PRM™ Regulator
MPRM28Ax360M120A00
High-Efficiency Converter
Features & Benefits
Product Ratings
• 28V input (14.0 – 50V),
non-isolated ZVS buck-boost regulator
• 26.0 – 50.0V adjustable output range
• 200W output power in 1.11in2 footprint
• 95.5% typical efficiency, at full load
• 667W/in3 (42W/cm3) power density
• 4.7MHrs MTBF (MIL-HDBK-217 Plus Parts Count, 25°C)
• Full VI Chip® package
32.5 x 22.0 x 6.73mm
Typical Applications
• Land/Air/Sea Unmanned Vehicles/Drones
• Communications
• Radar
• Mobile Weapons
VIN = 14.0 – 50.0V
POUT = 200W
VOUT = 36V
(26.0 – 50.0V Trim)
IOUT = 5.56A
Product Description
The VI Chip® PRM Regulator is high efficiency converter,
operating from a 14.0 to 50.0VDC input to generate a regulated
26.0 – 50.0VDC output. The ZVS buck-boost topology enables high
switching frequency operation with high conversion efficiency.
High switching frequency reduces the size of reactive components
enabling power density up to 667W/in3.
The Full VI Chip package is compatible with standard
pick‑and‑place and surface mount assembly processes with a
planar thermal interface area and superior thermal conductivity.
In a Factorized Power Architecture™ system, the PRM and
downstream VTM™ current multiplier minimize distribution and
conversion losses in a high‑power solution, providing an isolated,
regulated output voltage.
The MPRM28Ax360M120A00 can be configured for adaptive‑loop
output regulation, if needed. In adaptive-loop operation, the
MPRM28Ax360M120A00 utilizes a unique feed-forward scheme
that enables precise regulation of an isolated PoL voltage without
the need for remote sensing and voltage feedback.
Note: Product images may not highlight current product markings.
PRM™ Regulator
Page 1 of 25
Rev 1.0
06/2020
MPRM28Ax360M120A00
Typical Applications
MPRM28Ax360M120A00
VH
PR
MVTM36Bx045M027A00
TM
SC
PC
PC
IL
TM
CD
RCD
OS
VC
VC
ROS
RL-FACT
150mΩ
SG
VIN
Fuse
Power Ground
2.2mF
Aluminum
+IN
+OUT
–IN
–OUT
+OUT
+FACT
LFACT
0.4µH
–FACT
Power Ground
+IN
ECL
VEE
–OUT
–IN
Isolation Boundary
–5.2V
23A
MPRM28Ax360M120A00 + MVTM36Bx045M027A00 isolated adaptive-loop configuration for negative supply
MVTM36Bx030M040B00
PC
TM
VC
+OUT
+IN
–IN
MPRM28Ax360M120A00
–OUT
Isolation Boundary
VH
PR
MVTM36Bx030M040B00
TM
SC
PC
PC
IL
Enable*
QPC
RCD
PRM Signal Ground
VIN
OS
VC
ROS
2.2mF
Aluminum
VC
RL-FACT
150mΩ
SG
Fuse
VIN Return
TM
CD
+IN
+OUT
–IN
–OUT
+OUT
+FACT
LFACT
0.4µH
CFACT
22µF
–FACT
+IN
–IN
LVCMOS
–OUT
Isolation Boundary
MPRM28Ax360M120A00 + two MVTM36Bx030M040B00s for isolated 180W-logic supply
PRM™ Regulator
Page 2 of 25
Rev 1.0
06/2020
3.3V
54A
MPRM28Ax360M120A00
Typical Applications (Cont.)
MPRM28Ax360M120A00
VH
PR
MVTM36Bx120M010A00
TM
SC
PC
PC
IL
Enable*
QPC
VC
ROS
+IN
2.2mF
Aluminum
–IN
VC
RL-FACT
150mΩ
SG
Fuse
VIN Return
OS
RIL
PRM Signal Ground
VIN
TM
CD
+OUT
+OUT
+FACT
LFACT
0.4µH
–OUT
+IN
–FACT
MPRM28Ax360M120A00 + MVTM36Bx120M010A00 current-limited battery charger
Rev 1.0
06/2020
62.5A
10A
10ms pulse
+ 10% D.C.
