74126 IC Quad Bus Buffer Tri-State in Pakistan

The 74LS48 features active-high outputs for driving lamp buffers or common-cathode LEDs. They have full ripple-blanking input/output controls and a lamp test input. Display patterns for BCD input count above 9 are unique symbols to authenticate input conditions. Their circuits incorporate automatic leading and/or trailing-edge zero-blanking control (RBI\ and RBO\). Lamp test (LT\) of these types may be performed at any time when the BI\/RBO\ node is at a high level. They contain an overriding blanking input (BI\), which can be used to control the lamp intensity by pulsing or to inhibit the outputs. Inputs and outputs are entirely compatible for use with TTL logic outputs.

The 74LS138 is a 3:8 Decoder IC that is commonly used in decoding or de-multiplexing circuits for memory decoding or data routing purposes. It is designed for high-speed operations and has three enable pins to make it easier to cascade with other ICs. The device decodes 1-of-8 lines, set by x3 binary select inputs & three enable inputs. The LS138 can be used as an 8- output demultiplexer by using one active LOW Enable input as data input & the other Enable inputs as strobes. The IC has an operating voltage from 1.0V to 5.5V with a low power consumption of 32mW. The propagation delay is around 21nS.

This circuit is a synchronous up/down 4-bit binary counter. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change together when so instructed by the steering logic. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple clock) counters. The outputs of the four master-slave flip-flops are triggered by a low-to-high level transition of either count (clock) input. The direction of counting is determined by which count input is pulsed while the other count input is held high. The counter is fully programmable; that is, each output may be preset to either level by entering the desired data at the inputs while the load input is low. The output will change independently of the count pulses.