DI Driver Rev F - National Instruments

DI Driver Rev F - National Instruments
DI Driver Module Kit User’s Manual
D000020 Rev F
July 2012
Drivven, Inc. • 12001 Network Blvd • Bldg E, Ste 110 • San Antonio, Texas 78249 • USA
Phone : 210.248.9308
Web : www.drivven.com , E-mail : [email protected]
Drivven, Inc.
DI Driver Module Kit
HIGH VOLTAGE: This device normally operates at voltages up to 175 volts.
Extreme care should be taken to protect against shock. Even when the device is
completely powered down, allow approximately three minutes for the internal
high voltage to dissipate. Do not touch any of the module screw terminals or
injector terminals while the device is powered.
© Drivven, Inc. 2011 • DI Driver Module Kit User’s Manual • D000020 • Rev F
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DI Driver Module Kit
Contents
Introduction ......................................................................................................................... 4
Module Specifications ........................................................................................................ 5
Pinout .................................................................................................................................. 6
Hardware ............................................................................................................................. 6
Powering the Module .......................................................................................................... 7
Platform Compatibility ....................................................................................................... 9
Internal Boost Power Supply ............................................................................................ 11
Direct Injector Drivers ...................................................................................................... 16
Connecting Injectors to the Module .................................................................................. 36
Compliance and Certifications .......................................................................................... 38
Physical Specifications and Characteristics ...................................................................... 39
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DI Driver Module Kit
Introduction
The Direct Injector Driver Module Kit provides a CompactRIO (cRIO) module for driving a wide
variety of diesel and gasoline direct injectors, including many piezo actuated injectors. The kit
includes LabVIEW FPGA and RT VIs for controlling the driver channels. Each DI driver channel
is individually controlled for timing and duration, but channel operation may not overlap. The
module cannot control piezo and solenoid actuator types simultaneously. When configured for
piezo mode, channel 3 is not available and must have its terminals shorted together.
Features:










3-channel solenoid injector drivers
2-channel piezo injector drivers (in piezo mode)
Up to 175V internal boost power supply
Up to 40A peak current drive
Operates from 6V to 32V battery
Optional external input for high voltage supply (up to 175V)
o Internal boost supply automatically shuts down when external high voltage is
applied > 24V
Circuit protection and diagnostics
o Protected against INJ+/- short to battery / high voltage
o Protected against INJ+/- short to GND
o Internal power supply overload protection
o Internal power supply over-charge protection
o Module temperature protection
o Open circuit detection
o Fault flags reported for all above conditions
LabVIEW FPGA and RT VIs for engine-synchronous, multi-pulse injection control
strategies
o Up to 16 pulses per injection cycle (Engine Speed Limited)
o Configurable for any combination of angle and time triggering
o Current control profile
 Up to 8 phases
 Each phase provides settings for upper and lower current dithering
setpoints
 Duration and drive voltage (battery or boost) specified for each phase
 First phase can be configured to end after first peak
Drivven’s DI Calibrator application assists with firing injectors on a test bench for
configuring the injector current/voltage profile
Piezo injector operation for unipolar drive
o Inverted piezo drive supported (Discharge=ON, Charge=OFF)
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Module Specifications
Table 1. Module Specifications
Parameter Description
Value
Units
Number of Channels for Solenoid Injectors
Number of Channels for Standard Piezo Injectors
Number of Channels for Inverted Piezo Injectors
Main Battery (BATT) Input Range
Recommended Main Battery Input Power Capacity
External Power (EXT PWR) for Boost Power Supply
(1)
Replacement
Maximum Module Internal Power Dissipation
(2)
Maximum Current Drive to Injectors
(3)
Maximum Recommended Injection Command Duration
(4)
Maximum Injection Events Per Engine Cycle
(5)
Minimum Time Between Injection Events
Maximum Single IPhase Element Duration
Maximum BackBoostTime
Maximum OneShot Time
Maximum HVTarget Setpoint
(7)
Maximum Internal Module Temperature Before Critical Fault
(7)
Short Circuit Fault Threshold (During Injection Events)
(7)
Short Circuit Fault Threshold (Outside Injection Events)
(6)
Open Circuit Fault Threshold
(7)
High Voltage Fault Threshold
3
2
1
7-32
>=100
VDC
W
7-175
VDC
10
40
5
16
0
1.6
1.6
5
175
85
44
20
1.5
195
Watts
A
msec
msec
msec
msec
msec
V
C
A
A
A
V
Notes:
(1) When using an external high voltage power supply connected to the EXT PWR terminal, do
not connect this high voltage supply to the BATT terminal. The BATT terminal should still be
connected to a separate supply of 7-32V. The ground of the external high voltage supply should
be connected to the GND terminal 8.
