SN74BCT646

Pinout




Specifications

Supply voltage range, V_CC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 V to 7 V
Input voltage range: Control inputs (see Note 1)  . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 V to 7 V
                                 I/O ports (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . .  0.5 V to 5.5 V
Voltage range applied to any output in the disabled or power-off state, V_O. . . . . . 0.5 V to 7 V
Voltage range applied to any output in the high state, V_O . . . . . . . . . . . . . . . . . . . 0.5 V to V_CC 
Current into any output in the low state: SN54BCT646. . . . . . . . . . . . . . . . . . . . . . . . . . . .  96 mA
                                                                 SN74BCT646 . . . . . . . . . . . . . . . . . . . . . . . . . . .  128 mA
Operating free-air temperature range: SN54BCT646 . . . . . . . . . . . . . . . . . . . . 55°C to 125°C
                                                              SN74BCT646.   . . . . . . . . . . . . . . . . . . . . . . 0 °C to 70°C
Storage temperature range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65°C to 150°C

Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.


Description

These SN74BCT646 devices consist of bus transceiver circuits,D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal registers. Data on the A or B bus is clocked into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input. Figure 1 illustrates the
four fundamental bus-management functions that can be performed with the BCT646.


SN74BCT646 Output-enable (OE) and direction-control (DIR)inputs are provided to control the transceiver functions. In the transceiver mode, data present at the high-impedance port may be stored in either register or in both.


The SN74BCT646 select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The direction control (DIR) determines which bus will receive data when OE is low. In the isolation mode (OE high), A data may be stored in one register and/or B data may be stored in the other register.


When an output function is disabled, the input function is still enabled and may be used to store and transmit data. Only one of the two buses, A or B, may be driven at a time.


The SN54BCT646 is characterized for operation over the full military temperature range of 55°C to 125°C. The SN74BCT646 is characterized for operation from 0°C to 70°C.