DCM™ DC-DC Converter
DCM3623x50T13A6y7z
S
®
US
C
C
NRTL
US
Isolated, Regulated DC Converter
Features & Benefits
Product Ratings
VIN = 9 V to 50 V
POUT = 160 W
VOUT = 12.0 V
(7.2 V to 13.2 V Trim)
IOUT = 13.40 A
• Isolated, regulated DC-DC converter
• Up to 160 W, 13.40 A continuous
• 91.5% peak efficiency
• 436 W/in3 Power density
Product Description
• Wide input range 9 – 50 Vdc
The DCM Isolated, Regulated DC Converter is a DC-DC
converter, operating from an unregulated, wide range input to
generate an isolated 12.0 Vdc output. With its high frequency
zero voltage switching (ZVS) topology, the DCM converter
consistently delivers high efficiency across the input line range.
Modular DCM converters and downstream DC-DC products
support efficient power distribution, providing superior power
system performance and connectivity from a variety of
unregulated power sources to the point-of-load.
• Safety Extra Low Voltage (SELV) 12.0 V Nominal Output
• 2250 Vdc isolation
• ZVS high frequency switching
n Enables low-profile, high-density filtering
• Fully operational current limit
• OV, OC, UV, short circuit and thermal protection
• 3623 through-hole ChiP package
Leveraging the thermal and density benefits of Vicor’s ChiP
packaging technology, the DCM module offers flexible thermal
management options with very low top and bottom side
thermal impedances. Thermally-adept ChiP based power
components enable customers to achieve cost effective power
system solutions with previously unattainable system size,
weight and efficiency attributes, quickly and predictably.
n 1.524” x 0.898” x 0.284”
(38.72 mm x 22.8 mm x 7.21 mm)
Typical Applications
•
•
•
•
Industrial
Process Control
Transportation / Heavy Equipment
Defense / Aerospace
Part Ordering Information
Product
Function
Package
Size
Package
Type
Max
Input
Voltage
Range
Ratio
Max
Output
Voltage
Max
Output
Power
Temperature
Grade
Option
50
T
13
A6
y
7z
T = -40°C – 125°C
70 = Enhanced VOUT
Regulation / Analog
Control Interface Version
DCM
36
23
x
DCM =
DC-DC
Converter
Length
in mm
x 10
Width
in mm
x 10
T=
Through hole
ChiPs
Internal Reference
DCM™ DC-DC Converter
Rev 1.1
Page 1 of 23
01/2020
M = -55°C – 125°C
DCM3623x50T13A6y7z
Typical Application
DCM
TR
EN
FT
R1
F1
+IN
L1
VIN
R2
+OUT
L2
C1
COUT-EXT
–IN
Load 1
C2
Non-isolated
Point-of-Load
Regulator
–OUT
Load 2
Typical Application 1: Single DCM3623x50T13A6y7z, to a non-isolated regulator, and direct to load
DCM
TR
EN
F1
CY1
T1
VIN
FT
R1
CY3
+IN
L1
+OUT
L2
C1
COUT-EXT
–IN
CY2
R2
CY5
CY4
–OUT
CY6
Typical Application 2: Single DCM3623x50T13A6y7z with common- and differential-mode input filters
DCM™ DC-DC Converter
Rev 1.1
Page 2 of 23
01/2020
C2
CLOAD
Load
DCM3623x50T13A6y7z
Pin Configuration
TOP VIEW
1
2
+IN
A
A’
+OUT
TR
B
B’
-OUT
EN
C
C’ +OUT
FT
D
-IN
E
D’
-OUT
3623 ChiP Package
Pin Descriptions
Pin
Number
Signal Name
Type
A1
+IN
INPUT POWER
B1
TR
INPUT
Enables and disables trim functionality. Adjusts output voltage when trim active.
C1
EN
INPUT
Enables and disables power supply
D1
FT
OUTPUT
E1
-IN
INPUT POWER
RETURN
Negative input power terminal
A’2, C’2
+OUT
OUTPUT POWER
Positive output power terminal
B’2, D’2
-OUT
OUTPUT POWER
RETURN
Negative output power terminal
Function
Positive input power terminal
Fault monitoring
DCM™ DC-DC Converter
Rev 1.1
Page 3 of 23
01/2020
DCM3623x50T13A6y7z
Absolute Maximum Ratings
The absolute maximum ratings below are stress ratings only. Operation at or beyond these maximum ratings can cause permanent damage to the device.
Electrical specifications do not apply when operating beyond rated operating conditions.
Parameter
Comments
Input Voltage (+IN to –IN)
Input Voltage Slew Rate
Min
Max
Unit
-0.5
65.0
V
-1
1
V/µs
TR to - IN
-0.3
3.5
V
EN to -IN
-0.3
3.5
V
-0.3
3.5
V
5
mA
15.6
V
FT to -IN
Output Voltage (+Out to –Out)
Dielectric withstand (input to output)
-0.5
Basic insulation
2250
Vdc
T Grade
-40
125
°C
M Grade
-55
125
°C
T Grade
-40
125
°C
M Grade
-65
125
°C
22.0
A
Internal Operating Temperature
Storage Temperature
Average Output Current
Figure 1 — Thermal Specified Operating Area: Max Output Power
Figure 2 — Electrical Specified Operating Area
vs. Case Temp, module at minimum full load efficiency
DCM™ DC-DC Converter
Rev 1.1
Page 4 of 23
01/2020
DCM3623x50T13A6y7z
Electrical Specifications
Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the
temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade.
