TLC5617, TLC5617A

PROGRAMMABLE DUAL 10-BIT DIGITAL-TO-ANALOG CONVERTERS

SLAS151B – JULY 1997 – REVISED MARCH 2000

16

POST OFFICE BOX 655303

APPLICATION INFORMATION

DSP serial interface

Utilizing a simple 3-wire serial interface, the TLC5617A can be interfaced to TMS320 compatible serial ports.

The 5617A has an internal state machine that counts 16 clocks after receiving a falling edge of CS and then

disable further clocking in of data until the next falling edge is received on CS. Therefore the CS can be

connected directly to the FS pins of the serial port and only the leading falling edge of the DSP will be used to

start the write process. The TLC5617A is designed to be used with the TMS320Cxx DSP in burst mode serial

port transmit operation.

SCLK

DIN

CS

TLC5617

CLKX

DX

FSX

TMS320C32

DSP

VCC

OUT A

OUT B

GND

REFIN

2.5 V dc

FSR

To Source

Ground

Analog

Output

Analog

Output

CLKR

Figure 22. Interfacing The TLC5617 To TMS320C32 DSP

SPI serial interface

Both the TLC5617 and TLC5617A are compatible with SPI, QSPI, or Microwire serial standards. The hardware

connections are shown in Figure 23 and Figure 24. The TLC5617A has an internal state machine that counts

16 clocks after the falling edge of CS and then internally disables the device. The internal edge is ORed together

with CS so that the rising edge can be provided to CS prior to the occurrence of the internal edge to also disable

the device.

general serial interface

The TLC5617 3-wire interface is compatible with the SPI, QSPI, and Microwire serial standards. The hardware

connections are shown in Figure 23 and Figure 24.

The SPI and Microwire interfaces transfer data in 8-bit bytes, therefore, two write cycles are required to input

data to the DAC. The QSPI interface, which has a variable input data length from 8 to 16 bits, can load the DAC

input register in one write cycle.