AM1808 design queries

K Md Feroz Irfan

Expert 7225 points

Other Parts Discussed in Thread: AM1808, PCA9306, SN74AVC4T245, SN74AVCH8T245, TRS3386E

Dear Team,

Our plan is to use AM1808 SOM board and develop a customized carrier board as per our application.

Our query are as mentioned below:

Can I2c signal of the AM1808 be directly interface to an RTC (DS3232) or do I need to place a level shifter.

Similar query for SPI and SCI interface.

I am not using any JTAG interface all the communication and programming is done by serial port, Can I remove all the JTAG I.C. I suppose this can be a handy thing for debug. isn't it?

Can you please help clarify?

Best Regards

Feroz

over 14 years ago

0 Abhijit Das84416 over 14 years ago

TI__Intellectual 880 points

Hello Feroz,

Recommended power supply of DS3232 (RTC) 2.3 V to 5.5 V. But signal Level of I2C Peripheral of the AM1808 is generate max 1.3 V / 1.2. So should be placed

Level Shifter like PCA9306. If the connected Periphery's (RTC) power supply is 1.3V then only level shifter is not required. Same recommendation for SPI interface also. If I2C peripheral generates the clocks 3.3V level then also level is not required.

Regards

Abhijit

0 K Md Feroz Irfan over 14 years ago in reply to Abhijit Das84416

TI__Expert 7225 points

Sorry, customer needs similar inputs on GPIOs

Best Regards

Feroz

0 Abhijit Das84416 over 14 years ago in reply to K Md Feroz Irfan

TI__Intellectual 880 points

Feroz,

Can you please elaborate please.What is exact requirement.

Abhijit

0 suraj kumar over 14 years ago in reply to Abhijit Das84416

Prodigy 50 points

HI this is Suraj,

I want to interface DS3232 to AM1808 through I2c interface, Can you pl suggest, Do I need to connect PCA9306 or not.

I want to connect PIC33 to AM1808 through SPI interface, Do I need to connect a level shifter, can you recomend some I.C

0 Abhijit Das84416 over 14 years ago in reply to suraj kumar

TI__Intellectual 880 points

Hello Firoz, Suraj,

For Interface DS3232 to AM1808 through I2C protocol PCA9306 should connect.

For Interface PIC33 to AM1808 through SPI protocol SN74AVC4T245 4 - bit Voltage Trans later (level shifter) should connect.

PIC33 mean which are you considering dsPIC33 Series?

Abhijit

0 suraj kumar over 14 years ago in reply to Abhijit Das84416

Prodigy 50 points

Hi Abhijit,

I2C,SPI-clear.

we are using dspic33FJ256GP710A. I need to connect some 8-GPIO of AM1808 to dspic. Can u suggest some level shifter for the same.

0 suraj kumar over 14 years ago in reply to suraj kumar

Prodigy 50 points

pl also suggest for sci interface from AM1808 to dspic33f.

0 Abhijit Das84416 over 14 years ago in reply to suraj kumar

TI__Intellectual 880 points

Hello Suraj,

1. Power supply of dspic33FJ256GP710A 3.3 to 3.6V. The GPIO of the AM1808 is configurable for 1.8 & 3.3 V .If you configure the 3.3V GPIO then you can interface with PIC

33f without level translator otherwise use SN74AVCH8T245 (8-BIT DUAL-SUPPLY BUS TRANSCEIVER).

2. For SCI to PC interface AM1808 to PIC33F series you connect Tx of Am1808 to Rx of PIC33 & TX of PIC33F to AM1808 with PCA9306 level shifter. If you can use for PC Interface the TRS3386E is recommended .Please follow the Following link.

http://focus.ti.com/paramsearch/docs/parametricsearch.tsp?family=analog&familyId=543&uiTemplateId=NODE_STRY_PGE_T

-Abhijit

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AM1808 design queries