VICOR 4623, 3623 User Manual
USER GUIDE | UG:017
Analog Control 3623 and 4623 ChiP DCMs
Evaluation Board
Arthur Russell
VI Chip® Applications Engineering
October 2014
Contents Page
Introduction 1
Contents 3
Features 3
Board Description 4
General Components 4
Test Points Description 6
Schematic, Assembly Drawing
and Bill of Materials 7
Recommended Test
Equipment 14
Basic Connections 14
Board Operation Details 14
Trim Control 15
Fault Monitoring 15
Chassis Ground 16
Paralleling 16
Introduction
The Analog Control 3623 and 4623 ChiP DCM evaluation boards described in this document are
designed to be used with the DCM family of isolated, DC-DC converters. The 3623 DCM board is used
for the analog control, low input voltage 3623 ChiP products, while the 4623 DCM board is used for
the analog control, high input voltage (offline) 4623 ChiP products.
The DCM evaluation board can be configured for various enabling and fault monitoring schemes,
as well as to exercise various modes of trimming, depending on the application requirements. The
evaluation board can be used to evaluate DCMs in either a stand-alone configuration, or as an
array of modules.
Enable options:
1. On-board mechanical switch (default)
2. External control
Trim options:
1. Fixed trim operation (default): the TR pin is permitted to float at initial startup.
The DCM disables output trimming and the output trim is programmed to the nominal rated V
2. Variable trim operation, on-board variable resistor: The trim pin voltage is ratiometric,
with a rheostat working against a pull-up resistor inside the DCM to VCC.
3. Variable trim operation, off-board control: The trim pin voltage is controlled via external
programming control, which is referenced to the –IN of each specific DCM in the system.
OUT
.
Fault monitor options:
1. On-board LED: the FT pin drives a visible LED for visual feedback on fault status.
2. On-board optocoupler: the FT pin drives an on-board optocoupler to bring
fault status across the primary-secondary isolation boundary.
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 1
IMPORTANT NOTICE:
Hazardous voltages are present on the DCM Evaluation Board under power.
PERSONAL CONTACT WITH LINE VOLTAGE MAY RESULT IN SEVERE INJURY, DISABILITY, OR
DEATH. IMPROPER OR UNSAFE HANDLING OF THIS BOARD MAY RESULT IN SERIOUS INJURY
OR DEATH.
Read the precautions below entirely BEFORE using the DCM Evaluation Board. Do not operate the
evaluation board unless you have the appropriate safety precautions in place on your bench to
guarantee safety.
The list below is not comprehensive and is not a substitute for common sense and
good practice.
During operation, the power devices and surrounding structures can be operated
safely at high temperatures.
Remove power and use caution when connecting and disconnecting test probes
and interface lines to avoid inadvertent short circuits and contact with hot surfaces.
Never use a jumper in place of the fuse.
When testing electronic products always use approved safety glasses. Follow good
laboratory practice and procedures.
Avoid creating ground loops when making measurements of the isolated input
or output voltage.
Care should be taken to protect the user from accidental contact when
under power.
Care should be taken to avoid reversing polarities if connecting to the opposite
(solder) side of the board.
The product evaluation boards described in this document are designed for
general laboratory evaluation, and are not suitable for installation in
end user equipment.
Refer to the specific DCM module data sheet for electrical, thermal, and mechanical
product details
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 2
These boards provide a convenient way to evaluate/demonstrate the performance of Vicor’s DCM
products. Kelvin connections are provided for accurate voltage measurements on power nodes. Sockets
are provided to permit quick installation and changing of bulk filtering capacitors. The evaluation board
also provides lugs for input/output connections, test points and sockets for easy connection to standard
test-equipment, and a high performance air cooled heatsink assembly.
Contents
The evaluation board arrives with the following contents:
1 x DCM evaluation board
1 x top and belly heatsink assembly (pre-installed)
1 x hardware kit
Features
The DCM evaluation board has the following features:
1. Input and output lugs for source and load connections
2. Input fuse (appropriately rated)
3. Basic input filtering, including sockets to add through-hole input aluminum-electrolytic capacitors
for additional source decoupling
Note: The filtering used in the eval board is for demonstration purposes only and might not be the optimal
solution for all applications. For optimal filter design for parallel array application, consult the datasheet of the
DCM in use and the online filter design tool at:
http://app2.vicorpower.com/filterDesign/intiFilter.do
4. Basic output filtering, including sockets to add through-hole output
aluminum-electrolytic capacitors
5. Toggle switch for enabling and disabling the DCM via the ENABLE pin
6. Trim control selection
a. Using potentiometer
b. Using external voltage source
c. Open, to disable trimming and latch the model nominal trim condition
7. Provisions to replace input and output differential mode inductors with wire loops,
for oscilloscope/shunt based current measurements
8. Oscilloscope probe jack for accurate, high frequency output voltage measurements
9. Dual paralleling connectors for ENABLE, TRIM, FAULT and SGND signal connections, for daisy
chaining control to other DCM evaluation boards in an array
10. Kelvin voltage test points for all power pins
11. Top and bottom heatsink assembly for the DCM
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 3
Board Description
The following section provides a detailed description of the evaluation board components, test points
and sockets.
