TEXAS INSTRUMENTS SN54LVTH18512 SN54LVTH182512 SN74LVTH18512 SN74LVTH182512 handbook
This document describes the features and characteristics of models such as SN54LVTH18512, SN54LVTH182512, SN74LVTH18512, and SN74LVTH182512. These products are 3.3V ABT SCAN test devices with 18-bit universal bus transceivers. They support mixed-mode signal operation, compatible with 5V input and output voltages with 3.3V VCC. They can operate with unregulated battery down to 2.7V. The UBT (Universal Bus Transceiver) combines D-type latches and D-type flip-flops for operation in transparent, latched, or clocked mode. Bus hold on data inputs eliminates the need for external pullup/pulldown resistors. The B-port outputs of 'LVTH182512 devices have equivalent 25-Ω series resistors, so no external resistors are required. They are compatible with the IEEE Std 1149.1-1990 (JTAG) test access port and boundary-scan architecture. The SCOPE instruction set includes the required instructions and optional CLAMP and HIGHZ, supporting parallel-signature analysis at inputs, pseudo-random pattern generation from outputs, sample inputs/toggle outputs, binary count from outputs, device identification, and even-parity opcodes. Package options include 64-pin plastic thin shrink small outline (DGG) and 64-pin ceramic dual flat (HKC) packages using 0.5-mm center-to-center spacings.
