Integrator's Manual GR47/GR48

5. SYSTEM CONNECTOR INTERFACE
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LZT 123 7589 R1A
Hard Shutdown Sequence
Figure 5.4 Hard Shutdown Sequence
(4) To implement the Hard Shutdown of the GR47, the ON/OFF pulse must
be held low until the sequence is complete. Ensure that ON/OFF is not
released before VIO has been deactivated by the module.
5.6.1 VIO - 2.75V Supply
VIO provides an output voltage derived from an internal 2.75V regulator.
Its electrical characteristics are shown below.
You can use this output for the following:
• to indicate that the radio device is powered;
• to power interface circuits, external to the radio device.
ON/OFF
VIO
t
HSD
t
PULSE
Symbol Parameters Conditions Min. Typ Max Unit
t
Time to complete
hardware
shutdown
2-11s
t
Application ON/
OFF pulse width
ON/OFF low
until VIO is
disabled
t 10 - s
Parameter Min. Typ. Max. Units
Output Voltage (I
load
= 50 mA) 2.70 2.75 2.85 V
Load current 75 mA