Texas Instruments AMC1203PSAR

Overview

AMC1203 from Texas Instruments is a precision, basic-isolated delta-sigma modulator optimized for shunt-based current sensing in high-noise industrial power systems. It features ±280mV linear input range, 10MHz internal clock, ±1mV max offset error, ±2% max gain error, and 3500V_PEAK isolation per VDE 0884-17 - enabling direct connection to motor drive current-sense shunts.

For engineers reviewing the AMC1203 datasheet, AMC1203 pinout, AMC1203 application, or AMC1203 equivalent, this page delivers verified technical context, pin-level design meaning, real-world use cases in motor drives and UPS, and validated alternative options - all grounded in TI's SBAS427E production data (June 2025 revision).

Technical Context

The AMC1203 implements a second-order, switched-capacitor delta-sigma modulator with SiO₂ capacitive isolation barrier, delivering a 1-bit bitstream synchronized to its internally generated 10MHz clock (±2MHz tolerance). Its differential analog front-end has 28kΩ dynamic input resistance and supports common-mode voltages from 0V to AVDD.

Output bitstream requires external digital low-pass filtering (e.g., sinc3 with OSR=256) to achieve 16-bit resolution, 87dB dynamic range, and 39kSPS effective data rate. The isolation barrier provides 15kV/µs CMTI and meets both UL1577 (2500V_RMS/1min) and VDE 0884-17 (3500V_PEAK) safety standards.

Key Specifications

Pinout & Package

AMC1203PSAR uses the PSA (8-pin SOP) package: 5.27mm × 7.9mm gull-wing footprint with 1.27mm pitch. Pin 1 marked by bevelled corner; pins 1–4 on left side (high-side), pins 5–8 on right side (low-side), separated by isolation barrier.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar isolated delta-sigma modulator applications.

Compared with AMC1303L25DWV and ISO124U, the AMC1203PSAR provides the best balance of cost, 10MHz clock integration, and verified 15kV/µs CMTI for mainstream industrial motor control - avoiding over-specification while meeting VDE 0884-17 basic isolation and 39kSPS effective throughput.

Availability

AMC1203PSAR is available at Aetrix Electronics and suitable for industrial motor drives, frequency inverters, uninterruptible power supplies (UPS), and isolated power conversion circuits requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AMC1203PSAR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability ICs for industrial, automotive, and communications markets.

The AMC1203 belongs to TI's precision isolated modulator product line, designed specifically for high-accuracy, noise-immune current sensing in industrial motor control and power conversion systems operating from –40°C to +105°C.

FAQ

What is the primary function of the AMC1203PSAR in a motor drive system?

The AMC1203PSAR serves as a galvanically isolated delta-sigma modulator that converts shunt-resistor voltage drops into a synchronized 1-bit bitstream for digital filtering. In motor drives, it enables accurate, noise-immune phase current measurement - directly supporting field-oriented control algorithms. Its ±280mV input range, 10MHz internal clock, and 15kV/µs CMTI make AMC1203PSAR ideal for high-power IGBT-based inverters where ground potential differences and EMI are critical concerns.

Does the AMC1203PSAR require an external clock source?

No, the AMC1203PSAR integrates a 10MHz internal clock generator, and its CLKOUT pin provides a buffered, synchronous clock signal for downstream digital filters. This eliminates the need for external oscillators or crystals, reducing BOM cost and PCB layout complexity. The clock operates across the full –40°C to +105°C temperature range with ±2MHz tolerance, and its stability is sufficient for sinc3 filtering at OSR=256 to achieve 16-bit effective resolution.

How does the AMC1203PSAR achieve isolation without optical components?

The AMC1203PSAR uses a silicon-dioxide (SiO₂) capacitive isolation barrier fabricated monolithically on-chip. This barrier separates the high-side analog circuitry (AVDD, INP, INN, AGND) from the low-side digital interface (DVDD, DOUT, CLKOUT, DGND), enabling 3500V_PEAK basic isolation per VDE 0884-17. Unlike optocouplers, this technology provides superior CMTI (≥15kV/µs), lifetime stability, and immunity to magnetic fields - making AMC1203PSAR highly reliable in electrically noisy motor drive environments.

What digital filtering is required to obtain usable data from the AMC1203PSAR?

The AMC1203PSAR outputs a 1-bit bitstream that must be processed by a digital low-pass filter - typically a third-order sinc (sinc³) filter with oversampling ratio (OSR) of 256. When implemented in hardware (e.g., TI C2000 SDFM) or FPGA, this yields 16-bit resolution, 87dB SNR, and 39kSPS effective output rate. The filter decimates the 10MHz bitstream into a lower-rate parallel word; AMC1203PSAR itself performs no decimation - the filtering is entirely external and determines final resolution, latency, and bandwidth.

Can the AMC1203PSAR be used with shunt resistors outside the ±280mV range?

The AMC1203PSAR is specified for linear operation only within ±280mV differential input (VFSR). Exceeding this range causes clipping and nonlinearity - though absolute maximum rating allows ±320mV before hard clipping. For shunts generating >280mV, external attenuation or gain scaling is required. However, doing so degrades SNR and introduces resistor drift/tolerance errors. AMC1203PSAR is optimized for 1–5mΩ shunts at 100–500A; using it outside this range compromises its key advantages of direct interface and guaranteed DC accuracy.