RFM67W Datasheet, PDF (29/37 Pages) List of Unclassifed Manufacturers – ISM TRANSMITTER MODULE

RFM 67W
8. Reference Design Performance
This section details the measured typical performance of the reference design described in the preceding section.
8.1. Power Output versus Consumption
20
90
17 dBm Match Pmeas
15
14 dBm Match Pmeas
80
17 dBm Match Imeas
14 dBm Match Imeas
10
70
5
60
0
50
-5
40
-10
30
-15
-20
-20
-15
-10
-5
0
5
Programmed Power (dBm)
20
PA1 Only
10
PA1 and 2 Enabled
10
15
20
Figure 24. Typical Power Consumption of the Reference Design versus Measured and Programmed Power
Output at 915 MHz
The measured current consumption of the RFM67W versus programmed and measured output power is shown in the
preceding figure. The green curves correspond to measurements (made at 915 MHz) using the low power matching of
Section 7.7. The measured consumption displays two distinct regimes: Above a programmed power of -3 dBm both high
and low power amplifiers of PA1 are active. Below, however, only the low power amplifier within PA1 is enabled allowing
enhanced efficiency for operation below this programmed power output.
The blue portion of the curve (13 to 17 dBm operation) uses the matching illustrated in Section 7.6. Note that not only must
both power amplifiers be enabled to access these output powers, but also the OCP (current limiter) for the PA must be
disabled or the limit adjusted to 100 mA accordingly.
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