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EZR32HG220F32R68 Can't achieve 20 dBm TX power
Hello Odei, Yes, for a custom design it is always possible to need to adjust the RF match component values to achieve the best performance and you should always consider the reference design information in the app note as a starting point for tuning a new custom design. Since we do not have the 433 MHz reference information for the direct tie topology, the strategy might be to start with values between the 315 MHz and 490 Mhz matching values and adjust up or down one or two values as needed for tuning, assuming the layout graphics and layer stack-up follow the reference design mentioned earlier. Best regards, |
41 days ago |
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EZR32HG220F32R68 Can't achieve 20 dBm TX power
Also, more specifically for EZR32HG, refer to AN627 for lower power designs and AN648 for higher power designs
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51 days ago |
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EZR32HG220F32R68 Can't achieve 20 dBm TX power
Hello Odei, The schematic matching circuit follows the reference design we post on-line, https://www.silabs.com/documents/public/schematic-files/BRD4542B-A00-pkg.zip, however it is possible the PCB layout does not follow the reference design regarding artwork, layer stack-up and PCB material permittivity value. Such differences can result in a different impedance presented at the radio which would probably attenuate the TX power output at the antenna input. Take a look at the reference design layout files and compare to your design. If there are significant differences, you may need to adjust the matching circuit component values. AN1275 may help with this effort. Best regards, |
51 days ago |
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Updated
EFR32 Series 1 Maximum External Pull-up / down Resistor Values on Zigbee and Thread Wireless Knowledge Base
QuestionEFR32 Series 1 – What is the maximum value resistor to use for a GPIO pull-up / down? AnswerMaximum external pull-up / down resistor value for Industrial rated devices operating in temperatures up to -40/85° C. EFR32 (all GPIOs except PB14/PB15): 10 M ohms EFR32 (PB14/PB15): 9.1 M ohms
Maximum external pull-up / down resistor value for High Temperature Industrial rated devices operating in temperatures up to +125° C. EFR32 (all GPIOs except PB14/PB15): 4.12 M ohms EFR32 (PB14/PB15): 1.8 M ohms
Use of an external pull-up or pull-down resistor instead of the internal pull-up or pull-down on an EFR32 GPIO provides an opportunity for reduced current draw in certain applications, particularly in battery powered designs. The reason for this is the maximum value resistance that works as a pull-up or pull-down for an EFR32 GPIO pin is much greater than the internal pull-up or pull-down resistance listed in the EFR32 datasheets (around 43k ohms), which equates to significant power savings in which one or more pull-up or pull-down resistors are frequently drawing current. For example, a battery operated open / closed sensor switch may be required to have a pull-up or pull-down on the switch circuit. The firmware may be monitoring for a high level on the switch / GPIO circuit. In the case of a normally closed switch, when the switch is engaged, the resulting circuit to ground through the switch is detected by the firmware and acted upon. Depending upon how often or how long the switch is activated, the resulting power drain through the pull-up or pull-down could significantly shorten the overall lifespan of the battery. In this type of situation, use a large value external resistor instead of the internal pull-up or pull-down configuration of the GPIO pin in order to reduce the current draw and extend battery life.
To arrive at 9.1M ohms / 10 M ohms / as the maximum safe resistor pull-up / down value to use in temperature range -40° C to 85° C, we first determine the GPIO maximum input leakage current. Characterization testing of Engineering IC test lots have revealed an upper limit of 30 nA for industrial temperature rated devices and an upper limit of 110 nA for high temperature industrial rated devices. The exception are GPIOs PB14/PB15 which are revealed to have an upper limit of 50 nA in the range of -40° C to 85° C, and 250 nA at 125° C.
