SN74LVC821A - 10-Bit Bus-Interface Flip-Flop With 3-State Outputs

This 10-bit bus-interface flip-flop is designed for 1.65-V to 3.6-V V_CC operation.

The SN74LVC821A features 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. This device is 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 device provides 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 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 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.

Inputs can be driven from either 3.3-V or 5-V devices. This feature allows the use of this device as a translator in a mixed 3.3-V/5-V system environment.

This device is fully specified for partial-power-down applications using I_off. The I_off circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.

To ensure the high-impedance state during power up or power down, 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.

Products containing the "SN74LVC821A" keyword are: SN74LVC821ADBR , SN74LVC821ADBR , SN74LVC821ADBR(P/B) , SN74LVC821ADBRG4 , SN74LVC821ADBRG4 , SN74LVC821ADGVR , SN74LVC821ADGVR , SN74LVC821ADGVRG4 , SN74LVC821ADW , SN74LVC821ADW , SN74LVC821ADWE4 , SN74LVC821ADWG4 , SN74LVC821ADWG4 , SN74LVC821ADWR , SN74LVC821ADWR , SN74LVC821ANSR , SN74LVC821ANSR , SN74LVC821ANSRE4 , SN74LVC821APW , SN74LVC821APWE4

• Operates From 1.65 V to 3.6 V
• Inputs Accept Voltages to 5.5 V
• Max t_pd of 7.3 ns at 3.3 V
• Typical V_OLP (Output Ground Bounce)
     <0.8 V at V_CC = 3.3 V, T_A = 25°C
• Typical V_OHV (Output V_OH Undershoot)
     >2 V at V_CC = 3.3 V, T_A = 25°C
• Supports Mixed-Mode Signal Operation on All Ports (5-V Input/Output Voltage With 3.3-V V_CC)
• I_off Supports Partial-Power-Down Mode Operation
• Latch-Up Performance Exceeds 250 mA Per JESD 17
• ESD Protection Exceeds JESD 22
  • 2000-V Human-Body Model (A114-A)