TLC5618, TLC5618A

PROGRAMMABLE DUAL 12-BIT DIGITAL-TO-ANALOG CONVERTERS

SLAS156E – JULY 1997 – REVISED SEPTEMBER 1999

16

POST OFFICE BOX 655303

APPLICATION INFORMATION

Table 2 shows the function of program bits D15 – D12.

Table 2. Program Bits D15 – D12 Function

PROGRAM BITS

DEVICE FUNCTION

D15

D14

D13

D12

DEVICE FUNCTION

1

X

X

X

Write to latch A with serial interface register data

and latch B updated with buffer latch data

0

X

X

0

Write to latch B and double buffer latch

0

X

X

1

Write to double buffer latch only

X

0

X

X

12.5

µs settling time

X

1

X

X

2.5

µs settling time

X

X

0

X

Powered-up operation

X

X

1

X

Power down mode

function of the latch control bits (D15 and D12)

Three data transfers are possible. All transfers occur immediately after CS goes high and are described in the

following sections.

latch A write, latch B update (D15 = high, D12 = X)

The serial interface register (SIR) data are written to latch A and the double buffer latch contents are written to

latch B. The double buffer contents are unaffected. This program bit condition allows simultaneous output

updates of both DACs.

Serial

Interface

Register

D12 = X

D15 = High

Latch A

Latch B

Double

Buffer Latch

To DAC A

To DAC B

Figure 20. Latch A Write, Latch B Update

latch B and double-buffer 1 write (D15 = low, D12 = low)

The SIR data are written to both latch B and the double buffer. Latch A is unaffected.

Serial

Interface

Register

D12 = Low

D15 = Low

Latch A

Latch B

Double

Buffer Latch

To DAC A

To DAC B

Figure 21. Latch B and Double-Buffer Write