Hi,

Thanks a lot for the answers. I still have a few questions about the schematic. 

In the JTAG section of the schematic what are these TP3, TP4 and TP5 sections and why are they going to the ground?

In the same schematic the SV2 jumper pin 2 is connected to FET_VCC. What is this FET_VCC? Do I need it for the JTAG programming to work properly or can  I omit it?

In the power section schematic that I've pasted below;

1. What is use of the IC1: TPS72215?

2. What is the use of the IC2: TEXAS_TPS773DGK8?

3. What is the use of the reverse biased connected Zener diodes D3?

4. On the right there is switch S6 with wich we can connectted the Power Supply directly to a battery or VDDB. Does this mean that if I'm generating my  power supply from an external LDO I connect that output to the VDDB?

5. What is the mini USB Connector for? Is that used for interfacing with the PC?

6. What is TP10 and why is the RST/NMI seperated from the VDDSW through a 22k ohms resistor?

Thanks a lot for your answers and I look forward to hear back from you soon.

letshacklife said:

In the JTAG section of the schematic what are these TP3, TP4 and TP5 sections and why are they going to the ground?

These are test points that can be used for example by a scope probe when probing the PCB.  Or for attaching more circuitry that needs ground.

letshacklife said:

In the same schematic the SV2 jumper pin 2 is connected to FET_VCC. What is this FET_VCC? Do I need it for the JTAG programming to work properly or can  I omit it?

FET_VCC is the power source from the MSP-FET tool.  This tool supplies its own power and the EVM can use this supply to power the EVM on its own.  To do this S6 needs to be set to "Supply" side.  The circuit on the lower-left corner is for JTAG level shifting.  Since the '152H can only handle up to 1.65V signals and the MSP-FET does not go down this far on its own, this circuit was used.

letshacklife said:

1. What is use of the IC1: TPS72215?

It is a LDO that takes in about 3V and regulates down to 1.5V - the range that the '152H needs.

letshacklife said:

2. What is the use of the IC2: TEXAS_TPS773DGK8?

It is a LDO that takes in 5V from USB and regulates down to 3.3V.

letshacklife said:

3. What is the use of the reverse biased connected Zener diodes D3?

They prevent current from the FET supply and the 3.3V LDO from flowing into each other, when one is not powered.  They isolate the power areas. 

letshacklife said:

4. On the right there is switch S6 with wich we can connectted the Power Supply directly to a battery or VDDB. Does this mean that if I'm generating my  power supply from an external LDO I connect that output to the VDDB?

Yes.  Also keep in mind that VDDB alone will not power the '152H.  There is an internal battery switch that needs to be closed (by RF possible), that will supply the the power from VDDB to VDDSW.  This can be done externally if necessary by simply powering VDDSW directly.  Under any circumstance, the device will always work from RF scavenged energy.

letshacklife said:

5. What is the mini USB Connector for? Is that used for interfacing with the PC?

It is only for external power.

letshacklife said:

6. What is TP10 and why is the RST/NMI seperated from the VDDSW through a 22k ohms resistor?

TP10 stands for Test Point 10 - useful for debugging purposes. The 22k Ohm resistor is a pull-up for the reset of the '152H.  The chip has an internal pull-up, but an external one is also needed.

Hi,

Thanks a lot for the reply. I've the following follow up questions:

4. On the right there is switch S6 with wich we can connectted the Power Supply directly to a battery or VDDB. Does this mean that if I'm generating my  power supply from an external LDO I connect that output to the VDDB?

Yes.  Also keep in mind that VDDB alone will not power the '152H.  There is an internal battery switch that needs to be closed (by RF possible), that will supply the the power from VDDB to VDDSW.  This can be done externally if necessary by simply powering VDDSW directly.  Under any circumstance, the device will always work from RF scavenged energy.

Question: Let's assume that I do not want to power up the 152H externally but only with an external LDO which boosts the voltage from a battery. In such a case will it be sufficient to connect the output of the LDO directly to the VDDSW to power up the 152H? Or do I need to short circuit both the VDDB and VDDSW in order to power up the 152H? 

5. What is the mini USB Connector for? Is that used for interfacing with the PC?

             It is only for external power.

Question: In the case, as described above, if I use an LDO to power up the 152H, then I do not need the USB for powering right? 

