Novatel HS 3001, Integration Manual

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Modem Power-on And Recovery Techniques
The HS 3001 provides module integrators with improved modem power-on and recovery
techniques, while maintaining backwards compatibility to Enabler IIIG integrations. The
addition of an internal power switch and an input power-on logic select pin allows users the
flexibility to maintain backwards compatibility or select different power-on options. This
internal power switch also allows integrators the flexibility of not supplying an external power
switch. Pin 37, previously a reset pin, has been replaced with a device power ON/OFF pin.
This pin controls the internal power switch.
Pin 85 (PSLOGIC) allows users to select the default behavior of the ON/OFF control (Pin 37).
Once power is applied via the internal power switch, Pin 35 (PON) is used like a phone on/off
switch.
Power Switch Logic Detect (Pin 85)
Pin 85 is a hardware input pin used to determine the functionality of the ON/OFF pin (Pin 37).
If Pin 85 is tied to VBAT, Modem ON/OFF (Pin 37) defaults to high when open circuit, and the
modem power switch will be ON. If Pin 85 is left open, Modem ON/OFF (Pin 37) defaults to
low when open circuit and the modem will be OFF (requires ON/OFF to be driven high to
power on).
We do not recommend externally connecting Pin 85 to ground.
ON/OFF (PIN 37)
Pin 37 is the ON/OFF control input for the modem's internal power switch. When it is high,
the modem's power switch will be ON. When it is low, the modem power will be OFF.
In order for the device to power on, pin 35 must be tied low or pulled low after power has
been applied. The device will not power on if it is left floating.