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I input a 6bits_code_min=0dec or 6b_code_max=62dec value into the DAC6 by means WriteStall API and I get unexpected Voutput value.
Theoretically the DAC6 datasheets told us:
Vout=(Vrefhi-AGND)*ACap/FCap+AGND
Taking into account my reference Vdd/2+/-BandGap I must to have:
Vout(max)=3.76V
Vout(min)=2.5V
Instead of this I obtain a more or less a Vout=3.7 V and after that the value is going down until reach
aproximattely 2.5V. I put the analog outputs in High Z.
The C code is simple:
"PSoCAPI.h" // PSoC API definitions for all User Modules
#define
DAC_MAX ( 62 ) // Define max DAC value as 62
unsigned
unsigned
int
void
{
DAC6_Start(DAC6_HIGHPOWER);
BUFFER_Start(BUFFER_HIGHPOWER);
{
DAC6_WriteStall(bDACValue);
for(i = 0xFF; i != 0; i--); // Delay loop
}/*while*/
char bDACValue = DAC_MAX; // Variable for the DAC value char j; // Variable for an index i; main() // Start DAC6 in HIGH power mode while ( 1 ) // Repeat forever //for(j=0; j<62; j++){ for (i = 0xFF ; i != 0 ; i--); // Delay loop for (i = 0xFF ; i != 0 ; i--); // Delay loop} /*main*/
Anyone could tell me what's going on? Thanks
#include
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PSoC 1
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i have same problem if you get any hint please help me also
i dont get perfect 3.3 and 0 voltage on analog pin by using DAC
actually when i enter 0 offset i its function { DAC8_1_WriteBlind(BYTE bOutputValue);} it should give me 0 volt output but it give 0.38 volt and when i set 254 offset it gives me 2.95 volts,it should give me 3.3 volt
i am using this chip on 3.3 voltage..
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i think you need to select
ref mux =(Vdd/2)+/-(Vdd/2)
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Do you have OpAmp Bias andA_Buff_Power, global resources, set
to high power ? The CM range of analog amps is affected by their
bias. Datasheet covers this in specs.
Also depends on what part you are using. See V swing analog buffer
below.
http://www.cypress.com/?rID=2746 AN13666
Regards, Dana.