Question: Debugging : Confusing?

If I'm developing a system with an external battery which goes through a boost/LDO IC, I therefore have the power from that LDO chip. Now if I need to debug my 152H uc program I need to use the JTAG right? in such a case where should I connect the jumpers? I do not want to drain my battery for the sake of debugging ?  I'm not fully sure if I understood correctly? If I connect the JTAG, then the JTAG power supply of the MSP-FET would drive the 152H and in such a case I do not need the battery? Is this right? 

I've additional questions regarding the MCU section schematic:

1. Why are the P1.5, P1.6 and P1.7 pins connected to switches S3,S4 and S5 via 100k ohms resistors?

2. Why do we need the switches S3, S4 and S5?

3. Why is P1.4 connected via a 10k ohm resistor only and why is its output going to the BSS138LT1? What is the use of the part BSS138LT1?

Antenna

How did you arrive at the values of 39 pF and 8.2 pF fort the capacitors C14 and C7? 

letshacklife said:

In such a case will it be sufficient to connect the output of the LDO directly to the VDDSW to power up the 152H? Or do I need to short circuit both the VDDB and VDDSW in order to power up the 152H? 

No, you don't need a short to VDDB, powering VDDSW is enough.

letshacklife said:

Question: In the case, as described above, if I use an LDO to power up the 152H, then I do not need the USB for powering right? 

Yes, you don't need USB for powering if you already have another power supply.

letshacklife said:

 I'm not fully sure if I understood correctly? If I connect the JTAG, then the JTAG power supply of the MSP-FET would drive the 152H and in such a case I do not need the battery? Is this right? 

For debugging you could use the FET power to power the chip and the battery would not be needed.  You would have to find a way to disconnect the battery though, in this case.  Also you would need an 1.5V LDO.

letshacklife said:

Why are the P1.5, P1.6 and P1.7 pins connected to switches S3,S4 and S5 via 100k ohms resistors?

2. Why do we need the switches S3, S4 and S5?

Because they are needed by the ROM to determine which features to enable.  Check the RF430FRL15xH Firmware Users Guide (5 Interfacing a Host Controller) for information on what pull-ups/down to use.  These are only necessary if the "Default" or "SensorHub" project is used.  For the "NFC" example these resistors  and switches are not needed.

letshacklife said:

Why is P1.4 connected via a 10k ohm resistor only and why is its output going to the BSS138LT1? What is the use of the part BSS138LT1?

Antenna

Since the RF430FRL152H is a 1.5V part, it cannot drive an LED directly.  The BSS138LT1 simply provides the drive the LED needs.

letshacklife said:

How did you arrive at the values of 39 pF and 8.2 pF fort the capacitors C14 and C7? 

These need to be determined if a custom PCB is done.  There are references on how to tune an antenna.  Check this guide out:

RF430FRL15xH NFC ISO 15693 Sensor Transponder Practical Antenna Design (http://www.ti.com/lit/pdf/sloa217)

Also I would recommend to check the minimum required components example circuit in the datasheet

http://www.ti.com/lit/ds/symlink/rf430frl152h.pdf (Applications, Implementation, and Layout, Section 7)

Hi,

Thanks for the answers. I've a few more questions to follow up:

1.  For debugging you could use the FET power to power the chip and the battery would not be needed.  You would have to find a way to disconnect the battery though, in this case.  Also you would need an 1.5V LDO.

You mean the LDO must output a 1.5 Volts right?

2. Why are the P1.5, P1.6 and P1.7 pins connected to switches S3,S4 and S5 via 100k ohms resistors?

2. Why do we need the switches S3, S4 and S5?

Because they are needed by the ROM to determine which features to enable.  Check the RF430FRL15xH Firmware Users Guide (5 Interfacing a Host Controller) for information on what pull-ups/down to use.  These are only necessary if the "Default" or "SensorHub" project is used.  For the "NFC" example these resistors  and switches are not needed.

I do not get your point about the Default, SensorHub and NFC examples. Where are these examples? What do these applications have to do with the JTAG debugger?

In my design, I've a sensor that is connected to the 152H and an LDO that drives the uC. 

