TMS570LC4357-SEP: Request for Application Notes

Dhir Gandhi

Part Number: TMS570LC4357-SEP
Other Parts Discussed in Thread: TPS73801-SEP, TMS570LC4357, HALCOGEN

Tool/software:

Hello,

The application notes and layout guidelines for the TMS570LC4357-SEP do not appear to be included in its datasheet. While a link to TI Designs is provided, it does not contain any reference designs specific to this MCU. Could you please share any available application notes, reference designs, or documentation relevant to the TMS570LC4357-SEP?

Edit 1:
1. I would also like to understand the typical current consumption from the voltage reference when both ADCs are in use.

2. I’m a bit skeptical about the maximum current consumption of 10 mA mentioned in the datasheet - it seems quite high. Could you please clarify or confirm this value?

Edit 2:

3. Could you let me know which pins can I use to monitor PWM input?

4. I am planning to use the TPS73801-SEP LDO set to 3.3V as both the ADC reference voltage and VCCAD. However, I have some concerns regarding the variation in Vfb and Ifb over temperature.

Based on the datasheet, considering a Vfb variation of 1.21 V ± 0.035 V, my calculations suggest that Vout could vary by as much as 3.3±0.1 V. However, the load regulation curve indicates only about a 7 mV variation under typical conditions. This discrepancy is a bit confusing.

Since I intend to use this LDO as both the reference voltage and the supply for an NTC voltage divider circuit, and all ADC channels will be used solely for monitoring temperature from these NTCs, I’m concerned that this potential voltage drift might introduce significant errors in the temperature measurements.

Could you please clarify the expected variation in Vout over temperature in this application, and whether this approach is viable for accurate temperature sensing?

4 months ago

0 Erin Bowrie 4 months ago

TI__Genius 10210 points

Hi Dhir,

If you go to the main page of the product, you can click on the Technical Documentation to see the available application notes. There's 60+ documents, so something will surely cover what you need! The TIDesigns page didn't have any reference designs for the TMS that I could find.

Thanks,
Erin

0 Dhir Gandhi 4 months ago in reply to Erin Bowrie

Prodigy 180 points

Hello Erin,

I couldn't find any document for power supply recommendation and decoupling capacitors in the technical documentation. Also, could you let me know which pins can I use to monitor PWM input?

+1 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Hi Dhir,

My sincere apologies for the delayed response, i was off for some days and didn't get time to work on this issue.

You can use our TMS570LC4357 Lauchpad or HDK schematic and layout files are reference.

LAUNCHXL2-570LC43 Development kit | TI.com

TMDX570LC43HDK Development kit | TI.com

And we also have some reference designs for Hercules controllers in below link:

TI Reference Designs Library

--
Thanks & regards,
Jagadish.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Thanks Jagadish!

0 Dhir Gandhi 3 months ago in reply to Dhir Gandhi

Prodigy 180 points

I had a query regarding the V19 and W18 pins. Why are there 2 pins for one single ADC channel? Do I need to short these pin or I can give input to any one pin and leave another one floating?

0 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Dhir Gandhi said:
I had a query regarding the V19 and W18 pins. Why are there 2 pins for one single ADC channel? Do I need to short these pin or I can give input to any one pin and leave another one floating?

Either you can short and take it as one pin or you can just take any one of them, this doesn't affect the behavior because those both pins are shorted internally in controller.

The reason for duplication is given in below thread:

(+) TMS570LC4357: TMS570LC4357: how to treat pin "V19" and "W18" for AD2IN[24] - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

--
Thanks & regards,
Jagadish.

0 jagadish gundavarapu 3 months ago in reply to jagadish gundavarapu

TI__Guru 69811 points

(+) TMS570LC4357: ADC Pin Mulitplexing - AD2IN[24] - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Here they are suggesting connecting same signal to both the terminals, you can follow the same method.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Thanks for clarifying Jagadish

0 Dhir Gandhi 3 months ago in reply to Dhir Gandhi

Prodigy 180 points

Hi Jagadish,

I need help configuring the clock tree in Haclogen for the following interfaces:

UART – 230.4 kbps
CAN – 1 Mbps
SPI – 133 MHz

Could you guide me on how to set up the clocks to ensure stable performance for these peripherals?

I also had some other queries:

Could you let me know which clock source determines the maximum speed achievable on the GIO pins?
Can I use the LBIST, PBIST test modes of the MCU if I ground the TEST pin?
In the SPI configuration section of Halcogen, what does the internal clock configuration refer to?

Thanks!

+1 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Hi Dhir,

Dhir Gandhi said:
UART – 230.4 kbps

CAN – 1 Mbps

SPI – 133 MHz

Could you guide me on how to set up the clocks to ensure stable performance for these peripherals?

All these peripherals are input with VCLK1 only, and you can keep the 75Mhz like as default given in HALCoGen:

This should be fine for above all your required baudrates.

Dhir Gandhi said:
Could you let me know which clock source determines the maximum speed achievable on the GIO pins?

(+) TMS570LS1227: frequency, GPIO - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Refer above thread and same thing should be applicable for this device as well.

Dhir Gandhi said:
Can I use the LBIST, PBIST test modes of the MCU if I ground the TEST pin?

TEST pin doesn't have any relationship with LBIST and PBIST test modes. This TEST pin mainly using in JTAG related modes.