–
–IN
–OUT
Isolation Boundary
PRM™ Regulator
Page 3 of 25
13.8V
10A
MPRM28Ax360M120A00
Pinout
1
VC
A
PC
B
2
TOP VIEW
3
4
Top-side indicator
A
VH
B
SC
C
SG
TM
C
IL
D
D
OS
NC
E
E
NC
PR
F
F
CD
G
G
H
H
J
J
K
K
L
L
M
M
N
N
P
P
+IN
+OUT
–IN
–OUT
Full VI Chip®
Pin Descriptions
Pin Number
Signal Name
Type
A1, A2
VC
BIDIR
A3, A4
VH
OUTPUT
B1, B2
PC
BIDIR
Primary control; pull low to disable the PRM
B3, B4
SC
INPUT
Secondary control; regulation reference voltage
C1, C2
TM
OUTPUT
C3, C4
SG
REF
D1, D2
IL
INPUT
Current-limit adjust
D3, D4
OS
INPUT
Output set; output voltage divider network port
E1, E2
NC
n/a
Factory use only
E3, E4
NC
n/a
Factory use only
F1, F2
PR
BIDIR
Control node voltage
F3, F4
CD
INPUT
Compensation device for AL regulation
+IN
INPUT POWER
+OUT
OUTPUT POWER
–IN
INPUT POWER RETURN
–OUT
OUTPUT POWER RETURN
G1 – K1,
G2 – K2
G3 – K3,
G4 – K4
L1 – P1,
L2 – P2
L3 – P3,
L4 – P4
PRM™ Regulator
Page 4 of 25
Function
VTM control and temperature feedback for AL regulation
9V auxiliary voltage source
Temperature monitor
Signal ground
Positive input power terminal
Positive output power terminal
Negative input power return; connected internally to SG
Negative output power return
Rev 1.0
06/2020
MPRM28Ax360M120A00
Part Ordering Information
Part Number
Package Type
Temperature Grade
Option
Tray Size
MPRM28AF360M120A00
F = Full VI Chip® SMD
M = –55 to 125°C
00 = AL PRM
40 parts per tray
All products shipped in JEDEC standard high-profile (0.400in thick) trays (JEDEC Publication 95, Design Guide 4.10).
Storage and Handling Information
Note: For compressive loading refer to Application Note AN:036, “Recommendations for Maximum Compressive Force of Heat Sinks.”
Attribute
Comments
Specification
Storage Temperature Range
–65 to 125°C
Operating Internal Temperature Range (TINT)
–55 to 125°C
Weight
15g
Nickel
Lead Finish
0.51 – 2.03µm
Palladium
0.02 – 0.15µm
Gold
0.003 – 0.050µm
MSL Rating
MSL4
Method per Human Body Model Test
JEDEC JS-001-2012
Charged Device Model
JESD22-C101-E
ESD Rating
Class 1C, < ±2000V
CLASS C1, < ±500V
Reliability and Agency Approvals
Attribute
MTBF
Comments
Value
MIL-HDBK-217 Plus Parts Count, 25°C Ground Benign,
Stationary, Indoors / Computer Profile
MIL-HDBK-217 Plus Parts Count, 50°C Naval Sheltered,
Stationary, Indoors / Computer Profile
MIL-HDBK-217 Plus Parts Count, 65°C Airborne Inhabited Cargo,
Stationary, Indoors / Computer Profile
Unit
4.7
0.85
MHrs
0.67
Agency Approvals/Standards
CE Marked for Low Voltage Directive and RoHS Recast Directive, as applicable
Absolute Maximum Ratings
The ABSOLUTE MAXIMUM ratings below are stress ratings only. Operation at or beyond these maximum ratings can cause permanent damage to device.
Electrical specifications do not apply when operating beyond rated operating conditions. Operating beyond rated operating conditions for an extended period
of time may affect device reliability.
