ADS8588H: External ADC

Hello Ramesh,

ADS8588H is a pin-programmable ADC and interface mode(parallel, serial or byte), internal or external voltage reference and bipolar input range etc. can be selected according to the high or low voltage on specific pins, there is no need to write a command and program any registers, so there is no WRITE pin on ADC.

Regarding MAX1312 replacement, most pins will be same(CONVST,/CS etc), only few pins will be different(/WR etc), I can show you exact pin connections if you can let me know below questions:

1. Are you going to use parallel interface?

2. Internal voltage reference?

3. +/-10V input range?

4. No oversampling needed?

Unfortunately, we don't have a app note for interfacing this ADC with MCU, but ADS8588SEVM User's Guide with schematic can be a good reference.

Thanks.

Best regards

Dale

Hi Dale,

Thanks for your detailed reply.Pls find the answers below for your questions.

1. Are you going to use parallel interface?

YES,I need Parallel interface.

2. Internal voltage reference?

NO,I will use external reference.I found some guidelines for the same in the datasheet.Ur suggestion is mostly preferred.

3. +/-10V input range?

YES. +/- 10V input voltage range is preferred.

4. No oversampling needed?

NO. I don't need oversampling.

Kindly suggest exact pin connections of ADS8588H to be interfaced with TI MCU Part No:TMS320F28377DPTP

This will help me to validate & quick start my development activities.

Thanks & regards,

Ramesh P

Hi Ramesh,

I will get back to you soon, thanks.

Best regards

Dale

Hi Ramesh,

Thanks for your patience. There are different solutions to interface ADS8588H to TMS320F28377D MCU, the simplest way is using EMIF(External Memory Interface) after checked, below is a suggestion for the connections between ADS8588H and TMS320F28377D, fyi and please double check. If you have any questions about TMS320F28377D, please post your query on our C2000 32-bit Microcontroller Forum.

Except the Power supplies/Ground and Input pins on ADS8588H (refer to EVM User’s Guide for these connections):

(Pins on ADS8588H:   Pins on TMS320F28377D or others)

1. CONVSTA/CONVSTB:   any EPWMxA or EPWMxB pin .  Remark: Enhanced Pulse Width Modulator (ePWM) can set frequency and duty cycle easily

EMIF (External Memory Interface):

2. /CS and /RD(may be tied together):      /EM1CS

3. DB0~DB15:     EM1D0 ~ EM1D15

4. BUSY:      Any GPIO pin with X-BAR which is used to route the signal (BUSY from ADS8588H) on a GPIO pin to external interrupt IP block, TMS320F28377D can use this block to detect the BUSY’s edge to check if the ADS8588H’s conversion is finished.

5. FRSTDATA:    No connection if don’t care about it, or connect to any GPIO pin if care about it

6. OS0/OS1/OS2:     Connect all three pins to ground (no oversampling)

7. PAR/SER/BYTE(Pin 6):      Set to low (connect to ground) for parallel interface

8. RANGE:     Set to logic high (to DVDD by a pull up resistor) for +/-10V range

9. REFCAPA/REFCAPB:    Short together and decouple to analog ground with a low ESR 22-uF ceramic capacitor

10. REFGND:       Connect to analog ground directly

11. REFSEL:      Set to low (connect to ground) to disable internal voltage reference

12. REFIN:      External reference voltage must be provided to this pin

13. REGCAP1/REFCAP2:      Decouple separately to analog ground with a 1-uF capacitor

14. /STBY:      Set to logic high (to DVDD by a pull up resistor) for normal operation

15. RESET:     Any GPIO to have a reset signal after power up

Please let me know if you have any further question about ADS8588H, thanks.

Best regards

Dale