RF60 Datasheet, PDF (36/157 Pages) –

RF60 CRYSTAL-LESS SOC TRANSMITTER v1.0
The RF60 includes 2-wire C2 Debug and Programming interface. This debug logic supports inspection
memory, viewing and modification of special function registers (SFR), setting break points, single stepping,
and run and halt commands. All analog and digital peripherals are fully functional while debugging using
C2. The two C2 interface pins can be shared with user functions, allowing in-system debugging without
occupying package pins.
10.2. Setting Basic RF60 Transmit Parameters
The basic transmit parameters such as output power, modulation type, data rate, and operating frequency
are set by using applications programming interface (API) function commands. When using these func-
tions certain parameters are determined by using a calculator spread sheet. The RF60 development kit
(part number 4010-DKSKF 434) includes a calculator spread sheet that helps developers set the API func-
tion arguments to meet their desired design requirements. A summary of the calculator operations are
given below and more detailed descriptions are given in the individual sections of this data sheet.
10.2.1. Output Power
The output power of the RF60 depends on many parameters including the antenna impedance, the out-
put impedance of the PA, the nominal varactor setting, the battery supply voltage, and the bias current of
the PA. The calculator spreadsheet can calculate the required antenna impedance needed to achieve the
desired output power or it can estimate the output power given the antenna impedance. It has the following
input parameters:
Power Setup:
Power Target (dBm): This is the desired output power in dBm. The spreadsheet will always try and hit
this target.
Choose One of the Following: Maximize Radiated Power or Minimize PA current while Maximizing
Radiated Power. If only radiated power is to be maximized, the PA current is maximized and an
antenna impedance is found that maximizes the possible radiated power. Usually, this tends to
minimize the antenna impedance relative to the chip impedance. If the PA current is to be minimized
while still maximizing radiated power, the solution tends to equalize the antenna and on-chip
impedances. This increases the effective impedance of the system, which saves PA current at the
expense of radiation efficiency (as more power will now be consumed on-chip).
Frequency (MHz): The RF frequency of operation, range is 27 to 960 MHz.
Nominal Cap Word: This is the nominal setting of the power amplifier varactor, range is 0 to 511.
External Diff Cap (pF): This is an external capacitor placed across the TXP and TXM pins. Assuming
this has a much larger quality factor than the on-chip varactor, there may be antenna efficiency
advantages of using this external component.
Q-Factor External Cap: This is the quality factor of the external capacitor. Typical values would be 250-
300.
Antenna Setup:
Alpha (bLevel/deg C): The sensitivity of the antenna resistance vs temperature change. If constant
radiated power vs temperature is desired, this constant may be used to compensate the PA drive
strength. See the API section on power control.
Beta (bLevel/wCap): The sensitivity of the antenna resistance vs capacitance change. If constant
radiated power vs tuning capacitance change is desired this constant may be used to compensate the
PA drive strength. See the API section on power control. The algorithm attempts to keep the PA output
voltage multiplied by the PA capacitance constant due to fluctuations in the external component values
of the loop antenna.
Approx Efficiency (%): The approximate antenna efficiency.
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