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RC1x21 Output Power vs Input Voltage

−6.00

−4.00

−2.00

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

100

1000

10000

Differential Input Voltage (mVppd)

Input at 26 MHz

Output at 325 MHz

T=25 degrees

Input Impedance <800 ohms

Input is sinusoidal

Measured at max gain

INTEGRATED SYNTHESIZERS

PLL Programming

TRF1121

TRF1221

SLWS170A – APRIL 2005 – REVISED DECEMBER 2005

Figure 4 shows the output power, two-tone imtermodulation level, LO leakage and gain deviation from ideal vs

gain state while Figure 5 shows the upconverter gain variation vs temperature.

NOTE: If left unconnected, the GAIN[0], GAIN[1], GAIN[2], GAIN[3], GAIN[4], and TXEN pins rest on logic Low.

Figure 6. Output Power vs Input Voltage

Synthesizer #1 (UHF) and synthesizer #2 (S-band) are both integrated in the TRF1121/TRF1221. These two

PLLs can be programmed via a 3-wire serial bus (CLK, DATA, and EN) from the baseband processor. The timing

specs are given in the AC Timing table.

Synthesizer #2 has a step size of 1 MHz, while Synthesizer #1 offers a step size of 50 kHz, both assuming an

18-MHz reference frequency. Different reference frequencies yield different step sizes, many of which may be

non-integer.

NOTE:

If left unconnected, the DATA, CLK and EN pins rest on logic High. EN is level

sensitive.

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