Datasheet
SLAS232A − JUNE1999 − REVISED JULY 2002
12
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
general function
The TLV5627 is an 8-bit single supply DAC based on a resistor string architecture. The device consists of a serial
interface, speed and power-down control logic, a reference input buffer, a resistor string, and a rail-to-rail output
buffer.
The output voltage (full scale determined by external reference) is given by:
2REF
CODE
2
n
[V]
Where REF is the reference voltage and CODE is the digital input value within the range of 0
10
to 2
n
−1, where
n=8 (bits). The 16-bit data word, consisting of control bits and the new DAC value, is illustrated in the data format
section. A power-on reset initially resets the internal latches to a defined state (all bits zero).
serial interface
The device has to be enabled with CS set to low. A falling edge of FS starts shifting the data bit-per-bit (starting
with the MSB) to the internal register on the falling edges of SCLK. After 16 bits have been transferred or FS
rises, the content of the shift register is moved to the DAC latch, which updates the voltage output to the new
level.
The serial interface of the TLV5627 can be used in two basic modes:
D Four wire (with chip select)
D Three wire (without chip select)
Using chip select (four-wire mode), it is possible to have more than one device connected to the serial port of
the data source (DSP or microcontroller). The interface is compatible with the TMS320 family. Figure 15 shows
an example with two TLV5627s connected directly to a TMS320 DSP.
TMS320
DSP
XF0
XF1
FSX
DX
CLKX
TLV5627
CS
FS DIN SCLK
TLV5627
CS
FS DIN SCLK
Figure 15. TMS320 Interface