Agilent Unveils Optically Isolated, Programmable ADC for Motor Control

7/28/2004 - Agilent Technologies Inc. (NYSE: A) introduced an optically isolated, programmable analog-to-digital (A/D) converter optimized for measuring motor-phase currents in variable-speed motor-drive control systems. The new A/D converter is designed for general-purpose applications such as conveyors, fans and blowers.

The two-chip (HCPL-7560 and HCPL-0872) optically isolated A/D converter is designed specifically for interfacing directly to microcontroller/DSP-based motor-drive systems. The HCPL-7560 isolated sigma-delta modulator allows direct measurement of current by means of a current-sensing resistor. The HCPL-0872 digital interface IC is programmable to allow trade-offs between resolution and speed. The Agilent two-chip solution accelerates time-to-market by eliminating the need to design a complex and costly ASIC.

"The new two-chip solution is exactly what our customers need for reducing the complexity of their mid-range motor inverter products," said Kheng-Jam Lee, worldwide marketing manager for Agilent's Isolation Products Division. "This chipset is part of our continuing commitment to provide the broadest line of easy-to-use component solutions for power control."

The HCPL-7560 isolated modulator provides isolation-mode transient immunity of 15 kV/microsecond and a high noise margin by means of a sigma-delta oversampling A/D modulator that converts a low-bandwidth analog input into a high-speed, digital data stream. By choosing an appropriate current-sensing resistor, any range of current can be monitored from less than 1 A to more than 100 A.

The HCPL-0872 digital interface IC converts the single-bit data stream from the isolated modulator into 15-bit output words and provides a serial output interface that is compatible with SPI, QSPI or Microwire synchronous bus protocols for direct microcontroller interface. Resolution and conversion-time trade-offs are achieved by programming the HCPL-0872 to one of five available conversion modes. Additional programmable features include a pre-trigger circuit that can reduce conversion time to 200 nanoseconds, a fast over-range detector for quickly detecting short circuits within 3 microseconds, an offset calibration to eliminate initial offset and an adjustable threshold detector for detecting non-short overload conditions.

To assure performance, safety and reliability in industrial environments, both ICs are specified for operation over the -40 C to +85 C temperature range. The HCPL-7560 features a 3750 VRMS dielectric withstand voltage rating, and has received the following regulatory approvals: UL 1577, CSA and IEC/EN/DIN EN 60747-5-2.

The HCPL-7560 isolated modulator is supplied in a standard 8-pin, plastic dual-inline package (PDIP) or a gull-wing, surface-mount, 8-pin PDIP. The HCPL-0872 digital interface IC is supplied in a surface-mount, 16-pin, 300-mil-wide SOIC package, with tape-and-reel form available.

U.S. Pricing and Availability
The Agilent HCPL-7560 is priced at $4.63 each and the HCPL-0872 at $2.44 each, both in 1,000-piece quantities. Both products are available now through Agilent's direct sales channel and worldwide distribution partners. More information is available at

About Agilent Technologies
Agilent Technologies Inc. (NYSE: A) is a global technology leader in communications, electronics, life sciences and chemical analysis. The company's 28,000 employees serve customers in more than 110 countries. Agilent had net revenue of $6.1 billion in fiscal year 2003. Information about Agilent is available on the Web at

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