Parameter
Min
Max
Unit
+IN to –IN
Continuous, non-operating
Comments
–0.3
60
V
+OUT to –OUT
Continuous, non-operating
–0.3
60
V
–0.3
VC to –OUT
PC to SG
TM to SG
IL, PR, SC, OS, CD
To SG
VH to SG
20
V
±2000
mA
–0.3
7
V
–0.3
7
V
±20
mA
–0.3
11
V
–0.5
11
V
±100
mA
±100
mA
SG to –IN
Continuous Output Current
6.6
A
Internal Operating Temperature
M-Grade
–55
125
°C
Storage Temperature
M-Grade
–65
125
°C
PRM™ Regulator
Page 5 of 25
Rev 1.0
06/2020
MPRM28Ax360M120A00
Functional Block Diagram
+OUT
+IN
CIN_INT
5uF
COUT_INT
5uF
ROS_TOP_INT
69.8k
ROS_SERIES_INT
80.6
OS
Reference and
Soft-Start
+
G=1
PC
Modulator Control
&
Fault Protection
Type 2 Compensation
RSC_REF
10k
G=5
VREF
1.22V
–
Error
Amplifier
CSC_INT
0.22µF
+
IL
PR
∫
Average
Current
Limit
IAL = V–OUT / RCD
–
VH
RPR_INT
+
IPR_SLAVE
SC
Fast Overcurrent, Short
Circuit Protection
VH
9V
SG
CD
14V
10ms
–IN
PRM™ Regulator
Page 6 of 25
Vc start
pulse
generator
VC
RS
5m
–OUT
Adaptive Loop
Rev 1.0
06/2020
MPRM28Ax360M120A00
Electrical Specifications
Specifications apply over all line, load and trim voltage conditions unless otherwise noted; boldface specifications apply over the temperature range of
–55ºC ≤ TINT ≤ 125°C. All other specifications are at TINT = 25°C unless otherwise noted.
Attribute
Symbol
Conditions / Notes
Min
Typ
Continuous, operating
14.0
28.0
0V ≤ VIN ≤ 50.0V
0.001
Max
Unit
Power Input Specifications
Input Voltage Range
Input Voltage Slew Rate
VIN
dVIN/dt
50.0
V
1000
V/ms
No-Load Power Dissipation
PNL
PC high, VIN = 28.0V, VOUT = 36.0V
1.1
1.35
W
Input Quiescent Current
IQC
PC low, VIN = 28.0V, VOUT = 36.0V
21
30
mA
7.6
A
Input Current
IIN_DC
IOUT = 5.56A, VIN = 28.0V, VOUT = 36.0V
7.48
Input Capacitance (Internal)
CIN_INT
Effective value, VIN = 28.0V
30.0
µF
RC-IN
Effective value, VIN = 28.0V
2
mΩ
Input Capacitance (Internal) ESR
Power Output Specifications
Output Voltage Set Point
Rated Output Voltage Trim Range
Output Voltage Line Regulation
VOUT_SET
No connection to SC, excluding ROS tolerance and
burst‑mode operation
35.28
VOUT-REG-LINE
VOUT-REG-LOAD
Total Regulation Error
VOUT-REG-TOTAL
At module output, AL inactive
Output Voltage Load Regulation (AL) VOUT-ALREG-LOAD At module output, maximum AL compensation,
Total Regulation Error (AL)
VOUT-ALREG-TOTAL excluding external resistor tolerances
Rated Output Power
Rated Output Current
POUT
IOUT
FSW_NOM
Switching Frequency
Output Capacitance (internal)
Output Capacitance (internal) ESR
Output Turn-On Delay
Output Voltage Rise Time
Efficiency, Ambient
Efficiency, Hot
Output Voltage Ripple
FSW
V
50.0
V
0.1
0.2
%
0.1
0.2
%
0.4
%
2.0
%
3.0
%
200
W
26.0
VOUT
Output Voltage Load Regulation
36.72
36.0
1.0
TCASE < 85°C;
See Figure 2 for thermal derating TCASE > 85°C
VIN = 28.0V, VOUT = 36.0V, IOUT = 3.33A
Over rated line, trim and temperature,
up to 3.34A load and exclusive of burst mode
Over rated line, trim and temperature,
up to 5.56A load and exclusive of burst mode
5.56
A
1.45
MHz
0.7
1.45
MHz
0.45
1.45
MHz
1.2
1.33
COUT_INT
Effective value, VOUT = 36.0V
26
µF
RC-OUT
Effective value, VOUT = 36.0V
2
mΩ
tOFF
From VIN first crossing VIN-UVLO+ to soft-start ramp,
PC floating
97
144
ms
tRISE-VOUT
From soft-start begin to VOUT settled to within 5%,
no external SC capacitor
4.0
8.0
12.0
ms
VIN = 28.0V, VOUT = 36.0V, IOUT = 5.56A, TCASE = 25°C
95.0
95.5
%
VIN = 28.0V, VOUT = 36.0V, IOUT = 3.34A, TCASE = 25°C
93.8
94.2
%
94.0
95.4
%
93.0
94.3
%
225
mVP-P
ηAMB
ηHOT
VOUT_PP
VIN = 28.0V, VOUT = 36.0V,
IOUT = 5.56A, TCASE = 100°C
VIN = 28.0V, VOUT = 36.0V,
IOUT = 3.34A, TCASE = 100°C
VIN = 28.0V, VOUT = 36.0V, IOUT = 5.56A,
COUT-EXT = 0µF, 20MHz BW
Load Capacitance (Electrolytic)
CLOAD-ALEL
0.1Ω ≤ ESR ≤ 1Ω, effective value at PRM output
0
63
µF
Load Capacitance (Ceramic)
CLOAD-CER
2mΩ ≤ ESR ≤ 200mΩ, effective value at PRM output
0
25
µF
See Figure 27, effective value at PRM output
0
63
µF
1.35
V
Load Capacitance (Total)
CLOAD-TOTAL
Load Transient Voltage Deviation
VTRANS
Load Transient Recovery Time
tTRANS
PRM™ Regulator
Page 7 of 25
10% ↔ 100% load step, 10A/µs, COUT-EXT = 0µF,
deviation from initial set point
10% ↔ 100% load step, 10A/µs, COUT-EXT = 0µF,
settled to within 10% final value (AL inactive)
Rev 1.0
06/2020
1.04
150
µs
MPRM28Ax360M120A00
Electrical Specifications (Cont.)
