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Preliminary
Product Description
Ordering Information
Typical Applications
Features
Functional Block Diagram
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
Optimum Technology Matching Applied
Si BJT
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1
2
3
4
5
6
7
14
13
12
11
10
9
8
I INPUT A
I INPUT B
Q INPUT A
Q INPUT B
BG OUT
I IF OUT
Q IF OUT
VCC
LO INPUT
GND
GND
GND
I OUT
Q OUT
QUAD
DIV.
BY 2
RF2713
QUADRATURE MODULATOR/DEMODULATOR
Digital and Analog Receivers and
Transmitters
High Data Rate Digital Communications
Spread-Spectrum Communication Systems
Interactive Cable Systems
Portable Battery-Powered Equipment
The RF2713 is a monolithic integrated quadrature modu-
lator/demodulator. The demodulator is used to recover
the I and Q baseband signals from the amplified and fil-
tered IF. Likewise, the inputs and outputs can be reconfig-
ured to modulate I/Q signals onto an RF carrier. The
RF2713 is intended for IF systems where the IF fre-
quency ranges from 100kHz to 250MHz, and the LO fre-
quency is two times the IF. The IC contains all of the
required components to implement the modulation/
demodulation function and contains a digital divider type
90 phase shifter, two double balanced mixers, and base-
band amplifiers designed to interface with Analog to Digi-
tal Converters. The unit operates from a single 3V to 6V
power supply.
3V to 6V Operation
Modulation or Demodulation
IF From 100kHz to 250MHz
Baseband From DC to 50MHz
Digital LO Quadrature Divider
Low Power and Small Size
RF2713
Quadrature Modulator/Demodulator
RF2713 PCBA-D Fully Assembled Evaluation Board (Demodulator)
RF2713 PCBA-M Fully Assembled Evaluation Board (Modulator)
7
Rev A2 010129
0.157
0.150
0.068
0.053
0.244
0.229
0.008
0.004
0.018
0.014
8 MAX
0 MIN
0.034
0.016
0.009
0.007
0.337
0.334
0.050
Package Style: SOIC-14
Preliminary
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RF2713
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Absolute Maximum Ratings
Parameter
Rating
Unit
Supply Voltage
-0.5 to 7.0
V
DC
IF Input Level
500
mV
PP
Operating Ambient Temperature
-40 to +85
C
Storage Temperature
-40 to +150
C
Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Overall
T = 25C, V
CC
=3.0V, IF = 100MHz,
LO= 200MHz, F
MOD
= 500kHz
IF Frequency Range
0.1 to 250
MHz
For IF frequencies below ~2.5MHz, the LO
should be a square wave. IF frequencies
lower than 100kHz are attainable if the LO is
a square wave and sufficiently large DC
blocking capacitors are used.
Baseband Frequency Range
DC to 50
MHz
Input Impedance
1200 || 1pF
Each input, single-ended
LO
Frequency
Twice (2x) the IF frequency. For IF frequen-
cies below ~2.5MHz, the LO should be a
square wave. IF frequencies lower than
100kHz are attainable if the LO is a square
wave and sufficiently large DC blocking
capacitors are used.
Level
0.06 to 1
V
PP
Input Impedance
500 || 1pF
Demodulator
Configuration
IF
IN
=28mV
PP
, LO= 200mV
PP
, Z
LOAD
=10k
Output Impedance
50 || 1pF
Each output, I
OUT
and Q
OUT
Maximum Output
1.4
V
PP
Saturated
Voltage Gain
20
dB
V
CC
= 3.0V
22.5
24
25.1
dB
V
CC
= 5.0V
Noise Figure
24
dB
Single Sideband, IF Input of device reac-
tively matched
35
dB
Single Sideband, 50
shunt resistor at IF
Input
Input Third Order Intercept Point
(IIP
3
)
-22
dBm
V
CC
= 3.0V, IF Input of device reactively
matched
-11
dBm
V
CC
= 3.0V, 50
shunt resistor at IF Input
-19
V
CC
= 5.0V, IF Input of device reactively
matched
-8
dBm
V
CC
= 5.0V, 50
shunt resistor at IF Input
-28
dBm
V
CC
= 5.0V, IF Input of device reactively
matched, Z
LOAD
= 50
I/Q Amplitude Balance
0.1
0.5
dB
Quadrature Phase Error
1
DC Output
800
mV
V
CC
= 3.0V, I
OUT
and Q
OUT
to GND
2.0
2.4
2.8
V
V
CC
= 5.0V, I
OUT
and Q
OUT
to GND
DC Offset
<10
100
mV
I
OUT
to Q
OUT
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).
