Datasheet RF2909, RF2909PCBA Datasheet (RF Micro Devices)

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Product Description

Ordering Information

Typical Applications

Features

Functional Block Diagram

RF Micro Devices, Inc.
7628 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

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SiGe HBT

Si CMOS

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12

24

23

22

21

20

19

18

17

16

15

14

13

Q SIG

Q REF

GND1

NC

LO IN+

LO IN-

NC

VCC1

GND2

VCC2

INSTGT

APC

I SIG

I REF

NC

GND6

GND5

RF OUT

GND4

GND3

PLLON

TX PD

PC 2

PC1

+45°

-45°

Σ

DC

BIAS

PWR
CTRL

RF2909

3V 915MHZ SPREAD-SPECTRUM

TRANSMITTER IC

• Direct Sequence Spread Spectrum

• Spread Spectrum Cordless Phones

• Portable Battery Powered Equipment

• GMSK, QPSK, DQPSK, QAM Modulation

• 915 MHz ISM Applications

The RF2909 is a monolithic integrated transmitter IC
capable of universal direct modulation. The quadrature
modulator allows for a variety of modulation formats and
compound carriers. The transmitter has two power control
modes. Two inputs can be controlled digitally for stepping
output power 1mW, 10mW, or 70mW output power. Or,
the output level can be adjusted by an analog input from
1mW to 80mW. The quadrature mixers have differential
inputs, and are internally biased; a DC blocking capacitor
is r equired if external DC levels are present. The LO is
split with a passive network tuned for 915MHz.

• 2.7V to 5V Power Supply

• 1mW,10mW, 70 mW Digital Output
Power

• 20dB Analog Power Control Range

• Excellent Phase & Amplitude Balance

• Compatible with t he RF2908

RF2909 3V 915MHz Spread-Spectrum Transmitter IC
RF2909 PCBA Fully Assembled EvaluationBoard

11

Rev B1 010904

.069
.053

.050
.016

8°MAX

0°MIN

.010
.008

.157
.150

.244
.228

1

.344
.337

.012
.008

.025

.010
.004

.033

Package Style: SSOP-24

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Absolute Maximum Ratings

Parameter Rating Unit

Supply Voltage -0.5 to +5.5 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=3.3V

Frequency Range 100 902-928 1100 MHz Phase shift optimized for 915MHz
Power Level -10 dBm Differential
Input Impedance 50 Ω 915MHz

Modulation Input

Frequency Range DC 10 500 MHz 50Ω source, I,Q=500mV

p-p

Reference Voltage (V

REF

)1.7V

Modulation for P

OUT

Power (I & Q)

500 mV

p

Differential, 1Vpsingle ended

Maximum Modulation (I & Q) 1 V

p

Differential, 1.5Vp single ended

Quadrature Phase Error 3 5 °
I/Q Amplitude Imbalance .35 db
Input Impedance 3 kΩ Differential

RF Output

VDD=3.3V, LO power=-10dBm,
LOfrequency=915MHz, SSB, I/Q=1V

PP

sine wave, 100KHz
Digital Output Power 1, 10, 70 mW See Table I for control logic
Output Impedance 50 Ω
Output VSWR 1.5:1 With external matching (see app. schematic)
Second Harmonic Output -25 dBc
Other Harmonics Output -30 dBc
Sideband Suppression 30 dB P

OUT

=10mW

Carrier Suppression 27 dB Modulation DC offset can be externally

adjusted for op timum suppression. Carrier

suppression is then typically better than

40dB.

Output Level Control

Analog Power Control Range 20 dB
Analog Power Control Voltage

(APC)

0 3.6 V Input voltage to pin 12 must be less than

3.6V or V

CC

(whichever is less).