Specifications apply over all line, load and trim voltage conditions unless otherwise noted; boldface specifications apply over the temperature range of
–55ºC ≤ TINT ≤ 125°C. All other specifications are at TINT = 25°C unless otherwise noted.
Attribute
Symbol
Conditions / Notes
Min
Typ
Max
Unit
13.5
14.0
V
12.7
13.8
V
2.0
V
Powertrain Protections
Input Undervoltage Turn-ON
VIN_UVLO+
Powertrain recovery
Input Undervoltage Turn-OFF
VIN_UVLO–
Powertrain shut down
Input Undervoltage Hysteresis
VIN_UVLO_HYST
12.0
(VIN_UVLO+) – (VIN_UVLO–)
0.2
0.8
Input Overvoltage Turn-ON
VIN_OVLO–
Powertrain recovery
50.2
51.3
Input Overvoltage Turn-OFF
VIN_OVLO+
Powertrain shut down
Input Overvoltage Hysteresis
VIN_OVLO_HYST
(VIN_OVLO+) – (VIN_OVLO–)
Output Overvoltage Turn-OFF
VOUT_OVP
Minimum Current Limited VOUT
VOUT_UVP
Overtemperature
Shut-Down Set Point
TOTP
Controller temperature
V
52.9
56.0
V
0.2
1.6
5.8
V
54
56
60
V
4.0
V
130
°C
Fault Protection Response Time
tPROT
1
µs
Fault Protection Recovery Time
tPROT-RECOVERY
100
ms
PRM™ Regulator
Page 8 of 25
Rev 1.0
06/2020
MPRM28Ax360M120A00
Signal Specifications
Specifications apply over all line, load and trim voltage conditions unless otherwise noted; boldface specifications apply over the temperature range of
–55ºC ≤ TINT ≤ 125°C. All other specifications are at TINT = 25°C unless otherwise noted.
VC: VTM™ Control
Signal Type
State
Power
Output
Start Up
Attribute
AL
Operation
Conditions / Notes
Min
Typ
Max
Unit
13
16
V
VC Voltage
VVC_START
IVC = 400mA
12
VC Available Current
IVC_START
VVC = 12V
200
VC Pulse Duration
PC to VC Delay
Analog
Input/Output
Symbol
7
tVC
tPC_VC
mA
10
16
ms
18
50
µs
8.00
8.24
A/A
CD to VC
Transfer Function
IVC / ICD
7.76
VC Rated Current
IVC_ALCOMP
0
2
mA
VC Voltage Range
for AL Compensation
VVC_ALCOMP
0
2
V
VREF / VVC_ALCOMP
59
66
V/V
VREF_AL+
0
125
mV
Unit
VC to VREF
Transfer Function
Rated VREF AL
Comp. Range
62.5
VH: Auxiliary Voltage
Signal Type
State
Symbol
Conditions / Notes
Typ
Max
8.7
9.0
9.3
V
5
mA
30
nF
VVH
VH Rated Current
IVH
Any
VH Rated External
Bypass Capacitor
CVH-EXT
Standby
VH Fault Voltage
VVH_FLT
0
PC to VH Delay
tPC_VH
1.0
5.0
ms
VH Fault Response Time
tFR_VH
290
500
µs
Min
Typ
Max
Unit
4.7
5.0
5.3
V
1.8
mA
1.85
2.35
V
60
90
µA
150
mV
Transition
Over rated VH load current
Min
VH Voltage
Normal
Operation
Analog
Output
Attribute
If required, bypass to SG only
To VH < 1.5V
V
PC: Primary Control
Signal Type
State
Analog
Output
Normal
Operation
Standby
Digital
Input/Output
Transition
Start Up
PRM™ Regulator
Page 9 of 25
Attribute
PC Voltage
Symbol
VPC
No external load
PC Current
IPC
PC Voltage
VPC_DISABLE
PC Bias Current
IPC_DISABLE
PC Enable Hysteresis
VPC_HYSTER
PC Voltage
VPC_ENABLE
PC Delay Time
tON
Conditions / Notes
After tOFF, VPC = 0V.
