Datasheet

AISG Integrated Transceiver
MAX9947
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Applications Information
Emission Output Profile
The AISG standard defines the maximum spectrum emis-
sion that all the OOK modulating devices must be compli-
ant with. Such a spectrum is represented in Figure 3.
The MAX9947 is compliant with the AISG standard.
An external 470pF capacitor connected between RXIN
and ground is recommended for compliance above
25MHz (see the Typical Application Circuit (Connectivity
at the Base) and Typical Application Circuit (Connectivity
at the Tower)).
Figure 2. The MAX9947 on the Tower: Communication Flow is from the Tower to the Base
Table 1. Bit-Time Duration Selector
Figure 3. AISG Standard Modem Spectrum Emission Mask
*DIRMD1 and DIRMD2 are internally pulled down.
IDLE (LOGIC-LEVEL HIGH)
IDLE
IDLE
START
BIT
t
TX
1 1 1
0 0 0 0
1 STOP BIT IDLE
IDLE
IDLE (LOGIC-LEVEL LOW)
DIR
RXOUT
TXOUT AND RXIN
TXIN
DIRMD2* DIRMD1* AISG DATA RATE (kbps) UNITY BIT TIME (µs)
0 0 9.6 104.16
0 1 38.4 26.04
1 0 115.2 8.68
1 1 Not used Not used
9kHz
1MHz
1MHz
400kHz
200kHz
f
O
10MHz 20MHz 30MHz 400MHz 12.75GHz
-67dBm
-125dBm
-36dBm-36dBm
-25dBm-25dBm
-5dBm-5dBm
+5dBm