Enfora Enabler II-G Assisted GPS Modem Integration Guide 6.6.8. General Purpose Input/Output
Seven general-purpose input/output signals are provided along with one fixed output. Each of
these signals may be selected as inputs or outputs except GPIO-5, which is an output pin only.
They may be used independently as a user-specified function, or may be used to provide
modem control and status signals. Several examples of modem control signals are: power
shutdown command, register/deregister on network command, and transmitter disable.
Several examples of modem status signals are: registration status and ready-for-power-down
status to be used with power shutdown command signal.
I/O Lines Parameter/Conditions MIN TYP MAX UNIT
VIL Input Voltage – Low -0.5 0.9 Vdc
VIH Input Voltage – High 2.0 3.4 Vdc
VOL Output Voltage – Low 0.64 Vdc
VOH Output Voltage – High 2.4 3.0 Vdc
IIL / IIH Input Leakage Current -1 1 μA
IOL / IOH Rated Output Current 2 mA
6.6.9. Analog-To-Digital Input
Analog-To-Digital Input Parameter/Conditions MIN TYP MAX UNIT
ADCBRES ADC Binary Resolution 10 Bits
ADCREF ADC Reference Voltage 1.75 Vdc
VADC ADC Range 0 1.75 Vdc
ZADC ADC Input Impedance 100 kΩ
6.6.10. Digital-To-Analog Output
Digital-To-Analog Output Parameter/Conditions MIN TYP MAX UNIT
DACBRES DAC Binary Resolution 10 Bits
TSSettling Time 10 μS
VOMAX Output Voltage with Code
Maximum
2.0 2.2 2.4 Vdc
VOMIN Output Voltage with Code
Minimum
0.18 0.24 0.3 Vdc
6.6.11. Handset Microphone Input
Parameter Conditions MIN TYP MAX UNIT
Maximum Input Range –
Mic(+) to Mic(-) Inputs 3 dBm0 (Max. digital
sample amplitude when PGA
gain set to 0 dB)
32.5 mVrms
Nominal Ref. Level –
Mic(+) to Mic(-) -10 dBm0
Differential Input Resistance –
Mic(+) to Mic(-) 100 kΩ
Microphone Pre-Amplifier Gain 25.6 dB
Bias Voltage on Mic(+) 2.0 or 2.5 V 2.0 2.5 Vdc
Mic Bias Current Capability 0 0.5 mA