TLC5615C_15 Datasheet, PDF (10/23 Pages) Texas Instruments – 10-BIT DIGITAL-TO-ANALOG CONVERTERS

TLC5615C, TLC5615I
SLAS142E – OCTOBER 1996 – REVISED JUNE 2007
www.ti.com
The data from DOUT requires 16 falling edges of the input clock and, therefore, requires an extra clock width.
When daisy chaining multiple TLC5615 devices, the data requires 4 upper dummy bits because the data transfer
requires 16 input-clock cycles plus one additional input-clock falling edge to clock out the data at the DOUT
terminal (see Figure 1).
The two extra (sub-LSB) bits are always required to provide hardware and software compatibility with 12-bit data
converter transfers.
The TLC5615 three-wire interface is compatible with the SPI, QSPI, and Microwire serial standards. The
hardware connections are shown in Figure 12 and Figure 13.
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.
SCLK
SK
DIN
TLC5615
CS
SO Microwire
Port
I/O
DOUT
SI
NOTE A: The DOUT-SI connection is not required for writing to
the TLC5615 but may be used for verifying data
transfer if desired.
Figure 12. Microwire Connection
SCLK
SCK
DIN
TLC5615
CS
MOSI
SPI/QSPI
I/O Port
DOUT
MISO
CPOL = 0, CPHA = 0
NOTE A: The DOUT-MISO connection is not required for writing to the
TLC5615 but may be used for verifying data transfer.
Figure 13. SPI/QSPI Connection
DAISY-CHAINING DEVICES
DACs can be daisy-chained by connecting the DOUT terminal of one device to the DIN of the next device in the
chain, providing that the setup time, t_su(CSS) (CS low to SCLK high), is greater than the sum of the setup time,
t_su(DS), plus the propagation delay time, t_pd(DOUT), for proper timing (see digital input timing requirements section).
The data at DIN appears at DOUT, delayed by 16 clock cycles plus one clock width. DOUT is a totem-poled
output for low power. DOUT changes on the SCLK falling edge when CS is low. When CS is high, DOUT
remains at the value of the last data bit and does not go into a high-impedance state.
LINEARITY, OFFSET, AND GAIN ERROR USING SINGLE-ENDED SUPPLIES
When an amplifier is operated from a single supply, the voltage offset can still be either positive or negative.
With a positive offset, the output voltage changes on the first code change. With a negative offset the output
voltage may not change with the first code depending on the magnitude of the offset voltage.
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