Refer to the datasheet table 4.37 for Input leakage current (IIOLEAK), Input low voltage (VIOIL) and Input high voltage (VIOIH) http://www.silabs.com/Support%20Documents/TechnicalDocs/EFR32MG1-DataSheet.pdf
Having determined the leakage current, we then calculate the minimum input high voltage for the GPIO by multiplying the minimum IOVDD Operating supply voltage, 1.62 V (table 4.2 of the datasheet) by 0.7 (Table 4.37), giving us 1.134 V (1.62 * 0.7 = 1.134 V). Next, we determine the allowable voltage drop across the external pull-up by subtracting the minimum Input high voltage from the minimum IOVDD Operating supply voltage, (1.62 V – 1.134 V = 0.486 V). By using Ohm’s Law to divide the voltage drop of the external pull-up by the threshold leakage current value and multiplying the result by 0.95, we safely determine the appropriate pull-up resistor value with a 5% margin. For high temperature industrial range of -40° C to +125° C, (0.486 V / 0.000000110 A * 0.95 = 4.2 M ohms), we reduce the pull-up resistor value to 4.12 M ohms as the nearest commercially available resistor value. For the temperature range of -40° C to +85° C, (0.486 V / 0.00000003 A * 0.95 = 15.39 M ohms), we limit the pull-up resistor value to 10 M ohms. The reason is anything greater in resistance than 10 M ohms is simply not reliable as the circuit will be affected by the resistances of many contaminants such as moisture and dirt, etc. For EFR32 GPIO PB14/15, the equation is (0.486 V / 0.00000005 A * 0.95 = 9.2 M ohms), where we limit the pull-up resistor to 9.1 M ohms as the nearest commercially available resistor value.
Similarly, for the pull-down value we calculate the maximum input low voltage for the GPIO by multiplying 0.3 (table 4.37) by the minimum IOVDD Operating supply voltage, (0.3 V * 1.62 V = 0.486 V). The result, 0.486 V, is the allowable voltage drop for the external pull-down resistor. By using Ohm’s Law to divide the voltage drop of the external pull-down by the threshold leakage current value and multiplying the result by 0.95, we safely determine the appropriate pull-down resistor value with a 5% margin. For the high temperature industrial range of -40° C to +125° C, (0.486 V / 0.00000011 A * 0.95 = 4.2 M ohms), and for the temperature range of -40° C to +85° C, (0.486 V / 0.00000003 A * 0.95 = 15.39 M ohms), we again limit the pull-down resistor value to 10 M ohms for reliability.
The same formulas used above when applied to PB14/15 for the temperature range of -40° C to +125° C result in maximum pull-up/down resistor values of 1.8 M ohms. (0.486 V / 0.00000025 A * 0.95 = 1.85M ohms).
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Dec 01 2020, 7:23 PM |
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Updated
Powering External Circuits from EFR32 Series 1 and EFR32 Series 2 DC-DC on Zigbee and Thread Wireless Knowledge Base
The on board voltage regulator lends itself for use in powering more than just certain power pins on the EFR32 itself. Typically the DC-DC is recommended for powering the EFR32 RFVDD, DVDD and sometimes the PAVDD power pins (for desired transmit power levels 13 dBm and lower). There may also be custom applications where it is appropriate to use the DC-DC regulated output for powering additional EFR32 power supply pins or even other device power pins. In cases where the DC-DC is to be used for powering peripherals and / or the IOVDD supply, the designer should:
Note that all validation testing has been at 1.8V and therefore datasheet parameters may be different for DC-DC outputs other than 1.8 V.
Some EFR32 Series 1 and Series 2 variants DC-DC default to Bypass mode coming out of RESET and remain in Bypass mode until software enables the DC-DC. Bypass mode effectively shorts the main supply to the DC-DC output pin. Review the datasheet for the particular EFR32 part number to verify the DC-DC default operation coming out of RESET.
If one of the peripheral devices is also an EFR32, do not power that EFR32’s DVDD pin, due to DVDD will short to AVDD internally upon exiting reset and cause a potential over-current situation for the source DC-DC.
For additional information about the EFR32 DC-DC, please review application notes AN948 and AN948.2.
When done, Silicon Labs recommends you submit your finalized design for review in the customer portal. |
Dec 01 2020, 4:39 PM |
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Updated
Using a TCXO with an EFR32 Series 1 Device on Zigbee and Thread Wireless Knowledge Base
QuestionHow do I connect a TCXO to an EFR32 Series 1 SoC? AnswerA TCXO clock source can be used to supply the EFR32 main clock. Reconfiguration of the HFXO register settings in the Clock Management Unit will be required for operation with a TCXO. Consult the EFR32 Reference Manual for additional details regarding the following settings:
Be sure to physically connect the TCXO to the HFXTAL_N pin for the above register settings. The HFXTAL_P pin should be no-connect.
