TLC3574IDW Datasheet, PDF (19/49 Pages) Texas Instruments – 5-V ANALOG,3-/5-V DIGITAL, 14-/12-BIT, 200-KSPS, 4-/8-CHANNEL SERIAL ANALOG-TO-DIGITAL CONVERTERS WITH 10-V INPUTS

TLC3574, TLC3578, TLC2574, TLC2578
5ĆV ANALOG, 3Ć/5ĆV DIGITAL, 14Ć/12ĆBIT, 200ĆKSPS, 4Ć/8ĆCHANNEL
SERIAL ANALOGĆTOĆDIGITAL CONVERTERS WITH ±10ĆV INPUTS
SLAS262C − OCTOBER 2000 − REVISED MAY 2003
circuit description (continued)
data format
INPUT DATA FORMAT (BINARY)
MSB
LSB
ID[15:12]
ID[11:0]
Command
Configuration data field or filled with zeros
OUTPUT DATA FORMAT (READ CONVERSION/FIFO)
TLC3574 and TLC3578
TLC2574 and TLC2578
MSB
LSB
MSB
LSB
OD[15:2]
OD[1:0]
OD[15:4]
OD[3:0]
Conversion result
Don’t Care
Conversion result
Don’t Care
14-BIT (TLC3574/78)
Bipolar Input, Offset Binary: (BOB)
Negative full scale code = VFS− = 0000h, Vcode = −10 V
Midscale code = VBZS = 2000h, Vcode = 0 V
Positive full scale code = VFS+ = 3FFFh, Vcode = 10 V − 1 LSB
Bipolar Input, Binary 2s Complement: (BTC)
Negative full scale code = VFS− = 2000 h, Vcode = −10 V
Midscale code = VBZS = 0000h, Vcode = 0 V
Positive full scale code = VFS+ = 1FFFh, Vocde = 10 V − 1 LSB
12-BIT (TLC2574/78)
Bipolar Offset Binary Output: (BOB)
Negative full scale code = 000h, Vcode = −10 V
Midscale code = 800h, Vcode = 0 V
Positive full scale code = FFFh, Vcode = 10 V − 1 LSB
Bipolar Input, Binary 2s Complement: (BTC)
Negative full scale code = 800 h, Vcode = −10 V
Midscale code = 000h, Vcode = 0 V
Positive full scale code = 7FFh, Vocde = 10 V − 1 LSB
operation description
The converter samples the selected analog input signal, then converts the sample into digital output according
to the selected output format. The converter has four digital input pins (SDI, SCLK, CS, and FS) and one digital
output pin (SDO) to communicate with the host device. SDI is a serial data input pin, SDO is a serial data output
pin, and SCLK is a serial clock from host device. This clock is used to clock the serial data transfer. It can also
be used as conversion clock source (see Table 2). CS and FS are used to start the operation. The converter
has a CSTART pin for external hardware sampling and conversion trigger, and INT/EOC for interrupt purpose.
device initialization
After power on, the status of EOC/INT is initially high, and the input data register is set to all zeros. The device
must be initialized before starting conversion. The initialization procedure depends on the working mode. The
first conversion result must be ignored after power on.
Hardware Default Mode: Nonprogrammed mode, default. After power on, two consecutive active cycles
initiated by CS or FS put the device into hardware default mode if SDI is tied to DV_DD. Each of these cycles must
last 16 SCLK at least. These cycles initialize the converter and load CFR register with 800h (bipolar offset binary
output code, normal long sampling, internal OSC, single-ended input, one-shot conversion mode, and EOC/INT
pin as INT). No additional software configuration is required.
Software Programmed Mode: Programmed. If the converter needs to be configured, The host must write
A000H into converters first after power on, then performs the WRITE CFR operation to configure the device.
start of operation cycle
Each operation consists of several actions that the converter takes according to the command from the host.
The operation cycle includes three periods: command period, sampling period, and conversion period. In the
command period, the device decodes the command from host. In the sampling period, the device samples the
selected analog signal according to the command. In the conversion period, the sample of the analog signal
is converted to digital format. The operation cycle starts from the command period, which is followed by one
or several sampling and conversion periods (depending on the setting), and finishes at the end of last
conversion period. The operation is initiated by the falling edge of CS or the rising edge of FS.
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