Preliminary
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Parameter
Specification
Unit
Condition
Min.
Typ.
Max.
Modulator Configuration
IF
IN
=28mV
PP
, LO= 200mV
PP
,
Z
LOAD
= 1200
Maximum Output
200
mV
PP
Saturated
Input Voltage
90
mV
PP
Single Sideband, 1dB Gain Compression.
Voltage Gain
6
dB
Single Sideband
I/Q Amplitude Balance
0.1
dB
Quadrature Phase Error
<1
Carrier Suppression
25
dBc
Unadjusted. Carrier Suppression may be
optimized further by adjusting the DC offset
level between the A and B inputs.
Sideband Suppression
30
dBc
Power Supply
Voltage
2.7 to 6
V
Operating limits
Current
8
mA
V
CC
= 3.0V
8
10
12
mA
V
CC
= 5.0V
Preliminary
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Pin
Function
Description (Demodulator Configuration)
Interface Schematic
1
I INPUT A
When the RF2713 is configured as a Quadrature Demodulator, both
mixers are driven by the IF. Whether driving the mixers single-endedly
(as shown in the application schematic) or differentially, the A Inputs
(pins 1 and 3) should be connected to each other. Likewise, both B
Inputs (pins 2 and 4) should be connected to each other. This ensures
that the IF will reach each mixer with the same amplitude and phase,
yielding the best I and Q output amplitude and quadrature balance.
Note that connecting the inputs in parallel changes the input imped-
ance (see the Gilbert Cell mixer equivalent circuit). The single-ended
input impedance (as shown in the application circuit) becomes 630
,
but in the balanced configuration, the input impedance would remain
1260
.
The mixers are Gilbert Cell designs with balanced inputs. The equiva-
lent schematic for one of the mixers is shown on the following page.
The input impedance of each pin is determined by the 1260
resistor
to V
CC
in parallel with a transistor base. Note from the schematic that
all four input pins have an internally set DC bias. For this reason, all
four inputs (pins 1 through 4) should be DC blocked. The capacitance
values of the blocking capacitors is determined by the IF frequency.
When driving single-endedly, both the series (pins 1 and 3) and shunt
(pins 2 and 4) blocking capacitors should be low impedances, relative
to the 630
input impedance.
2
I INPUT B
Same as pin 1, except complementary input.
See pin 1.
3
Q INPUT A
Same as pin 1, except Q Buffer Amplifier.
See pin 1.
4
Q INPUT B
Same as pin 3, except complementary input.
See pin 1.
5
BG OUT
Band Gap voltage reference output. This voltage output is held con-
stant over variations in supply voltage and operating temperature and
may be used as a reference for other external circuitry. This pin should
not be loaded such that the sourced current exceeds 1mA. This pin
should be bypassed with a large (0.1
F) capacitor.
6
I IF OUT
This pin is not used in the Demodulator Configuration, but must be con-
nected to V
CC
in order to properly bias the I mixer.
7
Q IF OUT
Same as pin 6, except Q mixer.
Same as pin 6.
