7437 Quad Two input NAND in Pakistan

74LS Series ICs are High-Speed Logic gates, ideally a little faster than the 74HC series but more power consumption is required. They are implemented with a Low-Power Schottky diode technology to achieve high switching speed. 74LS148 is one of the 74LS series IC. 74LS148 ICs contain an 8 to 3-Bit priority encoder that converts 8 Data Lines to 3-Line binary. Cascading circuitry (enable input EI and enable output EO) has been provided to allow octal expansion without the need for external circuitry.

Each counter has a divide-by-two section and either a divide-by-five (LS90), divide-by-six (LS92) or divide-by-eight (LS93) section which are triggered by a HIGH-to-LOW transition on the clock inputs. Each section can be used separately or tied together (Q to CP) to form BCD, bi-quinary, modulo-12, or modulo-16 counters. All of the counters have a 2-input gated Master Reset (Clear), and the LS90 also has a 2-input gated Master Set (Preset 9).

The 74HC165 is a high-speed Si-gate CMOS device and is pin-compatible with low-power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC165 are 8-bit parallel-load or serial-in shift registers with complementary serial outputs (Q7 and Q7) available from the last stage. When the parallel load (PL) input is LOW, parallel data from the D0 to D7 inputs are loaded into the register asynchronously. When PL is HIGH, data enters the register serially at the Ds input and shifts one place to the right (Q0 –> Q1 –> Q2, etc.) with each positive-going clock transition. This feature allows parallel-to-serial converter expansion by tying the Q7 output to the DS input of the succeeding stage. The clock input is a gated-OR structure that allows one input to be used as an active LOW clock enable (CE) input. The pin assignment for the CP and CE inputs is arbitrary and can be reversed for layout convenience. The LOW-to-HIGH transition of input CE should only take place while CP is HIGH for predictable operation. Either the CP or the CE should be HIGH before the LOW-to-HIGH transition of PL to prevent shifting the data when PL is activated.