Start up is assured with >100kΩ load on PC
VIN pre-applied
Rev 1.0
06/2020
0.6
2.5
3.0
V
1.0
5.0
ms
MPRM28Ax360M120A00
Signal Specifications (Cont.)
Specifications apply over all line, load and trim voltage conditions unless otherwise noted; boldface specifications apply over the temperature range of
–55ºC ≤ TINT ≤ 125°C. All other specifications are at TINT = 25°C unless otherwise noted.
SC: Secondary Control
Signal Type
State
Normal
Operation
Analog
Input
Any
Attribute
SC Voltage
Symbol
VSC
Conditions / Notes
No external connection to SC
Min
Typ
Max
Unit
1.182 1.222 1.262
V
VSC
V
10.1
kΩ
SC Voltage Trim Range
VSC_TRIM
0.25
SC series R to VREF
RSC_INT
9.9
SC Bypassing to SG
CSC_INT
SC Bypassing to SG,
External
CSC_EXT
10.0
0.22
0
µF
1.0
µF
PC to SC Delay
tPC_SC
1.0
5.0
ms
SC Fault Response Time
tFR_SC
19.5
50
µs
Min
Typ
Max
Unit
2.95
3.00
3.05
V
4.20
V
Transition
TM: Temperature Monitor
Signal Type
State
Attribute
TM Voltage
TM Voltage Range
Normal
Operation
TM Gain
TM Rated Current
Analog
Output
TM Ripple
Standby
Transition
TM Fault Current
Symbol
VTM_AMB
Conditions / Notes
Controller temperature = 27°C
2.14
VTM
ATM
10
VTM-PP
ITM_FAULT
mV/°C
100
ITM_NORMAL
µA
Powertrain in burst mode
75
mVP-P
High‑impedance state
0
mA
PC to TM Delay
tPC_TM
18.0
50
µs
TM Fault Response Time
tFR_TM
1.0
2.0
µs
Typ
Max
Unit
100
mA
SG: Signal Ground
Signal Type
State
Analog
Reference
Any
Attribute
Rated SG Current
Symbol
ISG
PRM™ Regulator
Rev 1.0
Page 10 of 25 06/2020
Conditions / Notes
Min
–100
MPRM28Ax360M120A00
Signal Specifications (Cont.)
Specifications apply over all line, load and trim voltage conditions unless otherwise noted; boldface specifications apply over the temperature range of
–55ºC ≤ TINT ≤ 125°C. All other specifications are at TINT = 25°C unless otherwise noted.
IL: Current Limit Adjust
Signal Type
State
Attribute
IL Voltage Setpoint
Analog Input
Normal
Operation
Symbol
Conditions / Notes
Min
Typ
Max
Unit
VIL_SET
1.00
V
IL Resistance to VIL_SET
RIL
5
kΩ
IL Voltage range
VIL
0.10
RIL-RNG
440
IL external resistor range
V
open
Ω
OS: Output Set
Signal Type
Analog
Input
State
Any
Attribute
Symbol
OS Internal Series Resistor
OS Internal Top Resistor
OS External
Resistor Range
Min
Typ
Max
Unit
ROS_SERIES_INT
79.8
80.6
81.4
Ω
ROS_TOP_INT
69.1
69.8
70.5
kΩ
1.67
2.37
3.36
kΩ
Min
Typ
Max
Unit
ROS_SG
Conditions / Notes
With SC at nominal
PR: Control Node Port
Signal Type
State
Analog
Output
Normal
Operation
Attribute
Symbol
Conditions / Notes
PR Active Range
VPR
0.79
PR Available Current
IPR
2.0
7.4
V
mA
CD: Compensation Device
Signal Type
State
Analog
Input/Output
AL Operation
Attribute
Symbol
CD Voltage Range
VCD
CD Rated Current
ICD
CD Resistor Range
RCD
Conditions / Notes
0 – 5.56A range
PRM™ Regulator
Rev 1.0
Page 11 of 25 06/2020
Min
0
1.16
Typ
Max
Unit
0.29
V
250
µA
kΩ
MPRM28Ax360M120A00
Specified Operating Area
The following figures present typical performance at TCASE = 25ºC, unless otherwise noted. See associated figures for general trend data.