Attribute
Symbol
Conditions / Notes
Min
Typ
9
30
Max
Unit
Power Input Specifications
Input voltage range
VIN
Continuous operation
Inrush current (peak)
IINRP
With maximum COUT-EXT, full resistive load
50
V
25.0
A
Input capacitance (internal)
CIN-INT
Effective value at nominal input voltage
28.6
µF
Input capacitance (internal) ESR
RCIN-INT
At 1 MHz
0.39
mΩ
Input inductance (external)
LIN
Differential mode, with no further line bypassing
1
µH
1.0
W
1.5
W
3.4
W
4.6
W
No Load Specifications
Input power – disabled
PQ
Input power – enabled with no load
PNL
Nominal line, see Fig. 3
0.5
Worst case line, see Fig. 3
Nominal line, see Fig. 4
1.3
Worst case line, see Fig. 4
Power Output Specifications
Output voltage set point
Rated output voltage trim range
Output voltage regulation
VOUT-NOM
At VIN = 30V, nominal trim at 100% load, TINT = 25ºC
11.94
12.0
12.06
V
VOUT-TRIMMING
Trim range over temp, with > 10% rated load.
Specifies the Low, Nominal and High Trim conditions.
7.2
12.0
13.2
V
At nominal line, nominal trim, full load and
ambient temperature
-0.5
0.5
At nominal line, nominal trim and:
• Load >20% of full load and ambient temperature
• Full load and over temperature
-1.0
1.0
All other conditions
(does not include light load regulation)
-2.5
2.5
The total output voltage set-point accuracy from the
calculated VOUT based on load, temp and trim.
Excludes:
• ΔVOUT-LL
• %VOUT-REGULATION
-3.0
3.0
%
0% to 10% load, additional VOUT relative to VOUT
accuracy; see Design Guidelines section
-0.00
2.40
V
Continuous, VOUT ≤ 12.0 V
160
W
13.40
A
%VOUTREGULATION
Output voltage accuracy
Output voltage light load regulation
%VOUT-ACCURACY
ΔVOUT-LL
Rated output power
POUT
Rated output current
IOUT
Continuous, VOUT ≥ 12.0 V
Output current limit
IOUT-LM
Of rated IOUT max. Fully operational current limit, for
nominal trim and below
Current limit delay
tIOUT-LIM
The module will power limit in a fast transient event
Efficiency
η
100
120
150
%
%
1
ms
91.5
%
Full load, nominal line, nominal trim
90.8
Full load, over line and temperature, nominal trim
88.9
%
50% load, over rated line, temperature and trim
86.0
%
VOUT-PP
20 MHz bandwidth. At nominal trim, minimum COUT-EXT and
at least 10 % rated load
Output capacitance (internal)
COUT-INT
Effective value at nominal output voltage
Output capacitance (internal) ESR
RCOUT-INT
At 1 MHz
Output capacitance (external)
COUT-EXT
Excludes component temperature coefficient For load
transients that remain > 10% rated load
1000
10000
µF
Output capacitance (external)
COUT-EXT-TRANS
Excludes component temperature coefficient For load
transients down to 0% rated load, with static trim
10000
10000
µF
Excludes component temperature coefficient For load
transients down to 0% rated load, with dynamic trimming
10000
10000
µF
TRANS-TRIM
RCOUT-EXT
At 10 kHz, excludes component tolerances
Output voltage ripple
Output capacitance (external)
Output capacitance, ESR (ext.)
COUT-EXT-
DCM™ DC-DC Converter
Rev 1.1
Page 5 of 23
01/2020
420
10
mV
123
µF
2.900
mΩ
mΩ
DCM3623x50T13A6y7z
Electrical Specifications (cont.)
Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the
temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade.
Attribute
Symbol
Conditions / Notes
Min
Typ
Max
Unit
40
ms
Power Output Specifications (Cont.)
Initialization delay
tINIT
See state diagram
25
Output turn-on delay
tON
From rising edge EN, with VIN pre-applied. See timing
diagram
200
Output turn-off delay
tOFF
From falling edge EN. See timing diagram
Soft start ramp time
tSS
At full rated resistive load, with min COUT-EXT.
Output voltage threshold for max
rated load current
Output current at startup
Monotonic soft-start threshold
voltage
Minimum required disabled duration
Minimum required disabled duration
for predictable restart
Voltage deviation (transient)
Settling time
VOUT-FL-THRESH
IOUT-START
VOUT-MONOTONIC
600
31
During startup, VOUT must achieve this threshold before
output can support full rated current
Max load current at startup while VOUT
is below VOUT-FL_THRESH
Output voltage rise becomes monotonic with 10% of
preload once it crosses VOUT-MONOTONIC
µs
µs
ms
6.0
1.33
V
A
6.0
V
tOFF-MIN
This refers to the minimum time a module needs to be
in the disabled state before it will attempt to start via EN
2
ms
tOFF-MONOTONIC
This refers to the minimum time a module needs to be in
the disabled state before it is guaranteed to exhibit
monotonic soft-start and have predictable startup timing
100
ms
%VOUT-TRANS
tSETTLE
Minimum COUT_EXT (10 ↔ 90% load step).