So in such a case while developing and debugging (please correct me if I'm wrong), I certainly need the JTAG debugger. So for this I do eed the S3, S4, S5 switches with the 100 k ohms resisters? or can I connect the JTAG pins of the RF152H directly to those 4 pins of the FET debugger (not sure of this option)? 

On the same lines of thought, can I connect the JTAG pin of MSP-FET directly to the TCK or do I need to interface it with the 10k R6 resistor in series? 

3. In the MCU schematic section: 

- What is the JMP1 with the 160k for?

- Why does the TDO go via the JMP1 to the collector of U2? Why is the U2 included in the design?

- What are the functions of the Q2, R7 (220) and U7 (alarm)?

4. I2C SPI section

- Why are U4 and U6 IC's needed for the I2C and SPI protocols? 

- If I connect multiple sensors (slaves that operate on 1.5 volts) with pull-up resistors to the RF152H without these ICs would it work?

letshacklife said:

You mean the LDO must output a 1.5 Volts right?

Ideally.  It can be up to 1.65V if necessary.

letshacklife said:

I do not get your point about the Default, SensorHub and NFC examples. Where are these examples? What do these applications have to do with the JTAG debugger?

These are example starting firmware projects.  Check out the '152H product page here: http://www.ti.com/product/RF430FRL152H and select the "Tools and Software" tab.  Then browse to the software section.

These example projects are important if you want to use the ROM code that is in the chip.  Example ROM functionality like ISO/IEC 15693 RF stack, sensor logging into FRAM, I2C/SPI host control support and other.  For more information on the ROM functionality, check out this link: http://www.ti.com/lit/pdf/slau603

You could take the option of not using the ROM at all, in which case, like in the NFC example the pull-up or pull-down resistors on the JTAG lines would not be needed.  These resistors are only sampled if you program the default or SensorHub examples into the device.  These resistors on the JTAG lines have really nothing to do with JTAG functionality other then sharing the same pins.  Generally when the chip is in production JTAG is not active. The resistors were chosen such that JTAG can be used and not be effected by them.

letshacklife said:

So in such a case while developing and debugging (please correct me if I'm wrong), I certainly need the JTAG debugger. So for this I do eed the S3, S4, S5 switches with the 100 k ohms resisters? or can I connect the JTAG pins of the RF152H directly to those 4 pins of the FET debugger (not sure of this option)? 

Yes, you definitely need the JTAG debugger for developing and debugging.  However, you should consider if the JTAG level shifters be on a separate board that can attach to the product when testing.

The switches are implemented on the EVM for flexibility.  If you choose to use the ROM sensor support, (Default or SensorHub examples) you could simply replace the switches with resistors connected to ground or VDDSW (depending on the configuration that you need - again reference the document provided earlier)

The MSP-FET does not go to 1.65V natively.  Therefore level-shifters are needed.  You could consider an already available level-shifter tool so that you don't have to develop one yourself.  it is available here: http://www.ti.com/tool/msp-ts430l092#buy .

letshacklife said:

On the same lines of thought, can I connect the JTAG pin of MSP-FET directly to the TCK or do I need to interface it with the 10k R6 resistor in series? 

No, all the JTAG signals should be connected directly to the device pins (after the level-shifter).  The 10k resistor was only needed for the mosfet.

letshacklife said:

What is the JMP1 with the 160k for?

This was needed to bias the light sensor properly. This should not be needed in your application.

letshacklife said:

Why does the TDO go via the JMP1 to the collector of U2? Why is the U2 included in the design?

This was done to save power.  Instead of the light sensor being always biased by VDDSW and drawing current when not being used, a GPIO (TDO) could be used to bias it only when the ADC is sampling this sensor.  This feature is disabled by default.

letshacklife said:

What are the functions of the Q2, R7 (220) and U7 (alarm)?

As explained before, since the '152H cannot drive an LED directly, an amplifier is needed. These components are that amplifier.

letshacklife said:

- Why are U4 and U6 IC's needed for the I2C and SPI protocols? 

They are level shifters to interface I2C/SPI to a BoosterPack or LaunchPad.

letshacklife said:

- If I connect multiple sensors (slaves that operate on 1.5 volts) with pull-up resistors to the RF152H without these ICs would it work?

Yes, this should work.  You should make sure that the sensors can detect 1.5V signals.