8
Q OUT
Q Mixer's Baseband Output. This pin is NOT internally DC blocked and
has DC present due to internal biasing. This is an emitter-follower type
output with an internal 2k
pull-down resistor. Even though the AC out-
put impedance is ~50
, this pin is intended to drive only high imped-
ance loads such as an opamp or an ADC. The output transistor is NOT
biased such that it can drive a large signal into a 50
load. DC cou-
pling of this output is permitted provided that the DC impedance to
ground, which appears in parallel with the internal pull-down resistor, is
significantly greater than 2k
.
9
I OUT
Same as pin 8, except Q Mixer's Baseband Output.
Same as pin 8.
10
GND
Ground connection. Keep traces physically short and connect immedi-
ately to ground plane for best performance.
11
GND
Same as pin 10.
12
GND
Same as pin 10.
1260
1260
INPUT A
V
CC
V
CC
INPUT B
IF OUT
I/Q OUT
2 k
V
CC
Preliminary
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Pin
Function
Description (Demodulator Configuration)
Interface Schematic
13
LO INPUT
High impedance, single-ended modulator LO input. The LO applied to
this pin is frequency divided by a factor of 2 and becomes the "Carrier".
For direct demodulation, the Carrier is equal in frequency to the center
of the input IF spectrum (except in the case of SSB/SC). The input
impedance is determined by an internal 500
bias resistor to V
CC
. An
external blocking capacitor should be provided if the pin is connected to
a device with DC present. Matching the input impedance is typically
achieved by adding a 51
resistor to ground on the source side of the
AC coupling capacitor. For the LO input, maximum power transfer is not
critical. The internal LO switching circuits are controlled by the voltage,
not power, into the part. In cases where the LO source does not have
enough available voltage, a reactive match (voltage transformer) can
be used. The LO circuitry consists of a limiting amplifier followed by a
digital divider. The limiting amp ensures that the flip-flop type divider is
driven with a square wave over a wide range of input levels. Because
the flip-flop uses the rising and falling edges of the limiter output, the
quadrature accuracy of the Carrier supplied to the mixers is directly
related to the duty cycle, or equivalently to the even harmonic content,
of the input LO signal. In particular, care should be taken to ensure that
the 2xLO level input to this pin is at least 20dB below the LO level. Oth-
erwise, the LO input is not sensitive to the type of input wave form,
except for IF frequencies below ~2.5MHz, in which case the LO input
should be a square wave, in order to ensure proper triggering of the
flip-flops. IF frequencies below 100kHz are attainable if the LO is a
square wave and sufficiently large DC blocking capacitors are used.
14
VCC
Voltage supply for the entire device. This pin should be well bypassed
at all frequencies (IF, LO, Carrier, Baseband) that are present in the
part.
500
500
LO IN
V
CC
V
CC
Preliminary
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Pin
Function
Description (Modulator Configuration)
Interface Schematic
1
I INPUT A
When the RF2713 is configured as a Quadrature Modulator, each
mixer is driven by an independent baseband modulation channel (I and
Q). The mixers can be driven single-endedly (as shown in the modula-
tor application circuit) or differentially. When driving single-endedly, the
B Inputs (pins 2 and 4) should be connected to each other. This
ensures that the baseband signals will reach each mixer with the same
DC reference, yielding the best carrier suppression. Note that the input
impedance changes according to the drive mode (see the mixer equiv-
alent circuit on the previous page). The single-ended input impedance
(as shown in the modulator application circuit) is 1200
for each of the
two inputs. In the balanced configuration, the input impedance would
be 2400
for each of the two inputs.
The mixers are Gilbert Cell designs with balanced inputs. The equiva-
lent schematic for one of the mixers is shown on the previous page.
The input impedance of each pin is determined by the 1200
resistor
to V
CC
in parallel with a transistor base. Note from the schematic that
all four input pins have an internally set DC bias. For this reason, all
four inputs (pins 1 through 4) should be DC blocked. The capacitance
values of the blocking capacitors is determined by the baseband fre-
quency. When driving single-endedly, both the series (pins 1 and 3) and
shunt (pins 2 and 4) blocking capacitors should be low impedances, rel-
ative to the input impedance.
