Space System Managers – Architecture and Performance

Power Matters.TM
Space System Managers
Architecture and Performance
Microsemi Space Forum 2015
Mathieu Sureau
Director of IC Design Engineering
© 2015 Microsemi Corporation. Company Proprietary.
1
Space System Manager Concept
 Space System Manager (SSM) is a special purpose analog
or power IC
 The SSM IC is intended to work with an FPGA:
• I/O levels and timing are compatible.
• The SSM has a minimal amount of hard coded internal
logic.
FPGA
FPGA
Communication
Interface
Companion IC
Space System Manager
Bus
Management
Storage
Sequential
Processing
Bus
Management
Bus Managed
MUX, ADC, DAC
Registers
Calibration and
Test
Pipelined
Processing
© 2015 Microsemi Corporation. Company Proprietary.
Real Time
Sensing/Driving
Power Matters.TM
2
Space System Manager Characteristics
 Both the Space System Manager and the FPGA are
standard parts that are space qualified and DLA listed.
 The SSM standard attributes are:
• Radiation Tolerant: 100krad TID; 50krad ELDRS, SE tolerant
• Inputs are cold spared and dielectrically isolated
• ESD and overvoltage clamping
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
3
IC Process for Fault Isolation
 The SSM uses a special Dielectric Isolated (DI) process such that if any
channel within the IC becomes compromised due to an external fault, the
remaining IC continues to function normally.
• There is not a common substrate connection that you find with other IC
processes.
• This process is similar in performance to the isolation achieved in
hybrid circuits.
• Isolation between tubs is at least 350V.
Dielectric Isolation
Cross Section
Silicon Tub
Silicon Tub
Silicon Dioxide Isolation
Silicon Dioxide Isolation
Poly-Silicon Isolation
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
4
IC Process for Cold Sparing
 An isolated ESD structure for each SSM pin along with
design techniques considering low leakage with power
removed allows the SSM to be cold spared (becomes a high
impedance with the power removed).
VCC
Cold Sparing
Typical ESD Protection
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
5
SSM Application Versatility
 SSMs take advantage of commonality between applications.
• Servo motor drivers require high power switches and position sensing.
• Telemetry monitoring requires an analog MUX, ADC and bi-level
inputs.
Different applications using the same IC part numbers.
Application 1
FPGA
LX7720
Power
Driver
3 ph
BLDC
Optic
Sense
Application 2
FPGA
© 2015 Microsemi Corporation. Company Proprietary.
LX7720
Power
Driver
Bipolar
Step
Resolver
Power Matters.TM
6
System Manager System Integration
 FPGA HDL module examples are:
• Spacecraft communication bus
• Motor micro-stepping
HDL Modules
• Brushless DC servo loop
+
• Resolver to digital conversion
Register Map
• Sigma Delta filtering and decimation
 SSM registers examples:
+
Power Sizing &
• Programmable current source
Programming
• ADC input range setting
Components
• MUX selection of inputs
 External Components adjust:
• External NMOS power sizing for motor drivers
• Bi-level threshold levels
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
7
Space System Manager vs. Discrete
Components
FPGA
Driver
A/D
Analog
Multiplexer
MOSFET
Comparators
Amplifier
 A typical circuit uses an FPGA with analog interface functions
implemented with many single function ICs and discrete components.
 SSM integrates commonly used functions into one package to reduce
circuit board area and weight.
 Although utilization may not be 100% for the space system manger, it is
still likely to be a more compact solution.
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
8
Space System Manager vs. Custom IC
 The custom rad-hard mixed-signal solution provides an
efficient solution but presents a number of challenges:
• Development cost for a Mixed-Signal custom for space applications is
typically $1M-$2M
• Development time typically of 1-2 year.
• Qualification is typically 6 months to 1 year.
• Time to production 2-3 years.
 Unlike the SSM, with a custom ASIC:
• Very few players are able to budget such development.
• The solution typically has minimal flexibility if requirements change.
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
9
Reducing Risk While Maximizing
Integration
Discrete Solution
Space System
Manager
Custom ASIC
Solution
Low
Low
High
Months
Months
Years
Qualification
Fast
Fast
Long
Risk
Small
Small
Moderate
Flexibility
High
High
Low
Power
Worst
Good
Best
Average
Excellent
Excellent
Poor
Good
Best
NRE
Development Time
Reliability
Size and Weight
Value
Proposition
High
flexibility
High
integration
Shorter
development
time
© 2015 Microsemi Corporation. Company Proprietary.
Minimum
risk
Power Matters.TM
10
The LX7730
Radiation Tolerant Telemetry Controller
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
11
LX7730: 64 Analog Input Telemetry
Controller
 Single ended sensing for 64 sensors with