VIN-INIT
INITIALIZATION
SEQUENCE
EN = False
tMIN-OFF delay
NON LATCHED
FAULT
tOFF
ult
Fa oved
m
Re
Powertrain: Stopped
FT = True
tINIT delay
Powertrain: Stopped
FT = True
Powertrain: Stopped
FT = True
EN = True and
No Faults
tON delay
EN = False
tOFF delay
In
p
In ut O
pu V
tU L
VL O o
O r
VIN > VIN-UVLO+ and
not Over-temp
TR mode latched
STANDBY
or
O
L
V LO
t O UV
u
t
p
In npu
I
EN = False
tOFF-MIN delay
SOFT START
VOUT Ramp Up
tss delay
Powertrain: Active
FT = Unknown
RUNNING
tSS Expiry
Ou
tpu
Regulates VOUT
Powertrain: Active
FT = False
tO
or
mp
r-te
P
Ove put UV
Out
REINITIALIZATION
SEQUENCE
tINIT delay
Powertrain: Stopped
FT = True
Fault Removed
Ov
e
Ou r-tem
tpu
p
t U or
VP
VP
tO
pu
ut
O
VP
NON LATCHED
FAULT
tFAULT
Powertrain: Stopped
FT = True
LATCHED
FAULT
EN = False
DCM™ DC-DC Converter
Rev 1.1
Page 8 of 23
01/2020
Powertrain: Stopped
FT = True
Output
Input
DCM™ DC-DC Converter
Rev 1.1
Page 9 of 23
01/2020
FT
ILOAD
FULL LOAD
IOUT
VOUT
VOUT-UVP
FULL LOAD
VOUT-NOM
TR
VTR-DIS
EN
VIN
VIN-UVLO+/VIN-INIT
VIN-OVLO+/-
tINIT
tON
1
Input Power On
- Trim Inactive
tSS
2
3
Ramp to TR
Full Load Ignored
tOFF
tMIN_OFF
4
EN
Low
tSS
tON
5
EN
High
tOFF
6
Input
OVLO
tSS
tOFF
7
Input
UVLO
tSS
tOFF
8
Input
returned
to zero
DCM3623x50T13A6y7z
Timing Diagrams
Module Inputs are shown in blue; Module Outputs are shown in brown.
Output
Input
DCM™ DC-DC Converter
Rev 1.1
Page 10 of 23
01/2020
FT
ILOAD
FULL LOAD
IOUT
VOUT
VOUT-UVP
VOUT-NOM
FULL LOAD
TR
VTR = nom
VTR-EN
EN
VIN
VIN-UVLO+/VIN-INIT
VIN-OVLO+/-
tINIT
tON
9
Input Power On
- Trim Active
tSS
VOUT-OVP
10
Vout
based on
VTR
tOFF
11
Load dump
and reverse
current
tINIT
tON
tSS
12
Vout OVP
(primary
sensed)
13
Latched
fault cleared
RLOAD
tIOUT-LIM
14
Current Limit
with Resistive
Load
tFAULT
15
Resistive
Load with
decresing R
tINIT
16
Overload induced
Output UVP
tON
tSS
DCM3623x50T13A6y7z
Timing Diagrams (Cont.)
Module Inputs are shown in blue; Module Outputs are shown in brown.
DCM3623x50T13A6y7z
Typical Performance Characteristics
The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data.
Figure 3 — Disabled power dissipation vs. VIN
Figure 6 — Full Load Efficiency vs. VIN, at low trim
Figure 4 — No load power dissipation vs. VIN, at nominal trim
Figure 7 — Full Load Efficiency vs. VIN, at nominal trim
Figure 5 — Ideal VOUT vs. load current, at 25°C case
Figure 8 — Full Load Efficiency vs. VIN, at high trim
DCM™ DC-DC Converter
Rev 1.1
Page 11 of 23
01/2020
DCM3623x50T13A6y7z
Typical Performance Characteristics (cont.)
The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data.
Figure 12 — Nominal powertrain switching frequency vs. load,
at nominal trim
Figure 9 — Efficiency and power dissipation vs.load at TCASE = -40°C,
nominal trim
Figure 13 — Effective internal input capacitance vs. applied voltage
Figure 10 — Efficiency and power dissipation vs.load at TCASE = 25°C,
nominal trim
Figure 11 — Efficiency and power dissipation vs.load at TCASE = 90°C,
nominal trim
Figure 14 — Startup from EN, VIN = 30 V, COUT_EXT = 10000 µF,
RLOAD = 0.896 Ω
DCM™ DC-DC Converter
Rev 1.1
Page 12 of 23
01/2020
DCM3623x50T13A6y7z
Typical Performance Characteristics (cont.)
The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data.
Figure 15 — Nominal powertrain switching frequency vs. load,
Figure 16 — Output voltage ripple, VIN = 30 V,
VOUT = 12.0 V, COUT_EXT = 1000 µF, RLOAD = 0.896 Ω
at nominal VIN
DCM™ DC-DC Converter
Rev 1.1
Page 13 of 23
01/2020
DCM3623x50T13A6y7z
General Characteristics
Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the
temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade.