General Components
1. DCM (PS01)
2. Input lugs: Sized for #10 hardware. Use these for making connection to the input source.
This board does not contain reverse polarity protection. Check for proper polarity before
applying the power.
3. Input fuse (F01 & F02): Appropriately rated for the DCM model on the board.
4. Input filter: Ceramic input capacitors (C15-C22), filtering inductor (L01) and damping resistor
(R08) provide input filtering. Sockets (H01-H02, H03-H04) can be used for easy installation of
aluminum-electrolytic input capacitors. The 3623 board also adds H09-H10 for additional
input bypassing.
5. Enable / Disable switch (SW01): When actuator is in top position towards “ON” text on the board,
the ENABLE pin will be open and the DCM will be enabled. When actuator is in bottom position
towards “OFF” text on the board, the ENABLE pin will be connected to SGND and the DCM will be
disabled. When switch SW01 is ON, an external voltage source can control the ENABLE state.
6. Header-jumper for trim control (J09): Provides the option to enable the trim function to set the
DCM programmed trim value via either the on board trim rheostat or an external voltage source:
a. Using potentiometer (R26)
b. Using external voltage source.
7. Output lugs: Sized for #10 hardware. Use these lugs to connect the output directly to the load.
8. Output oscilloscope probe Jack (J01): Used for making accurate scope measurements of the output
voltage (e.g. ripple). The jack is directly compatible with many common passive voltage probes
models. Remove the grounding lead and insulating barrel of the probe and insert the probe tip and
barrel directly into the jack, ensuring that the probe tip seats in the center socket of the jack. To
avoid the risk of an inadvertent short circuit, do not attempt to install while power is applied.
9. Output filter: Output capacitor (C201), filtering inductor (L02) and damping resistors (R16-R17), and
ceramic output capacitors (C02-C05) provide output filtering. Sockets H05-H06, and H03-H04 can
be used for easy installation of aluminum-electrolytic output capacitors.
10. High side current sense wire loops: By depopulating the associated inductor and damping resistors,
all input or output currents can be passed through a wire loop or use with an oscilloscope current
probe. The wire loop is installed at the large pair of plated through-holes near the applicable
inductor location.
11. Dual paralleling wire-to-board connectors (J02 and J03): Used for bussing control signals and their
reference (ENABLE, SHARE, FAULT, and SGND) across board assemblies during parallel operation.
The connector style provides simple “strip and insert” use with 18 – 24 AWG solid wires. Once
inserted, a spring loaded barb retains each wire with no need for soldering. To release the wire,
insert a thin bladed tool (AVX 06-9276-7001-01-000 or similar) into the slot above each
wire entry point.
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 4
Figure 1
3623 DCM evaluation
board photo, top side
Figure 2
4623 DCM evaluation
board photo, top side
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 5
Table 1
Primary referred
test point descriptions
Table 2
Secondary referred
test point descriptions
Test Points Description
Test nodes are labeled and include a SMT test point for attaching miniature probes, clips or hooks.
Name Description
+IN_FUSED,
+IN_FILT,
–IN
+IN_DCM,
–IN_DCM
PRI_SG
EXT_EN Testpoint to drive the ENABLE signal (relative to PRI_SG) using an external source.
PRI_EN Testpoint to measure the ENABLE signal (relative to PRI_SG).
EXT_TR Testpoint to drive the TRIM signal (relative to PRI_SG) using an external source.
PRI_TR Testpoint to measure the TRIM signal (relative to PRI_SG).
PRI_FT Testpoint to measure the FAULT signal (relative to PRI_SG).
Name Description
+OUT_DCM,
–OUT_DCM
+OUT_DCM_SHNT,
+OUT,
–OUT
SEC_SG
FT_SEC
+5 V
Provide measurement testpoints for the input voltage to the board in various locations, rela-
tive to the –IN board lug. +IN_FUSED is taken after input fusing, +IN_FILT is taken after the
input filtering network.
Provide Kelvin connection to input pins of the DCM. Use these test points for measuring the
input voltage at the module, excluding errors due to finite connection resistance leading up
to the module.
Testpoint for Signal Ground on the primary/input side of the isolation boundary. This is the
reference for all primary side control circuitry and all control pins of the DCM.
Output voltage test points provide Kelvin connection to output pin group of the DCM. Use
these test points for measuring the output voltage at the module, excluding voltage errors
due to finite connection resistance and the module output current.
Provides measurement testpoints for the output voltage in various locations, relative to the
–OUT board lug. +OUT_DCM_SHNT is taken before the output filtering, and +OUT is taken
at the +OUT board lug.
Testpoints for the +5V bias supply return, and for measuring the FT_SEC fault monitor out-
put.
Testpoint to measure the FAULT signal relative to SEC_SG once it has passed through the
opto-coupler, if used. Bias power must be supplied to +5V for voltage output to appear here.
Testpoint to provide a bias voltage (relative to secondary ground) for the fault opto-coupler,
if used.
UG:017 vicorpower.com Applications Engineering: 800 927.9474 Page 6
Loading...