AMC1204_14 Datasheet, PDF (15/37 Pages) Texas Instruments – 20MHz, Second-Order, Isolated Delta-Sigma Modulator for Current-Shunt Measurement

AMC1204
AMC1204B
www.ti.com
SBAS512D – APRIL 2011 – REVISED DECEMBER 2013
GENERAL DESCRIPTION
The AMC1204 and AMC1204B are single-channel, second-order, delta-sigma (ΔΣ) modulators designed for
medium- to high-resolution analog-to-digital conversions. The isolated output of the converter (DATA) provides a
stream of digital ones and zeros. The time average of this serial output is proportional to the analog input
voltage.
Figure 41 shows a detailed block diagram of the AMC1204 and AMC1204B. The analog input range is tailored to
directly accommodate a voltage drop across a shunt resistor used for current sensing. The SiO₂-based
capacitive isolation barrier supports a high level of magnetic field immunity as described in the application report
ISO72x Digital Isolator Magnetic-Field Immunity (SLLA181A, available for download at www.ti.com). The external
clock input simplifies the synchronization of multiple current sense channels on system level. The extended
frequency range of up to 20MHz supports higher performance levels compared to the other solutions available
on the market.
Isolation Barrier
VINP
VINN
2nd-Order
DS Modulator
+
-
V_REF
+
-
3-State
Output
Buffer
DATA
POR
Buffer
2.5V
V_REF
V_REF
CLKIN
Figure 41. Detailed Block Diagram
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Product Folder Links: AMC1204 AMC1204B
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