GMSK Packet Data Modem
CMX909B
Operating Characteristics
For the following conditions unless otherwise specified:
Xtal Frequency = 4.096MHz, Bit Rate = 8k bits/sec, Noise Bandwidth = Bit Rate,
V
DD
= 3.0V to 5.5V, Tamb = -40°C to +85°C.
Notes
Min.
Typ.
Max.
Units
DC Parameters
I
I
I
I
I
I
(Running, V = 3.0V)
1
1
1
1
1
1
-
-
-
-
-
-
2.0
2.9
0.4
0.9
TBA
TBA
TBA
TBA
TBA
TBA
-
mA
mA
mA
mA
µA
DD
DD
DD
DD
DD
DD
DD
(Running, V = 5.0V)
DD
(Powersave, V = 3.0V)
DD
(Powersave, V = 5.0V)
DD
(Powersave + No Bias)
(Powersave + No Bias or Xtal)
-
µA
AC Parameters
Tx Output
TXOP Impedance (not powersaved)
TXOP Impedance (powersaved)
Signal Level
2
2
3
4
3
-
-
1.0
300
1.0
4
2.5
-
1.1
6
kW
kW
V pk-pk
Bits
0.9
-
Tx Data Delay
TXOP dc offset (wrt Tx mode with data)
(in Tx mode, no data)
(in Rx mode)
-
-
-
TBA
TBA
TBA
-
-
-
mV
mV
mV
(in Powersave, Bias enabled)
Rx Input
RXIN Impedance (at 100Hz)
RXIN Amp Voltage Gain (I/P = 1mVrms at 100Hz)
Input Signal Level
10.0
-
-
-
1.3
-
MW
V/V
V pk-pk
Bits
-
0.7
-
500
1.0
3.5
5
6
Rx Data Delay
Xtal/Clock Input
‘High’ Pulse Width
‘Low’ Pulse Width
Input Impedance (at 100Hz)
Gain (I/P = 1mVrms at 100Hz)
7
7
40
40
10.0
20
-
-
-
-
-
-
-
-
ns
ns
MW
dB
µC Interface
Input Logic ‘1’ Level
Input Logic ‘0’ Level
Input Leakage Current (Vin = 0 to V
Input Capacitance
Output Logic ‘1’ Level (l = 120µA)
Output Logic ‘0’ Level (l = 360µA)
8, 9
8, 9
8, 9
8, 9
9
70%
-
-5.0
-
90%
-
-
-
-
-
-
V
DD
30%
+5.0
-
V
DD
)
µA
pF
DD
10.0
-
-
-
-
V
DD
OH
9,10
10
10%
10
V
DD
µA
OL
‘Off’ State Leakage Current (Vout = V
)
DD
Notes:
1. Not including any current drawn from the modem pins by external circuitry other than R3,
X1, C3 and C4.
2. Small signal impedance, at V = 5.0V and Tamb = 25°C.
DD
3. For ‘…1111000011110000...’ bit sequence, at V = 5.0V and Tamb = 25°C
DD
(output level is proportional to V ).
DD
4. Measured between issuing first task after idle and the centre of the first bit at TXOP
(See Figure 7).
5. For optimum performance, measured at RXFB pin,
for a ‘...11110000...’ bit sequence, at V = 5.0V and Tamb = 25°C.
DD
ã 2001 Consumer Microcircuits Limited
44
D/909B/1
CMLMICRO [ CML MICROCIRCUITS ]
