longer supplied.
The ?165 and ?LS165A are 8-bit serial shift registers that shift the data in the direction of QA toward QH when clocked. Parallel-in access to each stage is made available by eight individual, direct data inputs that are enabled by a low level at the shift/load (SH/LD\) input. These registers also feature gated clock (CLK) inputs and complementary outputs from the eighth bit. All inputs are diode-clamped to minimize transmission-line effects, thereby simplifying system design.
Clocking is accomplished through a two-input positive-NOR gate, permitting one input to be used as a clock-inhibit function. Holding either of the clock inputs high inhibits clocking, and holding either clock input low with SH/LD\ high enables the other clock input. Clock inhibit (CLK INH) should be changed to the high level only while CLK is high. Parallel loading is inhibited as long as SH/LD\ is high. Data at the parallel inputs are loaded directly into the register while SH/LD\ is low, independently of the levels of CLK, CLK INH, or serial (SER) inputs.