Microchip Space System Managers

The Space System Manager (SSM) is a special purpose analog mixed signal IC that integrates mixed signal functions commonly used in satellite systems.  The SSM IC can interface with radiation tolerant FPGAs such as those offered in Microsemi’s portfolio of FPGA solutions.

Features of the Space System Manager ICs:

• Provide a higher level of integration than basic devices by specifically focusing on common spacecraft interfaces through FPGA programmability
• Can be adjusted to particular settings by changing the internal command registers
• Expandable solution by using only a portion of the SSM or using several SSMs
• Reduces part count resulting in smaller size, decreased weight and increased reliability

Microsemi has two ICs in the Space System Manager Family

• The LX7730 Radiation Tolerant Telemetry Controller
• The LX7720 Position / Motor Controller

LX7720

The LX7720 is a spacecraft motor driver that is radiation-hardened by design and works with either a space FPGA controller such as RTG4, RTAX-S/SL, and RT PolarFire, or a space MCU such as SAMRH71F20, SAMV71Q21RT, and SAM3X8ERT.

The LX7720 contains four half-bridge drivers with floating current sense for motor coil driving, six bi-level inputs for sensing Hall effect sensors or rotary encoders, and a resolver or LVDT interface to digital with primary coil driver.

The LX7720 works with an FPGA or MCU system controller to provide a complete closed loop motor driver with coil current feedback and rotation or linear position sensing. With flexible programming, the combined system can provide motor control for stepper motors, brushless DC and permanent magnet motors. Position sensing supports encoders, Hall effect sensors, resolvers, synchros, and LVDTs.

The LX7720 contains 7 sigma delta modulators for analog sampling. Sinc3 filtering and decimation is performed in the FPGA or microcontroller with available IP modules. Four of the modulators sample the voltage across floating current sense inputs and three modulators sample differential analog inputs such as the outputs of a resolver transformer. Speed versus accuracy tradeoffs can be exploited.

The LX7720 supports a ground potential difference between the motor and signal grounds in the range of -10V to +8V and motor supply voltages up to 60V. Resolver or LVDT carrier frequencies from 360Hz to 20kHz are supported.

Features

• Four half-bridge N-channel MOSFET drivers
• Four floating differential current sensors
• Pulse modulated resolver/LVDT transformer driver
• Three differential resolver/LVDT sense inputs
• Six threshold adjustable bi-level logic inputs for Hall effect sensor/encoder interfaces
• Fault detection
• Radiation tolerant: 100krad(Si) TID, 50krad(Si) ELDRS, SEL immune up to 60MeV.cm²/mg and 125°C (fluence of 107 particles/cm²)

Applications

• Motor driver servo control
• Linear actuator servo control
• Stepper, BLDC, PMSM motor driver
• Robotics

LX7730

The LX7730 is a spacecraft telemetry manager that is radiation-hardened by design and works with either a space FPGA controller such as RTG4, RTAX-S/SL, and RT PolarFire, or a space MCU such as SAMRH71F20, SAMV71Q21RT, and SAM3X8ERT.

The LX7730 contains a 64 universal input multiplexer that can be configured for a mix of differential and/or single ended sensor inputs. The internal programmable current source can be directed to any of the 64 universal inputs. The universal inputs can be acquired by the internal 12-bit ADC at a sample rate up to 13kHz. The universal inputs also function as variable bi-level inputs with the threshold set by an internal 8-bit DAC. There is an additional 10-bit current DAC with complementary outputs. Finally, there are 8 fixed threshold bi-level inputs with logic outputs.

The LX7730 is register programmable with 17 addressable 8-bit registers. Two options are available for communication with the host system controller. First there is an 8-bit parallel bus with 5 address bits, a parity bit, and a read/write bit that can communicate at a speed of up to 25Mword/s. The second option is a pair of 12.5Mbit/s SPI interfaces that support redundant communication to two different hosts.

The LX7730 has enable registers that allow most of the device to be shut down to reduce power consumption, and supports cold sparing on its signal pins. The dielectric isolated process is failsafe.

The LX7730LMFQ offers lower guaranteed operating and standby supply currents than the LX7730MFQ, as shown in the Electrical Characteristics. Operation is identical in all other respects. All other references to LX7730 in this data sheet apply to the LX7730LMFQ, LX7730MFQ, and LX7730LMMF.

The LX7730(L)MFQ is packaged in a 132-pin hermetic ceramic quad flat pack. The LX7730LMMF is packaged in a lead-free 208 pin non-hermetic plastic quad flat pack. Both parts operate over a 55°C to 125°C temperature range, and are radiation tolerant to 100krad(Si) TID and 50krad(Si) ELDRs, as well as single event effects.

Features

• 64 channel analog input multiplexer
• Break-Before-Make switching
• 13ksps 12-bit ADC
• 1% precision 5V voltage reference
• 3% precision adjustable current source
• Threshold monitoring
• 8 bi-level analog inputs and logic outputs
• 8 additional bi-level inputs from the multiplexer
• 10-bit DAC
• Parallel interface or dual SPI interface
• Radiation tolerant: 100krad(Si) TID, 50krad(Si) ELDRS, SEL immune up to 87MeV.cm²/mg and 125°C (fluence of 108 particles/cm²)

Applications

• Spacecraft health monitoring
• Attitude control
• Payload equipment