Logic device/transceiver/encoder

Octal Bus Transceiver with 3-State Outputs 20-SOIC -40 to 85

The MC100LVEL16 is a differential receiver. This device is powered from a 3.3 V supply and has the same functionality as device EL16. LVEL16 has a wider range of VIHCMR than EL16 equivalents. Compared to the EL16, the output transition time and propagation delay of the LVEL16 are well suited for interfacing with high frequency power supplies from 3.3 V supplies. In an open input condition, the Q input will be pulled down to VEE and the Qbar input will be biased to VCC / 2. In this case, the Q output is forced low. The VBB pin is used as an internally generated power supply for this device only. For the single-ended input case, connect the unused differential input to VBB as the switch reference voltage. VBB can also re-bias AC-coupled inputs. When used, decouple VBB and VCC with 0.01 μF capacitors and limit current source or sink to 0.5 mA. VBB should be left open when not in use.

The VHCT138A is an advanced high-speed CMOS 3-8 decoder fabricated on a silicon-gate CMOS process. It achieves high operating speeds similar to equivalent bipolar Schottky TTLs while maintaining CMOS low power consumption. When the device is enabled, 3 binary select inputs (A0, A1, and A2) determine which output (O#0-O#7) will go low. When enable input E3 is held low, or E#1 or E#2 is held high, the decode function is disabled and all outputs go high. The E3, E#1, and E#2 inputs are used to simplify cascading connections and serve as address decoders for the memory system. A protection circuit ensures that 0V to 7V is applied to the input pin regardless of the supply voltage at VCC = 0V and the output pin. These circuits prevent device damage due to mismatched supply and input/output voltages. The device can be used as an interface between 3-V systems and 5-V systems as well as two power systems, such as battery backup.