I have seen several good questions and answers on this forum regarding the use of a PA for extending range of the nRF51422/nRF51822 devices. I have a battery-powered application that requires very low power consumption. The devices recommended in other posts have a relatively high power consumption, both in active and in shutdown modes. The solution also needs to operate at less than 3.0 V power supply voltage.
Important advice from other posts includes: (a) avoid the use of an LNA; (b) use a Nordic recommended balun (e.g. Johanson Tech 2450BM14E0003) between the Nordic device and the PA device, and use a PA with a single-ended input.
Heeding that advice, I find the Texas Instruments CC2595 (www.ti.com/.../cc2595.pdf) to possibly meet the requirements. It has a single-ended input, operates from 2 V to 3.6 V, and offers 98 mA current consumption when active and less than 1 uA when shutdown.
Here are my questions:
(1) Can this device be operated in the reverse (receive) direction without an RF switch (i.e. will it go into the "throughput mode" described in this post when it is disabled devzone.nordicsemi.com/.../)
(2) Assuming the answer to (1) is no, what are the considerations required for selection and proper use of an RF switch for this purpose? For instance, is it sufficient to simply bypass the PA with a single switch, or should one or both input and output of the PA be switched out of the RF path? Also, is there a recommended minimum isolation attenuation for the switch?
Thanks for your help!