Analog Power Control Input

Current

1 µA

Analog Power Output 80 mW V

APC

= 2.8V, PC1=“0”, PC 2=“0”

Digital Power Output, High 70 mW APC=0V, PC 1=“0”, PC 2=“1”
Digital Power Output, Med 10 mW APC=0V, PC 1=“1”, PC 2=“0”
Digital Power Output, Low 1 mW APC=0V, PC 1=“0”, PC 2=“0”
PC 1/PC 2 “ON” 1 Threshold Voltage
PC 1/PC 2 “OFF” 2 Threshold Voltage

Standby Mode

Turn On/Off Time 0.15 1 µS
Power Down “ON” 2 V Threshold voltage; Part is turned “ON”
Power Down “OFF” 1 V Threshold voltage; Part is turned “OFF”

Caution! ESD sensitive device.

RF MicroDevices believesthe furnished information iscorrect and accurate
at the time of this printing. However, RF Micro D evices reserves theright to
make changes t oits products without notice.RF Micro Devices does not
assume responsibility forthe use ofthe described product(s).

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Parameter

Specification

Unit Condition

Min. Typ. Max.

Power Supply

Voltage 3.3 V Specifications

2.7 5.0 V Operating limits

Current 175 200 mA Total, Digital High Power, V

APC,VPC1

=0V,

V

PC2=VCC

45 60 Total, Digital Medium Power, V

APC

,

V

PC2

=0V, V

PC1=VCC

30 40 mA Total, Digital Low Power, V

APC,VPC1

,

V

PC2

=0V

130 180 mA Total, Linear Power, V

APC

=2.8V, V

PC1

,

V

PC2

=0V

1.5 5 mA PLL Buffer amp on.
1 µA Standby mode

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Pin Function Description Interface Schematic

1QSIG

Baseband input to the Q mixer. A DC bias of approximately 1.7V is
present at this pin.A DC blocking capacitor is needed if the signal has a
different DC level. Maximum output power is obtained when the input
signal has a peak-to-peak amplitude of 1V. The input impedance of this
pin is 3kΩ. 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. The SIG and REF pins may be
driven deferentially to increase conversion gain.

2QREF

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

See pin 1.

3GND1

Ground connection for the modulator circuits. Keep traces physically
short and connect immediately to ground plane for best performance.

4NC
5LOIN+

Balanced LO Input Pin. This pin is internally DC biased and should be
DC blocked if connected to a device with a DC level present. For single­ended input operation, one pin is used as an input and the other LO
input is AC coupled to ground. The balanced input impedance is 100Ω.
The single-ended input impedance is 50Ω.

6LOIN-

Same as pin 4, except complementary input. S ee pin 5.

7NC
8 VCC1

This pin is used to supply Vccto the modulator circuits. A RF bypass
capacitor should be connected directly to this and ground.

9 GND2

Ground connection. This pin is used for RF ground of the power control
circuitry and the PA driver amplifier. Keep traces physically short and
connect immediately to ground plane for best performance.

10 VCC2

This pin is used to supply Vccto the power control and pre amp cir­cuitry. A RF bypass capacitor should be connected directly to this and

ground.

11 INSTGT

Interstage bias point between pre amp and power amp. This pin should
bepulleduptoV

cc

with an 8.2nH inductor for 915MHz.

See pin 18.

12 APC

Analog power control input. This pin can be used as a linear power out­put control with a range of 20 dB. Maximum output power is achieved
when APC is high. APC is”wire-or’d” with the digital controls, therefore
should be low when using the digital control. The DC input voltage to
the pin shouldalways be less than 3.6V.

13 PC 1

This digital power control input sets the medium current and power out­put, 10mW. It is “wire-or’d” with APC and PC 2 and can be overcome
by either. Therefore, APC and PC 2 must be low to use this setting.

14 PC 2

This digital power control input se t the high current and power output,
100mW. It is “wire-or’d” with APC and PC 1 and can override both of
those controls. Th erefore, PC 2 must be low to use other settings.

15 TX PD

Enables all of the IC except for the LO buffer when > 2V.