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Dec 01 2020, 3:49 PM |
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Updated
Using a TCXO with an EFR32 Series 1 Device on Zigbee and Thread Wireless Knowledge Base
QuestionHow do I connect a TCXO to an EFR32? AnswerA TCXO clock source can be used to supply the EFR32 main clock. Reconfiguration of the HFXO register settings in the Clock Management Unit will be required for operation with a TCXO. Consult the EFR32 Reference Manual for additional details regarding the following settings:
Be sure to physically connect the TCXO to the HFXTAL_N pin for the above register settings. The HFXTAL_P pin should be no-connect.
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Dec 01 2020, 3:48 PM |
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Updated
EFR32 Maximum External Pull-up / down Resistor Values on Zigbee and Thread Wireless Knowledge Base
QuestionEFR32 Series 1 – What is the maximum value resistor to use for a GPIO pull-up / down? AnswerMaximum external pull-up / down resistor value for Industrial rated devices operating in temperatures up to -40/85° C. EFR32 (all GPIOs except PB14/PB15): 10 M ohms EFR32 (PB14/PB15): 9.1 M ohms
Maximum external pull-up / down resistor value for High Temperature Industrial rated devices operating in temperatures up to +125° C. EFR32 (all GPIOs except PB14/PB15): 4.12 M ohms EFR32 (PB14/PB15): 1.8 M ohms
Use of an external pull-up or pull-down resistor instead of the internal pull-up or pull-down on an EFR32 GPIO provides an opportunity for reduced current draw in certain applications, particularly in battery powered designs. The reason for this is the maximum value resistance that works as a pull-up or pull-down for an EFR32 GPIO pin is much greater than the internal pull-up or pull-down resistance listed in the EFR32 datasheets (around 43k ohms), which equates to significant power savings in which one or more pull-up or pull-down resistors are frequently drawing current. For example, a battery operated open / closed sensor switch may be required to have a pull-up or pull-down on the switch circuit. The firmware may be monitoring for a high level on the switch / GPIO circuit. In the case of a normally closed switch, when the switch is engaged, the resulting circuit to ground through the switch is detected by the firmware and acted upon. Depending upon how often or how long the switch is activated, the resulting power drain through the pull-up or pull-down could significantly shorten the overall lifespan of the battery. In this type of situation, use a large value external resistor instead of the internal pull-up or pull-down configuration of the GPIO pin in order to reduce the current draw and extend battery life.
To arrive at 9.1M ohms / 10 M ohms / as the maximum safe resistor pull-up / down value to use in temperature range -40° C to 85° C, we first determine the GPIO maximum input leakage current. Characterization testing of Engineering IC test lots have revealed an upper limit of 30 nA for industrial temperature rated devices and an upper limit of 110 nA for high temperature industrial rated devices. The exception are GPIOs PB14/PB15 which are revealed to have an upper limit of 50 nA in the range of -40° C to 85° C, and 250 nA at 125° C.
