SN74LV138A中文资料3 线至 8 线解码器/多路解复用器数据手册TI规格书

描述 Description

The 'LV138A devices are 3-line to 8-line decoders/demultiplexers designed for 2-V to 5.5-V VCC operation. These devices are designed for high-performance memory-decoding or data-routing applications requiring very short propagation delay times. In high-performance memory systems, these decoders can be used to minimize the effects of system decoding. When employed with high-speed memories utilizing a fast enable circuit, the delay times of these decoders and the enable time of the memory usually are less than the typical access time of the memory. This means that the effective system delay introduced by the decoder is negligible. The conditions at the binary-select inputs (A, B, C) and the three enable inputs (G1, G2A, G2B) select one of eight output lines. The two active-low (G2A, G2B) and one active-high (G1) enable inputs reduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented without external inverters and a 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing applications. These devices are fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down.

特性 Features

• 2-V to 5.5-V VCC Operation
• Max tpd of 9.5 ns at 5 V
• Typical VOLP (Output Ground Bounce) CC = 3.3 V, TA = 25°C
• Typical VOHV (Output VOH Undershoot) >2.3 V at VCC = 3.3 V, TA = 25°C
• Support Mixed-Mode Voltage Operation on All Ports
• Ioff Supports Partial-Power-Down Mode Operation
• Latch-Up Performance Exceeds 250 mA Per JESD 17
• ESD Protection Exceeds JESD 22
• 2000-V Human-Body Model (A114-A)
• 200-V Machine Model (A115-A)
• 1000-V Charged-Device Model (C101)