Attribute
Symbol
Conditions / Notes
Min
Typ
Max
Unit
Mechanical
Length
L
38.34/[1.509]
38.72/[1.524]
39.1/[1.539]
mm/[in]
Width
W
22.67/[0.893]
22.8/[0.898]
22.93/[0.903]
mm/[in]
Height
H
7.11/[0.28]
7.21/[0.284]
7.31/[0.288]
mm/[in]
Volume
Vol
Weight
W
Lead finish
No heat sink
6.41/[0.39]
cm3/[in3]
24.0/[0.85]
g/[oz]
Nickel
0.51
2.03
Palladium
0.02
0.15
Gold
0.003
0.051
T-Grade
-40
125
°C
M-Grade
-55
125
°C
µm
Thermal
Operating internal temperature
Thermal resistance top side
Thermal resistance leads
Thermal resistance bottom side
TINT
θINT-TOP
θINT-LEADS
θINT-BOTTOM
Estimated thermal resistance to maximum
temperature internal component from
2.00
°C/W
4.40
°C/W
2.40
°C/W
17.7
Ws/°C
isothermal top
Estimated thermal resistance to
maximum temperature internal
component from isothermal leads
Estimated thermal resistance to
maximum temperature internal
component from isothermal bottom
Thermal capacity
Assembly
Storage temperature
TST
HBM
ESD rating
CDM
T-Grade
-40
125
°C
M-Grade
-65
125
°C
Method per Human Body Model Test
ESDA/JEDEC JDS-001-2012
Charged Device Model JESD22-C101E
CLASS 1C
V
CLASS 2
Soldering [1]
Peak temperature top case
[1]
For further information, please contact
factory applications
Product is not intended for reflow solder attach.
DCM™ DC-DC Converter
Rev 1.1
Page 14 of 23
01/2020
135
°C
DCM3623x50T13A6y7z
General Characteristics (Cont.)
Specifications apply over all line, trim and load conditions, internal temperature TINT = 25ºC, unless otherwise noted. Boldface specifications apply over the
temperature range of -40°C < TINT < 125°C for T grade and -55°C < TINT < 125°C for M grade.
Attribute
Symbol
Conditions / Notes
Min
Typ
Max
Unit
Safety
Dielectric Withstand Test
VHIPOT
IN to OUT
2250
Vdc
IN to CASE
2250
Vdc
OUT to CASE
707
Vdc
Reliability
MIL-HDBK-217 FN2 Parts Count 25°C
Ground Benign, Stationary, Indoors /
MTBF
3.39
MHrs
5.68
MHrs
Computer
Telcordia Issue 2, Method I Case 3, 25°C,
100% D.C., GB, GC
Agency Approvals
cTÜVus, EN 60950-1
Agency approvals/standards
cURus, UL 60950-1
CE Marked for Low Voltage Directive and RoHS Recast Directive, as applicable
DCM™ DC-DC Converter
Rev 1.1
Page 15 of 23
01/2020
DCM3623x50T13A6y7z
Pin Functions
The DCM will latch trim behavior at application of VIN (once VIN
exceeds VIN-UVLO+), and persist in that same behavior until loss of
input voltage.
n At application of VIN, if TR is sampled at above VTRIM-DIS, the
module will latch in a non-trim mode, and will ignore the TR
input for as long as VIN is present.
+IN, -IN
Input power pins. -IN is the reference for all control pins, and
therefore a Kelvin connection for the control signals is
recommended as close as possible to the pin on the package, to
reduce effects of voltage drop due to -IN currents.
n At application of VIN, if TR is sampled at below VTRIM-EN, the TR
will serve as an input to control the real time output voltage.
It will persist in this behavior until VIN is no longer present.
+OUT, -OUT
Output power pins.
If trim is active when the DCM is operating, the TR pin provides
dynamic trim control at a typical 30 Hz of -3dB bandwidth over the
output voltage. TR also decreases the current limit threshold when
trimming above VOUT-NOM.
EN (Enable)
This pin enables and disables the DCM converter; when held low the
unit will be disabled. It is referenced to the -IN pin of the converter.
The EN pin has an internal pull-up to VCC through a
10 kΩ resistor.
FT (Fault)
The FT pin provides a Fault signal.
n Output enable: When EN is allowed to pull up above the enable
Anytime the module is enabled and has not recognized a fault, the
FT pin is inactive. FT has an internal 499 kΩ pull-up to Vcc, therefore
a shunt resistor, RSHUNT, of approximately 50 kΩ can be used to
ensure the LED is completly off when there is no fault, per the
diagram below.
threshold, the module will be enabled. If leaving EN floating, it is
pulled up to VCC and the module will be enabled.
n Output disable: EN may be pulled down externally in order
to disable the module.
n EN is an input only, it does not pull low in the event of a fault.
TR (Trim)
Whenever the powertrain stops (due to a fault protection or
disabling the module by pulling EN low), the FT pin becomes active
and provides current to drive an external circuit.
The TR pin is used to select the trim mode and to trim the output
voltage of the DCM converter. The TR pin has an internal pull-up to
VCC through a 10.0 kΩ resistor.
When active, FT pin drives to VCC, with up to 4 mA of external
loading. Module may be damaged from an over-current FT drive,
thus a resistor in series for current limiting is recommended.
The FT pin becomes active momentarily when the module starts up.
Typical External Circuits for Signal Pins (TR, EN, FT)
DCM
VCC
10kΩ
10kΩ
Output Voltage
Reference, Current
Limit Reference and
Soft Start control
TR
Soft Start and
Fault Monitoring
EN
RTRIM
499kΩ
Fault
Monitoring
FT
RSERIES
SW
RSHUNT
Kelvin –IN connection
DCM™ DC-DC Converter
Rev 1.1
Page 16 of 23
01/2020
D
DCM3623x50T13A6y7z
Design Guidelines
Finally, note that when the load current is below 10% of the rated
capacity, there is an additional ∆V which may add to the output
voltage, depending on the line voltage which is related to light load
boosting. Please see the section on light load boosting below for
details.
