SN74ALVCH16821

ACTIVE

3.3-V 20-Bit Bus-Interface Flip-Flop with 3-State Outputs

SN74ALVCH16821

ACTIVE

Product details

Number of channels 20 Technology family ALVC Input type Standard CMOS Output type 3-State Clock frequency (max) (MHz) 150 IOL (max) (mA) 24 IOH (max) (mA) -24 Supply current (max) (µA) 40 Features Balanced outputs, Bus-hold, Over-voltage tolerant inputs, Very high speed (tpd 5-10ns) Operating temperature range (°C) -40 to 85 Rating Catalog
Number of channels 20 Technology family ALVC Input type Standard CMOS Output type 3-State Clock frequency (max) (MHz) 150 IOL (max) (mA) 24 IOH (max) (mA) -24 Supply current (max) (µA) 40 Features Balanced outputs, Bus-hold, Over-voltage tolerant inputs, Very high speed (tpd 5-10ns) Operating temperature range (°C) -40 to 85 Rating Catalog
SSOP (DL) 56 190.647 mm² (18.42 mm × 10.35 mm) TSSOP (DGG) 56 113.4 mm² (14 mm × 8.1 mm)
  • Member of the Texas Instruments Widebus™ Family
  • Bus Hold on Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors
  • Latch-Up Performance Exceeds 250 mA Per JESD 17
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)

Widebus is a trademark of Texas Instruments.

  • Member of the Texas Instruments Widebus™ Family
  • Bus Hold on Data Inputs Eliminates the Need for External Pullup/Pulldown Resistors
  • Latch-Up Performance Exceeds 250 mA Per JESD 17
  • ESD Protection Exceeds JESD 22
    • 2000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)

Widebus is a trademark of Texas Instruments.

This 20-bit bus-interface flip-flop is designed for 1.65-V to 3.6-V VCC operation.

The SN74ALVCH16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The 20 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 need for interface or pullup components.

OE\ does not affect the internal operation 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 VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

This 20-bit bus-interface flip-flop is designed for 1.65-V to 3.6-V VCC operation.

The SN74ALVCH16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The 20 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 need for interface or pullup components.

OE\ does not affect the internal operation 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 VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

Active bus-hold circuitry holds unused or undriven inputs at a valid logic state. Use of pullup or pulldown resistors with the bus-hold circuitry is not recommended.

Download View video with transcript Video

Similar products you might be interested in

open-in-new Compare alternates
Pin-for-pin with same functionality to the compared device.
SN74ABT16821 ACTIVE 20-Bit Bus Interface Flip-Flops With 3-State Outputs Voltage range 4.5V to 5.5V, average propagation delay 4.6ns, average drive strength 64mA

Technical documentation

No results found. Please clear your search and try again.
View all 3
Top documentation Type Title Format options Date
* Data sheet SN74ALVCH16821 datasheet (Rev. F) Aug 30, 2004
Application note Power-Up Behavior of Clocked Devices (Rev. B) PDF | HTML Dec 15, 2022
Application note An Overview of Bus-Hold Circuit and the Applications (Rev. B) Sep 17, 2018

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Simulation model

SN74ALVCH16821 IBIS Model (Rev. A)

SCEM038 (9 KB) - IBIS model
Supported products & hardware
Package Pins CAD symbols, footprints & 3D models
SSOP (DL) 56 Ultra Librarian
TSSOP (DGG) 56 Ultra Librarian

Ordering & quality

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos