Datasheet RF2423, RF2423PCBA Datasheet (RF Micro Devices)

NOT FOR NEW DESIGNS

5-35

5

MODULATORS AND

UPCONVERTERS

Product Description

Ordering Information

Typical Applications

Features

Functional Block Diagram

RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA

Tel [phone]

Fax [phone]

http://www.rfmd.com

Optimum Technology Matching® Applied

Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS

!

SiGe HBT

Si CMOS

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

GC

PHASE

VDD1

GND2

LO IN

GND1

I REF

I SIG

STAND BY

VDD2

VDD3

GND3

RF OUT

GND4

Q REF

Q SIG

POWER

CONTROL

Σ

-45°
+45°

RF2423

100mW SPREAD-SPECTRUM TRANSMITTER IC

• Digital and Analog Communic a ti on Syst ems

• Spread-Spectrum Communication Systems

• Portable Battery-Powered Equipment

• GMSK, QPSK, DQPSK, QAM Modulation

• AM, SSB, DSB Modulation

The RF2423 is a monolithic integrated transmitter IC
capable of universal d irect modulation for UHF AM, PM,
or compound carriers. The transmitter may be used
stand-alone for applications requiring not more than
100mW output power, or may be used to drive a final
power amplifier. The maximum output level is 100mW,
and is adjustable over a 25dB range by a single positive
voltage. This low-cost IC implements differential amplifi­ers for the modulation inputs, 90 degree carrier phase
shift network, carrier limiting ampl ifiers , tw o match ed dou­bly-balanced mixers, variable gain summing amplifier for
level control, and 100mW linear (class AB) output ampli­fier.

• Single 5V Power Supply

• 100mW Output Power Into 50Ω

• 25dB Gain Control Range

• Excellent Phase & Amplitude Balance

• Digitally Controlled Stand-By Mode

• 800MHz to 1000MHz Operation

RF2423 100mW Spread-Spectrum Transmitter IC
RF2423 PCBA Fully Assembled Evaluation Board

5

Rev A3 001218

.010
.004

.065
.043

.244
.228

.050
.016

.010
.007

.157
.150

.393
.386

.018
.014

1

.050

8°MAX

0°MIN

Package Style: SOP-16

5-36

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Absolute Maximum Ratings

Parameter Rating Unit

Supply Voltage -0.5 to +7.5 V

DC

Power Down Voltage (VPD)V

DD

+0.4 V

DC

Input LO and RF Levels +6 dBm
Operating Ambient Temperature -40 to +85 °C
Storage Temperature -40 to +150 °C

Parameter

Specification

Unit Condition

Min. Typ. Max.

Carrier Input (LO IN)

T=25°C, VDD=5.3V, VGC=5.3V

Frequency Range 800 to 1000 MHz
Power Level 0 to +6 dBm
Input Impedance 55-j120 Ω 915MHz

Modulation Input

Frequency Range DC to 100 MHz
Reference Voltage (V

REF

) 2.0 to 3.0 V

Modulation for 100mW Output

Power (I & Q)

V

REF

±2 V

Maximum Modulation (I & Q) V

REF

±2.5 V

Quadrature Phase Error ±3 °
Input Impedance 3000 Ω
DC Offset (I & Q) 40 200 mV

RF Output

VDD=5.3V, VGC=5.3V, LO power=0dBm,
LOfrequency=915MHz, SSB, I/Q=2.0V

P

sine wave, V

REF

=3V

Output Power +22 +22 dBm

-15 -10 +5 dBm V

GAIN

=0V

Output Impedance 50 Ω
Output VSWR 2:1
Second Harmonic Output -45 dBc
Other Harmonics Output <-20 dBc
Sideband Suppression 25 35 dB
Carrier Suppression 22 30 dB Modulation DC offset can be externally

adjusted for optimum suppression. Carrier
suppression is then typically better than
40dB.

Output Level Control

Control Range 25 dB
Control Voltage 1 to 4 V
Control Input Current <1.5 mA

Standby Mode

Turn On/Off Time <100 ns
STANDBY Input Impedance >50 kΩ
Power Down “ON” V

CC

V Threshold voltage; Part is turned “ON”

Power Down “OFF” 0 V Threshold voltage; Part is turned “OFF”

Power Supply

Voltage 5 V Specifications

4.5 to 6.0 V Operating limits

Current 60 110 170 mA Total, 100mW output power

50 mA Total, minimum output power

2 20 mA Standby mode

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).

5-37

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Pin Function Description Interface Schematic

1GC

Gain control of the RF amplifier. This pin can be used to control the out­put power over a 25dB range. Output power is the lowest when the
control voltage is 1V or lower , and the highest when set to 4V or higher.
When a fixed maximum output level is needed, it is recommended to
connect this pin to VDD.

2 PHASE

This pin adjusts 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. Therefore it is not recom­mended to use this pin; leave it not connected. Do NOT connect it to
ground. For compensating large errors in the I/Q signals supplied to the
device or in control loops, this pin may prove useful.

3VDD1

Power supply to all circuits except the RF output stages. It is recom­mended to put some RF decoupling on this pin, though it is not critical.
An optional 0.1µF capacitor is required if no other low frequency
bypass capacitor is nearby.

4GND2

Ground connection for the gain controlled RF amplifier. Keep traces
physically short and connect immediately to ground plane for best per­formance.

