AMC1203
www.ti.com
SBAS427–FEBRUARY 2008
1-Bit, 10MHz, 2nd-Order, Isolated Delta-Sigma Modulator
1
FEATURES
DESCRIPTION
2
•
16-Bit Resolution
The AMC1203 is a 1-bit, 10MHz, isolated delta-sigma
(ΔΣ) modulator with an output buffer separated from
the input interface circuitry by a silicon dioxide (SiO2)
isolation barrier. This barrier provides galvanic
isolation of up to 4000VPEAK. Used in conjunction with
isolated power supplies, these devices prevent noise
currents on a data bus or other circuits from entering
the local ground and interfering with or damaging
sensitive circuitry.
•
•
•
•
•
•
SNR: 80.5dB min
THD: –88dB max (AMC1203B)
±280mV Input Range with +5V Supply
Internal 2.5V Reference Voltage: 1% Accuracy
Gain Error: ±1% (AMC1203B)
UL1577, IEC60747-5-2 (VDE0884, Rev. 2), and
IEC61010-1 Approved
The AMC1203 modulator operates from a +5V supply
with a dynamic range of 95dB. The differential inputs
are ideal for direct connection to shunt resistors or
other low-level signal sources. With the appropriate
digital filter and modulator rate, the device can be
used to achieve 16-bit analog-to-digital (A/D)
conversion with no missing codes. An effective
resolution of 14 bits and an SNR of 85dB (typical)
can be maintained with a sinc3 filter with a decimation
ratio of 256.
–
Isolation: 4000VPEAK,
Working Voltage: 560V
–
Transient Immunity: 15kV/µs
•
•
Typical 25-Year Life at Rated Working Voltage
(see Application Report SLLA197)
Operating Temperature Range:
–40°C to +105°C
APPLICATIONS
The modulator output is translated to a balanced
signal and then transferred by the capacitive isolation
barrier. Across the isolation barrier, a differential
comparator receives the logic transition information,
and then sets or resets a flip-flop and the output
circuit accordingly.
•
Shunt Based Current Sensing in:
–
–
–
–
Motor Control
Uninterruptible Power Supplies
Power Inverters
Industrial Process Control
The AMC1203 is available in an SO-8 gull-wing
package. SO-8 and SO-16 packages are planned for
release in 2008. The AMC1203 is characterized for
operation over the ambient temperature range of
–40°C to +105°C.
Isolation Barrier
+
VIN+
-
2nd-Order
Output
MDAT
Buffer
VREF
DS Modulator
+
VIN-
-
POR
BIAS
POR
+
Buffer
20MHz
RC
-
Output
Buffer
VREF
MCLK
Oscillator
2.5V
+
VREF
-
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2
All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated