Building HVAC systems and high speed industrial requirements characterised by distributed, intelligent control systems made simpler with new 8 channel digital output micro PLC card from Maxim. According to Maxim, MAXREFDES63 is ultra-small PLC that provides 70x faster speed, uses over 20 per cent less power, and occupies 40 per cent less space than existing solutions—all factors required for faster, more localised, smaller end products.
In reference to Maxim media release, the credit-card-sized reference design integrates the MAX14900E, a microcontroller, isolated I/O port, power supplies, UART, and USB port to simplify incorporating the device into the final OEM product design, as well as provide a means for quick evaluation. The technical specification of the microcontroller highlights, “The MAX14900E is an octal power switch that features per-channel configuration for high-side or push-pull operation. Low propagation delay, high-rate load-switching makes the device suitable for next-generation high-speed PLC systems. The MAX14900E is configured, monitored, and driven by an SPI and/or parallel interface. In parallel mode, eight logic inputs directly control the outputs and the serial interface can be used for configuration/monitoring. Serial mode utilises the serial interface for both setting and configuration, and features CRC error detection to ensure robust SPI communication. The MAX14900E is available in a 48-pin (7mm x 7mm) QFN-EP or standard 48-pin TQFN-EP package, and is specified over the -40°C to +125°C temperature range.”
Key advantages offered by the PLC card:
- Low power, high voltage: The eight digital channels require just 3mA (maximum) of supply current; operates from a wide supply range of 10V to 36V and thus compatible with the 24V rail of many factory systems.
- High speed and drive: With an input-‐to-‐output propagation delay of 0.3usec (typical)/0.8usec (maximum), it can support fast switching rates of up to 100KHz in push pull configuration. On-‐resistance, a critical factor in static power dissipation is just 85mΩ (typical) and 165mΩ (maximum). It can drive current loads up to 850mA; outputs can be used in parallel to achieve even higher drive-‐current rating.
- High integration and space savings: Housed in a tiny, 48-‐pin 7mm × 7mm QFN package; uses significantly less board space.
- Data integrity: Offers per-‐channel and global diagnostics/monitoring via its SPI port, while users can access the I/O via an eight-‐bit parallel port. The serial link includes CRC error detection for enhanced data-‐link integrity.