5 LO IN

Modulator LO input. A series 22nH inductor can be used for matching.
This pin is NOT internally DC blocked. An external blocking capacitor
must be provided if the pin is connected to a device with DC present. A
DC path to ground (i.e. an inductor or resistor to ground) is, however,
acceptable at this pin. If a blocking capacitor is required, a value of
33pF is recommended.

6GND1

Ground connection for the baseband, LO and mixer circuits. Keep
traces physically short and connect immediately to ground plane for
best performance.

7I REF

Reference voltage for the I mixer. This voltage should be the same as
the DC voltage supplied to the I SIG pin. To obtain a carrier suppres­sion of better than 25dB it may be tuned ±0.15V (relative to the I SIG
DC voltage). Without tuning, it will typically be better than 25dB. Input
impedance of this pin is about 3kΩ.

8I SIG

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 VDD2/2. Input imped­ance of this pin is about 3kΩ.

9Q SIG

Baseband input to the Q 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 VDD2/2. Input
impedance of this pin is about 3kΩ.

10 Q REF

Reference voltage for the Q mixer. This voltage should be the same as
the DC voltage supplied to the Q SIG pin. To obtain a carrier suppres­sion of better than 25dB it may be tuned ±0.15V (relative to the Q SIG
DC voltage). Without tuning it will typically be better than 25dB. Input
impedance of this pin is about 3kΩ.

10 k

Ω

5 k

Ω

GC

PHASE

4 k

Ω

LO IN

1 k

Ω

2 k

Ω

2 k

Ω

I SIGI REF

1 k

Ω

1 k

Ω

2 k

Ω

2 k

Ω

Q SIGQ REF

1 k

Ω

5-38

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Pin Function Description Interface Schematic

11 GND4

Ground connection for the RF driver and output stage. Keep traces
physically short and connect immediately to ground plane for best per­formance. Having a good ground connection on this pin is extremely
important due to the high RF levels in the circuits connected to this pin.

12 RF OUT

50Ω RF output. This pin is not internally DC blocked and an external
blocking capacitor of 22pF is needed.

13 GND3

Ground connection for the RF driver and output stage. Keep traces
physically short and connect immediately to ground plane for best per­formance. Having a good ground connection on this pin is extremely
important due to the high RF levels in the circuits connected to this pin.

14 VDD3

Power supply for the RF output stage. A 33pF external bypass capaci­tor is required and an optional 0.1µF will be required if no other low fre­quency bypass capacitors are nearby . The trace length between the pin
and the bypass capacitors should be minimized. The ground side of the
bypass capacitors should connect immediately to ground plane.
Having good bypassing on this pin is especially important because of
the high levels of RF signal on the circuits connected to this pin.

15 VDD2

Power supply f or the RF driver stage. A 33pF external bypass capacitor
is required and an optional 0 .1µF will be required if no other low fre­quency bypass capacitors are near by. The trace length between the
pin and the bypass capacitors should be minimized. The ground side of
the bypass capacitors should connect immediately to ground plane.
Having good bypassing on this pin is especially important because of
the high levels of RF signal on the circuits connected to this pin.

16 STANDBY

Standby mode control. When this pin is 0V all circuits are turned off,
and when this pin is VD D all circuits are operating. This is a high
impedance input, internally connected to the gate of a few transistors.
To minimize current consumption in power down mode, this pin should
be as close to 0 V as possible, or even a little negative. Turn-on voltage
of some parts of the circuit may be as low as 0.0 V. In order to maxi­mize output power this pin should be as close to VDD as possible dur­ing normal operation.

RF OUT

V

DD

5-39

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Application Schematic

C

Note 1

Note 1 100 nF

C

22 nH

CMOS

R

R

C

100 nF

V

DD

R

C

R

22 pF

V

REF

100 nF

V

DD

V

REF

I INPUT

LO INPUT

GAIN
CONTROL

STANDBY

RF OUTPUT

Q INPUT

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

POWER

CONTROL

Σ

-45°

+45°

33 pF SMD capacitor mounted as close to the package pin as possible, grounded
through via to the ground plane with minimum inductance.

The values of R and C depend on the lowest frequency of the baseband signal.

NOTE 1:

NOTE 2:

5-40

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Evaluation Board Schema t ic

(Download Bill of Materials from www.rfmd.com.)

C3
36 pF

C6
100 nF

C7
100 pF

R2
33

Ω

C1
36 pF

P2-2

P2-5

C5
100 nF

C4
100 nF

P2-1

P1-3

P1-4

L1
22 nH

R1
22

Ω

R3
0

Ω

P1-2

P1-1

R4
22

Ω

C2
36 pF

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

POWER

CONTROL

Σ

-45°

+45°

P2-4

LO IN

J1

RF OUT

J2

P2-4

P1-1

P1-3

P1

IREF

QREF

QSIG

1
2
3
4
5

P2-1
P2-2

P2

GND

PHASE

LEVEL

1
2
3
4
5

GND

ISIG

STBY

VDD

P1-2

P1-4 P2-4

P2-5

2423400 Rev -

5-41

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS

Evaluation Board Layout

1.25” x 1.25”

Board Thickness 0.031”; Board Material FR-4

5-42

RF2423

Rev A3 001218

5

MODULATORS AND

UPCONVERTERS

NOT FOR NEW DESIGNS