Product Specs

TPRMTPRM ProductSpec.doc Proprietary Information Tellus Technology, Inc.
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/CTS 6 O Clear to send output from the modem
A logic low indicates that the modem is able to accept data. A
logic high indicates that the modem is not able to accept data
and therefore the host should not send any data. If data is sent
while this output is high, the data will not be received correctly
by the modem. This is a CMOS output.
/RTS 7 I Ready to send input from the host
A logic low indicates that the host is able to accept data. A
logic high indicates that the host is not able to accept data;
therefore, the modem should not send any data. If data is sent
while this input is high, the data may not be received correctly
by the host. This is a CMOS input.
TX_IND 9 O Transmit indication
This CMOS output goes logic high when the modem is
transmitting
RSSI 10 O Received signal strength
This CMOS output must see a high impedance load. It
provides an indication of received signal level. For basic
indication, route to the base of a transistor through a 10K
resistor with the emitter grounded. When the transistor
collector sinks current, then RF signal is being received.
RESET 11 I Reset input
This is a CMOS input, providing a hardware reset to the
modem. Set to a logic high to reset the modem. The pulse
width must be at least 1us in duration.
Reserved 12 N/A Reserved. This pin must be left unconnected at this time.
Inputs: RXD, /RTS, RESET
These are Schmitt Trigger inputs.
Vt
+
= 3.0 V (typical)
Vt
-
= 2.0 V (typical)
Vt
+
- Vt
-
= 0.5 V (min)
Outputs: TXD, /CTS, TX_IND
V
oh
= 0.7 VDD (min), I
oh
= -2.5 mA
= V
dd
– 0.5 (min), I
oh
= -100 A
V
ol
= 0.45 V (max), I
oh
= 2.5 mA