SN54ABT162841, SN74ABT162841 20-BIT BUS-INTERFACE D-TYPE LATCHES WITH 3-STATE OUTPUTS

SCBS665B - JUNE 1996 - REVISED MAY 1997

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features

• Members of the Texas Instruments Widebus^TM Family
• Output Ports Have Equivalent 25- Series Resistors, So No External Resistors Are Required
• State-of-the-Art EPIC-IIB^TM BiCMOS Design Significantly Reduces Power Dissipation
• 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
• High-Impedance State During Power Up and Power Down
• Distributed V_CC and GND Pin Configuration Minimizes High-Speed Switching Noise
• Flow-Through Architecture Optimizes PCB Layout
• Package Options Include Plastic 300-mil Shrink Small-Outline (DL), Thin Shrink Small-Outline (DGG) Packages and 380-mil Fine-Pitch Ceramic Flat (WD) Package Using 25-mil Center-to-Center Spacings

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

description

These 20-bit transparent D-type latches feature noninverting 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers.

The 'ABT162841 can be used as two 10-bit latches or one 20-bit latch. While the latch-enable (1LE or 2LE) input is high, the Q outputs of the corresponding 10-bit latch follow the data (D) inputs. When LE is taken low, the Q outputs are latched at the levels set up at the D inputs.

A buffered output-enable (1OE\ or 2OE\) input can be used to place the outputs of the corresponding 10-bit latch in either a normal logic state (high or low logic levels) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.

The outputs, which are designed to sink up to 12 mA, include equivalent 25- series resistors to reduce overshoot and undershoot.

OE\ does not affect the internal operation of the latches. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.

When V_CC is between 0 and 2.1 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 2.1 V, OE\ 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.

The SN54ABT162841 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT162841 is characterized for operation from -40°C to 85°C.

View more information about generic part numbers:SN74ABT162841

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