Member of the Texas Instruments

WidebusE Family

EPICE (Enhanced-Performance Implanted

CMOS) Submicron Process

DOCE (Dynamic Output Control) Circuit

Dynamically Changes Output Impedance,

Resulting in Noise Reduction Without

Speed Degradation

Dynamic Drive Capability Is Equivalent to

Standard Outputs With IOH and IOL of

±24 mA at 2.5-V VCC

Overvoltage-Tolerant Inputs/Outputs Allow

Mixed-Voltage-Mode Data Communications

Ioff Supports Partial-Power-Down Mode

Operation

Latch-Up Performance Exceeds 100 mA Per

JESD 78, Class I

Packaged in Thin Shrink Small-Outline

Package

description

A Dynamic Output Control (DOC) circuit is implemented, which, during the transition, initially lowers the output

impedance to effectively drive the load and, subsequently, raises the impedance to reduce noise. Figure 1

shows typical VOL vs IOL and VOH vs IOH curves to illustrate the output impedance and drive capability of the

circuit. At the beginning of the signal transition, the DOC circuit provides a maximum dynamic drive that is

equivalent to a high-drive standard-output device. For more information, refer to the TI application reports, AVC

Logic Family Technology and Applications, literature number SCEA006, and Dynamic Output Control (DOCE)

Circuitry Technology and Applications, literature number SCEA009.

This 22-bit flip-flop is operational at 1.2-V to 3.6-V VCC, but is designed specifically for 1.65-V to 3.6-V VCC

operation.

The 22 flip-flops of the SN74AVC16722 are edge-triggered D-type flip-flops with clock-enable (CLKEN) input.

On the positive transition of the clock (CLK) input, the device stores data into the flip-flops if CLKEN is low. If

CLKEN is high, no data is stored.

A buffered output-enable (OE) input places the 22 outputs in either a normal logic state (high or low) or the

high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly.

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.