STATES OF OPERATION

Copyright Semtech, 1997-2001

DOC5-FJL-DS-106

www.semtech.com

7

can be used to handle several system management tasks for small, portable

system designs, thus saving space and additional components for the

System Designer. Such system management tasks include those listed

below.

However, since most of the system management tasks are application and

hardware-dependent, detailed implementation information is outside the

scope of this document. For application examples and sample schematics,

contact Semtech Technical Support.

System shut-down/wake-up signal

shut-down/wake-up signal which can be invoked either by a special

keyboard combination or after a programmed period of user inactivity.

Purchase of any version of the UR5HCFJL encoder conveys a license to utilize the Self-Power Management

feature only through use of the UR5HCFJL in a PS/2-compatible keyboard subsystem.

of operation, implemented to

minimize the power consumption of

the keyboard subsystem. The

following diagram illustrates the

three states of operation of the

is in the Sleep State. Power

consumption in this state is

approximately 2 µA at 5 Volts of

the Active State only when there is

an event to process, such as a

keystroke, a command from the

system, or data from the external

PS/2-compatible device.

in the Stand-By State if an external

device is connected to the auxiliary

port or if one or more LEDs are

turned on.

In the Stand-By State, the IC

consumes approximately 600 µA at

5 Volts. Transition from one state to

the other does not require any input

from the system.

SLEEP

STATE

STAND BY

STATE

ACTIVE

STATE

Figure 2: States of Operation of

UR5HCFJL