IN Brief:
- Four DCL32xx00 devices provide two forward channels or one forward and one reverse channel.
- Typical current consumption is 0.2mA per channel at 1Mbps, with data rates up to 25Mbps.
- The SOIC8-N devices provide 3,000Vrms isolation and operate from -40°C to 125°C.
Toshiba Electronic Devices & Storage has launched four dual-channel digital isolators for industrial equipment, adding lower-current two-channel options to its DCL standard isolator family.
The DCL32xx00 series comprises the DCL320C00 and DCL320D00, each providing two forward channels, and the DCL321C00 and DCL321D00, which provide one forward and one reverse channel. Volume shipments have started.
Typical current consumption is 0.2mA per channel at 1Mbps, while maximum data rate is 25Mbps. The devices operate from supplies between 2.25V and 5.5V and across a temperature range of -40°C to 125°C.
Each device uses magnetic coupling to transfer digital signals across the isolation barrier. Toshiba specifies a minimum isolation voltage of 3,000Vrms for 60 seconds and minimum common-mode transient immunity of 30kV/µs, with the four parts supplied in a 4.9mm by 6.0mm by 1.75mm SOIC8-N package.
The two channel arrangements address different interface requirements. The DCL320C00 and DCL320D00 carry both isolated signals in the same direction, while the DCL321C00 and DCL321D00 provide one channel in each direction. The latter arrangement suits bidirectional communications where transmitted and received signals both have to cross the isolation boundary.
Industrial controls use digital isolation to exchange information between circuits that cannot share a direct electrical connection. Motor drives, inverters, PLC I/O, sensors, actuators, and switching power systems can all contain low-voltage control electronics operating close to noisy or higher-voltage circuitry, particularly where measurement and command signals cross between control and power domains.
The isolator preserves the logical connection while interrupting the direct conductive path. Its propagation characteristics, transient immunity, insulation performance, and default output state therefore become part of the behaviour of the complete control or communication channel.
Lower current consumption is particularly useful as channel counts rise. A single isolator contributes only a small part of a system’s power budget, but dense control boards can contain multiple isolation channels alongside microcontrollers, interface transceivers, sensors, gate drivers, and auxiliary power supplies.
Reducing the current required by those channels can lower the load on isolated bias rails and reduce heat generation inside compact equipment. The benefit is greatest in designs where several channels operate continuously rather than switching only occasionally.
The 25Mbps maximum data rate places the DCL32xx00 family below Toshiba’s faster isolator ranges. The company already offers other DCL devices for higher-speed communications, leaving the new series aimed at applications where low current, two-channel integration, and industrial isolation specifications outweigh the need for maximum interface bandwidth.
Propagation delay is specified at up to 52ns across the rated temperature range under Toshiba’s stated conditions. Control and serial-interface designers still have to include that delay in their timing budgets, particularly where an isolated path sits inside a feedback or synchronisation chain.
The C and D variants also provide different default output behaviour. C-designated parts default low when the input is undefined, while D-designated devices default high. That allows designers to select the logic state presented on the isolated side during conditions such as power-up or loss of a valid input.
Combined with the SOIC8-N package, the four versions give designers a compact set of directional and default-state options without moving to a larger quad-channel device. Toshiba’s DCL portfolio now covers both those lower-power two-channel requirements and applications demanding greater channel density or higher data rates.
