Texas Instruments Incorporated

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GC1012B 3.3V DIGITAL TUNER

SLWS138B

This document contains information which may be changed at any time without notice

5.0

APPLICATION NOTES

5.1

POWER AND GROUND CONNECTIONS

The GC1012B chip is a very high performance chip which requires solid power and ground

a circuit board with dedicated power and ground planes and with at least two decoupling capacitors (0.01

and 0.1

µf) adjacent to each GC1012B chip. If dedicated power and ground planes are not possible, then

IMPORTANT

The GC1012B chip may not operate properly if these power and ground guidelines are violated.

5.2

STATIC SENSITIVE DEVICE

The GC1012B chip is fabricated in a high performance CMOS process which is sensitive to the high

voltage transients caused by static electricity. These parts can be permanently damaged by static electricity

and should only be handled in static free environments.

5.3

100 MHZ OPERATION

Care must be taken in generating the clock when operating the GC1012B chip at its full 100 MHz

clock rate. The user must insure that the clock is above 2 volts for at least 4 nanoseconds and is below 0.8

volts for at least 4 nanoseconds. At 1000 MHz the clock period is only 10 nanoseconds so that the clock

must have a duty cycle of exactly 50%, and the rise and fall times can only be 1 nanosecond each. One

must also be careful to prevent clock undershoot below ground. An ideal clock at 100 MHz would be a

square wave with a low voltage of 0.5 volts and a high voltage of 2.5 volts.

5.4

REDUCED VOLTAGE OPERATION

The power consumed by the GC1012B chip can be greatly reduced by operating the chip at the

voltage, GRAYCHIP recommends driving the GC1012B chip inputs with 5 volt to 3 volt interface chips.