Caen ELS FMC-Pico-1M4 User manual

FMC-Pico-1M4 User’s Manual
3
FMC-Pico-1M4
4-channel 20 bit 1 MSPS FMC
Floating Ammeter
User’s Manual
All Rights Reserved
© CAEN ELS s.r.l.
Rev. 1.3 –November 2018
FMC –FPGA MEZZANINE CARD

FMC-Pico-1M4 User’s Manual
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CAEN ELS s.r.l.
Via Vetraia, 11
55049 Viareggio (LU) –Italy
Mail: [email protected]
Web: www.caenels.com

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Table Of Contents
1. INTRODUCTION................................................................................................8
1.1 FMC-PICO-1M4 OVERVIEW...........................................................................8
1.2 DEVICE DESCRIPTION .....................................................................................9
2. INSTALLATION AND OPERATION............................................................12
2.1 GROUND CONNECTIONS................................................................................12
2.2 SIGNALS DEFINITIONS AND PINOUT ..............................................................14
2.3 SIGNAL DESCRIPTIONS..................................................................................16
3. CONTROLLING THE FMC............................................................................17
3.1 DIGITAL INTERFACE......................................................................................17
3.2 TIMING DIAGRAMS .......................................................................................18
3.3 TIMING CHARACTERISTICS ...........................................................................19
3.4 EEPROM INTERFACES .................................................................................20
3.5 CAENELS AMC-PICO-8 .............................................................................23
4. ORDERING OPTIONS.....................................................................................24
4.1 OPTIONAL CODES .........................................................................................24
5. TECHNICAL SPECIFICATIONS ..................................................................25
5.1 ELECTRICAL SPECIFICATIONS .......................................................................25
5.2 EQUIVALENT INPUT NOISE............................................................................26
5.3 DIGITAL INTERFACE AND POWER SUPPLY REQUIREMENTS...........................27
6. MECHANICAL DIMENSIONS.......................................................................28

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Document Revisions
Document Revision
Date
Comment
1.0
November 20th, 2014
First Release
1.1
January 20th, 2015
Ordering options updated
1.2
July 21th, 2015
Photo updated, EEPROM
description added
1.3
November 11th, 2018
Model FMC-PICO-1M4 and
technical specifications added

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Safety information - Warnings
CAEN ELS will repair or replace any product within the guarantee period if
the Guarantor declares that the product is defective due to workmanship or materials
and has not been caused by mishandling, negligence on behalf of the User, accident or
any abnormal conditions or operations.
Please read carefully the manual before operating any part of the instrument
WARNING
Do NOT open the boxes
CAEN ELS d.o.o. declines all responsibility for damages or injuries
caused by an improper use of the Modules due to negligence on behalf of the
User. It is strongly recommended to read thoroughly this User's Manual before
any kind of operation.
CAEN ELS d.o.o. reserves the right to change partially or entirely the contents of this
Manual at any time and without giving any notice.
Disposal of the Product
The product must never be dumped in the Municipal Waste. Please check your local
regulations for disposal of electronics products.

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Read over the instruction manual carefully before using the instrument.
The following precautions should be strictly observed before using the device:
WARNING
Do not use this product in any manner not
specified by the manufacturer. The protective
features of this product may be impaired if it is
used in a manner not specified in this manual.
Do not use the device if it is damaged. Before
you use the device, inspect the instrument for
possible cracks or breaks before each use.
Do not operate the device around explosives gas,
vapor or dust.
Always use the device with the cables provided.
Turn off the device before establishing any
connection.
Do not operate the device with the cover
removed or loosened.
Do not install substitute parts or perform any
unauthorized modification to the product.
Return the product to the manufacturer for
service and repair to ensure that safety features
are maintained
CAUTION
This instrument is designed for indoor use and in
area with low condensation.

