Transcript MEDA-WS-FE-ASIC-AMICSA

MEDA
Mars Environmental Dynamics Analyzer
for NASA/JPL’s Mars 2020 mission
MEDA Wind Sensor Front End ASIC
S. Espejo, J. Ceballos-Cáceres, A. Ragel-Morales, S. Sordo-Ibáñez,
L. Carranza-González, J.M. Mora-Gutiérrez, M.A. Lagos-Florido,
J. Ramos-Martos
IMSE-CNM (CSIC/Universidad de Sevilla)
Parque Científico y Tecnológico Cartuja, Calle Américo Vespucio s/n, 41092,
Sevilla, SPAIN
mailto: [email protected]
AMICSA 2016, 12-16 June 2016, Gothenburg, Sweden
MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
MEDA Instruments for Mars 2020
The MEDA Wind Sensor
The MEDA WS Front-End ASIC
Circuitry description
Experimental results (example)
Summary
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 NASA’s/JPL’s Mars 2020 Mission
Images taken from & further details at: http://mars.nasa.gov/mars2020/
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 MEDA: Mars Environmental Dynamics Analyzer
 A set of sensors that will provide measurements of:
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Temperature
Wind speed & direction
Pressure
Relative humidity
Dust size & shape
 Principal Investigator: José Antonio Rodríguez-Manfredi
Centro de Astrobiología, Instituto Nacional de Técnica Aeroespacial, Spain
Further details at: http://mars.nasa.gov/mars2020/mission/science/for-scientists/instruments/meda/
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 MEDA Wind-Sensor Concept
 Developed at Polytechnic University of Catalonia (*1)
 Evolved version of a similar sensor used in REMs (*2)
(*1) M. Domínguez, V. Jiménez, J. Ricart, L. Kowalski, J. Torres, S. Navarro, J. Romeral, and L. Castañer, “A hot film
anemometer for the martian atmosphere,” Planetary and Space Science, vol. 56, pp. 1169 – 1179, June 2008
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(*2) http://cab.inta-csic.es/rems/es/
MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The MEDA WS FE ASIC: PARTICIPANTS
• CAB:
– MEDA Instruments coordination
• Polytechnic University of Catalonia:
– Wind sensor concept
– ASIC Specification
• CRISA:
– ASIC specification
– Design-process quality control
– High-level digital code of the control and communications FSM
• IMSE-CNM-CSIC:
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Analogue architecture and blocks
RH Digital lybrary
Synthesis and back-end of the digital part
ASIC design and verification, RH techniques
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The MEDA WS FE ASIC:
Process Technology & Previous work
• Standard 0.35mm CMOS technology, from AMS
(Austria Micro Systems)
• Only 3.3V transistors used along the chip
• Builds on previous efforts by the authors in the past
years:
– Characterization of radiation and low-temperature effects
on devices in this technology
– Development and validation of a rad-hard library of digital
cells
– Previous development of several other mixed-signal space
ASICs
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The MEDA Wind-Sensor Front-End ASIC (I)
 Must measure various temperatures
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Temp measurements based on external Pt resistors
Must provide bias current
Must measure and digitalize voltages
 Must control the temperature of external “hot-dies”,
keeping it constant at prescribed values
 Must provide and measure the heating power
required to do so
 Must interact and communicate with the
Instruments Control Unit (ICU)
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The MEDA Wind-Sensor Front-End ASIC (II)
External
SENSORS
MUXES
(4-wire
interfaces)
AD CONVERSION
CHANNEL
Calibration
Levels
data
SIGNAL
CONDITIONING
Internal
Signals
Voltage & Current
references for all
circuit blocks
ASIC
Temp
ICU
RS-422 R&Ts
(Clock & data)
data
DIGITAL
CONTROL BLOCK
commands &
data
SCAN
PATH
GATOs
GDTOs
Programming buses
(address & data)
MUXES
VDD/3
POR
Programmed External
Dies Temps (DACs)
Miscell.
