RF2454
• Digital and Spread Spectrum Systems
• AM, SSB, DSB Modulation
• GMSK, QPSK, DQPSK, QAM Modulation
• Image-Reject Upconverters
• Private Mobile Radio Systems
1
Si CMOS
POWER
CONTROL
I SIG 4
I REF 5
.065
.043
8 °MAX
0°MIN
.050
.016
.010
.007
!"
• Single 3V to 5V Power Supply
• Low Power and Small Size
• CMOS Compatible Power Down Control
1 3 GND2
• Excellent Amplitude and Phase Balance
• Low Broadband Noise Floor
• 200MHz to 600MHz Operation
1 1 GND
Σ
1 0 GND1
+45°
-45°
Q REF 6
9 PHASE
Q SIG 7
8 LO IN
.244
.228
1 4 RF OUT
1 2 GND
PD 3
VDD1 2
VDD2 1
5
.050
SiGe HBT
Si Bi-CMOS
GaAs MESFET
GaAs HBT
Si BJT
.010
.004
.344
.337
.018
.014
MODULATORS AND
UPCONVERTERS
.157
.150
The RF2454 is a monolithic integrated universal modulation system capable of generating modulated AM, PM, or
compound carriers in the VHF and UHF frequency range.
The IC contains all of the required components to implement the modulation function including differential amplifiers for the baseband inputs, a 90° hybrid phase splitter,
limiting LO amplifiers, two balanced mixers, a combining
amplifier, and an output RF amplifier which will drive a
50Ω load. Component matching, which can only be
accomplished with monolithic construction, is used to full
advantage to obtain excellent amplitude balance and high
phase accuracy. The unit features low power consumption, single power supply operation and adjustment free
operation with no external parts required to operate the
part as specified.
Rev A4 000710
Powered by ICminer.com Electronic-Library Service CopyRight 2003
RF2454
RF2454 PCBA
VHF Quadrature Modulator
Fully Assembled Evaluation Board
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
5-49
RF2454
Supply Voltage
Power Down Voltage
Input LO and RF Levels
Operating Ambient Temperature
Storage Temperature
Rating
Unit
-0.5 to +7.5
-0.5 to VDD +0.4
+10
-40 to +85
-40 to +150
VDC
VDC
dBm
°C
°C
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Specification
Min.
Typ.
Max.
Parameter
Unit
T=25°C, VDD =5VDC, I&Q inputs=2VPP
LO Input
200 to 600
-3 to +6
1.2:1
Input Impedance
86-j242
MHz
dBm
Frequency Range
Power Level
Input VSWR
Ω
63-j139
50-j106
-1
+1
50
1.5:1
-140
25
25
18
Turn On/Off Time
PD Input Resistance
Power “ON”
Power “OFF”
dB
°
+3
dBm
>40
>40
dBm/Hz
dB
dB
With external 50Ω termination; see application schematic, note A.
At 200MHz, without external 50Ω termination.
At 400MHz, without external 50Ω termination.
At 600MHz, without external 50Ω termination.
I & Q signals for 0dBm output power.
I & Q signals for +5dBm output power.
In-phase and quadrature signals.
ISIG -IREF and QSIG -QREF; to achieve maximum carrier suppression.
From 350MHz to 450MHz.
VDD =5V, LO Power=0dBm, LO
Freq=400MHz, SSB, I&Q input=0.7VPP
Modulation DC offset can be externally
adjusted for optimum suppression. Suppression is typically better than 25dB without
adjustment.
<100
>1
VCC
0
ns
MΩ
V
V
Threshold voltage
Threshold voltage
5
3 to 5.5
28
0.5
V
V
mA
mA
Specifications
Operating Limits
Operating
Power Down
±3
Power Down
RF Output
Output Power
Output Impedance
Output VSWR
Broadband Noise Floor
Sideband Suppression
Carrier Suppression
150
0.2
±1
Amplitude Error (I/Q)
Quadrature Phase Error
MHz
V
V
V
V
Ω
mV
DC to 100
2.0 to 3.0
VREF ±0.7
VREF ±1.5
VREF ±2.5
3000
50
Frequency Range
Reference Voltage (VREF)
Modulation (I&Q)
Modulation (I&Q)
Maximum Modulation (I&Q)
Input Resistance
DC Offset
Modulation Input
MODULATORS AND
UPCONVERTERS
5
Condition
Absolute Maximum Ratings
Parameter
Power Supply
Voltage
Current
5-50
Powered by ICminer.com Electronic-Library Service CopyRight 2003
39
2
Rev A4 000710
RF2454
I SIG
I REF
6
Q REF
7
Q SIG
8
LO IN
5
10
GND1
11
GND
12
13
GND
GND2
PHASE
9
I SIG
Reference voltage for the I mixer. This voltage should be the same as
See pin 4.
the DC voltage supplied to the I SIG pin. To obtain a carrier suppression of better than 40dB it may be tuned ±0.15V (relative to the I SIG
DC voltage). Without tuning, it will typically be better than 25dB.
