ISO1228: 4 pcs ISO1228 in daisy chain

Chen Alex1

Genius 3815 points

Part Number: ISO1228

hi SIR

I want to design a DI module, which use 32 ch DI, so need 4 pcs ISO1228,

May I know how to set up the HW circuit?

thanks

if i don't need the LED, should floating the part? or short whether source or sink mode

how to set up the R Limit in source /sink module

thanks

over 1 year ago

0 Andrew J over 1 year ago

TI__Mastermind 29665 points

Hello Alex,

Thanks for reaching out. The LED pins can be shorted to ground as long as the customer is not using wire-break detection. Use a standard diode in place of the LED if the wire-break detect is needed. Please see the below datasheet snippet.

Best,
Andrew

0 Chen Alex1 over 1 year ago in reply to Andrew J

Genius 3815 points

HI Andrew

1.how to set up the R Limit in source /sink module?

2. how to set up the HW when ISO1228 in Daisy chain;COMM SEL, OUT EN, F0 F1?

Thanks

0 Andrew J over 1 year ago in reply to Chen Alex1

TI__Mastermind 29665 points

Hello Alex,

You can use ISO1228-CALC Calculation tool | TI.com to set voltage thresholds and current limits.
1. This is also outlined in the 8.2.3.1 Detailed Design Procedure.
Details on daisy chain mode can be found in 7.3.9 SPI Interface Timing - Daisy Chain. The pin configuration should be as follows:
1. COMM_SEL = VCC1
2. OUT_EN = VCC1
3. F0 = 'X' - don't care. F0 and F1 are used to configure the input filters
4. F1 = 'X' - don't care

Best,
Andrew

Isolation

Isolation forum

ISO1228: 4 pcs ISO1228 in daisy chain