6.02
200
Output Current (A)
Output Power (W)
210
190
180
170
160
5.56
5.10
4.63
4.17
150
14
18
22
26
30
38
34
42
46
50
14
18
22
26
Line Voltage (V)
TCASE:
> 85°C
< 85°C
30
38
34
42
46
50
46
50
Line Voltage (V)
TCASE:
Figure 1 — Rated output power vs line voltage,
nominal trim and above
> 85°C
< 85°C
Figure 2 — Rated output current vs. line voltage,
nominal trim and below
Typical Performance Characteristics
The following figures present typical performance at TCASE = 25ºC, unless otherwise noted. See associated figures for general trend data.
30
1.2
Power Dissipation (W)
Input Current (mA)
28
26
24
22
20
18
16
14
12
10
1.1
1.0
0.9
0.8
0.7
0.6
0.5
14
18
22
26
30
34
38
42
46
50
14
18
Line Voltage (V)
TCASE:
–55°C
25°C
Figure 3 — Disabled input current vs. line voltage
22
26
30
34
38
42
Line Voltage (V)
100°C
TCASE:
–55°C
25°C
100°C
Figure 4 — No-load power dissipation vs. VIN at nominal trim
PRM™ Regulator
Rev 1.0
Page 12 of 25 06/2020
MPRM28Ax360M120A00
Typical Performance Characteristics (Cont.)
96
10
94
9
Power Dissipation (W)
Efficiency (%)
The following figures present typical performance at TCASE = 25ºC, unless otherwise noted. See associated figures for general trend data.
92
90
88
86
84
82
80
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
0.56
1.11
1.67
2.22
Load Current (A)
VIN:
16V
14V
28V
50V
VIN:
Figure 5 — Efficiency at 25°C case temperature,
VOUT = 26V
Power Dissipation (W)
Efficiency (%)
94
92
90
88
86
84
82
1.11
1.67
2.22
2.78
3.34
3.89
16V
14V
4.45
5.0
5.56
3.89
4.45
5.0
5.56
28V
50V
14
13
12
11
10
9
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
Load Current (A)
28V
50V
VIN:
Figure 7 — Efficiency at 25°C case temperature,
VOUT = 36V
16V
14V
28V
50V
Figure 8 — Power dissipation at 25°C case temperature,
VOUT = 36V
96
15
Power Dissipation (W)
94
Efficiency (%)
16V
14V
Load Current (A)
VIN:
3.34
Figure 6 — Power dissipation at 25°C case temperature,
VOUT = 26V
96
0.56
2.78
Load Current (A)
92
90
88
86
84
13
11
9
7
5
3
82
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
3.6
0.4
4.0
0.8
1.2
1.6
VIN:
14V
16V
28V
Figure 9 — Efficiency at 25°C case temperature,
VOUT = 50V
2.0
2.4
2.8
3.2
3.6
Load Current (A)
Load Current (A)
VIN:
50V
14V
16V
28V
50V
Figure 10 — Power dissipation at 25°C case temperature,
VOUT = 50V
PRM™ Regulator
Rev 1.0
Page 13 of 25 06/2020
4.0
MPRM28Ax360M120A00
Typical Performance Characteristics (Cont.)
96
10
94
9
Power Dissipation (W)
Efficiency (%)
The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data.