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The following table shows the general environmental requirements for a correct
operation of the instrument:
Environmental Conditions
Requirements
Operating Temperature
0°C to 50°C
Operating Humidity
30% to 85% RH (non-condensing)
Storage Temperature
-10°C to 60°C
Storage Humidity
5% to 90% RH (non-condensing)
This manual refers to the following boards:
-FMCPICO1M4XA - FMC-PICO-1M4 - 4-channel 20-bit 1 MSPS FMC
Dual-Range Floating Ammeter;
-FMCPICO1M4C3 - FMC-PICO-1M4-C3 - FMC-PICO-1M4-C3 - 4-channel
FMC Bipolar Floating Picoammeter (±10 mA, ±500 µA, BW=300 kHz);

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1.Introduction
This chapter describes the general characteristics and main features of FMC-
Pico-1M4 mezzanine cards.
1.1 FMC-Pico-1M4 Overview
The CAEN ELS FMC-Pico-1M4 is a standard FPGA Mezzanine Card (FMC)
Low Pin Count (LPC) daughter board that allows high resolution monitoring of
bipolar currents up to 1 mA (standard configuration) with maximum sampling rate of
1 MHz. It is mechanically and electrically compliant to the FMC standard
(ANSI/VITA 57.1).
The front-end is composed of a specially designed transimpedance input stage
for current sensing combined with analog signal conditioning and filtering stages
making use of state-of-the-art electronics. The 20-bit resolution is obtained from
independent, simultaneous sampling and low-delay SAR (Successive Approximation
Register) Analog to Digital Converters (ADCs).
Each channel has two full-scale measuring ranges, up to ±1 mA and ±1 µA
(customizable upon request) respectively and the current source can be floating up to
±300 V respect to the FMC ground. The floating capability of the inputs is perfectly
suitable for applications where the detector or current source needs to be biased.
The analog front end is designed in order to achieve low noise, low
temperature dependence and very small unbalance between channels. The analog
characteristics can be further improved by requesting a factory calibration of the
channels. Calibration data are stored in the on-board EEPROM memory that can be
read via an I2C bus on the FMC connector.
A metallic shield has a dual function of shielding the analog front end from
external noise sources and also galvanically isolates the internal electronics that could
be floating up to ±300 V.
A trigger signal can be fed to the FMC connector in order to start the
conversion of data samples: this feature allows synchronizing the board acquisition to
an external event - e.g. machining revolution frequency in storage rings.
Data readout is performed via separate SPI links - i.e. one for each channel,
sharing the same clock signal.

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1.2 Device Description
Both sides and the front view of the FMC-Pico-1M4 can be seen on the
following Figure 1, Figure 2 and Figure 3.
Figure 1: FMC-Pico-1M4 side 1
Figure 2: FMC-Pico-1M4 side 2
Figure 3: FMC-Pico-1M4 front view
The FMC-Pico-1M4 device is composed of the following building blocks:
the analog front-end;
the ADC and isolation section;
the range selection block;
the power supply part.

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The block diagram of the whole device can be seen on the Figure 4.
Figure 4: FMC-Pico-1M4 block diagram
The analog front end is built from several functional blocks (Figure 5). The
current signal is fed to the device through the LEMO triaxial connector. The next
stage is current-to-voltage conversion where the current signal is transformed to a
voltage one and filtered. The voltage signal is then converted in a digital
representation using a high performance analog-to-digital converter. Before the
digital data stream reaches the FMC connector it is galvanically isolated from the
analog front end. The digital voltage levels are also adapted to the FMC carrier ones.
Each analog front end has two measurement ranges which can be
independently selected from channel to channel.
Figure 5: detailed block diagram of a single channel
The power supply part is responsible for the generation of the appropriate
isolated power supply rails (+5 V, -5 V and 2.5 V), which are required for the high-
quality analog-to-digital signal conversion.
There are several light emitting diodes (LEDs) on the FMC-Pico-1M4 board.
The four green ones are signaling the presence of the power supply voltages that are
supplied from the carrier board (12P0V, 3P3V, 3P3VAUX and VADJ).
The group of three red LEDs shows the status of power supply voltages that
are generated on-board by the power supply module. The user can freely use two
additional yellow LEDs upon its discretion (board status signaling, range selection,
etc.).