internal
signals
(test and
diagnosis)
Band (SelfGap Biased)
ASIC
Temp
Alarm
clock
Control signals
data
(power counts)
THERMAL CONTROL LOOPs
EXTERNAL
LTC RESISTOR
& VREF
MEASUREMENT
V&I
References
EXTERNAL
RESET & POR
OBSERVATION
WS
Temp
Alarm
Dies Temp:
sensor bias &
signals
POWER
(HEAT)
(variable)
POWER
(residual)
EXTERNAL DIES:
HEATERS & TEMP
SENSORS
Residual
POWER SINKS
Block containing Configuration Register(s)
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The MEDA Wind-Sensor Front-End ASIC (III)
Die size: 5 x 5 mm
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 External Interface (Pins)
 Communication (Rx & Tx) and clock (6 pins)
• RS-422 differential signals
• Rx (2), Tx (2), Clk 2.4MHz (2)
 External analog input channels (18 pins)
• 9 differential external input channels
 Thermal control loops (36 pins)
• 12 thermal control loops
• Each: Current bias and Temp measurement (1), heating current (1),
and current sink (1)
 Power and Ground (29 pins)
• 6 power domains. Non-paired VDD/GND distribution
 Miscellaneous uses (11 pins)
• Vref (1), Iref (1), Rst (1), Scan-path (4), Observability (2+2)
 Total: 100 pins. Package: CQFP-100
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The ADC channel
– The input channels multiplexer
– Bias current/voltage for input signals and sensors
– The ADC channel
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Preamplifier
ADC-FSM
Oscillator
Analogue integrator
Comparator
Reference signal
– ADC channel calibration
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The ADC channel
From
VOLTAGES REFERENCE
BLOCK
Programmable
from 0 to 750mA, 4 bits
VCM-ref VREF (level-shift) VCM-ref VREF (ADC)
ZeroCrossed
INP
INN
PREAMP-1
PREAMP-2
INTEGRATOR
COMPARATOR
gain
level-shift
integrator control
comparator control
From
DIGITAL
CONTROL
BLOCK
From
BONDING PADS &
INTERNAL SIGNALS
OSCILLATOR
ADC-FSM
(50 MHz)
start
eoc
data-out
To/From DIGITAL
CONTROL BLOCK
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The ADC channel
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Instrumentation Amplifier
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The ADC itself
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Comparator
• Fast clock (~50MHz)
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Oscillator
• Same R-type and same C-type than those used in the integrator
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 Reference voltage:
• From band-gap and scaling amplifier
• Set of DC input levels used for real time
on-line calibration:
 Offset error
 Gain error
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Thermal Control Loops
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The bias current sources
The comparator
The heating current sources
The DACs
ASIC
Hot Die
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Thermal Control Loops
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Clocked Switched-Capacitor comparators
Auto-zero
Regenerative Latch
Very low offset (< 0.1mV)
– Resistive string DAC
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 The Communication & Digital Control Unit (FSM)
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Receives and executes commands, and sends data to/from the instrument control unit
(ICU).
Communicates through an UART at 9600 bauds. RS-422 differential signals.
Reads and writes configuration and data registers.
Controls the operation of the thermal control loops (comparators, heating currents,
counts additional heating current pulses to each hot die).
Controls the AD conversion channel, and the sequence of conversion of the 20 channels
that are time-multiplexed, according to various operating modes.
Receives the alert signals from the over-temperature sensors corresponding to the hotdies and the ASIC itself, and takes the corresponding actions when required.
Enables and disables different circuit blocks in the ASIC.
Receives parity checks from the registers in the ASIC, and reports to the ICU in case of
errors.
Works in various operating modes: cyclic mode, on-request mode, test-mode, …
Includes a scan-path port for testability purposes.
High-level design by CRISA.
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 Auxiliary Blocks
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Band Gap and Voltage Reference
PTAT
Current Reference
High-Temp Alarms & Auto Shut Down.
Power-on Reset
Power Supply Voltage measurement
RS-422 Receivers and Transmitter
Reference levels for ADC calibration
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 RHBD Techniques and Low-Temp issues (I)
• Known techniques available in the literature
• Builds on previous work by the authors in the characterization of radiation and
low temperature effects on this specific CMOS technology [7],[8].
• Analogue circuitry: full-custom, enclosed-layout transistors (ELTs) for nmos,
regular layout for pmos (TID)
• Guard-rings around nmos and pmos devices (SEEs).
• Specific type of converter, size of capacitors (SET).
• Role of the ASIC: allows sporadic wrong behaviour.
• Similar mixed-signal ASICs designed and tested using the same procedures in
the same technology have been shown to be latch-up free up to at least 80
MeV·cm2/mg. Same result is expected.
• Digital sections: semi-custom. RHBD digital cells library developed. Same RHBD
techniques than in analogue circuitry.
• All registers in the ASIC include parity-check. Parity errors are reported to the
digital control unit, which in turn reports this events to the ICU.
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 RHBD Techniques and Low-Temp issues (II)
• The ASIC is specified to operate within -128 ºC to 50 ºC, ambient temperature.
• Electrical simulations: foundry provided models are not qualified below -55ºC.
• The authors have measured transistors I-V characteristics down to -110ºC and
verified that the transistor models can be used with reasonable accuracy down
to this limit.
• The actual temperature operation range of the die will be quite above the
ambient-temperature operation range, due to self heating (low density of Mars
atmosphere)
• Specific radiation (TID & SEE) and low temperature tests in a "Mars Chamber",
are planned for the coming months.
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 Experimental Results
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Communication and Control functions: operative
The ADC channel: operative, within specs
Thermal Control loops: operative, within specs
Miscellaneous functions: operative, within specs
– Specific set of boards
– Raspberry Pi for communications
– Sample hot dies from UPC
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 ADC Channel
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 Thermal Control Loops
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MEDA Wind-Sensor Front-End ASIC, AMICSA 2016
 Summary
 A rad-hard, mixed-signal ASIC in a standard 0.35 mm
CMOS technology has been designed, fabricated and
functionally tested.
 The ASIC is an analogue front-end for the MEDA
wind sensor for NASA's Mars2020 mission
 Additional radiation and low temperature
measurements are underway. Expected to be
satisfactory based on previous ASICs designed in the
same technology using the same RHBD techniques
and the same rad-hard digital library.
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