(2) The recommended maximum time at 40A is 100usec
(3) Longer injection durations are possible, but the duty cycle of the driver should be taken into
consideration. For example a single one-shot pulse on an injector test stand could safely be
200msec. Therefore injection duty cycle, current levels, and module temperature should be
considered.
(4) This is a software limit. However, overall injection duty cycle, current levels and module
temperature should be considered. Sixteen injection events per engine cycle may overload the
module depending on engine speed and current levels.
(5) The software can be configured to have multiple injection commands which merge. However,
the injector will need a certain amount of time to close the valve at the end of an injection
command. This is a property of the injector.
(6) If the current during an injection command does not exceed this level, then an Open Circuit
Fault will be reported. However, this does not effect the operation of the driver. The Open Circuit
Fault is for information only.
(7) These conditions will cause a critical fault and shutdown operation of the module. A manual
fault clearing via software must take place to resume operation.
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Pinout
Hardware
The DI Driver Module Kit provides three channels for driving unipolar solenoid and piezo injectors
in a National Instruments CompactRIO module. An internal boost power supply is included for
providing up to 175V for driving peak solenoid currents up to 40A.
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Powering the Module
The DI Driver module requires power from two different sources.
One source is from the CompactRIO backplane male high density D-Sub 15-pin (HD15)
connector which mates with the module’s female HD15 connector. This power source provides a
regulated 5 volts and ground to various digital logic functions within the module. The
CompactRIO 5V source is active whenever the CompactRIO or R-Series Expansion Chassis is
properly powered. The module should be powered at the HD15 connector by plugging it into a
CompactRIO or R-Series Expansion Chassis. The module’s HD15 connector should not be
connected to any other device.
Another required power connection is at the external screw terminal connector block provided
with the module. The main power terminals are labeled BATT (0) and GND (9). Typical power
sources will be from automotive 12VDC or 24VDC battery systems. However, the module can
accept power from a range of 7VDC to 32VDC.
Caution – You must use a UL Listed power supply with the Drivven DI Driver Module.
With the internal boost power supply and injector outputs disabled, the module requires up to
100mA from the external supply. The total power required to operate the module and drive
injectors is according to the following formula:
Where:
Ip (A) = Peak current
Ih (A) = Hold current
HVTarget (V) = High Voltage Target from internal boost supply
BattV (V) = Battery voltage supplied to BATT(0)
Tip (sec) = Time of peak current phase
DurAve (sec) = Average duration of all injection pulses within an engine cycle
RPMmax (RPM) = Maximum engine speed in RPM
Nchan = Number of channels used
Npulse = Number of injection pulses per engine cycle
The above formula assumes a 4-stroke engine cycle. For 2-stroke engines, multiply the result by
2.
Table 2. Example power calculation.
Parameter
Ip (A)
Ih (A)
HVTarget (V)
BattV (V)
Tip (sec)
DurAve (sec)
RPMmax (RPM)
Nchan
Npulse
Power (W)
Continuous Current (A)
Value
25
15
75
13.8
0.000100
0.000800
4500
3
2
65
4.5
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A 100W power supply is sufficient for most applications. Power requirements may peak up to
150W for more demanding applications.
The external battery ground is isolated, within the module, from the CompactRIO 5V supply
ground. However, the external battery ground and the CompactRIO ground may be connected
externally.
The module will not be recognized by software without both power supplies active at the HD15
connector and the external screw terminal block.
Warning: The external battery supply input terminals are not reverse voltage polarity
protected. Connecting power to the module in reverse polarity will damage the module.
This event is not covered by warranty. Please refer to the
DrivvenReverseBatteryNotice.pdf document (available on the website) for a recommended
solution for protecting a system from reverse battery polarity.