Building Blocks and System Design
The DCM™ converter input accepts the full 9 to 50 V range, and it
generates an isolated trimmable 12.0 Vdc output.
The DCM converter provides a tightly regulated output voltage;
please refer to the Output Voltage Load Regulation specification in
the Electrical Specifications table.
Use 0 V for ∆VOUT-LL when load is above 10% of rated load. See section
on light load boosting operation for light load effects on output voltage.
The DCM3623x50T13A6y7z is designed to be used in applications
where the output power requirements are up to 160 W.
Output Current Limit
The DCM features a fully operational current limit which effectively
keeps the module operating inside the Safe Operating Area (SOA) for
all valid trim and load profiles. The current limit approximates a
“brick wall” limit, where the output current is prevented from
exceeding the current limit threshold by reducing the output voltage
via the internal error amplifier reference. The current limit threshold
at nominal trim and below is typically 120% of rated output current,
but it can vary between 100% to 150%. In order to preserve the SOA,
when the converter is trimmed above the nominal output voltage,
the current limit threshold is automatically reduced to limit the
available output power.
Soft Start
When the DCM starts, it will go through a soft start. The soft start
routine ramps the output voltage by modulating the internal error
amplifier reference. This causes the output voltage to approximate a
piecewise linear ramp. The output ramp finishes when the voltage
reaches either the nominal output voltage, or the trimmed output
voltage in cases where trim mode is active.
During soft-start, the maximum load current capability is reduced.
Until Vout achieves at least VOUT-FL-THRESH, the output current must be
less than IOUT-START in order to guarantee startup. Note that this is
current available to the load, above that which is required to charge
the output capacitor.
When the output current exceeds the current limit threshold, current
limit action is held off by 1ms, which permits the DCM to
momentarily deliver higher peak output currents to the load. Peak
output power during this time is still constrained by the internal
Power Limit of the module. The fast Power Limit and relatively slow
Current Limit work together to keep the module inside the SOA.
Delaying entry into current limit also permits the DCM to minimize
droop voltage for load steps.
Trim Mode and Output Trim Control
When the input voltage is initially applied to a DCM, and after tINIT
elapses, the trim pin voltage VTR is sampled. The TR pin has an
internal pull up resistor to VCC, so unless external circuitry pulls the
pin voltage lower, it will pull up to VCC. If the initially sampled trim
pin voltage is higher than VTRIM-DIS, then the DCM will disable
trimming as long as the VIN remains applied. In this case, for all
subsequent operation the output voltage will be programmed to the
nominal. This minimizes the support components required for
applications that only require the nominal rated Vout, and also
provides the best output setpoint accuracy, as there are no additional
errors from external trim components.
Sustained operation in current limit is permitted, and no derating of
output power is required.
Some applications may benefit from well matched current
distribution, in which case fine tuning sharing via the trim pins
permits control over sharing. The DCM does not require this for
proper operation, due to the power limit and current limit behaviors
described here.
Current limit can reduce the output voltage to as little as the UVP
threshold (VOUT-UVP). Below this minimum output voltage
compliance level, further loading will cause the module to shut
down due to the output undervoltage fault protection.
If at initial application of VIN, the TR pin voltage is prevented from
exceeding VTRIM-EN, then the DCM will activate trim mode, and it will
remain active for as long as VIN is applied.
VOUT set point can be calculated using the equation below:
VOUT-FL = 4.9887 + (9.3897 • VTR/VCC)
(1)
Line Impedance, Input Slew rate and Input Stability Requirements
Connect a high-quality, low-noise power supply to the +IN and –IN
terminals. Additional capacitance may have to be added between +IN
and –IN to make up for impedances in the interconnect cables as
well as deficiencies in the source.
Or using the online tool, DCM Trim Calculator, find the value of VTR
or trim resistor to set the desired VOUT:
http://www.vicorpower.com/calculators
Excessive source impedance can bring about system stability issues
for a regulated DC-DC converter, and must either be avoided or
compensated by filtering components. A 1000 µF input capacitor is
the minimum recommended in case the source impedance is
insufficient to satisfy stability requirements.
Note that the trim mode is not changed when a DCM recovers from
any fault condition or being disabled.
Module performance is guaranteed through output voltage trim
range VOUT-TRIMMING. If VOUT is trimmed above this range, then certain
combinations of line and load transient conditions may trigger the
output OVP.
Additional information can be found in the filter design application
note:
www.vicorpower.com/documents/application_notes/vichip_appnote23.pdf
Overall Output Voltage Transfer Function
Taking trim (equation 1) into account, the general equation relating
the DC VOUT to programmed trim (when active), load is given by:
VOUT = 4.9887 + (9.3897 • VTR/VCC) + ∆VOUT-LL
Please refer to this input filter design tool to ensure input stability:
http://app2.vicorpower.com/filterDesign/intiFilter.do.
(2)
Ensure that the input voltage slew rate is less than 1V/us, otherwise a
pre-charge circuit is required for the DCM input to control the input
voltage slew rate and prevent overstress to input stage components.