92
90
88
86
84
82
80
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
0.56
1.11
1.67
2.22
Load Current (A)
VIN:
16V
14V
28V
50V
VIN:
Figure 11 — Efficiency at 100°C case temperature,
VOUT = 26V
Power Dissipation (W)
Efficiency (%)
94
92
90
88
86
84
82
1.11
1.67
2.22
2.78
3.34
3.89
4.45
16V
14V
5.0
5.56
3.89
4.45
5.0
5.56
28V
50V
14
13
12
11
10
9
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
Load Current (A)
28V
50V
VIN:
Figure 13 — Efficiency at 100°C case temperature,
VOUT = 36V
16V
14V
28V
50V
Figure 14 — Power dissipation at 100°C case temperature,
VOUT = 36V
96
16
Power Dissipation (W)
94
Efficiency (%)
16V
14V
Load Current (A)
VIN:
3.34
Figure 12 — Power dissipation at 100°C case temperature,
VOUT = 26V
96
0.56
2.78
Load Current (A)
92
90
88
86
84
14
12
10
8
6
4
82
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
3.6
0.4
4.0
0.8
1.2
1.6
VIN:
14V
16V
28V
Figure 15 — Efficiency at 100°C case temperature,
VOUT = 50V
2.0
2.4
2.8
3.2
3.6
Load Current (A)
Load Current (A)
VIN:
50V
14V
16V
28V
50V
Figure 16 — Power dissipation at 100°C case temperature,
VOUT = 50V
PRM™ Regulator
Rev 1.0
Page 14 of 25 06/2020
4.0
MPRM28Ax360M120A00
Typical Performance Characteristics (Cont.)
96
10
94
9
Power Dissipation (W)
Efficiency (%)
The following figures present typical performance at TC = 25ºC, unless otherwise noted. See associated figures for general trend data.
92
90
88
86
84
82
80
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
0.56
1.11
1.67
2.22
Load Current (A)
VIN:
16V
14V
28V
50V
VIN:
Figure 17 — Efficiency at –55°C case temperature,
VOUT = 26V
Power Dissipation (W)
Efficiency (%)
94
92
90
88
86
84
82
1.11
1.67
2.22
2.78
3.34
3.89
4.45
16V
14V
5.0
5.56
3.89
4.45
5.0
5.56
28V
50V
14
13
12
11
10
9
8
7
6
5
4
3
0.56
1.11
1.67
2.22
2.78
3.34
3.89
4.45
5.0
5.56
Load Current (A)
28V
50V
VIN:
Figure 19 — Efficiency at –55°C case temperature,
VOUT = 36V
16V
14V
28V
50V
Figure 20 — Power dissipation at –55°C case temperature,
VOUT = 36V
96
16
Power Dissipation (W)
94
Efficiency (%)
16V
14V
Load Current (A)
VIN:
3.34
Figure 18 — Power dissipation at –55°C case temperature,
VOUT = 26V
96
0.56
2.78
Load Current (A)
92
90
88
86
84
14
12
10
8
6
4
82
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
3.6
0.4
4.0
0.8
1.2
1.6
VIN:
14V
16V
28V
Figure 21 — Efficiency at –55°C case temperature,
VOUT = 50V
2.0
2.4
2.8
3.2
3.6
Load Current (A)
Load Current (A)
VIN:
50V
14V
16V
28V
50V
Figure 22 — Power dissipation at –55°C case temperature,
VOUT = 50V
PRM™ Regulator
Rev 1.0
Page 15 of 25 06/2020
4.0
MPRM28Ax360M120A00
Pin Functions
+IN, –IN
Input power pins.
+OUT, –OUT
Output power pins. –OUT uses a low-side current shunt to sense
the PRM output return current, therefore do not connect –OUT
to –IN since this would defeat this current measurement and
could lead to loss of output overcurrent protection or anomalous
adaptive-loop and constant current-limiting behavior.
VC: VTM™ Control
VC supplies power to one or two downstream VTMs during
start up. When the PRM is not connected to any VTM and the
AL function is unused, no VC connection is required, but a 1kΩ
resistor from VC to –OUT is permitted for backward compatibility.
When AL compensation is used, after the start-up pulse, VC is
a small current source proportional to module IOUT and RCD. A
resistor inside the downstream VTM from VC to –OUT sets the
dynamic voltage on VC, which is scaled and summed into the error
amplifier reference.
VH: Auxiliary Voltage Source
VH is an auxiliary supply voltage referred to SG. It is active when
the PRM is operating. VH can be used as a supply for low‑power
external control circuitry. To avoid electrical overstress to the
module, do not overload VH or exceed its maximum bypass
capacitor rating.
TM: Temperature Monitor
Once the PRM has started, TM outputs a voltage proportional
to the internal controller temperature. The voltage is ATM*
temperature (°C), and so at room temperature of 27°C the nominal
TM voltage will be 3.00V. TM can be used as a “power good” flag
to indicate PRM operation, provided that it is not loaded in excess
of its current rating.
