SN74ALS193ANSR

Counter Dividers Overview

The SN74ALS193ANSR is a synchronous, reversible 4-bit up/down binary counter from the Texas Instruments ALS logic family. It operates on a single supply voltage ranging from 4.5 V to 5.5 V. The device features separate UP and DOWN clock inputs for bidirectional counting, with outputs changing coincidently to eliminate ripple-clock spikes. Key electrical parameters include a maximum clock frequency of 30 MHz, a low-level output current of 8 mA, and a high-level output current of -0.4 mA. Propagation delays range from 3 ns to 23 ns depending on the signal path. It includes asynchronous clear, parallel asynchronous load, and look-ahead carry/borrow outputs for cascading.

Counter Dividers Feature Summary

• Fully synchronous operation eliminates output counting spikes associated with asynchronous counters by clocking all flip-flops simultaneously.
• Parallel asynchronous load capability allows the counter to be preset to any binary value independently of count pulses, enabling modulo-N division.
• Look-ahead circuitry provides dedicated carry and borrow outputs that facilitate direct cascading of multiple counters without external logic gates.

Counter Dividers Applications

• Synchronous bidirectional counting in digital systems
• Modulo-N frequency dividers using parallel preset inputs
• Cascaded multi-stage binary counters utilizing look-ahead carry and borrow outputs

Counter Dividers Procurement Notes

Verify the specific package variant against the datasheet, as the 'ANSR' suffix indicates a SOIC-16 surface-mount package. Confirm RoHS compliance status and lead finish details via the manufacturer's latest packaging addendum. Ensure the operating temperature range matches the commercial grade (0°C to 70°C) requirements of the application design.

Counter Dividers Selection Notes

Select this component when synchronous counting is required to prevent timing glitches common in ripple counters. The ALS series offers faster switching speeds compared to standard LS logic while maintaining compatible voltage levels. Use the parallel load feature for applications requiring non-standard counting sequences or specific start states without waiting for a full cycle reset.

Counter Dividers Part Context

This part belongs to the SN74ALS193A family of synchronous 4-bit up/down binary counters. It is functionally equivalent to the SN54ALS193A but rated for commercial temperatures rather than the military range. The device is part of the broader 74ALS logic family, designed to provide higher speed performance than standard TTL while reducing power consumption.

Counter Dividers Replacement Considerations

SN74ALS193AD

Counter Dividers FAQ

How does the SN74ALS193ANSR handle direction changes during counting?

The direction is determined by which count input (UP or DOWN) is pulsed while the other remains high. The device is fully synchronous, meaning outputs change coincidently regardless of the direction selected.

What is the purpose of the BO and CO outputs?

The Borrow (BO) and Carry (CO) outputs are look-ahead signals used for cascading. BO goes low when the count reaches zero during down-counting, and CO goes low when the count reaches fifteen during up-counting, allowing direct connection to subsequent stages.