Datasheet RF9938, RF9938PCBA Datasheet (RF Micro Devices)

RF9938

6

Typical Applications

• CDMA/TDMA/DCS1900 PCS Systems

• PHS 1500/ WLAN 2400 Systems

• General Purpose Upconverter

Product Description

The RF9938 is a complete upconverter designed for PCS
applications. The IC contains a double-balanced mixer
stage and an output buffer amplifier stage. This device
may also be used to directly BPSK modulate a carrier.
The mixer is a Gilbert cell with emitter degeneration resis­tors to provide high IP

push-pull configuration to reduce the overall current and
still provide a good 50Ω output match. The unit operates
at 3.6V and is designed as part of the RFMD PCS CDMA
Chip Set, consisting of a Transmit IF AGC Amp, this
Transmit Upconverter, a Receive LNA/Mixer, and a
Receive IF AGC Amp.

. The output stage is a class-B,

3

PCS UPCONVERTER/BPSK MODULATOR

• BPSK Modulation

• Micro-Cell PCS Base Stations

• Portable Battery-Powered Equipment

0.008

0.004

0.018

0.014

0.196

0.189

0.050

8° MAX

0° MIN

0.034

0.016

0.157

0.150

0.244

0.229

Dimensions in mm

0.009

0.007

NOTES:

1. Shaded lead is Pin 1.

2. All dimensions are excluding

3. Lead coplanarity -

0.068

0.053

mold flash.

0.005 with respect to datum "A".

-A-

6

MIXERS

Optimum Technology Matching® Applied

Si BJT GaAs MESFETGaAs HBT
Si Bi-CMOS

IF+

IF-

GND

LO+

ü

SiGe HBT

1

2

3

4

Si CMOS

8

RF OUT

7

VCC

6

GND

5

LO-

Functional Block Diagram

Package Style: SOIC-8

Features

• Supports Dual Mode Operation

• +8dBm Output Intercept Point

• Single 3.6V Power Supply

• Internally Matched Inputs and Outputs

• Buffered Output

• Double-Balanced Mixer

Ordering Information

RF9938 PCS Upconverter/BPSKModulator
RF9938 PCBA Fully Assembled EvaluationBoard

RF Micro Devices, Inc.
7628 Thorndike Road
Greensboro,NC 27409, USA

Tel [phone]

Fax [phone]

http://www.rfmd.com

Rev A3 010720

6-61

RF9938

Absolute Maximum Ratings

Parameter Rating Unit

Supply Voltage -0.5 to +7.0 V
Input RF Power +6 dBm

Operating Ambient Temperature -30 to +80 °C
Storage Temperature -30 to +150 °C

DC

Caution! ESD sensitive device.

RF Micro Devices believes thefurnished 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).

6

Parameter

Min. Typ. Max.

Overall

RF Output Frequency Range 1200 to 2500 MHz
Conversion Gain -3.8 -2.8 -1.0 dB
Noise Figure 14 dB
Output IP3 +5 +8 dBm P

Output ACP -64 dB Referenced to a 1.23MHz in-band power. At

Output VSWR 1.5:1 50Ω
Spurious Product Rejection 30 dBc Referenced to RF output

Specification

Unit Condition

T=25°C, VCC=3.6V,RF out=1880MHz,
LO=1750MHz @ -3dBm, IF=130M Hz

@ -10dBm in

=-13dBm per Tone

IN

±1.25MHz Offset (CDMA P

IF Input

IF Frequency DC to 200 MHz
Differential Input Impedance 265 Ω

MIXERS

IF to RF Output Isolation 30 dB
IF to LO Isolation 30 dB

LO Input

LO Frequency Range 1000 to 2700 MHz
LO Level -6 to 0 dBm
LO to RF Output Leakage -30 -20 dBm
RF to LO Isolation 30 dB
LO Input VSWR 2:1 50Ω

Power Supply

Voltage 3.6±5% V
Current Consumption 27 33 mA

=-10dBm)

IN

6-62

Rev A3 010720

RF9938

Pin Function Description Interface Schematic

1IF+

2IF­3GND

4LO+

5LO­6GND
7VCC

8RFOUT

Balanced IF 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 IF
input is AC coupled to ground. The balanced, as well as single-ended,
input impedance is 265Ω.

Same as pin 1, except complementary input.
Ground connection. Keep traces physically short and connect immedi-

ately to ground plane for best performance.
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, as well as single-ended,
input impedance is 50Ω.

Same as pin 4, except complementary input.
Same as pin 3.
Supply Voltage pin. External bypassing is required . External RF, LO,

and IF bypassing is required. The trace length between the pin a n d the
bypass capacitors should be minimized. Th e ground side of the bypass
capacitors should connect immediately to ground plane.

RF Output Pin. This pinis internally DCblocked. The output impedance
is 50Ω.

6

IF+

IF-

LO IN

Application Schemati c

1nF

1

1nF

2

3

33 pF

4

8

7

6

10 pF

5

RF OUT

V

CC

47 pF 100 nF

MIXERS

Rev A3 010720

6-63

RF9938

Evaluation Board Schema t ic

(Download Bill of Mat erials from www.rfmd.com.)

P1

P1-1

NC

1

VCC

2

GND

3

Drawing 9938400Rev -

6

SMA

J1

SMA

J2

IF IN

LO IN

C3

8pF

50

1:4 SETUP

Ω µ

strip

T1

C1

1nF

C2

1nF

C4

33 pF

strip

RF OUT

SMA

J3

P1-1

50

1

2

3

4

8

7

6

5

.9 pF(ATC)

Ω µ

C6

47 pFC7100 nF

C5

Evaluation Board Layout

MIXERS

1.4” x 1.4”

6-64

Rev A3 010720