Refer to the datasheet table 4.37 for Input leakage current (IIOLEAK), Input low voltage (VIOIL) and Input high voltage (VIOIH) http://www.silabs.com/Support%20Documents/TechnicalDocs/EFR32MG1-DataSheet.pdf
Having determined the leakage current, we then calculate the minimum input high voltage for the GPIO by multiplying the minimum IOVDD Operating supply voltage, 1.62 V (table 4.2 of the datasheet) by 0.7 (Table 4.37), giving us 1.134 V (1.62 * 0.7 = 1.134 V). Next, we determine the allowable voltage drop across the external pull-up by subtracting the minimum Input high voltage from the minimum IOVDD Operating supply voltage, (1.62 V – 1.134 V = 0.486 V). By using Ohm’s Law to divide the voltage drop of the external pull-up by the threshold leakage current value and multiplying the result by 0.95, we safely determine the appropriate pull-up resistor value with a 5% margin. For high temperature industrial range of -40° C to +125° C, (0.486 V / 0.000000110 A * 0.95 = 4.2 M ohms), we reduce the pull-up resistor value to 4.12 M ohms as the nearest commercially available resistor value. For the temperature range of -40° C to +85° C, (0.486 V / 0.00000003 A * 0.95 = 15.39 M ohms), we limit the pull-up resistor value to 10 M ohms. The reason is anything greater in resistance than 10 M ohms is simply not reliable as the circuit will be affected by the resistances of many contaminants such as moisture and dirt, etc. For EFR32 GPIO PB14/15, the equation is (0.486 V / 0.00000005 A * 0.95 = 9.2 M ohms), where we limit the pull-up resistor to 9.1 M ohms as the nearest commercially available resistor value.
Similarly, for the pull-down value we calculate the maximum input low voltage for the GPIO by multiplying 0.3 (table 4.37) by the minimum IOVDD Operating supply voltage, (0.3 V * 1.62 V = 0.486 V). The result, 0.486 V, is the allowable voltage drop for the external pull-down resistor. By using Ohm’s Law to divide the voltage drop of the external pull-down by the threshold leakage current value and multiplying the result by 0.95, we safely determine the appropriate pull-down resistor value with a 5% margin. For the high temperature industrial range of -40° C to +125° C, (0.486 V / 0.00000011 A * 0.95 = 4.2 M ohms), and for the temperature range of -40° C to +85° C, (0.486 V / 0.00000003 A * 0.95 = 15.39 M ohms), we again limit the pull-down resistor value to 10 M ohms for reliability.
The same formulas used above when applied to PB14/15 for the temperature range of -40° C to +125° C result in maximum pull-up/down resistor values of 1.8 M ohms. (0.486 V / 0.00000025 A * 0.95 = 1.85M ohms).
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Dec 01 2020, 3:47 PM |
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EFR32FG1: non-monotonic TX power regulation
Hello Vladimir,
What you have observed is not unexpected behavior. The actual TX power level response to TX power setting is expected to be different between custom designs due to differences in on-board impendances. The SDK firmware built for this part is adjusted for the particular WSTK evaluation board used as the reference for the EFR32FG1V131F128GM32. Your custom hardware may or may not have similar power setting responses to the WSTK evalution module. To fine tune the power settings for custom hardware, the firmware developer can create custom power curves described in AN1127; You have already taken the first step by characterizing the TX power versus TX power setting on your custom hardware. Best regards, |
Sep 14 2020, 7:20 PM |
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RHO pin on EFR32BG
Hello Vaishnavi, Does this design utilize a Wi-Fi device? If so, you should open a ticket on the customer support portal for further radio coexistence support. Take a look at AN1017 for the EFR32MG Zigbee device coexistence software features. Which protocol needs priority for the airwaves? Zigbee or BLE? Based on your description of the BLE slave and Zigbee master, it would seem the Zigbee device is meant to have priority for the airwaves. However if you mean the Zigbee is simply the host for the BLE device then you still need to determine which protocol needs priority for the air waves. RHO (Radio Hold Off) is an input that prevents the radio from transmitting when asserted. Generally any pin can be configured for RHO. The reason for the statement RHO is generally not required is an assumption the Wi-Fi has a PTA interface which negates the need for RHO since it has very limited capability compared to the PTA interface. However if your design does not have Wi-Fi, then a PTA interface is not applicable due to the EFR32 operates in slave mode only for PTA and requires the Wi-Fi to operate as master / arbiter of the airwaves. In the situation where no Wi-Fi is in the design, RHO can be be asserted from a control signal output from one of the EFR32s to the RHO pin of the other EFR32, thereby providing priority of the airwaves to the EFR32 with the control signal output. For example, if the protocol needing priority is Zigbee, the RX_ACTIVE feature described in AN1017 section 4.2.1.8 can be used to drive the RHO input of the BLE EFR32 during the Zigbee RX transaction. Best regards, |
Sep 01 2020, 5:53 PM |