TLC32040M Datasheet, PDF (2/30 Pages) Texas Instruments – ANALOG INTERFACE CIRCUIT

TLC32040M
ANALOG INTERFACE CIRCUIT
description (continued)
The antialiasing input filter comprises seventh-order and fourth-order CC-type (Chebyshev/elliptic transitional)
low-pass and high-pass filters, respectively, and a fourth-order equalizer. The input filter is implemented in
switched-capacitor technology and is preceded by a continuous time filter to eliminate any possibility of aliasing
caused by sampled data filtering. When no filtering is desired, the entire composite filter can be switched out
of the signal path. A selectable, auxiliary, differential analog input is provided for applications where more than
one analog input is required.
The A/D and D/A converters each have 14 bits of resolution. The A/D and D/A architectures ensure no missing
codes and monotonic operation. An internal voltage reference is provided on the TLC32040M to ease the design
task and to provide complete control over the performance of the integrated circuit. The internal voltage
reference is brought out to a pin and is available to the designer. Separate analog and digital voltage supplies
and grounds are provided to minimize noise and ensure a wide dynamic range. Also, the analog circuit path
contains only differential circuitry to keep noise to an absolute minimum. The only exception is the DAC sample
and hold, which utilizes pseudo-differential circuitry.
The output-reconstruction filter is a seventh-order CC-type (Chebyshev/elliptic transitional low-pass filter with
a fourth-order equalizer) and is implemented in switched-capacitor technology. This filter is followed by a
continuous-time filter to eliminate images of the digitally encoded signal.
The TLC32040M is characterized for operation from – 55°C to 125°C.
functional block diagram
26
IN +
25
IN –
24
AUX
IN +
AUX ²³
IN –
22
OUT +
OUT– ²¹
Band-Pass Filter
Serial
4
FSR
M
Port
M
U
A/D
X
5
DR
U
3
X
EODR
6
MSTR CLK
Receive Section
Internal
Voltage
Reference
10
SHIFT CLK
13
WORD/BYTE
Low-Pass Filter
12
DX
14
FSX
11
D/A
EODX
Transmit Section
20 19 ₁₈ 9
7
VCC ₊ VCC _– ANLG DTGL VDD
GND GND (DIG)
8
REF
2
RESET
4–2
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