PRM48JH480T250A00 Datasheet, PDF (38/44 Pages) Vicor Corporation – High Efficiency Converter

Arrays (Remote Sense Operation)
In Remote Sense Operation up to 10 PRMs of the same type may be
placed in parallel to expand the power capacity of the system. All
PRMs within the array are configured for Remote Sense Operation
and are driven by an external control circuit which considers the
control inputs and drives the CONTROL NODE bus. The following
high-level guidelines must be followed in order for the resultant
system to start up and operate properly, and to avoid overstress or
exceeding any absolute maximum ratings.
n All PRMs must be configured for Remote Sense Operation by
tying TRIM pins to SGND. It is recommended to make this
connection through a 0 Ω jumper for troubleshooting purposes.
n All PRMs in the array must be powered from a common power
source so that the input voltage to each PRM is the same.
n An independent fuse for each PRM +IN connection is required to
maintain safety certifications (see Fusing section).
n An independent inductor for each PRM +IN connection is
recommended when used in an array, to control circulating
currents among the PRM inputs and reduce the impact of beat
frequencies.
n Mismatches in both inductance, and resistance from the common
power source to each PRM should be minimized.
n ENABLE pins must be connected together for start up
synchronization and proper fault response of the array.
n Reference supply to the control loop voltage reference and
current sense circuitry must be enabled when all modules’ R_{EF_EN}
pins have reached their operational voltage levels.
n A single external control circuit must be implemented as
PRM48JH480x250A00
described in the Remote Sense Operation design guidelines. The
control circuit should drive the CONTROL NODE bus.
n CONTROL NODE pins must be connected together to enable
sharing. The bandwidth requirements of CONTROL NODE are low
enough that the bus can be considered a lumped element, rather
than a transmission line, and so star connections as well as daisy
chain connections are permitted.
n Each PRM must have its own local current shunt and current
sense circuitry to drive its IFB pin.
n The resistances between CONTROL NODE pins should be well
matched, to avoid introducing additional sharing mismatches.
The CONTROL NODE bus should not be routed under any PRM.
Parasitic capacitance to +IN or +OUT should be minimized.
n One PRM should be designated to provide the SGND reference,
VAUX, and REF_EN voltages for the external circuitry.
n The SGND pins of each PRM should be connected to the SGND
reference node on the board through a 1 Ω resistor.
n When operating within an array, the PRMs are de-rated to the
array rated power and current values provided for Remote Sense
Operation (P_{OUT_ARRAY}, I_{OUT_ARRAY}). The number of PRMs required
to achieve a given array capacity must consider these de-ratings
to avoid overstressing any PRM in the array.
n When using VAUX to power external circuitry, total current draw
including CONTROL NODE sink currents must be taken into
account to ensure the maximum VAUX current is not exceeded.
Arrays of more than 5 PRMs may require additional circuitry to
provide the required source current. Contact Vicor Applications
Engineering for more information.
V_IN
F₁
C_IN
[1]
GND
L_{IN 1}
[1]
GND
SGND 1
PRM 1
ENABLE
TRIM
AL
SHARE/
CONTROL NODE
VAUX
REF/
REF_EN
VC
VT
IFB
+IN
+OUT
–IN
SGND
–OUT
SGND 2
SGND 1
PRM 2
ENABLE
TRIM
AL
SHARE/
CONTROL NODE
VAUX
REF/
REF_EN
VC
VT
IFB
F₂
L_{IN 2}
[1]
GND
+IN
–IN
SGND
1Ω
SGND 1
SGND 2
+OUT
–OUT
Figure 39 — Non-Isolated Remote Sense Array Example
[1] _{Non-Isolated Configuration: –Out connected to -IN}
PRM^TM Regulator
Page 38 of 44
Rev 1.2
11/2015
IN OUT
GND
R_SS
10 k
C_SS
SGND 1
VTM Start Up Pulse
V+
VOUT
+IN
V–
–IN ^SGND
L_{F 1}
C_{F 1}
VREF
SGND 1
SGND 1
VTM 1
VC
+OUT
TM
PC
+IN
–IN
–OUT
PRIMARY
SECONDARY
ISOLATION BOUNDRY
VTM Start Up Pulse
V+
VOUT
+IN
V–
–IN ^SGND
L_{F 2}
VTM 2
VC
+OUT
TM
PC
+IN
C_{F 2}
–IN
–OUT
PRIMARY
SECONDARY
ISOLATION BOUNDRY
vicorpower.com
800 927.9474
C_OUT
[1]
GND
LOAD
[1]
GND