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11-241
RF2948B
Rev A6 040930
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Transmit Modulator and
LPF
Filter Gain
0
dB
Any setting
Baseband Filter 3dB Bandwidth
1
35
MHz
5th order Bessel LPF, Set by BW CTRL
Passband Ripple
0.1
dB
Group Delay
15
ns
At 35MHz, increasing as bandwidth
decreases.
Group Delay
400
ns
At 2MHz.
Ultimate Rejection
>80
dB
Input Impedance
3
k
Ω
Single-ended
Input AC Voltage
100
mVp-p
Linear, Single-ended.
Input P1dB
200
mVp-p
Single-ended.
Input DC Offset Requirement
1.6
1.7
1.8
V
For correct operation.
IF Frequency Range
45
500
MHz
Differential Output Resistance
22
k
Ω
Between output pins. Open collector when
TX on, Hi Z when TX off
Differential Output Capacitance
0.436
pF
Between output pins.
Shunt Output Capacitance
0.4
pF
From each pin to ground.
I/Q Phase Balance
0
±3
I/Q Gain Balance
0
±1
dB
Conversion Transconductance
0.0185
S
Single-ended voltage input to differential out-
put current conversion gain.
Carrier Output
-18
-26
dBc
Without external offset adjustments.
374MHz. Compared to modulated signal,
100mVP-P input.
Harmonic Outputs
-30
dBc
Transmit VGA and
Upconverter
VGA Gain Range
17
dB
VGA Control Voltage Range
1.0 to 2.0
V
Positive Slope
VGA Gain Sensitivity
17
dB/V
VGA Input Impedance
515-j994
Ω
374MHz
RF Mixer Output Impedance
50
Ω
With matching elements.
VGA/Mixer Conversion Gain
-3 to +14
dB
With 50
Ω match on the output.
VGA/Mixer Output Power
-9
dBm
1dB compression - Single Sideband,
TX GC=1.0V. (Desired signal power)
VGA/Mixer Output Power
-4
dBm
1dB compression - Single Sideband,
TX GC=2.0V. (Desired signal power)