描述 Description

These 20-bit latches feature 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 'ABT16841 can be used as two 10-bit latches or one 20-bit latch. The 20 transparent D-type latches provide true data at the outputs. While the latch-enable (1LE or 2LE) input is high, the Q outputs of the corresponding 10-bit latch follow the 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 output-enable input 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 VCC 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 VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16841 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16841 is characterized for operation from -40°C to 85°C.

特性 Features

? Members of the Texas InstrumentsWidebusTM Family
? State-of-the-ArtEPIC-II BTM BiCMOS Design Significantly Reduces Power Dissipation
? ESD Protection Exceeds 2000 V Per MIL-STD-883, 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 VOLP (Output Ground Bounce) CC = 5 V, TA = 25°C
? High-Impedance State During Power Up and Power Down
? Distributed VCC and GND Pin Configuration Minimizes High-Speed Switching Noise
? Flow-Through Architecture Optimizes PCB Layout
? High-Drive Outputs (-32-mA IOH, 64-mA IOL)
? Package Options Include Plastic 300-mil Shrink Small-Outline (DL) Package 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.