There is an optional power input to the external screw terminal connector block. The terminal is
labeled EXT PWR (7). The ground reference for EXT PWR (7) must be the same ground as
GND (9). This power input can range from 6V to 175V and is optionally used to provide the boost
voltage in place of the internal boost supply. Since the internal boost power supply is a significant
contributor to the internal module heat generation, this external power input may be necessary if
the injector drive requirements, in combination with maximum engine speeds, cause the internal
module temperature to exceed the limit. This topic is discussed in detail later in this manual.
When a voltage above 24V is applied to the EXT PWR (7) terminal, then the internal boost power
supply will automatically shut off, even if it is enabled via software. Even when EXT PWR (7) is
connected to an external high voltage power source, BATT (0) must still be connected to 6V to
32V in order for the module to be properly powered for general functions. In most applications
the EXT PWR (7) terminal is not necessary and should be left unconnected.
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Platform Compatibility
CompactRIO modules from Drivven are compatible within two different platforms from National
Instruments. One platform is CompactRIO (cRIO), typically consisting of a CompactRIO
controller and CompactRIO chassis as shown in Figure 1a below. Integrated cRIO chassis and
some sbRIO boards are also included in this compatible platform. Please contact Drivven for the
latest cRIO family compatibility information.
Figure 1a. CompactRIO platform compatible with Drivven CompactRIO modules.
The other platform is National Instruments PXI which consists of any National Instruments PXI
chassis along with a PXI RT controller and PXI-78xxR R-Series FPGA card. An R-Series
expansion chassis must be connected to the PXI FPGA card via a SHC68-68-RDIO cable. The
CompactRIO modules insert into the R-Series expansion chassis. This platform is shown in
Figure 1b below.
Figure 1b. PXI platform compatible with Drivven CompactRIO modules.
Drivven CompactRIO modules are not compatible with the National Instruments CompactDAQ
chassis.
Drivven CompactRIO modules REQUIRE one of the hardware support systems described above
in order to function. The modules may not be used by themselves and/or interfaced to third party
devices at the backplane HD15 connector. These efforts will not be supported by Drivven or
National Instruments.
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You can use Drivven C Series modules with NI cRIO-911x, NI cRIO-907x, and NI R Series
Expansion systems under the following conditions.
–Leave one empty chassis slot between Drivven and NI modules.
–Maintain an ambient system operating temperature of 0 to 45 °C.
–Typical specifications of NI modules may not apply when used in a system with
Drivven modules.
–Warranted specifications are guaranteed for all NI modules except thermocouple
modules when used in a system with Drivven modules.
–The NI 9214 is recommended for thermocouple measurements in cRIO systems
using Drivven modules.
-Scan Interface mode, auto-detection, and ID mode are not supported for Drivven
modules.
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Internal Boost Power Supply
The DI Driver Module contains an internal boost power supply which can be commanded to
maintain a voltage level from battery voltage up to 175V. The boost power supply can be
enabled or disabled at any time via software. It is disabled automatically whenever critical faults
occur and can only be enabled thereafter by clearing the faults. The high voltage is stored within
internal capacitors and used to drive the high-voltage, phases of the injector current profile.
HIGH VOLTAGE: This device normally operates at voltages up to 175 volts.
Extreme care should be taken to protect against shock. Even when the device is
completely powered down, allow approximately three minutes for the internal
high voltage to dissipate. Do not touch any of the module screw terminals or
injector terminals while the device is powered.
© Drivven, Inc. 2011 • DI Driver Module Kit User’s Manual • D000020 • Rev F
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Internal Boost Power Supply Performance
There are six critical factors which determine how well the internal boost power supply will
perform for a particular injector solenoid application. Those factors are:
 Injector solenoid resistance
 Injector solenoid inductance
 Peak current required to open the injector valve
 Working voltage requirement (HVTarget)
 Frequency of injection events
 Injector solenoid back-boost time (BackBoostTime)
We will discuss each of these factors one at a time.
Injector Solenoid Resistance
Typical common rail diesel injector solenoids will have a resistance of 1 ohm or less. This
resistance will waste, as heat, a portion of the energy supplied to the solenoid. It also affects the
maximum current achieved in the coil, which depends on the drive voltage applied. In general,
lower solenoid resistances are better for common rail solenoid injector applications.
