Texas Instruments 74LS series SN74LS161ANSR, synchronous 4-bit binary counter, positive-edge triggered, asynchronous reset, 25 MHz count rate, 4.75 V to 5.25 V supply, 0°C to 70°C, 16-SOIC surface-mount package.
| Parameter | Value |
|---|---|
| Series | 74LS |
| Logic type | Binary Counter |
| Trigger type | Positive Edge |
| Mounting | Surface Mount |
| Supply voltage | 4.75 V ~ 5.25 V |
| Operating temperature | 0°C ~ 70°C |
| Reset | Asynchronous |
| Timing | Synchronous |
| Package | Tape & Reel (TR); Cut Tape (CT) |
| Direction | Up |
| Count rate | 25 MHz |
| Case | 16-SOIC (0.209\", 5.30mm Width) |
| Number of elements | 1 |
| Number of bits per element | 4 |
The Texas Instruments SN74LS161ANSR is a 74LS-series synchronous 4-bit binary counter that increments on the positive edge of the clock. It includes an asynchronous reset (active low) that clears the outputs independently of the clock. The 25 MHz maximum count rate sets the timing budget for the system bus or sensor edge rate.
The 16-SO supplier device package matches standard SOIC-16 land patterns.
The SN74LS161AN is the through-hole DIP version, while the SN74LS161ANSR is the surface-mount 16-SOIC variant. The package suffix 'SR' indicates the SOIC reeled format.
Yes, the SN74LS161ANSR is a direct functional replacement for the generic 74LS161 — same synchronous 4-bit binary counter with asynchronous reset, same 25 MHz count rate, same 5 V supply. The 'SN' prefix indicates Texas Instruments manufacturing; the 'SR' suffix specifies the 16-SOIC surface-mount package. If your existing 74LS161 is in a DIP package, the footprint differs.