I have few questions regarding the HMC1020 RMS RF power detector that we use in some of our designs:1. I saw that in the new datasheet of HMC1020 the number of combinations of the SCI1-4 logic pins was reduced (earlier the combinations went from 0000 up to 1111, but now they are only up to 1100). What is the reason for that ?2. If I want to use the 1111 combination of SCI1-4 pins (for the longest integration time) or something closer, for example 1110, what would happen ? Would I get some unpredictable functionality ?3. Which SCI1-4 pins logic combination would you recommend us to use for getting integration time of 10mS (min.) of an 10MHz LTE signal ?
1. So, the reason the change was made was because that the designers at later stage found out that an SCI setting from 1101 to 1111 caused excessive leakage currents at high temperatures. This manifests itself as the lower half of the detection range completely saturating. (ie. You don’t get the specified low end sensitivity). These “forbidden” states do not damage the part; you just get this big loss of range. 2. Usage of SCI setting 1111 on HMC1010 and HMC1020 will not do any damage and the will probably work ok at 25 degC. But at high temp, there will be massive loss of detection range. So there is a complete family of these RF detectors HMC1010, HMC1020 and HMC1120. All the three parts can be operated down to arbitrarily low frequencies but HMC1120 has the most available board averaging because SCI setting 1111 is permitted. 3. This was already answered on the engineering zone. https://ez.analog.com/thread/73973The carrier bandwidth of 10 MHz is not a problem. The settings on the four SC pins control a trade-off between pp output noise and settling time. Most of the datasheet plots use a setting of 0110. These plots use WiBro and WCDMA signal sources (the release of this device pre-dates LTE. I would say that the behavior of the 4-carrier WCDMA signal will be fairly similar to your 10 MHz LTE carrier (the main difference is that the LTE carrier is about half the bw of four WCDMA carriers). Because your input signal is FDD, settling time may not be that important. So you could set the SC settings to the maximum allowable value of 1100. This will minimize output noise at the expense of response time.