simultaneous monitoring of 8 sensors
Differential (Kelvin) sensing of 32 sensors
Current demux to any input for driving
passive sensors
Voltage reference to bias bridge networks
ADC ranging accurately measures low
level voltage changes
Parallel
SPI_A
DAC out for level control
SPI_B
FPGA
8 bi-level logic translators
Internal LDOs
and Charge
Pump
VREF
8 Current
Levels
64
Channel
Sensor
MUX
12 Bit
ADC
Parallel
Interface
and
Registers
+
-
Level Detect
8 Bit
DAC
10 Bit Current DAC
+
8 Bi-Level Inputs
-
2.5V
LX7730
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
12
LX7730 Block Diagram
 64 universal General Purpose sensor
interfaces:
‒
‒
‒
‒
‒
64 single ended or 32 differential
ADC range pre-scaling
64 channel current source demux
Level monitoring of 8 SE channels
Break-before-make switching MUX
 25ksps 12 bit ADC
 Optional 2 pole anti-aliasing filter
 8 fixed bi-level logic interfaces
VDD
SPI_A
SPI_B
CLK
SSA
CLKA
MOSI_A
MISO_A
SSB
CLKB
MOSI_B
MISO_B
CE
OE
WE
A0
A1
A2
A3
A4
D0
D1
D2
D3
D4
D5
D6
D7
PTY
/ACK
RESET
BLO#
7
4
4
4
4
1 of 65 CH
Current MUX
Range Scaling/Offset Cor
4
1 of 9
MUX
Hi-Z
Dual 12
Serial or
Parallel
Interface
and
Registers
8
1 of 8
MUX
1 of 9
MUX
ITEST
Ch1 to 8
Ch9 to 16
Pos 1
Pos 2
Pos 8
Ch57 to 64
1 of 8 switch banks
SE_RTN
IA_OUT
ADC_IN
+
-
8 Bit
DAC
1 of 8 threshold blocks
IREF
P_DAC
10 Bit
DAC
10
N_DAC
1 of 8 bi-level input blocks
+
-
IREF
 10 bit current DAC





IA
+
-
2 Pole
AAF
12 Bit
ADC
‒ Internal or external threshold setting
IREF1/IREF2
‒ Complementary outputs
15V
Current
Programming
3
BLI#
Threshold
MUX
IREF
MUX
BL_TH
2.5V
IREF1
IREF1
IREF2
IREF2
EXT_REF
1% precision reference
2% current references
Parallel or Dual SPI interface
Built in test and calibration
+15 VCC input to internal regulators
5.00V Precision REF
VREF
VCC
+5V
+5V regulator
PCP
EXT_VEE
Charge Pump
Controller
NCP
VEE
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
13
Voltage Acquisition
 LX7730 has 64 voltage acquisition input channels
 The instrumentation amplifier converts differential inputs to
ground referenced. Common mode range is -5V to 5V
 Two analog multiplexers route one channel to the IA noninverting terminal and another channel to the common single
ended reference (SE RTN) for the inverting terminal
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
14
Current Source and De-MUX
 Current source can be routed to any one of the 64 CH# pins
 The current source can be set from 250uA to 4mA in 250uA
increments using the current source programming register
 Or the current source can be set using the 10 bit DAC to a
resolution of 10uA starting at 0
 Wide compliance range: -15V to 10V
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
15
Measuring resistive sensors
 The current source and de-MUX can be used with the
analog MUX and IA to make resistance measurements
 Single ended measurements will service the most channels
 Differential measurements reduce stray resistance affects
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
16
12 bit ADC
 The ADC has a dynamic range of 0 to 2V
 The IA pre-scaler sets channel range to 5V, 1V or 200mV
 The two poles of the anti-aliasing filter (AAF) can be set to
400Hz, 2kHz or 10kHz or infinity
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
17
Bi-Level Bank Comparator Mode