Injector Solenoid Inductance
Typical common rail injector solenoids will have an inductance of 1mH or less. Inductance acts to
resist current change through the coil. The higher the inductance, the longer it will take to
achieve the required peak current level, given a constant drive voltage. When the internal high
voltage is used as a current drive, there is a transfer of energy from the internal high voltage
capacitance to the injector solenoid. Longer drive times mean more energy will be depleted from
the internal high voltage capacitance. This causes the internal boost supply to work harder to
maintain the high voltage target. However, inductance is not a bad thing because it is
proportional to the magnetic force generated for opening the injector valve.
Peak Current Requirement
Higher peak-currents require more energy from the internal boost power supply because the
internally stored high voltage will be depleted at a higher rate.
Working Voltage Requirement
A higher working voltage maintained by the internal boost power supply will be able to drive the
peak current level in a shorter amount of time, thereby providing quicker valve opening times and
more predictable fuel injection quantities over a given injection duration. However, the boost
power supplies operate less efficient at higher voltages. Therefore the power supply must work
harder to maintain a higher working voltage. Typical times to reach 20 amps in common-rail
diesel injectors are on the order of 30 to 100 microseconds, with a working voltage of 100V.
Frequency of Injection Events
The frequency of injection events is directly proportional to the work required by the power supply
to maintain the working voltage.
Injector Back-Boost
In many scenarios, it is possible to get a significant and useful back-boost charge from the
injector solenoid at the end of each injection event. This back-boost from the solenoid mostly
depends on the hold-current level during the injection event, and the working voltage of the boost
power supply. In most cases, if the current profile is correctly configured, there will be a small
back-boost on the order of 5V to the power supply which will reduce the work required to maintain
the working voltage.
It is possible to incorrectly configure the module to use very little of the high voltage supply for
driving the peak-current while also setting a high hold-current level. This configuration can lead
to back-boosting the power supply over the required working voltage. The usage of the internal
high voltage supply should be used to prevent this from happening. If the working voltage
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exceeds 175V, then it will generate a fault and shut down automatically.
Power Supply Faults and Protections
There are a few critical faults related to the operation of the internal power supply which will
cause all operations of the module to shutdown automatically. The internal boost power supply
and injection control can be re-enabled by manually clearing the faults via software.
Power Supply Charge Fault (PSCharge)
If the power supply is actively attempting to recharge and detects that the voltage is not rising,
then the charge fault will be set. This fault would most likely occur if there was an internal
problem with the module, such as a capacitor failure.
Power Supply Overload Fault (PSOverLoad)
The DI driver module maintains an integrator of power supply usage. An internal counter
increments with each power supply voltage boost and decrements according to a fixed time
interval. If the integrator winds up to 3,800 counts, then an overload fault will be set. This is an
indication that the module temperature would soon rise beyond its maximum operating
temperature if not stopped. The module temperature fault may be tripped before the overload
fault, depending on the actual conditions.
Module Temperature Fault (ModuleTemperature)
Due to the standard CompactRIO module enclosure design, there is limited ability for heat to
escape the module. The power supply circuitry was designed with components carefully selected
for efficiency and compactness. Still, the primary source of heat within the DI Driver Module is
the internal boost power supply. If the internal module temperature rises above approximately
80C, then the module temperature fault will be set.
High Voltage Limit Fault (HighVoltageLimit)
If the charge on the internal power supply exceeds 175V, then the high voltage limit fault will be
set. This fault could occur due to internal problems with the module or due to excessive injector
solenoid back-boosting. Excessive solenoid back-boosting can be caused by a combination of
solenoids with very high inductance and using the internal boost supply very little.
The above faults are loosely tied together, in that certain conditions can lead to two or more of the
above faults. For example, the power supply may be loaded such that the board temperature will
reach its limit before the overload integrator limit is reached.
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Internal Boost Power Supply Benchmarks
For a better understanding of what the power supply is capable of, in terms of driving typical
common rail diesel injectors, below are some bench test results.
Table 3. Bench Test Results
Test Condition
External Battery Voltage (V)
HVTarget (V)
PeakCurrent (A)
PeakTime (msec)
HoldCurrent (A)
BackBoostTime (msec)
Number of injectors operated
Number of fuel pulses per cycle
Simulated engine speed (RPM)
Length of test (min)
Ambient temperature (C)
Final module temperature (C)
Temperature stabilized?
