| ??? 10/22/05 00:07 Read: times |
#102742 - RFBA is important current output of DAC Responding to: ???'s previous message |
Mike said:
I can't, however, figure out the purpose of two pins on the chip. Can anyone tell me what RFBA and RFBB are supposed to do on this chip. This DAC presents the output as a current, not a voltage. For this reason an additional OPamp is needed, which pulls-down OUTA/OUTB to virtualy ground and transforms the current which flows via RFBA/RFBB into a voltage. So, you must connect OUTA/OUTB and RFBA/RFBB as recommended in datasheet! R1, R2, R3 and R4 of figure 2 are only needed if you want to provide a gain adjustment. If not, then exchange them by shortcircuits, so that VIA/VIB is directly connected to REFA/REFB and RFBA/RFBB directly to VOA/VOB. Kai |
| Topic | Author | Date |
| TLC7628 DAC | 01/01/70 00:00 | |
| Ref Connections | 01/01/70 00:00 | |
| RFBA is important current output of DAC | 01/01/70 00:00 | |
| Ok, which is better | 01/01/70 00:00 | |
| An OPamp is needed anyway | 01/01/70 00:00 | |
| Drawbacks of Fig 6 | 01/01/70 00:00 | |
Source impedance is constant | 01/01/70 00:00 |