RF3854PCBA-41X View Datasheet(PDF) - RF Micro Devices

Part Name

Description

MFG CO.

RF3854PCBA-41X

LOW NOISE, MULTI-MODE, QUAD-BAND, QUADRATURE MODULATOR AND PA DRIVER

RF Micro Devices 

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RF3854

Pin

20

21

22

23

24

Pkg

Base

Function

MODE A

VCC1

Description

Mode control pin. See the Logic Truth table.

CMOS Logic inputs: Logic 0=0V to 0.4V; Logic 1=1.4V to VCC.

Supply for modulator, VGA and PA driver amplifiers.

Interface Schematic

See pin 6.

VCC1

LO Quadrature

Generator and

Buffers

I SIG P

I SIG N

MODE B

DIE FLAG

GND1

In-phase I channel positive baseband input port.

Best performance is achieved when the ISIGP and ISIGN are driven differ-

entially with a 1.2V common mode DC voltage. The recommended differ-

ential drive level (VISIGP-VISIGN) is 1.2VP-P for EDGE, 0.8VP-P W-CDMA

modulation and 1.0VP-P for GMSK modulation.

This input should be DC-biased at 1.2V. In sleep mode an internal FET

switch is opened, the input goes high impedance and the modulator is de-

biased.

Phase or amplitude errors between the ISIGP and ISIGN signals will result

in a common-mode signal which may result in an increase in the even

order distortion of the modulation in the output spectrum.

DC offsets between the ISIGP and ISIGN signals will result in increased

carrier leakage. Small DC offsets may be deliberately applied between the

ISIGP/ISIGN and QSIGP/QSIGN inputs to cancel out the LO leakage. The

optimum corrective DC offsets will change with mode, frequency and gain

control.

Common-mode noise on the ISIGP and ISIGN should be kept low as it may

degrade the noise performance of the modulator.

Phase offsets from quadrature between the I and Q baseband signals

results in degrades sideband suppression.

In-phase I channel negative baseband input port. See pin 22.

VCC2

x1

See pin 22.

Mode control pin. See the Logic Truth table.

CMOS Logic inputs: Logic 0=0V to 0.4V; Logic 1=1.4V to VCC.

Ground for LO section, modular, biasing, variable gain amplifier, and sub-

strate.

See pin 6.

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7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical

support, contact RFMD at (+1) 336-678-5570 or sales-support@rfmd.com.

Rev A1 DS070313

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