Injector under test
Test 1
Test 2
13.8
13.8
75
75
27
27
0.18
0.18
15
15
0.20
0.20
3
3
1
5
5000
2000
10
10
25
25
50
75
Y
N
Bosch P/N 0445 110 072
Mercedes Benz P/N 611 070 09 87
With air flow over the module, the duration of operation at heavy loads can be extended.
The internal power supply requires approximately 10 milliseconds to charge from 12V to 100V,
and approximately 20 milliseconds to charge from 12V to 150V. This charge-up process will
occur immediately when enabling the power supply. As long as the power supply is enabled, the
requested working voltage will be maintained while injection events are not commanded.
Depending on the working voltage, the user may hear a slow frequency of faint clicks from the
module. This is normal noise from the power supply.
The above table is a guide to the capability of the internal boost power supply. There are many
different possible solenoid current profiles that are required by as many different injector
solenoids. The DI Calibrator application can assist in determining whether the internal power
supply will meet those requirements. Drivven will determine calibration parameters for
customer’s injectors at no cost if the calibration data can be re-used. This does not include fuel
flow measurements. Drivven must be provided with current profile information and a test solenoid
or injector.
When the internal supply is disabled, the high voltage will bleed down to battery voltage from
175V in approximately 2 minutes.
While it is not ideal, for packaging considerations, to use an external high voltage power supply,
there is a screw terminal to the module for this purpose, in case the internal power supply cannot
meet the demands of the application. However, before deciding to use an external power supply,
consider using only two of the three available channels instead of all three. For example,
consider using three DI driver modules for a six cylinder engine. This will lighten the load on each
internal power supply.
Connecting an External Power Supply to EXT PWR (7)
An optional high voltage external power supply may be connected to EXT PWR (7) if the internal
boost power supply is overheating or not able to keep up with the injection requirements. Inside
the module, the external high voltage supply connects to the same internal capacitance as the
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internal boost supply. Expect an electrical spark when connecting a live high voltage power
supply to the EXT PWR (7) terminal. It is strongly recommended that a good permanent
connection be made before powering the external power supply. When an external high voltage
supply greater than 24V is detected, it will cause the internal boost supply to automatically
shutdown. The BATT (0) terminal must still be connected and powered by 6-32V even when
using an external high voltage supply connected to EXT PWR (7). A high voltage external power
supply is not necessary for most applications.
Suggested External High Voltage Supplies
TDK Lambda Genesys 100-15
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Direct Injector Drivers
Injector Driver Circuit Description
The DI Driver Module contains three solenoid direct injector drivers. Two Piezo injectors can also
be driven by this module and the details of that are discussed later in this section. The driver
channels share some circuitry, making it impossible for injection events to overlap among
channels within the same module. If injection events with different injectors must overlap, then
multiple modules should be employed. There is a high voltage circuit and a battery voltage circuit
which drive current to the injector load. The high voltage and battery voltage drive circuits are
shown below in the simplified schematics for operating various types of injectors.
Solenoid Injector Operation
A representative simplified schematic driving three solenoid injectors is shown in figure 2, below.
Figure 2. DI driver simplified schematic for solenoid injectors.
The user can programmatically specify up to eight sequential drive phases within each solenoid
injection command pulse via an 8-element IPhaseArray. Each phase is implemented sequentially
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and can specify upper and lower current dithering setpoints, phase duration, and drive circuit –
high voltage or battery voltage. The high voltage drive circuit should be used only as much as
necessary so that the internal boost power supply energy is conserved and not overloaded. The
solenoid current is controlled using a dual comparator feedback circuit for upper and lower
dithering thresholds. Other current and voltage sensing circuits are used for fault detection.
Figures 3-6, below, are oscilloscope images showing examples of current waveforms for four
different IPhaseArray configurations. Three of the examples show waveforms that are common
in the direct injection industry. The fourth waveform is for the purpose of showing the flexibility of
the IPhaseArray interface. The software interface to the DI Driver, including the IPhaseArray, is
described in the software section of this manual, however, some things are worth noting here.
The total duration of the injection command is not determined by the total durations of the
IPhaseArray elements. The total duration is determined by the Boolean command delivered to
the DI Driver FPGA express VI. Generating command pulses to the express VI is described in
the software section of this manual. If the Duration parameter of an IPhaseArray element is set to
0, then the current levels for that element will be carried out for the remainder of the injection
command.
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Figure 3a. Solenoid IPhaseArray configuration example 1.
