The ’LVTH18646A and ’LVTH182646A scan test devices with 18-bit bus transceivers and registers are members of the Texas Instruments (TI) SCOPE testability integrated-circuit family. This family of devices supports IEEE Std 1149.1-1990 boundary scan to facilitate testing of complex circuit board assemblies. Scan access to the test circuitry is accomplished via the 4-wire test access port (TAP) interface.
Additionally, these devices are designed specifically for low-voltage (3.3-V) VCC operation, but with the capability to provide a TTL interface to a 5-V system environment.
• Members of the Texas Instruments SCOPE™ Family of Testability Products
• Members of the Texas Instruments Widebus™ Family
• State-of-the-Art 3.3-V ABT Design Supports Mixed-Mode Signal Operation (5-V Input and Output Voltages With 3.3-V VCC)
• Support Unregulated Battery Operation Down to 2.7 V
• Include D-Type Flip-Flops and Control Circuitry to Provide Multiplexed Transmission of Stored and Real-Time Data
• Bus Hold on Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors
• B-Port Outputs of ’LVTH182646A Devices Have Equivalent 25-Ω Series Resistors, So No External Resistors Are Required
• Compatible With IEEE Std 1149.1-1990 (JTAG) Test Access Port and Boundary-Scan Architecture
• SCOPE Instruction Set
– IEEE Std 1149.1-1990 Required Instructions and Optional CLAMP and HIGHZ
– Parallel-Signature Analysis at Inputs
– Pseudo-Random Pattern Generation From Outputs
– Sample Inputs/Toggle Outputs
– Binary Count From Outputs
– Device Identification
– Even-Parity Opcodes
• Packaged in 64-Pin Plastic Thin Quad Flat (PM) Packages Using 0.5-mm
