Datasheet

DAC8564

www.ti.com

SBAS403D –JUNE 2007–REVISED MAY 2011

OPERATING EXAMPLES: DAC8564

For the following examples, ensure that DAC pins A0 and A1 are both connected to ground. Pins A0 and A1

must always match data bits DB22 and DB23 within the SPI write sequence/protocol. X = don't care. Value can

be either '0' or '1'.

Example 1: Write to Data Buffer A Through Buffer D; Load DAC A Through DAC D Simultaneously

• 1st: Write to data buffer A:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 0 0 0 0 0 D15 D14 D13 D12 D11–D0

• 2nd: Write to data buffer B:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 0 0 0 1 0 D15 D14 D13 D12 D11–D0

• 3rd: Write to data buffer C:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 0 0 1 0 0 D15 D14 D13 D12 D11–D0

• 4th: Write to data buffer D and simultaneously update all DACs:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 1 0 0 1 1 0 D15 D14 D13 D12 D11–D0

The DAC A, DAC B, DAC C, and DAC D analog outputs simultaneously settle to the specified values upon

completion of the 4th write sequence. (The DAC voltages update simultaneously after the 24th SCLK falling edge

of the fourth write cycle).

Example 2: Load New Data to DAC A Through DAC D Sequentially

• 1st: Write to data buffer A and load DAC A: DAC A output settles to specified value upon completion:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 1 0 0 0 0 D15 D14 D13 D12 D11–D0

• 2nd: Write to data buffer B and load DAC B: DAC B output settles to specified value upon completion:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 1 0 0 1 0 D15 D14 D13 D12 D11–D0

• 3rd: Write to data buffer C and load DAC C: DAC C output settles to specified value upon completion:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 1 0 1 0 0 D15 D14 D13 D12 D11–D0

• 4th: Write to data buffer D and load DAC D: DAC D output settles to specified value upon completion:

DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11–DB0

(A1) (A0) (LD1) (LD0) (DAC Sel 1) (DAC Sel 0) (PD0)

0 0 0 1 0 1 1 0 D15 D14 D13 D12 D11–D0

After completion of each write cycle, DAC analog output settles to the voltage specified.