DAC1282: DAC1282 not working

Hi Roobini,

I would highly recommend reviewing the DAC1282 datasheet, especially section 8.2.6 on page 23 and the basic connection diagram in Figure 50 on page 36.  See my specific responses below.

Best regards,

Bob B

Roobini Vasu said:

Part Number: DAC1282

Hi,

I have rigged up the circuit for DAC1282 but not getting any response at DOUT. I suppose all is fine except that i do not have any external crystal.

1. Should I connect external crystal oscillator to DAC1282 Clk pin? [BB] You must have a clock source for the DAC1282.

2. If so how should I connect it? Normally IC's have XTAL1 and XTAL2 pins across which crystal is connected, but here we have only one pin. How shall I go about it. [BB] You cannot use a crystal with the DAC1282.  The clock should come from a crystal oscillator or a low-jitter PLL clock source properly terminated.  The nominal clock frequency is 4.096MHz. 

3. Am operating at 1.406 MHz SPI clk and SPI mode 0 configuration. Is it okay? [BB] SPI timing diagram is shown in Figure 1 of the datasheet.  Section 8.3.1 discusses the serial interface operation.

4. Any pull up or pull down required at MOSI, MISO, SCLK etc ? [BB] No pull-up or pull-down is required, but a 50 Ohm resistor in series with the SCLK input is suggested (see Figure 50 in the datasheet).

Please help in this regards.

-Roobini Vasu