SN54ABT16501A, SN74ABT16501A
18-BIT UNIVERSAL BUS TRANSCEIVER
WITH 3-STATE OUTPUTS

SCBS459 - JANUARY 1994

features

• Members of the Texas Instruments Widebus^TM Family
• State-of-the-Art EPIC-IIB ^TM BiCMOS Design Significantly Reduces Power Dissipation
• UBT ^TM (Universal Bus Transceiver) Combines D-Type Latches and D-Type Flip-Flops for Operation in Transparent, Latched, or Clocked Mode
• ESD Protection Exceeds 2000 V Per MIL-STD-883C, Method 3015; Exceeds 200 V Using Machine Model (C = 200 pF, R = 0)
• Latch-Up Performance Exceeds 500 mA Per JEDEC Standard JESD-17
• Typical V_OLP (Output Ground Bounce) < 0.8 V at V_CC = 5 V, T_A = 25°C
• Flow-Through Architecture Optimizes PCB Layout
• Packaged in Plastic 300-mil Shrink Small-Outline and Thin Shrink Small-Outline Packages and 380-mil Fine-Pitch Ceramic Flat Packages Using 25-mil Center-to-Center Spacings

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

description

These 18-bit universal bus transceivers consist of storage elements that can operate either as D-type latches or D-type flip-flops to allow data flow in transparent or clocked modes.

Data flow in each direction is controlled by output-enable (OEAB and ), latch-enable (LEAB and LEBA), and clock (CLKAB and CLKBA) inputs. For A-to-B data flow, the device operates in the transparent mode when LEAB is high. When LEAB is low, the A data is latched if CLKAB is held at a high or low logic level. If LEAB is low, the A bus data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. When OEAB is high, the outputs are active. When OEAB is low, the outputs are in the high-impedance state.

Data flow for B to A is similar to that of A to B but uses , LEBA, and CLKBA. The output enables are complementary (OEAB is active high and is active low).

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

The SN74ABT16501A is available in TI's shrink small-outline package (DL), which provides twice the I/O pin count and functionality of standard small-outline packages in the same printed-circuit-board area.

The SN54ABT16501A is characterized over the full military temperature range of -55°C to 125°C. The SN74ABT16501A is characterized for operation from -40°C to 85°C.