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2.Installation and Operation
The FMC-Pico-1M4 board can be installed on the FMC carrier board which is
compliant to the FMC standard. The FMC-Pico-1M4 can be mounted on both low-pin
count (LPC - 160 pins) and high-pin count (HPC - 400 pins) FMC connectors. Only
the LPC pins are connected on the mezzanine module. The FMC carrier supports
VADJ voltage range between 1.8 V and 3.3V.
During the installation and handling the ESD precautions must be respected to
prevent electrostatic discharges.
2.1 Ground Connections
For safety and performance reasons the triaxial connectors are used for the
measurement current inlet. The measured current path is through the center wire and
the inner shield of the triaxial cable (see Figure 6). By convention the current that
flows from the source into the FMC board through the center wire is measured as
positive, on the contrary the current that is sinking by the source and flows from the
FMC board through the center wire is measured as negative. The return current path is
always established through the inner cable shield.
Figure 6: Measured current path
There can be large potential difference between the inner (GND ISO) and the
outer triaxial cable shield (EARTH) because of the front-end isolation (Figure 7). The
voltage between both shields must be limited as breakdown may occur so the
maximum value of the isolation voltage is given in the electrical specifications
section.
Figure 7: Definition of isolation voltage

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The outer shield of the triaxial cable must be grounded. Grounding can be
done in two different ways. The default way is assured by the ground connection
trough the FMC bezel which is connected to the grounded chassis (see Figure 8).
Figure 8: Grounding at the FMC bezel side
In addition it is possible also to make the ground connection using the current
source side (see Figure 9). In this case pay attention to realize a proper grounding
connection on the current source side.
Figure 9: Grounding at the current source side
To realize the second type of connection it is necessary to unsolder the two
connection jumpers on the top side of the FMC-Pico-1M4 board (see Figure 10).
Figure 10: Jumpers for connecting the bezel to the input connectors

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2.2 Signals Definitions and Pinout
Interface signals are grouped into six categories:
ADC Interface: signals which are interfacing ADCs on the FMC-Pico-1M4
board;
Range Selection: signals which are used for the selection of the
measurement ranges;
General Purpose LEDs: driving signals for the two general purpose LEDs;
System Management EEPROM: interface signals to the Module
Management EEPROM, used for the IPMI standard;
Application EEPROM: interface signals to the Application EEPROM
memory, that can be used from the application logic;
Power Supply Interface.
The definition of signal direction is as follows:
C2M: carrier board sources the signal (output), mezzanine board is the
signal sink (input);
M2C: mezzanine board sources the signal (output), carrier board is the
signal sink (input).
The LPC connector assignment of signals, its pin name and the direction,
sorted by category, are presented in the following tables.
ADC Interface
Signal name
LPC Pin Assignment
Pin Name
Direction
CNV
H10
LA04_P
C2M
SCK
H11
LA04_N
C2M
SCK_RTRN
G12
LA08_P
M2C
SDO1
H17
LA11_N
M2C
SDO2
H16
LA11_P
M2C
SDO3
H14
LA07_N
M2C
SDO4
H13
LA07_P
M2C
BUSY_CMN
G13
LA08_N
M2C
Table 1: ADC interface signals

