TLV5616C, TLV5616I

2.7 V TO 5.5 V LOW POWER 12-BIT DIGITAL-TO-ANALOG

CONVERTERS WITH POWER DOWN

SLAS152B – DECEMBER 1997 – REVISED MARCH 1999

12

POST OFFICE BOX 655303

APPLICATION INFORMATION

serial interface (continued)

If there is no need to have more than one device on the serial bus, then CS can be tied low. Figure 16 shows

an example of how to connect the TLV5616 to a TMS320, SPI, or Microwire port using only three pins.

TMS320

DSP

FSX

DX

CLKX

TLV5616

FS

DIN

SCLK

CS

SPI

SS

MOSI

SCLK

TLV5616

FS

DIN

SCLK

CS

Microwire

I/O

SO

SK

TLV5616

FS

DIN

SCLK

CS

Figure 16. Three-Wire Interface

Notes on SPI and Microwire: Before the controller starts the data transfer, the software has to generate a falling

edge on the I/O pin connected to FS. If the word width is 8 bits (SPI and Microwire), two write operations must

be performed to program the TLV5616. After the write operation(s), the DAC output is updated automatically

on the sixteenth positive clock edge.

serial clock frequency and update rate

The maximum serial clock frequency is given by:

f

SCLKmax +

1

t

wH(min) )

t

wL(min)

+ 20 MHz

The maximum update rate is:

f

UPDATEmax +

1

16

t

t

wL(min)

+ 1.25 MHz

The maximum update rate is a theoretical value for the serial interface, since the settling time of the TLV5616

has to be considered also.

data format

The 16-bit data word for the TLV5616 consists of two parts:

(D15 . . . D12)

(D11 ...D0)

D15

D14

D13

D12

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

D0

X

SPD

PWR

X

New DAC value (12 bits)

X: don’t care

SPD: Speed control bit.

1

→ fast mode

0

→ slow mode

PWR: Power control bit.

1

→ power down

0

→ normal operation

In power-down mode, all amplifiers within the TLV5616 are disabled.