Figure 3b. Current and voltage traces from solenoid IPhaseArray configuration example 1.
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Figure 4a. Solenoid IPhaseArray configuration example 2.
Figure 4b. Current and voltage traces from solenoid IPhaseArray configuration example 2.
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Figure 5a. Solenoid IPhaseArray configuration example 3.
Figure 5b. Current and voltage traces from solenoid IPhaseArray configuration example 3.
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Figure 6a. Solenoid IPhaseArray configuration example 4.
Figure 6b. Current and voltage traces from solenoid IPhaseArray configuration example 4.
Phase1FirstPeakEnable
The DI Driver module provides a software option, in the form of a Boolean control called
Phase1FirstPeakEnable, to transfer operation from the first phase to the second phase upon
reaching the first current peak corresponding to the first phase IUpper threshold. Figure 7, below,
shows an example of this mode of operation.
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Figure 7. Current and voltage traces from Phase1FirstPeakEnable=TRUE operating mode.
BackBoostTime
A global parameter which is critical for proper solenoid injector control is the BackBoostTime.
This time period directly follows the end of the injection command duration and allows the backemf of the injector solenoid to be directed to the internal power supply for back-boosting the
internal high voltage power supply. It also brings the injector solenoid current quickly to zero. If
BackBoostTime is set to zero, then injector current would be allowed to recirculate through the
injector until the energy dissipates. which would lead to unpredictable injector valve closing.
Therefore BackBoostTime should be calibrated long enough for the energy within the injector
solenoid to be fully discharged to the internal boost power supply. If BackBoostTime is greater
than zero, but too short, you will see the injector current bump up and recirculate until the energy
is fully dissipated. BackBoostTime should be extended until the current recirculation cannot be
seen on the scope solenoid current trace. A typical BackBoostTime is approximately 0.2
milliseconds. Injectors with higher inductance will have more energy to dissipate at the end of
injection and require a longer BackBoostTime. Figures 8-12, below, show five different values for
BackBoostTime applied to the same solenoid injector.
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Figure 8. BackBoostTime = 0.0 msec.
Figure 9. BackBoostTime = 0.025 msec.
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Figure 10. BackBoostTime = 0.050 msec.
Figure 11. BackBoostTime = 0.100 msec.
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Figure 12. BackBoostTime = 0.150 msec.
Piezo Injector Operation
The DI Driver module is capable of driving unipolar piezo injectors. Unipolar means that the
piezo injector is charged to a positive voltage and discharged to ground. Bipolar drive means that
the piezo injector can be charged to a positive or negative voltage. When driving piezo injectors,
only channels 1 and 2 are available for this mode. Channel 3 must be connected with a shorting
jumper between the Inj+ and Inj– terminals. Electrically, piezo injectors are a capacitive load, as
opposed to an inductive load from solenoid injectors. Solenoid injectors require current to be
driven through the solenoid in order to create the proper magnetic field within the injector body to
mechanically open a valve. Piezo injectors have a “stack” of piezo crystal elements which
respond mechanically to a voltage applied across the stack. The two pins of the piezo injector
are connected internally across the stack. As the voltage across the stack increases, the stack
expands, and exerts a force to open a fluid valve. The benefit of piezo injectors is the ability of
the piezo stack to respond mechanically quicker than a solenoid operated injector. It is difficult to
estimate the fuel quantity injected while the injector valve is in the process of opening. Therefore,
achieving a shorter time from the beginning of energizing the injector to fully opening the valve is
an advantage because the fuel injection quantity can be metered more precisely over the entire
injection command.
Since a piezo stack is electrically like a capacitor, it requires current in one direction, to charge up
to a specified voltage, and current out in the opposite direction to discharge. The typical charge
voltage required for piezo injectors ranges from 100V to 200V. Most piezo injectors in production
today require up to 165V and will vary based on desired fuel rail pressure. A piezo stack must be
charged up to the specified voltage at a rate which will not damage the stack. If the charge and
discharge rate is too fast, the stack will not last very long. Therefore the charge and discharge
current must be controlled. This can be done practically with an inductive element in series with
the piezo stack and treated similar to an inductive load, as far as current control is concerned.
However, the DI Driver module has a special piezo mode of operation which utilizes the same
IPhaseArray interface to control current to the piezo stack for charge and discharge rates. When
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charging the piezo stack, the final charge will be a few volts less than the HVTarget setpoint.