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Range Selection
Signal name
LPC Pin Assignment
Pin Name
Direction
R1
G10
LA03_N
C2M
R2
G09
LA03_P
C2M
R3
H08
LA02_N
C2M
R4
H07
LA02_P
C2M
Table 2: Range selection signals
General Purpose LEDs
Signal name
LPC Pin Assignment
Pin Name
Direction
LED1
D11
LA05_P
C2M
LED2
D12
LA05_N
C2M
Table 3: General purpose LED signals
System Management EEPROM
Signal name
LPC Pin Assignment
Pin Name
Direction
SM_SCL
C30
SCL
C2M
SM_SDA
C31
SDA
bidirectional
SM_GA0
C34
GA0
C2M
SM_GA1
D35
GA1
C2M
Table 4: System Management EEPROM interface signals
Application EERPOM
Signal name
LPC Pin Assignment
Pin Name
Direction
A_SCL
D23
LA23_P
C2M
A_SDA
D24
LA23_N
bidirectional
Table 5: Application EEPROM interface signals

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Power Supply Interface
Signal name
LPC Pin Assignment
Pin Name
Direction
VADJ
G39, H40
VADJ
C2M
3P3VAUX
D32
3P3VAUX
C2M
3P3V
C39, D36, D38, D40
3P3V
C2M
12P0V
C35, C37
12P0V
C2M
Table 6: Power supply interface signals
2.3 Signal Descriptions
CNV: Convert Input. A rising edge on this input initiates a new conversion;
SCK: Serial Data Clock Input. The conversion result or daisy-chain data from
another ADC is shifted out on the rising edges of this clock MSB first;
SCK_RTRN: Serial Data Clock Return. The return clock signal, which is
used for ADC data synchronization on the FMC carrier board;
SDO1-4: Serial Data Output. The conversion result or daisy-chain data is
output on this pin on each rising edge of SCK MSB first. The output data is in
2’s complement format;
BUSY_CMN: Common BUSY Indicator. Goes high at the start of a new
conversion and returns low when all the conversions have finished. BUSY
signals from all four ADCs are OR-ed to make one common BUSY_CMN
signal;
R1-R4: Range selection signal; when the line is high, RNG0 is selected on the
current channel, otherwise RNG1 is active;
LED1-LED2: User LEDs control signal; when high, the corresponding LED
is on;
SM_SCL, SM_SDA, SM_GA0 and SM_GA1 signals are connected to the
on-board Module Management EEPROM chip 24AA64. SM_SCL and
SM_SDA signals are used for the I2C communication protocol; SM_GA0 and
SM_GA1 are used to define the geographical address of the Module
Management EEPROM;
A_SCL and A_SDA signals are connected to the I2C bus for the
communication with the on-board Application EEPROM.
VADJ, 3P3VAUX, 3P3V and 12P0V are the signals that provide the power
supplies to the carrier board.

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3.Controlling the FMC
3.1 Digital Interface
The ADCs simultaneous conversion is controlled by CNV signal. A rising
edge on CNV will starts the conversion of the 4 input channels. Once a conversion
has been initiated, it cannot be restarted until the conversion is completed. For
optimum performance, CNV should be driven by a clean low jitter signal. Conversion
status is indicated by the BUSY output which remains high while the conversions are
in progress. To ensure that no errors occur in the digitized results, any additional
transitions on CNV should occur within 40 ns from the start of the conversion or after
the conversion has been completed. Once the conversion has completed, the ADCs
begin acquiring the input signal.
The ADCs have an internal clock that is trimmed to achieve a maximum
conversion time of 675 ns. With a minimum acquisition time of 312 ns, throughput
performance of 1Msps is guaranteed.
The ADCs transmit the acquired data using a serial digital interface. The
ADCs are galvanically isolated from the FMC connector. The isolation logic
introduce some delay on the SPI signals. The serial clock signal (SCK) is brought
back through the isolation (SCK_RTRN signal) in order to have a signal aligned with
the SDO data outputs (see Figure 11). For this reason, all the reads of the SDO lines,
have to be based on the edges of the SCK_RTRN signal.
Figure 11: Clock loopback block diagram
The serial output data are clocked out on the SDO pins when an external clock
is applied to the SCK pin. With a shift clock frequency of at least 64MHz (the max
shift clock frequency is 100 MHz), a 1MSps throughput is still achieved. The serial
output data changes state on the rising edge of the isolated SCK. The SDO lines have
to be read simultaneously from the FMC carrier logic (see Figure 12).

