High Performing ISOSD61 and ISOSD61L Galvanic Isolated Sigma-Delta Modulators for Industrial Applications

23 March 2021 - 0 Comments

STMicroelectronics has introduced the ISOSD61 and ISOSD61L, galvanic isolated Sigma-Delta modulators for delivering enhanced performance and reliability in industrial applications. The ISOSD61 has TTL/CMOS-compatible clock-input and data-output signal levels, while the ISOSD61L is compatible with Low-Voltage Differential Signaling (LVDS). With 86dB Signal-to-Noise Ratio (SNR) both the devices feature a 16-bit analog-to-digital converter (ADC).

These devices were designed to convert an analog input signal with an amplitude of up to ±320mV into a high-speed 1-bit digital data stream at up to 25Msamples/s. Isolation between the two sides is guaranteed up to 6kV maximum transient and surge isolation voltages, and up to 1.2kV maximum working voltage, under normal working conditions.

With 30kV/μs common-mode transient immunity the new device can be used in motor control, electric-vehicle charging stations, solar inverters, UPS, and server and telecom power supplies. The 25MHz sampling frequency makes them suitable for very wide input signal bandwidths; this translates into high-frequency signal-processing capability and measurement accuracy.

The ADC and isolated UART peripheral functions are integrated into a single chip, this reduced the bill of materials and increases noise immunity and reliability, lowering overall end-application cost. Housed in a SO16W surface-mount plastic package this fulfills 8mm creepage and clearance requirements.

Features of ISOSD61 and ISOSD61L

Up to 25 MHz external clock input for easier synchronization
±320 mV full-scale analog input range
16-bit resolution, no missing codes
13-bit typical ENOB
86 dB typical SNR
-83 dB typical THD
30 kV/µs typical High Common-mode transient immunity
6000 VPEAK Isolation Voltage VIOTM
1200 VPEAK Working Voltage VIORM
–40°C to +125°C extended industrial temperature range

Note: More technical information can be found in the ISOSD61 Datasheet linked at the bottom of this page and on the product pages of ISOSD61 and ISOSD61L Isolated Sigma-Delta Converters.