DCM™ DC-DC Converter
Rev 1.1
Page 17 of 23
01/2020
DCM3623x50T13A6y7z
Input Fuse Selection
The DCM is not internally fused in order to provide flexibility in
configuring power systems. Input line fusing is recommended at the
system level, in order to provide thermal protection in case of
catastrophic failure. The fuse shall be selected by closely matching
system requirements with the following characteristics:
falls. The converter remains disabled for a time tFAULT. Once recovered
and provided the converter is still enabled, the powertrain will again
enter the soft start sequence after tINIT and tON.
Temperature Fault Protections (OTP)
The fault logic monitors the internal temperature of the converter. If
the measured temperature exceeds TINT-OTP, a temperature fault is
registered. As with the under voltage fault protection, once a
temperature fault is registered, the powertrain immediately stops
switching, the output voltage of the converter falls, and the converter
remains disabled for at least time tFAULT. Then, the converter waits for
the internal temperature to return to below TINT-OTP before
recovering. Provided the converter is still enabled, the DCM will
restart after tINIT and tON.
n Current rating (usually greater than the DCM converter’s
maximum current)
n Maximum voltage rating (usually greater than the maximum
possible input voltage)
n Ambient temperature
n Breaking capacity per application requirements
n Nominal melting I2t
n Recommended fuse: See Agency Approvals for Recommended Fuse
Output Overvoltage Fault Protection (OVP)
The converter monitors the output voltage during each switching
cycle by a corresponding voltage reflected to the primary side control
circuitry. If the primary sensed output voltage exceeds VOUT-OVP, the
OVP fault protection is triggered. The control logic disables the
powertrain, and the output voltage of the converter falls.
http://www.vicorpower.com/dc-dc/isolatedregulated/dcm#Documentation
Fault Handling
Input Undervoltage Fault Protection (UVLO)
The converter’s input voltage is monitored to detect an input under
voltage condition. If the converter is not already running, then it will
ignore enable commands until the input voltage is greater than
VIN-UVLO+. If the converter is running and the input voltage falls
below VIN-UVLO-, the converter recognizes a fault condition, the
powertrain stops switching, and the output voltage of the unit falls.
This type of fault is latched, and the converter will not start again
until the latch is cleared. Clearing the fault latch is achieved by either
disabling the converter via the EN pin, or else by removing the input
power such that the input voltage falls below VIN-INIT.
External Output Capacitance
The DCM converter internal compensation requires a minimum
external output capacitor. An external capacitor in the range of 1000
to 10000 µF with ESR of 10 mΩ is required, per DCM for control loop
compensation purposes.
Input voltage transients which fall below UVLO for less than tUVLO
may not be detected by the fault proection logic, in which case the
converter will continue regular operation. No protection is required
in this case.
However some DCM models require an increase to the minimum
external output capacitor value in certain loading and trim
condition. In applications where the load can go below 10% of rated
load but the output trim is held constant, the range of output
capacitor required is given by COUT-EXT-TRANS in the Electrical
Specifications table. If the load can go below 10% of rated load and
the DCM output trim is also dynamically varied, the range of output
capacitor required is given by COUT-EXT-TRANS-TRIM in the Electrical
Specifications table.
Once the UVLO fault is detected by the fault protection logic, the
converter shuts down and waits for the input voltage to rise above
VIN-UVLO+. Provided the converter is still enabled, it will then restart.
Input Overvoltage Fault Protection (OVLO)
The converter’s input voltage is monitored to detect an input over
voltage condition. When the input voltage is more than the
VIN-OVLO+, a fault is detected, the powertrain stops switching, and the
output voltage of the converter falls.
After an OVLO fault occurs, the converter will wait for the input
voltage to fall below VIN-OVLO-. Provided the converter is still enabled,
the powertrain will restart.
Light Load Boosting
Under light load conditions, the DCM converter may operate in light
load boosting depending on the line voltage. Light load boosting
occurs whenever the internal power consumption of the converter
combined with the external output load is less than the minimum
power transfer per switching cycle. In order to maintain regulation,
the error amplifier will switch the powertrain off and on repeatedly,
to effectively lower the average switching frequency, and permit
operation with no external load. During the time when the power
train is off, the module internal consumption is significantly
reduced, and so there is a notable reduction in no-load input power
in light load boosting. When the load is less than 10% of rated Iout,
the output voltage may rise by a maximum of 2.4 V, above the
output voltage calculated from trim, temperature, and load
line conditions.
The powertrain controller itself also monitors the input voltage.
Transient OVLO events which have not yet been detected by the fault
sequence logic may first be detected by the controller if the input
slew rate is sufficiently large. In this case, powertrain switching will
immediately stop. If the input voltage falls back in range before the
fault sequence logic detects the out of range condition, the
powertrain will resume switching and the fault logic will not
interrupt operation Regardless of whether the powertrain is running
at the time or not, if the input voltage does not recover from OVLO
before tOVLO, the converter fault logic will detect the fault.
Output Undervoltage Fault Protection (UVP)
The converter determines that an output overload or short circuit
condition exists by measuring its primary sensed output voltage and
the output of the internal error amplifier. In general, whenever the
powertrain is switching and the primary-sensed output voltage falls
below VOUT-UVP threshold, a short circuit fault will be registered. Once
an output undervoltage condition is detected, the powertrain
immediately stops switching, and the output voltage of the converter
DCM™ DC-DC Converter
Rev 1.1
Page 18 of 23
01/2020
DCM3623x50T13A6y7z
Thermal Design
Based on the safe thermal operating area shown in page 5, the full
rated power of the DCM3623x50T13A6y7z can be processed provided
that the top, bottom, and leads are all held below 95°C. These curves
highlight the benefits of dual sided thermal management, but also
demonstrate the flexibility of the Vicor ChiP platform for customers
who are limited to cooling only the top or the
bottom surface.