Reference voltage for the Q mixer. This voltage should be the same as Same as pin 5.
the DC voltage supplied to the Q SIG pin. To obtain a carrier suppression of better than 40dB it may be tuned ±0.15V (relative to the Q SIG
DC voltage). Without tuning, it will typically be better than 25dB. The
SIG and REF inputs are inputs of a differential amplifier. Therefore the
REF and SIG inputs are interchangeable. If swapping the I SIG and I
REF pins, Q SIG and Q REF also need to be swapped to maintain correct phase. It is also possible to drive the SIG and REF inputs in a balanced mode. This will increase the gain.
Baseband input to the Q mixer. This pin is DC coupled. Maximum out- Same as pin 4.
put power is obtained when the input signal has a peak to peak amplitude of 5V. The DC level supplied to this pin should be 2.5±0.5V.
The input of the phase shifting network. This high impedance input can
LO IN
be matched with an external 56Ω termination resistor. This pin is internally connected to ground through a 4kΩ resistor. Putting a DC voltage
on this pin is not recommended. However, connecting this pin to
ground, e.g., through a shunt inductor, is allowed.
5
I REF
MODULATORS AND
UPCONVERTERS
4
PD
3
VDD1
Interface Schematic
Power supply for the RF Output amplifier. An external RF bypass
capacitor is needed. The trace length between the pin and the bypass
capacitor should be minimized. The ground side of the capacitor should
connect immediately to the ground plane.
Power supply for all other circuits. An external RF bypass capacitor is
needed.
Power Down control. When this pin is 0V all circuits are turned off, and
when +5V all circuits are operating. This is a high impedance input,
internally connected to the gates of a few FETs. To minimize current
consumption in power down mode, this pin should be as close to 0V as
possible. In order to maximize output power this pin should be as close
to +5V as possible during normal operation.
Baseband input to the I mixer. This pin is DC coupled. Maximum output
power is obtained when the input signal has a peak to peak amplitude
of 5V. The DC level supplied to this pin should be 2.5±0.5V. The SIG
and REF inputs are inputs of a differential amplifier. Therefore the REF
and SIG inputs are interchangeable. If swapping the I SIG and I REF
pins, the Q SIG and Q REF also need to be swapped to maintain the
correct phase. It is also possible to drive the SIG and REF inputs in a
balanced mode. This will increase the gain.
2
Description
Function
VDD2
Pin
1
This pin allows to adjust the phase of the I/Q signals. However, the control is very sensitive and hard to control. Control voltage change for a
few degrees adjustment is in the order of 10mV. Device to device and
temperature variation are not characterized. Therefor it is not recommended to use this pin and leave it not connected. Do NOT connect to
ground.For compensating large errors in the I/Q signals supplied to the
device or in control loops this pin may prove useful.
Ground connection of the LO phase shift network. This pin should be
connected directly to the ground plane.
Ground connection for other circuits. Keep traces short and connect to
ground plane immediately.
Same as pin 11.
PHASE
Ground connection for the RF output stage. A good ground connection
is especially important at this pin to avoid interference with other circuits.
Rev A4 000710
Powered by ICminer.com Electronic-Library Service CopyRight 2003
5-51
RF2454
Pin
14
Function
RF OUT
Description
Interface Schematic
50Ω output. This pin carries a DC voltage and an external blocking
capacitor is recommended.
!"
VDD
5
100 pF
1
3
4
11
100 Ω
100 Ω
5
6
7
10
-45°
9
100 pF
50 Ω µstrip
LO INPUT
8
56 Ω
Note A
Optional; input impedance is about 63-j139Ω at 400 MHz
without resistor. SMD resistor mounted adjacent to
package pin, grounded through a via to the ground plane.
NOTE A:
Coupling Capacitor
+45°
Σ
100 Ω
100 Ω
VREF
I INPUT
ZIN=100
12
Coupling Capacitor
I INPUT
ZIN=100
RF OUTPUT
13
MODULATORS AND
UPCONVERTERS
POWER
CONTROL
2
100 pF
POWER
DOWN
50 Ω µstrip
14
100 nF
CMOS
RF OUT
5-52
Powered by ICminer.com Electronic-Library Service CopyRight 2003
Rev A4 000710
RF2454
# $
!"
(Download Bill of Materials from www.rfmd.com.)
P2
P2-3
1
GAIN 1
2
GND
3
GAIN 2
2454400 Rev A
C3
100 pF
C2
100 nF
1
C1
33 pF
2
POWER
CONTROL
13
12
3
50 Ω µstrip
I SIG
J1
4
P1-3
+45°
-45°
9
6
C4
100 pF
50 Ω µstrip
8
LO IN
J3
R1
56 Ω
7
5
10
Σ
50 Ω µstrip
Q SIG
J2
RF OUT
J4
11
5
C5
33 pF
50 Ω µstrip
14
P1-1
MODULATORS AND
UPCONVERTERS
P2-1
Rev A4 000710
Powered by ICminer.com Electronic-Library Service CopyRight 2003
5-53
RF2454
# $%&
'('
MODULATORS AND
UPCONVERTERS
5
5-54
Powered by ICminer.com Electronic-Library Service CopyRight 2003
Rev A4 000710