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Figure 12: Parallel connection of the SDO lines
3.2 Timing Diagrams
The SDO signal is always driven. MSB (D19) of the new conversion data is
available at the falling edge of BUSY signal. This is the simplest way to operate the
four ADCs. The timing diagram is shown in Figure 13.
.
Figure 13: Timing diagram

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3.3 Timing Characteristics
Symbol
Parameter
Min
Typ
Max
Units
fSMPL
Maximum Sampling Frequency
1
Msps
tCONV
Conversion Time
615
675
ns
tACQ
Acquisition Time
286
ns
tCYC
Time Between Conversions
1
µs
tCNVH
CNV High Time
20
ns
tBUSYLH
CNV↑ to BUSY Delay
25
39
ns
tCNVL
Minimum Low Time for CNV
20
ns
tQUIET
SCK Quiet Time from CNV↑
15
ns
tSCK
SCK Period
10
ns
tSCKH
SCK High Time
4
ns
tSCKL
SCK Low Time
4
ns
tSSDISCK
SDI Setup Time From SCK↑
4
ns
tHSDISCK
SDI Hold Time From SCK↑
1
ns
tSCKCH
SCK Period in Chain Mode
13.5
ns
tDSDO
SDO Data Valid Delay from
SCK_RTRN↑
10.5
ns
tHSDO
SDO Data Remains Valid Delay
from SCK_RTRN↑
-1.5
ns
tDSDOBUSYL
SDO Data Valid Delay from
BUSY↓
7.5
ns
tDLY
SCK to SCK_RTRN delay
10
16
28
ns
Table 7: Timing characteristics

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3.4 EEPROM Interfaces
The FMC-Pico-1M4 carries two serial EEPROM chips (Microchip 24AA64)
with the same content and connected to two separated I2C interfaces:
System Management EEPROM: accessible using the reserved IPMI
interface (standard ANSI/VITA 57.1), for the management purposes;
Application EEPROM: accessible through I2C interface on the FMC
connector, for application purposes.
The address of the of the System Management EEPROM is configured using
the Geographical Addresses GA0 and GA1 as defined in the FMC standard
ANSI/VITA 57.1. The address pins of the Application EEPROM are fixed to a low
level, which set the address of this memory to 0b1010000 (0x50).
The content of both EEPROMs is the same, allowing user a flexible access to
calibration data both from FMC management logic and application logic. The content
of the memory is compliant with Intel IPMI Platform Management FRU Information
Storage Definition v1.0 standard.
As defined in the standard, the Board Info Area presents the following
information: Date of Man : Wed Jun 10 01:00:00 2015
Manufacturer : CAEN ELS d.o.o.
Product Name : FMC-Pico-1M4
Serial Number : 15001
Part Number : FMCPICO1M420
Figure 14: EEPROM Board Info Area
The Multi Record Area presents the power supply information as defined in
the FMC standard:
DC Load
Output number: 0 (P1 VADJ)
Nominal Volts: 2500 (mV)
minimum voltage: 1800 (mV)
maximum voltage: 3300 (mV)
Ripple and Noise pk-pk 0000 (mV)
Minimum current load 0000 (mA)
Maximum current load 0100 (mA)
DC Load
Output number: 1 (P1 3P3V)
Nominal Volts: 3300 (mV)
minimum voltage: 3120 (mV)
maximum voltage: 3460 (mV)
Ripple and Noise pk-pk 0000 (mV)
Minimum current load 0000 (mA)
Maximum current load 0100 (mA)
DC Load
Output number: 2 (P1 12P0V)
Nominal Volts: 12000 (mV)
minimum voltage: 11400 (mV)
maximum voltage: 12600 (mV)