STP24DP05 IC queries

[Meghla]

Hi Team,

We are using this STP24DP05 (24-bit constant current LED sink driver with output error detection) IC for a X*Y array of diodes to get high or low. The IC is interfaced with microcontroller using SDI pin of STP24DP05. We have some doubts kindly check-

1. How will the serial pin data transfers to  outputs R/G/B pin? does R1 , G1 & B1 gets data first then it goes to next R2,G2,B2? or it will first give data to R1-R8 then to next 8 bits goes to G1-G8 like that. 

2. Is LE/DM pin working as reset to all the pins? does the outputs of STP24DP05 gets refreshed when LE/DM is pulled down?

3. Can we keep OE pins as grounded ? 

 

[Peter BENSCH]

1. See data sheet, section 7.6, table 14 (shifter register data flow control).
2. LE\DM is not a reset pin, but a Latch Enable pin enabling the latch circuit for a new set of data from the SDI chain.
3. To be checked, but you need to switch at least OE-R\DM to enter the error detection mode.

Hope that helps?

Regards
/Peter

[Meghla]

Hi Peter,

Thanks for the reply.

1. We donot want error detection mode. In that case can we keep all three output enables as low ?

2. At what interval SDO comes out? what I understood from the timing diagram after sending out all the 24 parallel outputs it will send the SDO.

 

 

[Peter BENSCH]

1. as described in section 7 of the data sheet: if you do not require error detection mode, do not set LE\DM and /OE-RE\DM to H at the same time and over some clock cycles

2. yes, in normal mode SDO can be seen as an output of a shift register, i.e. the input data will occur after 24 clock cycles