16 PLLON

Enables the LO buffer amp when > 2V.Thiscan be switched on and off
independently of the rest of the IC. This amp draws 1.5mA typi­cally.This can be used to minimize load pulling of the VCO when the
transmitter is turned on. Buf fer amp is off when < 1V.

17 GND3

Ground connection for RF Power Amp. Keep traces physically s hort
and connect immediately to ground plane for best performance.

18 GND4

Same as pin16.

BIAS

Q REFQ SIG

BIAS

LO IN-LO IN+

APC

PC 1

PC 2

TX PD

PLLON

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Pin Function Description Interface Schematic

19 RF OUT

Power Amp output, open collector output.

20 GND5

Same as pin 17.

21 GND6

Same as pin 17.

22 NC
23 I REF

Reference voltage for the I mixer. This voltage should be the s ame as
the DC voltage supplied to the I SIG pin. To obtain a c arrier suppres­sion of better than 25dB it may be tuned ±0.15V (relative to the I SIG
DC voltage). Without tuning, the carr ier suppression will typically be
better than 25dB. The input impedance of this pin is 3kΩ.

24 I SIG

Baseband input to the I mixer. A DC bias of approximately 1.7V is
present at this pin.A DC blocking capacitor is needed if the signal has a
different DC level. Maximum output power is obtained when the input
signal has a peak to peak amplitude of 1V.The input impedance of this
pin is about 3 kΩ. The REF and SIG inputs are interchangeable. If
swapping the I SIG and I REF pins, the Q SIG and Q R EF also need to
be swapped to maintain the correct phase. The SIG and REF pins may
be driven differentially to increase conversion gain.

See pin 23.

Table I

Operation

Mode

TXPDPLL

ON

PC 1 PC 2 APC Function

Sleep Mode

Low Low Low Low 0V Entire chip is powered down. Total Icc<1µA.

PLL Buffer

Low H igh Low Low 0V LO Buffer is on. Icc=1.5mA

Linear Po Mode

High High Low Low 0-VccV Transmitter in on. Power output is proportional to APC.

Digital Po Mode

High High Low Low 0V Transmitter is on. Power out is 1mW.

Medium Power

High High High Low 0V Transmitter is on. Power out is 10mW.

High Power

High High Low High 0V Transmitter is on. Power out is 70mW.

RF OUT

INSTGT

BIAS

I REFI SIG

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Evaluation Board Schema t ic

(Download Bill of Materia ls from www.rfmd.com.)

1

2

3

4

5

6

7

8

9

10

11

12

24

23

22

21

20

19

18

17

16

15

14

13

+45°

-45°

Σ

DC

BIAS

PWR

CTRL

C1

10 nF

J1

QDATAB

C3
47 pF

J2

LO IN

C4
47 pF

J3

LO IN B

C5
47 pF

C7
47 pF

C6
10 nF

R1

10

Ω

VCC1

C9
47 pF

C8
10 nF

R2

10

Ω

VCC2

APC

PWRCTRL1

PWRCTRL2

TXCTRL

PLLCTRL

L1

2.2 nH

C2
10 nF

J6

IDATAB

C16
10 nF

J5

QMOD OUT

C10

4.0 pF

L3

10 nH

L2

3.9 nH

C12
33 pF

C11

3.0 pF

J4

RF OUT

C13
47 pF

C14
10 nF

C15

4.7 uF

VCC3

50Ωµstrip

50Ωµstrip

50Ωµstrip

50Ωµstrip

50Ωµstrip

50Ωµstrip

P1-1

P1-3

P1

VCC3
GND

1
2
3

PC2

P2-1

P2-3

P2

PC1
GND

1
2
3

TXCTRL

P3-1

P3-3

P3

PLLCTRL
GND

1
2
3

APC

P4-1

P4-3

P4

VCC2
GND

1
2
3

VCC1

2909400-

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Evaluation Board Layout

Board Size 1.7440" x 1.7480"

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