Simultaneous voltage checks for 8 single ended channels
Common threshold is controlled by an 8 bit DAC
Comparator outputs are a readable register location
Note: 64 to 1 channel AMUX is not usable in this mode
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
18
10 bit Current DAC
 The 10 bit current DAC is register controlled
 It has a 0 to 2mA range and a compliance from 0V to 3V
 Note: The 10 bit DAC should not be used as a DAC if it is
simultaneously being used to control the current source
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
19
8 Pass Through Bi-level Logic Translators
 Logic translators have input and output pin outs
 Threshold either internal 2.5V or pin programmable
 Hysteresis for noise immunity on slow ramping inputs
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
20
Digital interface





Digital interface can be SPI_A or SPI_B or parallel
Only one interface is active at a time
Registers are 8 bits in length
SPI pins are dual use for parallel interface
VDD logic supply also powers FPGA I/O
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
21
Power supplies




Requires a VCC (12V or 15V) and VDD for logic (2.5V to 5V)
Charge pump for negative rail (VEE) or disable if not used
1% reference with option to use external 5V reference
Redundant IREF avoids single point failure
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
22
Key Features





1kV ESD protection on CH pins, 2kV on all other pins
+/- 20V clamps on CH# pins and +/-15 for BLI# pins
Cold sparing on CH# pins and BLI# pins
Redundant IREF
Redundant SPI interface
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
23
LX7730: Application Figure
 Level control
 Temp sensors monitor
 Strain gauges monitor
 Bi-level logic translation
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
24
LX7730 Performance Highlights
Parameter
Comment
Min
Typ
Max
Units
SE or Diff sensor input
0
5
V
Differential Sensor common mode
-5
5
V
ADC conversion rate
25
kHz
ADC resolution
12
bits
Reference voltage
Internal VREF
4.95
MUX settling time
MUX leakage current
5.05
1.5
Power on or off
Bi-level threshold range
µs
100
nA
0.5
4.6
V
1
DAC compliance range
0
Sourcing
V
-100
Bi-level propagation delay
DAC full scale current
5.00
1.94
© 2015 Microsemi Corporation. Company Proprietary.
2.00
µs
3.0
V
2.06
mA
Power Matters.TM
25
LX7720 Power Driver w Position Feedback
 Provides MOSFET motor drivers for
‒ 3 phase motors
‒ Unipolar or bipolar steppers
‒ Individually controlled switches
 Up to 4 current sensors
‒ In-line (floating)
‒ High side or ground referenced
 Sensing for resolver or LVDT
 Detecting pulse sensors and limit
switches
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
26
LX7720 Block Diagram
Features:
• Four Half-Bridge N-channel
•
•
•
•
•
MOSFET drivers
Four floating differential current
sensors with ΣΔ modulated
processed outputs to FPGA
Pulse density modulated
resolver exciter
Three differential resolver
sensors with ΣΔ modulated
processed outputs to FPGA
Six bi-level logic inputs
5V GND isolation signal-to-motor
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
27
LX7720 is a companion to the RTG4 FPGA
 Fabric based motor control algorithm developed for RTG4 and LX7720
 Demonstration dual axis code available using SF2-MC-StarterKit
 Resolver to digital position feedback option
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
28
LX7720 PMSM Application
 Three phase PMSM motor
 Tracking resolver
 In line current sensing
 Phase D used for relay driver
with current sense in return
path.
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
29
LX7720 Bipolar Microstepper
 Bipolar stepper motor
 Return path current sensing
 Potentiometer position
sensing
 Limit switch sensing
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
30
LX7720 Performance Highlights
Parameter
Motor Power Supply
MOSFET driver impedance
Comment
Min
Typ
Max
Units
De-rated by 20%
20
48
150
V
Source or sink
Ω
1
PWM frequency
DC
200
kHz
Current sense range
-250
250
mV
Current sense accuracy
7
bits
Current sense latency
4
µS
Resolver carrier frequency
0.36
Resolver accuracy
Bi-level threshold range
20
16
0.5
Bi-level propagation delay
© 2015 Microsemi Corporation. Company Proprietary.
bits
4.6
1
kHz
V
µs
Power Matters.TM
31
Space System Manager Advantages
 Provides a high level of integration (smaller size and weight)
 Is a standard part so there is minimal design risk or






