TPS38700: EN9 - EN12 Pin Functions

Gordon McKenzie

Part Number: TPS38700

Hello,

I want to use the TPS38700 with as many sequencing outputs as possible, but the datasheet is very confusing.

There are mentions of all 12 being available in table 10.2, but table 10.1 immediately above says sequencer with NEM_PD. Also figure 5.1 refers to an 11-channel sequencer rather than 12.

Does this imply that the EN10 output is not available (always used as NEM_PD) and that the other 11 channels are available?

In table 8-14, showing the bits of the EN_ALT_F register, it says these bits are read only and loaded from NVM. That is not very helpful, when there is nothing to say what values are stored in NVM!

For the only device currently available (TPS38700C04NRGER), can you confirm the NVM read-only value in register 0x20 (EN_ALT_F), and confirm what functions are available on EN9, EN10, EN11 and EN12?

Thanks,

Gordon.

over 1 year ago

0 Oscar Ambriz over 1 year ago

TI__Expert 5510 points

Hello Gordon,

TPS38700 can be configured to be a 12 channel sequencer. Turn your attention to Figure 6-1, in this figure you will see that Pins 10-12 have three functions. Depending on the users application Pins10-12 can be set to sequencing outputs (EN) bringing the sequencer to a total of 12 sequencing outputs.

For TPS38700C04NRGER register 0x20 stores data 0x02 meaning PIN 10 is set to its alternative function NEM_PD. Pin 12 is not mapped to a sequence slot since it is set to Slot 0. Pins 9 and 11 are set to sequencing outputs.

It should be noted that the sequencing order and times can be adjusted over I2C to suit the users needs and depending on the size of the opportunity a custom OTP can be created to satisfy a user system requirements.

Regards,

Oscar Ambriz

0 Gordon McKenzie over 1 year ago in reply to Oscar Ambriz

Intellectual 580 points

Hello Oscar,

thanks for your reply. I do intent to reprogram the sequence over I2C but I'm still not sure how I can get the only available part (TPS38700C04NRGER) to act as a 12-channel sequencer. It seems that register 0x20 is set in NVM and read only, so it doesn't seem possible to set this to 0x00 as I would need to do (I think) to use all 12 pins as sequencing outputs. I'm currently at prototyping stage on a first run of boards so I don't imagine the volumes will be suitable for a custom OTP at present.

So, if I'm stuck with the TPS38700C04NRGER, can you confirm that EN10 can never be available as a sequencing output, meaning that only 11 channels are available with this specific part?

You also mention pin 12 (EN12) not mapped to a sequence slot - does this mean that pin 12 can only ever be on slot 0 (for both power-up and power down), or can this be overwritten by writing registers over I2C? If this one isn't configurable, does this mean that on this specific part there are actually 10 fully configurable sequencing channels (EN1-EN9 and EN11) with EN10 and EN12 not usable/configurable? This should still be workable, but I do need to know what the limitations are.

It would also be really helpful if the full NVM register contents for the TPS38700C04NRGER were available. Is there any way I can access this info?

Thanks,

Gordon.

+1 Oscar Ambriz over 1 year ago in reply to Gordon McKenzie

TI__Expert 5510 points

Hello Gordon,

TPS38700C03NRGERQ1 is currently the only part available and comes installed in our EVM. You are correct register 0x20 is read only and can only be written to at the initial configuration. I can confirm EN10 can never be available as a sequencing point and only 11 channels are available. EN12 can be assigned a slot over I2C. Additionally, you can change the slot times of the other ENx as you please to get your desired timing.

I will speak with the team to verify whether we can provide the current settings.

Regards,

Oscar Ambriz

+1 Oscar Ambriz over 1 year ago in reply to Oscar Ambriz

TI__Expert 5510 points

Hello Gordon,

The following list the data stored in the registers

ADDRES	NAME	HEX	ADDRES	NAME	HEX
0x20	EN_ALT_F	0x02	0x72	RTC_T1	0x00
0x21	AF_IN_OUT	0x02	0x73	RTC_T0	0x00
0x22	EN_CFG1	0x0F	0x74	RTC_A3	0xFF
0x23	EN_CFG2	0xFF	0x75	RTC_A2	0xFF
0x24	CLK_CFG	0xC0	0x76	RTC_A1	0xFF
0x25	GP_OUT	0x00	0x77	RTC_A0	0xFF
0x26	DEB_IN	0x00	0x80	WDT_CFG	0x00
0x27	LP_TTSHLD	0x00	0x81	WDT_CLOSE	0x00
0x28	CTL_1	0x00	0x82	WDT_OPEN	0x00
0x29	CTL_2	0xC3	0x83	WDTKEY	0x00
0x2A	TEST_CFG	0x03	0xF0	PROT1	0x00
0x2B	IEN_VENDOR	0x00	0xF1	PROT2	0x00
0x30	SEQ_CFG	0x00	0xF9	I2CADDR	0x3C
0x31	SEQ_USLOT	0x02
0x32	SEQ_DSLOT	0x02
0x33	PWR_EN1	0x15
0x34	PWR_EN2	0x11
0x35	PWR_EN3	0x24
0x36	PWR_EN4	0x24
0x37	PWR_EN5	0x42
0x38	PWR_EN6	0x61
0x39	PWR_EN7	0x11
0x3A	PWR_EN8	0x24
0x3B	PWR_EN9	0x42
0x3C	PWR_EN10	0x00
0x3D	PWR_EN11	0x42
0x3E	PWR_EN12	0x00
0x3F	PWR_CLK32OE	0x44
0x53	SLP_EN1	0x00
0x54	SLP_EN2	0x13
0x55	SLP_EN3	0x32
0x56	SLP_EN4	0x00
0x57	SLP_EN5	0x00
0x58	SLP_EN6	0x21
0x59	SLP_EN7	0x13
0x5A	SLP_EN8	0x32
0x5B	SLP_EN9	0x41
0x5C	SLP_EN10	0x00
0x5D	SLP_EN11	0x11
0x5E	SLP_EN12	0x00
0x5F	SLP_CLK32OE	0x00
0x70	RTC_T3	0x00
0x71	RTC_T2	0x00

0 Gordon McKenzie over 1 year ago in reply to Oscar Ambriz

Intellectual 580 points

Hello Oscar,

thanks very much for the confirmation and extra info. The list of register values is very helpful indeed.

Gordon.

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TPS38700: EN9 - EN12 Pin Functions