SN74ABT574AOctal Edge-Triggered D-Type Flip-Flops With 3-State Outputs | Flip Flops | 10 | Active | These 8-bit flip-flops 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 eight flip-flops of the SN54ABT574 and SN74ABT574A are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels set up at the data (D) inputs.
A buffered output-enable (OE)\ input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
OE\ does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
This device is fully specified for partial-power-down applications using Ioff. The Ioffcircuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.
These 8-bit flip-flops 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 eight flip-flops of the SN54ABT574 and SN74ABT574A are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the Q outputs are set to the logic levels set up at the data (D) inputs.
A buffered output-enable (OE)\ input can be used to place the eight outputs in either a normal logic state (high or low logic levels) or the high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
OE\ does not affect the internal operations of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.
To ensure the high-impedance state during power up or power down, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
This device is fully specified for partial-power-down applications using Ioff. The Ioffcircuitry disables the outputs, preventing damaging current backflow through the device when it is powered down. |
SN74ABT620Octal Bus Transceivers With 3-State Outputs | Buffers, Drivers, Receivers, Transceivers | 3 | Active | These octal bus transceivers provide for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The 'ABT620 devices provide inverted data at the outputs.
These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and OEBA\) inputs.
The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and OEBA\. When both OEAB and OEBA\ are enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 total) remain at their last states. In this way, each output reinforces its input in this configuration.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB 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 SN54ABT620 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT620 is characterized for operation from -40°C to 85°C.
These octal bus transceivers provide for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The 'ABT620 devices provide inverted data at the outputs.
These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and OEBA\) inputs.
The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and OEBA\. When both OEAB and OEBA\ are enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 total) remain at their last states. In this way, each output reinforces its input in this configuration.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB 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 SN54ABT620 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT620 is characterized for operation from -40°C to 85°C. |
SN74ABT623Octal Bus Transceivers With 3-State Outputs | Logic | 7 | Active | The SN54ABT623A and SN74ABT623 bus transceivers are designed for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The SN54ABT623A and SN74ABT623 provide true data at their outputs.
These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and OEBA\) inputs.
The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and OEBA\. Each output reinforces its input in this configuration. When both OEAB and OEBA\ are enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 total) remain at their last states.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB 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 SN54ABT623A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT623 is characterized for operation from -40°C to 85°C.
The SN54ABT623A and SN74ABT623 bus transceivers are designed for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The SN54ABT623A and SN74ABT623 provide true data at their outputs.
These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and OEBA\) inputs.
The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and OEBA\. Each output reinforces its input in this configuration. When both OEAB and OEBA\ are enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (16 total) remain at their last states.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB 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 SN54ABT623A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT623 is characterized for operation from -40°C to 85°C. |
SN74ABT640Octal Bus Transceivers With 3-State Outputs | Buffers, Drivers, Receivers, Transceivers | 6 | Active | The 'ABT640 bus transceivers are designed for asynchronous communication between data buses. These devices transmit inverted data from the A bus to the B bus or from the B bus to the A bus, depending on the level at the direction-control (DIR) input. The output-enable () input can be used to disable the device so that the buses are effectively isolated.
To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT640 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT640 is characterized for operation from -40°C to 85°C.
The 'ABT640 bus transceivers are designed for asynchronous communication between data buses. These devices transmit inverted data from the A bus to the B bus or from the B bus to the A bus, depending on the level at the direction-control (DIR) input. The output-enable () input can be used to disable the device so that the buses are effectively isolated.
To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT640 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT640 is characterized for operation from -40°C to 85°C. |
SN74ABT646AOctal Bus Transceivers And Registers With 3-State Outputs | Buffers, Drivers, Receivers, Transceivers | 18 | Active | These 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 ´ABT646.
Output-enable () 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 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 whenis low. In the isolation mode (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.
To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN74ABT646 is available in TI's shrink small-outline package (DB), which provides the same I/O pin count and functionality of standard small-outline packages in less than half the printed-circuit-board area.
The SN54ABT646 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT646 is characterized for operation from -40°C to 85°C.
These 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 ´ABT646.
Output-enable () 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 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 whenis low. In the isolation mode (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.