DC bias voltages may be supplied to the inputs pins, if required, in
order to increase the amount of carrier suppression. For example, the
DC levels on the reference inputs (pins 2 and 4) may be offset from
each other by adding different resistor values to ground. These resis-
tors should be larger than 2k
. Note from the mixer schematic that all
four input pins have an internally set DC bias. If DC bias is to be sup-
plied, the allowable ranges are limited. For 5V applications, the DC ref-
erence on both I pins or both Q pins must not go below 2.7V
DC
, and in
no case should the DC voltage on any of the four pins go below 2.0V
DC
or above 5.5V
DC
. IF a DC reference is to be supplied, the source must
also be capable of sinking current. If optimizing carrier suppression fur-
ther is not a concern, it is recommended that all four inputs (pins 1
through 4) be DC blocked.
2
I INPUT B
Same as pin 1, except complementary input.
See pin 1.
3
Q INPUT A
Same as pin 1, except Q Buffer Amplifier.
See pin 1.
4
Q INPUT B
Same as pin 3, except complementary input.
See pin 1.
5
BG OUT
Band Gap voltage reference output. This voltage output is held con-
stant over variations in supply voltage and operating temperature and
may be used as a reference for other external circuitry. This pin should
not be loaded such that the sourced current exceeds 1mA. This pin
should be bypassed with a large (0.1
F) capacitor.
6
I IF OUT
Connecting pins 6 and 7 to each other accomplishes the summing
function of the upconverted I and Q channels. In addition, because
these outputs are open collector type, they must be connected to V
CC
in order to properly bias the Gilbert Cell mixers. Maximum gain and out-
put power occur when the load on these two pins is ~1200
. In most
applications the impedance of the next stage will be lower and a reac-
tive impedance transforming match should be used if maximum gain
and output level are of concern. Biasing, DC blocking, and impedance
transformation can simultaneously be achieved with the shunt-L /
series-C topology shown in the Application Circuit. The inductance and
capacitance values are chosen to achieve a specific impedance trans-
forming ratio at a specific IF frequency. For applications where the gain
is not as critical, a 1200
resistor may be added in parallel with a
choke inductor in place of the matching inductor. If neither gain nor out-
put level is critical, the inductor may be replaced with a resistor that
sets the desired source impedance to drive the next stage. If the next
stage is an "open" at DC, the blocking capacitor may be eliminated.
1260
1260
INPUT A
V
CC
V
CC
INPUT B
IF OUT
Preliminary
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RF2713
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Pin
Function
Description (Modulator Configuration)
Interface Schematic
7
Q IF OUT
Same as pin 6, except complementary input.
Same as pin 6.
8
Q OUT
Pins 8 and 9 are not used in a normal quadrature modulator applica-
tion, and are left unconnected. Note, however, that the outputs of each
of these pins are independent upconverted I and Q channels. These
signals may be useful in other applications where independent IF chan-
nels are needed. Also note that these outputs are optimized as base-
band outputs for the demodulator configuration. As a result, the gain
rolls-off quickly with increasing frequency. This gain roll-off will limit the
usefulness of these pins as independent I and Q upconverters. If these
outputs are to be used, please refer to the Demodulator pin descrip-
tions regarding load impedances.
9
I OUT
Same as pin 8, except Q Mixer's Output.
Same as pin 8.
10
GND
Ground connection. Keep traces physically short and connect immedi-
ately to ground plane for best performance.
11
GND
Same as pin 10.
12
GND
Same as pin 10.
13
LO INPUT
High impedance, single-ended modulator LO input. The LO applied to
this pin is frequency divided by a factor of 2 and becomes the "Carrier".