There are various test modes (e.g. ATPG scan) used during production test that need to set this TEST pin high. Some of these modes are not functional modes and are not required / supported in application use. These test modes are for TI use only, so you can tie the TEST pin to ground directly on your PCB. We have connected it to GND via a resistor on the Launchpad so that we still maintain the ability to use these test modes if required.

Refer below threads once:

(+) RM44L920: Test Pin - purpose and grounding method - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(+) LAUNCHXL2-RM46: External JTAG Debug (TEST PIN) - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Dhir Gandhi said:
In the SPI configuration section of Halcogen, what does the internal clock configuration refer to?

Refer below thread once:

(+) TMS570LC4357: SPI Clock Questions - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

--
Thanks & regards,
Jagadish.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Thanks Jagadish!

0 Dhir Gandhi 3 months ago in reply to Dhir Gandhi

Prodigy 180 points

Hello Jagadish,

I have a couple of queries regarding the MCU design:

Oscillator Source Configuration
I plan to use a CMOS-output TCXO as the oscillator source (i.e., configuration (b) as shown in the image below). Could you please confirm if there are any specific requirements the TCXO must meet, particularly in terms of frequency stability? Also, how should I terminate OSCOUT if I use a TCXO?

Decoupling Capacitor Substitution
In the TMS570 EVK, 0.1 µF capacitors are used on the power supply pins. Due to a design constraint in our system, we may only be able to use 0.01 µF capacitors instead.
Could you advise if this substitution would affect the MCU’s performance? Additionally, please share any potential issues or risks associated with this change.
Also, are the 22 uF capacitors used to improve ripple performance or load transient response? would it be advisable to place larger tantalum capacitor with low-esr instead?

Edit 1:

1. If I configure ECLK as GIO, will both ECLK1 and ECLK2 have GIO functionality?

2. I also need help with the termination of unused pins of the MCU.I don't want to leave any Pin floating. Pls go through the attached excel file.
8357.TMS570 Pin Termination.xlsx

Edit 2:

What is the load capacitance of the OSCIN pin?

0 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Hi Dhir,

Dhir Gandhi said:
2. I also need help with the termination of unused pins of the MCU.I don't want to leave any Pin floating. Pls go through the attached excel file.
8357.TMS570 Pin Termination.xlsx

Please refer below suggestions regarding unused pins in the schematic

(+) TMS570LS1227: How to configure unused pins - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

And i am working on your remaining questions will update you as soon as possible.

Thanks & regards,
Jagadish.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Hello Jagadish, thanks for helping out.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Hello Jagadish,

Pls help me with the remaining queries.

+1 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Hi Dhir,

Dhir Gandhi said:
I plan to use a CMOS-output TCXO as the oscillator source (i.e., configuration (b) as shown in the image below). Could you please confirm if there are any specific requirements the TCXO must meet, particularly in terms of frequency stability? Also, how should I terminate OSCOUT if I use a TCXO?

If supplying an external clock signal directly to the OSCIN pin, ensure that the signal has minimal jitter and maintain the frequency stability within +-50 ppm.

Dhir Gandhi said:
In the TMS570 EVK, 0.1 µF capacitors are used on the power supply pins. Due to a design constraint in our system, we may only be able to use 0.01 µF capacitors instead.
Could you advise if this substitution would affect the MCU’s performance? Additionally, please share any potential issues or risks associated with this change.

Maybe you can use because in our launchpad schematic that is shown below

All supply pins don't have 0.1uf, some of them have 0.1uf and remaining pins have 0.01uf or lower only.

Dhir Gandhi said:
Also, are the 22 uF capacitors used to improve ripple performance or load transient response? would it be advisable to place larger tantalum capacitor with low-esr instead?

Yes, you can use it.

--
Thanks & regards,
Jagadish.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Hello Jagadish,

Thanks for the clarification. Pls also help me with the below queries:

If I configure ECLK as GIO, will both ECLK1 and ECLK2 have GIO functionality?
How should I terminate OSCOUT if I use a TCXO?
What is the load capacitance and current requirement of OSCIN pin?

+1 jagadish gundavarapu 3 months ago in reply to Dhir Gandhi

TI__Guru 69811 points

Dhir Gandhi said:
If I configure ECLK as GIO, will both ECLK1 and ECLK2 have GIO functionality?

Yes, you can use both as GIO.

Please refer below thread for ECLK1 as GIO:

(+) [FAQ] TMS570LC4357: How to use different peripherals pins (like Lin, MibSPI, N2HET, ECLK and RTP) as GIO - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Refer below threads for ECLK2 as GIO:
(18) TMS570LC4357: How to use ECLK1 (A12) and ECLK2 (K3) as GIO? - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

(18) On TMS570LC43, how to control ECLK2 in gio mode - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Dhir Gandhi said:
How should I terminate OSCOUT if I use a TCXO?

No need to terminate anything. You can leave unconnected, if you are using external clock signal on OSCIN.

Dhir Gandhi said:
What is the load capacitance and current requirement of OSCIN pin?

Don't connect any load capacitance if you are using external clock signal on OSCIN.

Thanks & regards,
Jagadish.

0 Dhir Gandhi 3 months ago in reply to jagadish gundavarapu

Prodigy 180 points

Thanks Jagadish!