SN74ABT38543
36-BIT REGISTERED TRANSCEIVER
WITH 3-STATE OUTPUTS

features

• Member of the Texas Instruments Widebus+^TM Family
• State-of-the-Art EPIC-IIB ^TM BiCMOS Design Significantly Reduces Power Dissipation
• ESD Protection Exceeds 2000 V Per MIL-STD-883C, Method 3015; Exceeds 200 V Using Machine Model (C = 200 pF, R = 0)
• Compatible With the IEEE Standard 1149.1 (JTAG) Serial Test Bus
• Typical V_OLP (Output Ground Bounce) < 0.8 V at V_CC = 5 V, T_A = 25°C
• Distributed V_CC and GND Pin Configuration Minimizes High-Speed Switching Noise
• High-Drive Outputs (-32-mA I_OH, 64-mA I_OL)
• Bus-Hold Inputs Eliminate the Need for External Pullup Resistors
• Packaged in 120-Pin Cavity-Shrink Quad Flat Pack With 14 × 14-mm Package Body Using 0.4-mm Lead Pitch

  Widebus+ and EPIC-IIB are trademarks of Texas Instruments Incorporated.
  

description

The SN74ABT38543 is a 36-bit (quad 9-bit) registered transceiver that contains four sets of D-type latches for temporary storage of data flowing in either direction. The device can be used as four 9-bit transceivers, two 18-bit transceivers, or one 36-bit transceiver. Separate latch-enable ( or ) and output-enable ( or ) inputs are provided for each register to permit independent control in either direction of data flow.

The A-to-B enable () input must be low in order to enter data from A or to output data from B. If is low and is low, the A-to-B latches are transparent; a subsequent low-to-high transition of puts the A latches in the storage mode. With and both low, the 3-state B outputs are active and reflect the data present at the output of the A latches. Data flow from B to A is similar but requires using the , , and inputs.

To ensure the high-impedance state during power up or power down, should be tied to V_CC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

Active bus-hold circuitry is provided to hold unused or floating inputs at a valid logic level.

The SN74ABT38543 is characterized for operation from -40°C to 85°C.