For modulation, the Carrier is the center of the modulated output spec-
trum (except in the case of SSB/SC). The input impedance is deter-
mined by an internal 500
bias resistor to V
CC
. An external blocking
capacitor should be provided if the pin is connected to a device with DC
present. Matching the input impedance is typically achieved by adding
a 51
resistor to ground on the source side of the AC coupling capaci-
tor. For the LO input, maximum power transfer is not critical. The inter-
nal LO switching circuits are controlled by the voltage, not power, into
the part. In cases where the LO source does not have enough available
voltage, a reactive match (voltage transformer) can be used. The LO
circuitry consists of a limiting amplifier followed by a digital divider. The
limiting amp ensures that the flip-flop type divider is driven with a
square wave over a wide range of input levels. Because the flip-flop
uses the rising and falling edges of the limiter output, the quadrature
accuracy of the Carrier supplied to the mixers is directly related to the
duty cycle, or equivalently to the even harmonic content, of the input LO
signal. In particular, care should be taken to ensure that the 2xLO level
input to this pin is at least 20dB below the LO level. Otherwise, the LO
input is not sensitive to the type of input wave form, except for IF fre-
quencies below ~2.5MHz, in which case the LO input should be a
square wave, in order to ensure proper triggering of the flip-flops. IF fre-
quencies below 100kHz are attainable if the LO is a square wave and
sufficiently large DC blocking capacitors are used.
14
VCC
Voltage supply for the entire device. This pin should be well bypassed
at all frequencies (IF, LO, Carrier, Baseband) that are present in the
part.
I/Q OUT
2 k
V
CC
500
500
LO IN
V
CC
V
CC
Preliminary
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Gilbert Cell Mixer Equivalent Circuit
LO/2+
LO/2-
IF+
IF-
I/Q INPUT B
I/Q INPUT A
Preliminary
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Application Schematic - Demodulator Configuration
Application Schematic - Modulator Configuration
1
2
3
4
5
6
7
14
13
12
11
10
9
8
QUAD
DIV.
BY 2
I OUT
Q OUT
LO
IF IN
10 nF
10 nF
10 nF
100 nF
V
CC
V
CC
100 nF
51
51
1
2
3
4
5
6
7
14
13
12
11
10
9
8
QUAD
DIV.
BY 2
LO
BASEBAND I
100 nF
100 nF
V
CC
10 nF
51
BASEBAND Q
100 nF
51
51
IF OUT
1 K
10 nF
V
CC
100 nF
100 nF
Preliminary
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Evaluation Board Schematic - Demodulator Configuration
(Download Bill of Materials from www.rfmd.com.)
Evaluation Board Schematic - Modulator Configuration
1
2
3
4
5
6
7
14
13
12
11
10
9
8
QUAD
DIV.
BY 2
R1
50
VCC
VCC
2713401-
C1
0.1 uF
J1
IF IN
C2
0.1 uF
C3
0.1 uF
C5
0.1 uF
R2
50
C4
0.1 uF
50
strip
J4
LO
50
strip
50
strip
J3
I OUT
50
strip
J2
Q OUT
P1-3
VCC
NC
GND
P1
1
2
3
CON3
1
2
3
4
5
6
7
14
13
12
11
10
9
8
QUAD
DIV.
BY 2
R1
50
VCC
2713400-
C1
0.1 uF
J1
I
C4
0.1 uF
C6
0.1 uF
R4
50
C5
0.1 uF
50
strip
J4
LO
50
strip
C2
0.1 uF
C3
0.1 uF
R3
1 k
J3
IF OUT
50
strip
R2
50
50
strip
J2
Q
VCC
P1
1
2
3
CON3
P1-1
VCC
NC
GND
Preliminary
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Evaluation Board Layout
Demodulator Configuration (2713 PCBA-D)
Board Size 2.0" x 2.0"
Board Thickness 0.031", Board Material FR-4
Preliminary
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Evaluation Board Layout
Modulator Configuration (2713 PCBA-M)
Board Size 2.0" x 2.0"
Board Thickness 0.031", Board Material FR-4
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