Thermal Resistance Top
Thermal Resistance Bottom
θINT-BOTTOM°C / W
Power Dissipation (W)
The OTP sensor is located on the top side of the internal PCB
structure. Therefore in order to ensure effective over-temperature
fault protection, the case bottom temperature must be constrained
by the thermal solution such that it does not exceed the temperature
of the case top.
Thermal Resistance Top
TCASE_BOTTOM(°C)
+
–
TCASE_TOP(°C)
Thermal Resistance Bottom
θINT-BOTTOM°C / W
Power Dissipation (W)
Thermal Resistance Leads
TCASE_BOTTOM(°C)
θINT-LEADS°C / W
TLEADS(°C)
TCASE_TOP(°C)
Figure 19 shows a scenario where there is no bottom side and leads
cooling. In this case, the heat flow path to the bottom is left open and
the equations now simplify to:
TINT – PD1 • θINT-TOP = TCASE_TOP
PDTOTAL = PD1
θINT-LEADS°C / W
TLEADS(°C)
+
–
TCASE_TOP(°C)
+
–
Figure 19 — One side cooling thermal model
Thermal Resistance Leads
+
–
+
–
MAX INTERNAL TEMP
θINT-TOP°C / W
MAX INTERNAL TEMP
θINT-BOTTOM°C / W
Power Dissipation (W)
TLEADS(°C)
TINT – PD1 • θINT-TOP = TCASE_TOP
TINT – PD3 • θINT-LEADS = TLEADS
PDTOTAL = PD1 + PD3
This analysis provides an estimate of heat flow through the various
pathways as well as internal temperature.
Thermal Resistance Bottom
θINT-LEADS°C / W
TCASE_BOTTOM(°C)
Figure 18 shows a scenario where there is no bottom side cooling.
In this case, the heat flow path to the bottom is left open and the
equations now simplify to:
Since the ChiP has a maximum internal temperature rating, it is
necessary to estimate this internal temperature based on a real
thermal solution. Given that there are three pathways to remove heat
from the ChiP, it is helpful to simplify the thermal solution into a
roughly equivalent circuit where power dissipation is modeled as a
current source, isothermal surface temperatures are represented as
voltage sources and the thermal resistances are represented as
resistors. Figure 17 shows the "thermal circuit" for a 3623 ChiP DCM,
in an application where both case top and case bottom, and leads are
cooled. In this case, the DCM power dissipation is PDTOTAL and the
three surface temperatures are represented as TCASE_TOP, TCASE_BOTTOM,
and TLEADS. This thermal system can now be very easily analyzed
with simple resistors, voltage sources, and a current source.
θINT-TOP°C / W
Thermal Resistance Leads
Figure 18 — One side cooling and leads thermal model
The ChiP package provides a high degree of flexibility in that it
presents three pathways to remove heat from internal power
dissipating components. Heat may be removed from the top surface,
the bottom surface and the leads. The extent to which these three
surfaces are cooled is a key component for determining the
maximum power that is available from a ChiP, as can be seen from
Figure 17.
Thermal Resistance Top
MAX INTERNAL TEMP
θINT-TOP°C / W
+
–
Figure 17 — Double side cooling and leads thermal model
Alternatively, equations can be written around this circuit and
analyzed algebraically:
TINT – PD1 • θINT-TOP = TCASE_TOP
TINT – PD2 • θINT-BOTTOM = TCASE_BOTTOM
TINT – PD3 • θINT-LEADS = TLEADS
PDTOTAL = PD1+ PD2+ PD3
Where TINT represents the internal temperature and PD1, PD2, and
PD3 represent the heat flow through the top side, bottom side, and
leads respectively.
Figure 20 — Thermal Specified Operating Area: Max Power
Dissipation vs. Case Temp for current
limited operation
DCM™ DC-DC Converter
Rev 1.1
Page 19 of 23
01/2020
DCM3623x50T13A6y7z
L1: 1 µH, minimized DCR;
R1: 0.3 Ω;
C1: Ceramic capacitors in parallel, C1 = 20 µF;
L2: L2 ≥ 0.15 µH;
R2: 1 Ω;
COUT-EXT: electrolytic or tantalum capacitor, 1000 µF ≤ C3 ≤10000 µF;
C4, C5: additional ceramic /electrolytic capacitors, if needed for
output ripple filtering;
Vicor provides a suite of online tools, including a simulator and
thermal estimator which greatly simplify the task of determining
whether or not a DCM thermal configuration is sufficient for a given
condition. These tools can be found at:
www.vicorpower.com/powerbench.
DCMs in current limit will operate with higher output current or
power than the rated levels. Therefore the Figure 20 Thermal Safe
Operating Area plot should be used for loads that drive the DCM in
to current limit for sustained operation.
In order to help sensitive signal circuits reject potential noise,
additional components are recommended:
R5: 301 Ω, facilitate noise attenuation for TR pin;
FB1, C2: FB1 is a ferrite bead with an impedance of at least 10 Ω at
100MHz. C2 can be a ceramic capacitor of 0.1µF. Facilitate noise
attenuation for EN pin.