When discharging the piezo stack the final discharge state will be 0 Volts.
The IPhaseArray is used differently during piezo mode. The eight elements of the IPhaseArray
are divided into two groups. The first four elements are used for charge, and the last four
elements are used for discharge. The BackBoostTime parameter is not used for piezo injector
operation. The DriveSrc Boolean for each IPhaseArray element is not applicable for piezo
injector operation because the high voltage driver circuit is always used. A representative
simplified schematic driving two piezo injectors is shown in figure 13, below.
Figure 13. DI driver simplified schematic for two piezo injectors.
The DI Driver module can also operate piezo injectors requiring an inverted charge scheme. The
inverted piezo mode is determined by the PiezoInvert Boolean discussed in the software section
of this manual. This means that the injector valve is closed when the stack is charged, and the
valve is opened when the stack is discharged. Only a single piezo injector may be operated by
channel 1 when operated in inverted mode. Channel 2 must be left disconnected, while channel
3 must be connected with a shorting jumper between the Inj+ and Inj– terminals. When
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PiezoInvert mode is enabled, the first four IPhaseArray elements are used for discharge and the
last four elements are used for charge. A representative simplified schematic driving a single
piezo injector in inverted mode is shown in figure 14, below.
Figure 14. DI driver simplified schematic for a single inverted piezo injector.
Figures 15-21, below, are oscilloscope images showing examples of current and voltage
waveforms for seven different IPhaseArray configurations for piezo injectors.
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Figure 15a. Piezo IPhaseArray configuration example 1.
Figure 15b. Current and voltage traces from Piezo IPhaseArray configuration example 1.
HVTarget = 150V. Charge time = 148 usec.
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Figure 16a. Piezo IPhaseArray configuration example 2.
Figure 16b. Current and voltage traces from Piezo IPhaseArray configuration example 2.
HVTarget = 150V. Charge time = 124 usec
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Figure 17a. Piezo IPhaseArray configuration example 3.
Figure 17b. Current and voltage traces from Piezo IPhaseArray configuration example 3.
HVTarget = 150V. Charge time = 188 usec
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Figure 18a. Piezo IPhaseArray configuration example 4.
Figure 18b. Current and voltage traces from Piezo IPhaseArray configuration example 4.
HVTarget = 150V. Charge voltage = 100V.
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Figure 19a. Piezo IPhaseArray configuration example 5.
Figure 19b. Current and voltage traces from Piezo IPhaseArray configuration example 5.
HVTarget = 150V. Charge voltage = 100V step, then 150V.
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Figure 20a. Piezo IPhaseArray configuration example 6.
Figure 20b. Current and voltage traces from Piezo IPhaseArray configuration example 6.
HVTarget = 150V. Inverted piezo operation.
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Figure 21a. Piezo IPhaseArray configuration example 7.
Figure 21b. Current and voltage traces from Piezo IPhaseArray configuration example 7.
HVTarget = 175V.
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Injector Types Supported
Many different types of solenoid and piezo injectors can be driven with this module, including
gasoline direct injectors. Drivven will help customers determine the appropriate settings and
operating limitations for any type of injector at no cost if the setup parameters can be re-used for
other customer projects. Drivven does not verify injector operation on a fuel flow bench. Instead,
Drivven will determine the optimum software settings to achieve a specified current/voltage
profile.
Injector Driver Circuit Faults and Protections
There are several scenarios which can lead to short circuits with the DI driver module. Each
possible short condition is detected by the module and a critical fault is reported. Each short
circuit fault will cause all power supply and injection control operations to shutdown automatically.
The power supply and injection control can be re-enabled by manually clearing the faults via
software.
Short Circuit Fault Conditions
INJ+ shorted to battery: This condition will immediately cause a ShortCircuit critical fault. Since
current is flowing through the injector solenoid, current rise times are limited by the load
inductance and the short will typically be detected at about 20A if the channel is off, and 45A if
the channel is on.
INJ- shorted to battery: This condition will immediately cause a ShortCircuit critical fault. Since
current is bypassing the injector solenoid, current rise times are extremely fast and could peak as
high as 200A before detection. However, the module can handle this current spike and shutdown
appropriately.