To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN74ABT646 is available in TI's shrink small-outline package (DB), which provides the same I/O pin count and functionality of standard small-outline packages in less than half the printed-circuit-board area.
The SN54ABT646 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT646 is characterized for operation from -40°C to 85°C. |
SN74ABT651Octal Bus Transceivers And Registers With 3-State Outputs | Integrated Circuits (ICs) | 6 | Active | These devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. Output-enable (OEAB and OEBA\) inputs are provided to control the transceiver functions. The select-control (SAB and SBA) inputs are provided to select whether real-time or stored data is transferred. A low input level selects real-time data, and a high input level selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT651 devices.
Data on the A or B bus, or both, can be stored in the internal D flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs, regardless of the select- or enable-control pins. When SAB and SBA are in the real-time transfer mode, it also is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and OEBA\. In this configuration, each output reinforces its input. When all the other data sources to the two sets of bus lines are at high impedance, each set remains at its last state.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB 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 (A to B).
The SN54ABT651 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT651 is characterized for operation from -40°C to 85°C.
The data output functions may be enabled or disabled by a variety of level combinations at OEAB or OEBA\. Data input functions are always enabled; i.e., data at the bus terminals is stored on every low-to-high transition of the clock inputs.
When select control is low, clocks can occur simultaneously if allowances are made for propagation delays from A to B (B to A) plus setup and hold times. When select control is high, clocks must be staggered to load both registers.
These devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. Output-enable (OEAB and OEBA\) inputs are provided to control the transceiver functions. The select-control (SAB and SBA) inputs are provided to select whether real-time or stored data is transferred. A low input level selects real-time data, and a high input level selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT651 devices.
Data on the A or B bus, or both, can be stored in the internal D flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs, regardless of the select- or enable-control pins. When SAB and SBA are in the real-time transfer mode, it also is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and OEBA\. In this configuration, each output reinforces its input. When all the other data sources to the two sets of bus lines are at high impedance, each set remains at its last state.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB 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 (A to B).
The SN54ABT651 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT651 is characterized for operation from -40°C to 85°C.
The data output functions may be enabled or disabled by a variety of level combinations at OEAB or OEBA\. Data input functions are always enabled; i.e., data at the bus terminals is stored on every low-to-high transition of the clock inputs.
When select control is low, clocks can occur simultaneously if allowances are made for propagation delays from A to B (B to A) plus setup and hold times. When select control is high, clocks must be staggered to load both registers. |
SN74ABT652AOctal Registered Transceivers With 3-State Outputs | Buffers, Drivers, Receivers, Transceivers | 7 | Active | These devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers.
Output-enable (OEAB and OEBA\) inputs are provided to control the transceiver functions. Select-control (SAB and SBA) inputs are provided to select either real-time or stored data for transfer. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. A low input selects real-time data, and a high input selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT652A.
Data on the A- or B-data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs, regardless of the select- or enable-control inputs. When SAB and SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and OEBA\. In this configuration, each output reinforces its input. When all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remains at its last state.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB 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 (A to B).
The SN54ABT652A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT652A is characterized for operation from -40°C to 85°C.
These devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers.
Output-enable (OEAB and OEBA\) inputs are provided to control the transceiver functions. Select-control (SAB and SBA) inputs are provided to select either real-time or stored data for transfer. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. A low input selects real-time data, and a high input selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT652A.
Data on the A- or B-data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs, regardless of the select- or enable-control inputs. When SAB and SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and OEBA\. In this configuration, each output reinforces its input. When all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remains at its last state.
To ensure the high-impedance state during power up or power down, OEBA\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB 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 (A to B).
The SN54ABT652A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT652A is characterized for operation from -40°C to 85°C. |
SN74ABT657AOctal Transceivers With Parity Generators/Checkers And 3-State Outputs | Logic | 4 | Active | The 'ABT657A transceivers have eight noninverting buffers with parity-generator/checker circuits and control signals. The transmit/receive (T/R\) input determines the direction of data flow. When T/R\ is high, data flows from the A port to the B port (transmit mode); when T/R\ is low, data flows from the B port to the A port (receive mode). When the output-enable (OE\) input is high, both the A and B ports are in the high-impedance state.