qualification risk
No development NRE
Designed to work with an FPGA so the flexibility is designedin
Designed for space applications so additional buffers and
level shifting are not necessary
Radiation tolerance of TID > 100kRad; ELDRS > 50KRad;
SEL tolerant
Cold spared
Fault tolerant
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
32
Thank You
Microsemi Corporation (MSCC) offers a comprehensive portfolio of semiconductor and system solutions for
communications, defense & security, aerospace and industrial markets. Products include high-performance and radiationhardened analog mixed-signal integrated circuits, FPGAs, SoCs and ASICs; power management products; timing and
synchronization devices and precise time solutions, setting the world's standard for time; voice processing devices; RF
solutions; discrete components; security technologies and scalable anti-tamper products; Ethernet solutions; Power-overEthernet ICs and midspans; as well as custom design capabilities and services. Microsemi is headquartered in Aliso
Viejo, Calif., and has approximately 3,600 employees globally. Learn more at www.microsemi.com.
Microsemi Corporate Headquarters
One Enterprise, Aliso Viejo, CA 92656 USA
Within the USA: +1 (800) 713-4113
Outside the USA: +1 (949) 380-6100
Sales: +1 (949) 380-6136
Fax: +1 (949) 215-4996
email: [email protected]
Microsemi makes no warranty, representation, or guarantee regarding the information contained herein or the suitability of its products and services for any particular
purpose, nor does Microsemi assume any liability whatsoever arising out of the application or use of any product or circuit. The products sold hereunder and any other
products sold by Microsemi have been subject to limited testing and should not be used in conjunction with mission-critical equipment or applications. Any
performance specifications are believed to be reliable but are not verified, and Buyer must conduct and complete all performance and other testing of the products,
alone and together with, or installed in, any end-products. Buyer shall not rely on any data and performance specifications or parameters provided by Microsemi. It is
the Buyer’s responsibility to independently determine suitability of any products and to test and verify the same. The information provided by Microsemi hereunder is
provided “as is, where is” and with all faults, and the entire risk associated with such information is entirely with the Buyer. Microsemi does not grant, explicitly or
implicitly, to any party any patent rights, licenses, or any other IP rights, whether with regard to such information itself or anything described by such information.
Information provided in this document is proprietary to Microsemi, and Microsemi reserves the right to make any changes to the information in this document or to any
products and services at any time without notice.
©2015 Microsemi Corporation. All rights reserved. Microsemi and the Microsemi logo are registered trademarks of Microsemi Corporation. All other
trademarks and service marks are the property of their respective owners.
© 2015 Microsemi Corporation. Company Proprietary.
Power Matters.TM
33