TLC5615C Datasheet, PDF (13/18 Pages) Texas Instruments – 10-BIT DIGITAL-TO-ANALOG CONVERTERS

serial interface (continued)
TLC5615C, TLC5615I
10-BIT DIGITAL-TO-ANALOG CONVERTERS
SLAS142C – OCTOBER 1996 – REVISED MARCH 2000
APPLICATION INFORMATION
SCLK
SK
SCLK
SCK
DIN
TLC5615
CS
SO Microwire
Port
I/O
DIN
TLC5615
CS
MOSI
SPI/QSPI
I/O Port
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
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.
The output amplifier attempts to drive the output to a negative voltage. However, because the most negative
supply rail is ground, the output cannot drive below ground and clamps the output at 0 V.
The output voltage then remains at zero until the input code value produces a sufficient positive output voltage
to overcome the negative offset voltage, resulting in the transfer function shown in Figure 14.
Output
Voltage
0V
Negative
Offset
DAC Code
Figure 14. Effect of Negative Offset (Single Supply)
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