INJ+ shorted to ground: This condition will cause a HighVoltageDriver critical fault or
LowVoltageDriver critical fault during an injection event. The fault reported depends on when
exactly the short condition occurs – during the high-voltage or low-voltage portion of the current
profile.
INJ- shorted to ground: This condition will cause a HighVoltageDriver critical fault or
LowVoltageDriver critical fault during an injection event. The fault reported depends on when
exactly the short condition occurs – during the high-voltage or low-voltage portion of the current
profile.
INJ+ shorted to INJ-: This condition will cause a HighVoltageDriver critical fault or
LowVoltageDriver critical fault during an injection event. The fault reported depends on when
exactly the short condition occurs – during the high-voltage or low-voltage portion of the current
profile.
INJ+ / INJ- Open Circuit: This condition is detected when the current during the injection event
does not exceed 1.5A. The OpenCircuit non critical fault is reported for the appropriate channel
and is automatically cleared upon the next pulse if the condition is removed.
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Connecting Injectors to the Module
Figure 22. Connecting solenoid injectors to the driver module.
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Figure 23. Connecting piezoelectric injectors to the driver module.
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Compliance and Certifications
Safety
This product meets the requirements of the following standards of safety for electrical
equipment for measurement, control, and laboratory use:
 IEC 61010-1, EN 61010-1
 UL 61010-1, CSA 61010-1
Electromagnetic Compatibility
This product meets the requirements of the following EMC standards for electrical
equipment for measurement, control, and laboratory use:
 EN 61326-1 (IEC 61326-1): Class A emissions; Industrial immunity
 EN 55011 (CISPR 11): Group 1, Class A emissions
 AS/NZS CISPR 11: Group 1, Class A emissions
 FCC 47 CFR Part 15B: Class A emissions
 ICES-001: Class A emissions
Caution: When operating this product, use shielded cables and accessories.
CE Compliance
This product meets the essential requirements of applicable European Directives as follows:
 2006/95/EC; Low-Voltage Directive (safety)
 2004/108/EC; Electromagnetic Compatibility Directive (EMC)
Environmental Management
NI is committed to designing and manufacturing products in an environmentally responsible
manner. NI recognizes that eliminating certain hazardous substances from our products is
beneficial to the environment and to NI customers. For additional environmental information, refer
to the NI and the Environment Web page at ni.com/environment. This page contains the
environmental regulations and directives with which NI complies, as well as other environmental
information not included in this document.
Waste Electrical and Electronic Equipment (WEEE)
EU Customers At the end of the product life cycle, all products must be sent to a WEEE
recycling center. For more information about WEEE recycling centers, National Instruments
WEEE initiatives, and compliance with WEEE Directive 2002/96/EC on Waste Electrical and
Electronic Equipment, visit ni.com/environment/weee.
Battery Replacement and Disposal
Battery Directive This device contains a long-life coin cell battery. If you need to replace it,
use the Return Material Authorization (RMA) process or contact an authorized National
Instruments service representative. For more information about compliance with the EU
Battery Directive 2006/66/EC about Batteries and Accumulators and Waste Batteries and
Accumulators, visit ni.com/environment/batterydirective.
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Management Methods for Controlling Pollution Caused by Electronic
Information Products Regulation (China RoHS)
Chinese Customers National Instruments is in compliance with the Chinese policy
on the Restriction of Hazardous Substances (RoHS) used in Electronic Information Products. For
more information about the National Instruments China RoHS compliance, visit
ni.com/environment/rohs_china.
电子信息产品污染控制管理办法( 中国RoHS)
中国客户 National Instruments符合中国电子信息产品中限制使用某些有害物质指令
(RoHS)。 关于National Instruments中国RoHS合规性信息,请登录
ni.com/environment/rohs_china。(For information about China RoHS compliance, go to
ni.com/environment/rohs_china.)
Physical Specifications and Characteristics
Weight: 170 grams
Maximum Altitude: 2000 m
Maximum Ambient Temperature: 45º C
Operating Humidity: 10% to 90% RH, noncondensing
Pollution Degree: 2
Ingress Protection: IP30
For Indoor Use Only
If you need to clean the module, wipe it with a dry towel
Safety Guidelines
Caution: Do not operate this module in a manner not specified in these operating
instructions. Product misuse can result in a hazard. You can compromise the safety protection
built into the product if the product is damaged in any way. If the product is damaged, return it to
National Instruments for repair.
D000020-UM
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