Suited for satellites with restrained space and large number of components so that essential spacecraft functions can be incorporated
The need to reduce size, weight and power (SWaP) on satellites and other space systems continue to challenge the aerospace market.
Now combining more than 20 commonly used functions into a single chip, the LX7720 radiation-hardened mixed-signal motor controller, which claims to be industry’s first highly integrated radiation-hardened by design (RHBD) motor control integrated circuit (IC), aims to reduce weight and board space relative to conventional discrete motor control circuits. By reducing the number of components on a system, developers can inspect and test fewer parts, while also minimising the physical points of potential failure due to a smaller number of connections and solder joints.
Highly Integrated
The LX7720 controller offers a unique solution for satellite manufacturers concerning board area and weight reduction by consolidating essential functions for the motor control and position sensing circuitry required for robotics, multi-axis pointing mechanisms and precise motion control of optical elements.
Some of the integrations into this device are:
- Four half-bridge N-channel Metal Oxide Semiconductor Field Effect Transistor (MOSFET) drivers.
- Four floating differential current sensors
- A pulse modulated resolver transformer driver
- Three differential resolver sense inputs,
- Six bi-level logic inputs
- Power drivers via external Field Effect Transistors (FETs)
- Loop control electronics for voltage or current control
- Position read-back (resolver, potentiometer, limit switches, etc,)
- Fault detection and more
Ideal spacecraft solution
The LX7720 serves as a mixed-signal companion IC to the selected digital IC used in the application. It is MIL-PRF-38535 Class V and Class Q qualified and has already been adopted by customers to enable various motor control applications in space robotics and human-rated space programs, making it an ideal solution for spacecraft applications involving motor driver servo control, linear actuator servo control and for driving stepper, brushless direct current (BLDC) and permanent-magnet synchronous (PMSM) motors.
The LX7720 offers radiation tolerance to 100 krad Total Ionization Dose (TID), 50 krad to Enhanced-Low-Dose-Rate-Sensitivity (ELDRS) exposure and is single event immune.
“As the reduction of weight and board space on satellites continues to challenge the aerospace market, we are pleased that to reinforce our commitment to developing innovative solutions with this highly reliable and highly integrated radiation-hardened motor controller,” said Bryan J. Liddiard, vice president of Microchip’s mixed-signal linear business unit. “The LX7720 enhances our ever-growing space product portfolio as we continue to expand a total system solution for our customers building these sophisticated satellites.”
Supporting Tools
Hardware support includes the LX7720 Daughter Board (DB) that interfaces with SAMRH71F20-EK Evaluation Kit and RTG4 FPGA Development Kit. These development platforms offer motor control software to allow application-specific evaluation with the LX7720-DB.
The LX7720 is available in MIL-PRF-38535 Class Q and V flows packaged in a 132-pin hermetic ceramic quad flatpack as well as a sub-QML screened option offered in a 208-pin plastic package. Samples and the LX7720-DB development boards are available from Microchip Technology.