Odd or even parity is selected by a logic high or low level on the ODD/EVEN\ input. PARITY carries the parity-bit value; it is an output from the parity generator/checker in the transmit mode and an input to the parity generator/checker in the receive mode.
In the transmit mode, after the A bus is polled to determine the number of high bits, PARITY is set to the logic level that maintains the parity sense selected by the level at ODD/EVEN\. For example, if ODD/EVEN\ is low (even parity selected) and there are five high bits on the A bus, PARITY is set to the logic high level so that an even number of the nine total bits (eight A-bus bits plus parity bit) are high.
In the receive mode, after the B bus is polled to determine the number of high bits, the error (ERR\) output logic level indicates whether or not the data to be received exhibits the correct parity sense. For example, if ODD/EVEN\ is high (odd parity selected), PARITY is high, and there are three high bits on the B bus, ERR\ is low, indicating a parity error.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT657A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT657A is characterized for operation from -40°C to 85°C.
The 'ABT657A transceivers have eight noninverting buffers with parity-generator/checker circuits and control signals. The transmit/receive (T/R\) input determines the direction of data flow. When T/R\ is high, data flows from the A port to the B port (transmit mode); when T/R\ is low, data flows from the B port to the A port (receive mode). When the output-enable (OE\) input is high, both the A and B ports are in the high-impedance state.
Odd or even parity is selected by a logic high or low level on the ODD/EVEN\ input. PARITY carries the parity-bit value; it is an output from the parity generator/checker in the transmit mode and an input to the parity generator/checker in the receive mode.
In the transmit mode, after the A bus is polled to determine the number of high bits, PARITY is set to the logic level that maintains the parity sense selected by the level at ODD/EVEN\. For example, if ODD/EVEN\ is low (even parity selected) and there are five high bits on the A bus, PARITY is set to the logic high level so that an even number of the nine total bits (eight A-bus bits plus parity bit) are high.
In the receive mode, after the B bus is polled to determine the number of high bits, the error (ERR\) output logic level indicates whether or not the data to be received exhibits the correct parity sense. For example, if ODD/EVEN\ is high (odd parity selected), PARITY is high, and there are three high bits on the B bus, ERR\ is low, indicating a parity error.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT657A is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT657A is characterized for operation from -40°C to 85°C. |
SN74ABT821A10-Bit Bus Interface Flip-Flops With 3-State Outputs | Integrated Circuits (ICs) | 4 | Active | These 10-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
The ten flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the devices provide true data at the Q outputs.
A buffered output-enable (OE\) input can be used to place the ten outputs 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 high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
OE\ does not affect the internal operations of the latch. Previously stored data can be retained or new data can be entered while the outputs are in the high-impedance state.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT821 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT821A is characterized for operation from -40°C to 85°C.
These 10-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
The ten flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the devices provide true data at the Q outputs.
A buffered output-enable (OE\) input can be used to place the ten outputs 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 high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
OE\ does not affect the internal operations of the latch. Previously stored data can be retained or new data can be entered while the outputs are in the high-impedance state.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT821 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT821A is characterized for operation from -40°C to 85°C. |
SN74ABT8239-Bit Bus-Interface Flip-Flops With 3-State Outputs | Logic | 5 | Active | These 9-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
With the clock-enable (CLKEN\) input low, the nine D-type edge-triggered flip-flops enter data on the low-to-high transitions of the clock. Taking CLKEN\ high disables the clock buffer, thus latching the outputs. Taking the clear (CLR\) input low causes the nine Q outputs to go low, independently of the clock.
A buffered output-enable (OE\) input can be used to place the nine outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT823 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT823 is characterized for operation from -40°C to 85°C.
These 9-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers.
With the clock-enable (CLKEN\) input low, the nine D-type edge-triggered flip-flops enter data on the low-to-high transitions of the clock. Taking CLKEN\ high disables the clock buffer, thus latching the outputs. Taking the clear (CLR\) input low causes the nine Q outputs to go low, independently of the clock.
A buffered output-enable (OE\) input can be used to place the nine outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components.
When VCCis 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 VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
The SN54ABT823 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT823 is characterized for operation from -40°C to 85°C. |