Standalone Operation
The following Figure 21 shows the configuration of the Enhanced
VOUT DCM. An input filter is required to attenuate noise coming from
the input source. In case of the excessive line inductance, a properly
sized decoupling capacitor CDECOUPLE is required as shown
in the following figure.
Note: Use an RCR filter network as suggested in the application note
AN:030 to reduce the noise on the signal pins.
If signal pins (TR, EN, FT) are not used, they can be left floating, and
DCM will work in the nominal output condition.
When common mode noise in the input side is not a concern, TR and
EN can be driven and FT received using -IN as a reference.
DCM
R5
+
+
VTR
R1
VEN
FB1
EN
C2
R3
F1
+IN
-IN
FT
+IN
L1
CDECOUPLE
TR
C1
R2
+OUT
R4
_ _
D1
Figure 21 — Enhanced VOUT DCM configuration circuit
DCM™ DC-DC Converter
Rev 1.1
Page 20 of 23
01/2020
COUT-EXT
-IN
-OUT
+OUT
L2
C4
C5
-OUT
DCM3623x50T13A6y7z
DCM Module Product Outline Drawing Recommended PCB Footprint and Pinout
38.72±.38
1.524±.015
11.43
.450
19.36
.762
0
1.52
.060
(2) PL.
11.40
.449
0
0
22.80±.13
.898±.005
1.02
.040
(3) PL.
0
1.52
.060
(4) PL.
TOP VIEW (COMPONENT SIDE)
.05 [.002]
7.21±.10
.284±.004
SEATING
.
PLANE
4.17
.164
(9) PL.
18.60
.732
0
18.60
.732
.41
.016
(9) PL.
8.25
.325
8.00
.315
2.75
.108
0
0
2.75
.108
1.38
.054
4.13
.162
1.38
.054
8.00
.315
0
8.25
.325
8.00±.08
.315±.003
4.13±.08
.162±.003
1.38±.08
.054±.003
+IN
0
2.03
.080
PLATED THRU
.25 [.010]
ANNULAR RING
(2) PL.
2.75±.08
.108±.003
-OUT
TR
0
EN
FT
8.00±.08
.315±.003
8.25±.08
.325±.003
+OUT
-IN
+OUT
2.75±.08
.108±.003
-OUT
8.25±.08
.325±.003
0
1.38±.08
.054±.003
0
18.60±.08
.732±.003
1.52
.060
PLATED THRU
.25 [.010]
ANNULAR RING
(3) PL.
18.60±.08
.732±.003
BOTTOM VIEW
RECOMMENDED HOLE PATTERN
(COMPONENT SIDE)
NOTES:
1- RoHS COMPLIANT PER CST-0001 LATEST REVISION.
DCM™ DC-DC Converter
Rev 1.1
Page 21 of 23
01/2020
2.03
.080
PLATED THRU
.38 [.015]
ANNULAR RING
(4) PL.
DCM3623x50T13A6y7z
Revision History
Revision
Date
Description
1.0
12/15/17
Initial release
1.1
01/27/20
Output voltage regulation specification format change
Updated state and timing diagrams
Updated Trim descriptions and typical external circuits diagram
Page Number(s)
n/a
DCM™ DC-DC Converter
Rev 1.1
Page 22 of 23
01/2020
5
8 – 10
16, 17
DCM3623x50T13A6y7z
Vicor’s comprehensive line of power solutions includes high density AC-DC and DC-DC modules and
accessory components, fully configurable AC-DC and DC-DC power supplies, and complete custom
power systems.
Information furnished by Vicor is believed to be accurate and reliable. However, no responsibility is assumed by Vicor for its use. Vicor
makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication. Vicor reserves
the right to make changes to any products, specifications, and product descriptions at any time without notice. Information published by
Vicor has been checked and is believed to be accurate at the time it was printed; however, Vicor assumes no responsibility for inaccuracies.
Testing and other quality controls are used to the extent Vicor deems necessary to support Vicor’s product warranty. Except where
mandated by government requirements, testing of all parameters of each product is not necessarily performed.
Specifications are subject to change without notice.
Visit http://www.vicorpower.com/dc-dc/isolated-regulated/dcm for the latest product information.
Vicor’s Standard Terms and Conditions and Product Warranty
All sales are subject to Vicor’s Standard Terms and Conditions of Sale, and Product Warranty which are available on Vicor’s webpage
(http://www.vicorpower.com/termsconditionswarranty) or upon request.
Life Support Policy
VICOR’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE
EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL COUNSEL OF VICOR CORPORATION. As used
herein, life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and
whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to
result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform
can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Per Vicor Terms
and Conditions of Sale, the user of Vicor products and components in life support applications assumes all risks of such use and indemnifies
Vicor against all liability and damages.
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Vicor and its subsidiaries own Intellectual Property (including issued U.S. and Foreign Patents and pending patent applications) relating to
the products described in this data sheet. No license, whether express, implied, or arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Interested parties should contact Vicor’s Intellectual Property Department.
The products described on this data sheet are protected by the following U.S. Patents Numbers:
RE40,072; 7,561,446; 7,920,391; 7,782,639; 8,427,269; 6,421,262 and other patents pending.
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Andover, MA, USA 01810
Tel: 800-735-6200
Fax: 978-475-6715
www.vicorpower.com
email
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All other trademarks, product names, logos and brands are property of their respective owners.
DCM™ DC-DC Converter
Rev 1.1
Page 23 of 23
01/2020