SG: Signal Ground
This is a low-current pin which provides a Kelvin connection to the
PRMs internal signal ground. Use this pin as the ground reference
for external circuitry and signals to avoid voltage drops caused by
high currents on input power return. SC is the ground reference
for PC, OS, CD, SC, VH and IL ports. Note that VC current should
return to –OUT and not SG.
IL: Current Limit Adjust
During operation, the PRM features constant-current-style output
current limiting, where IL sets the constant current threshold.
By adding a resistor RIL from IL to SG, the current limit threshold
can be reduced and the module will operate in constant-current
when the load current exceeds the programmed value. If full rated
current is needed or if constant current limiting is not needed,
then this pin should be left open. Note that this functionality
is enhanced compared to the MP028x036M12AL product fault
protection response to a slow current limit.
PR: Control Node Port
PR is the error amplifier output and is proportional to PRM output
power. No external connection to PR is needed.
PC: Primary Control
OS: Output Set
PC turns the PRM on and off. PC has an internal current source
to pull it to the enabled state if no external connection is
made. External control of PC should be implemented using an
open collector opto-coupler or transistor configuration that
cannot drive the pin to a high state. Attempting to drive PC
high with an external voltage source could cause electrical
overstress to the PRM.
OS provides access to the error amplifier inverting input through
an internal low-value resistor. An external resistor from OS to SG
is required to set the scale factor of the feedback from the PRM
output voltage to the control loop.
SC: Secondary Control
SC is driven by the internal voltage reference through RSC-INT. It
is summed with the output of the AL Compensation system to
provide the voltage reference for the error amplifier. An external
programming DAC or fixed resistor to SG can be used to set SC to
voltages lower than VSC for dynamic trimming or output margining.
Trimming with this method will preserve the AL compensation
scaling as well as the control loop compensation factors. A
capacitor from SC to SG can be used to slow down the soft-start
output voltage slew rate.
CD: Compensation Device
CD is used to set the adaptive‑loop scale factor. CD is a voltage
source proportional to IOUT, and an external resistor to SG programs
the resulting CD current. This current then acts on the VC port to
develop the added voltage to the control loop to increase VOUT.
When adaptive-loop compensation is not needed, CD should be
left open with no external connection.
PRM™ Regulator
Rev 1.0
Page 16 of 25 06/2020
MPRM28Ax360M120A00
Functional Description
Design Guidelines
The MPRM28Ax360M120A00 is a non‑isolated ZVS buck‑boost
regulator. It is specifically designed to provide a controlled
factorized‑bus distribution voltage for powering a downstream
VTM transformer.
Input Filter Stability
The PRM can be configured for two operating modes depending
on the application need. In applications with a downstream
VTM, the adaptive‑loop regulation circuitry within the PRM can
be configured with a negative load line to compensate for the
effective output resistance of the VTM, without the need for a
direct remote sense connection. This permits the resultant system
to preserve the isolation offered by the VTM transformer stage.
Regulating switch-mode power supplies like the PRM present
a negative impedance to the voltage source that is powering
them. To ensure stability of the regulation loop, the source
impedance and the parasitic resistance and inductance of the
interconnect lines must be considered. The high performance
ceramic decoupling capacitors placed locally to the input to the
PRM are effective in controlling reflected ripple current at the
switching frequency. However their low ESR means they will not
significantly damp an excessively high impedance of an upstream
voltage source.
In applications without a VTM, the adaptive‑loop circuitry can
be deactivated, allowing the PRM to serve as a general‑purpose
regulator, with tight regulation provided at the module output.
The regulator dynamic input impedance magnitude rEQ_IN can be
calculated by dividing the lowest line voltage by the full load input
current. To ensure stability, two cases must be considered.
PRM Start Up
Input Filter case 1; inductive source and local, external,
input decoupling capacitance with negligible ESR
(i.e., ceramic type)
Any time the PRM input voltage is within UVLO and OVLO and the
module is not disabled via the PC pin, it will attempt to start.
At start up, VH goes active and the VC pulse starts. The PRM
internal reference rises to generate the soft‑start ramp of module
output voltage. The soft‑start time can be increased by the addition
of a capacitor on SC. When a VTM is used, care must be taken not
to increase the soft‑start time so much that the VTM faults at the
end of the VC pulse due to undervoltage lockout.
The voltage source impedance can be modeled as a series RLINE
LLINE circuit. In order to guarantee stability the following conditions
must be verified:
RLINE >
LLINE
(CIN + CIN_EXT) • | rEQ_IN |
|
RLINE
