19-3323; Rev 0; 6/04
MAX5058 Evaluation Kit
General Description
The MAX5058 evaluation kit (EV kit) is a fully assembled
and tested circuit board that contains a high-efficiency,
50W, isolated, synchronously rectified forward convert-
er in the industry-standard 1/8th brick pinout. The cir-
cuit is configured for a +3.3V output voltage and pro-
vides up to 15A of output current. The circuit can be
powered from either a +36V to +72V or -36V to -72V DC
source in applications such as telecom/datacom (48V
modules), industrial environments, or in automotive 42V
power systems.
Using a clamped two-transistor power topology on the
primary side and synchronous rectifiers on the secondary
side achieves high efficiency up to 91% and is achieved
at 9A. The efficiency improvement on the secondary side
is achieved through synchronous rectification using the
MAX5058 secondary-side synchronous rectifier driver
and feedback generator controller IC, which drives two
n-channel MOSFETs. Additionally, the recovery of stored
leakage and magnetizing inductance energy at the pri-
mary side contributes to the overall efficiency improve-
ment. The primary side uses a MAX5051 parallelable,
clamped, two-switch power-supply controller IC. Galvanic
isolation up to 500V is achieved with an optocoupler,
pulse-signal transformer, and planar surface-mount
power transformer.
Operation at 250kHz allows the use of small magnetics
and output capacitors. The EV kit provides cycle-by-
cycle current-limit protection. Additional steady-state
fault protection is provided by an integrating fault pro-
tection that reduces average dissipated power during
continuous short-circuit conditions. The MAX5051 also
has a programmable undervoltage lockout (UVLO).
Multiple MAX5058 EV kits can be paralleled for
increased power capability when high output current is
required. Margin-up/down capability enables an
increase or decrease in the output voltage. The EV kit
demonstrates the MAX5058 look-ahead signal capabili-
ty, on-board error amplifier, and reference voltage
source. Remote-load voltage sensing allows accurate
voltage regulation at the load.
Warning: The MAX5058 EV kit is designed to operate
with high voltages. Dangerous voltages are present
on this EV kit and on equipment connected to it.
Users who power up this EV kit or power the
sources connected to it must be careful to follow
safety procedures appropriate to working with high-
voltage electrical equipment.
Under severe fault or failure conditions, this EV kit
may dissipate large amounts of power, which could
result in the mechanical ejection of a component or
of component debris at high velocity. Operate this kit
with care to avoid possible personal injury.
The user must supply an additional 100µF bulk stor-
age capacitor between the EV kit’s +VIN and -VIN
input terminals before powering up or the MAX5058
EV kit may be damaged.
Evaluates: MAX5051/MAX5058
Features
♦
50W High-Efficiency, Isolated Forward Converter
♦
Synchronously Rectified
♦
Differential Load-Share Bus for Paralleling
♦
±36V to ±72V Input Range
♦
+3.3V Output at 15A
♦
V
OUT
Regulation Better than ±0.5% Over Line and
Load
♦
89% Efficiency at 48V and 9A
♦
Cycle-by-Cycle Current-Limit Protection
♦
Programmable Integrating Fault Protection
♦
1/8th Brick Module Pinout
♦
250kHz Switching Frequency
♦
Soft-Start
♦
Margin-Up/Down Capability
♦
Remote-Load Voltage Sensing
♦
On-Board Error Amplifier and Reference Voltage
Source
♦
Fully Assembled and Tested
Ordering Information
PART
MAX5058EVKIT
TEMP RANGE
0°C to +50°C*
IC PACKAGE
28 TSSOP-EP
*With
100LFM airflow.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX5058 Evaluation Kit
Evaluates: MAX5051/MAX5058
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
100pF ±2%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H101G
390pF ±5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H391J
4.7µF ±10%, 10V X5R ceramic
capacitor (0805)
TDK C2012X5R1A475K
4.7µF ±10%, 6.3V X5R ceramic
capacitor (0805)
TDK C2012X5R0J475K
4700pF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H472K
0.1µF ±10%, 250V X7R ceramic
capacitor (1206)
TDK C3216X7R2E104K
0.22µF ±10%, 10V X7R ceramic
capacitor (0603)
TDK C1608X7R1C224K
4.7µF ±10%, 16V X7R ceramic
capacitor (1206)
TDK C3216X7R1C475K
1µF ±10%, 16V X7R ceramic
capacitors (0805)
Taiyo Yuden EMK212BJ105KG
0.47µF ±10%, 100V X7R ceramic
capacitors (1206)
TDK C3216X7R2A474K
1µF ±20%, 100V X7R ceramic
capacitor (1210)
TDK C3225X7R2A105M
270µF, 4V aluminum organic
capacitors (X)
Kemet A700X277M004ATE015
3.3µF ±10%, 6.3V X5R ceramic
capacitor (0805)
Taiyo Yuden JMK212BJ335KG
DESIGNATION
C17
QTY
1
DESCRIPTION
0.33µF ±10%, 10V X5R ceramic
capacitor (0603)
TDK C1608X5R1A334K
1000pF ±5%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H102J
1µF ±10%, 10V X5R ceramic
capacitors (0603)
TDK C1608X5R1A105K
220pF ±10%, 50V C0G ceramic
capacitors (0603)
TDK C1608C0G1H221K
4.7µF, 80V electrolytic capacitor
(6.3mm x 5.8mm)
Cornell-Dubilier AFK475M80D16B
2200pF ±10%, 2kV X7R ceramic
capacitor (1812)
TDK C4532X7R3D222K
1000pF, 250V X7R ceramic capacitor
(0603)
Murata GRM188R72E102K
0.047µF ±10%, 100V X7R ceramic
capacitor (0805)
TDK C2012X7R2A473K
0.1µF ±10%, 16V X7R ceramic
capacitors (0603)
TDK C1608X7R1C104K
0.15µF ±10%, 16V X7R ceramic
capacitor (0603)
Taiyo Yuden EMK107BJ154KA
0.047µF ±10%, 25V X7R ceramic
capacitor (0603)
TDK C1608X7R1E473K
1µF ±10%, 25V X7R ceramic
capacitor (0805)
TDK C2012X7R1E105K
C2
1
C18, C24
2
C3
1
C19, C30, C33
3
C4
1
C20, C37
2
C5, C40
2
C21
1
C6
1
C22
1
C7
1
C23
1
C8
1
C25
1
C9, C29
2
C26, C31
2
C10, C11
2
C27
1
C12
1
C28
1
C13, C14, C15
3
C32
1
C16
1
2
_______________________________________________________________________________________
MAX5058 Evaluation Kit
Component List (continued)
DESIGNATION
C34
QTY
1
DESCRIPTION
330pF ±5%, 250V C0G ceramic
capacitor (0603)
TDK C1608C0G2E331J
1µF ±10%, 50V X7R ceramic
capacitors (1206)
TDK C3216X7R1H105K
0.068µF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H683K
Not installed, ceramic capacitor
(0603)
150mA, 100V Schottky diode
(SOD-123)
Vishay BAT46W
1A, 100V Schottky diodes (SMA)
Diodes Incorporated B1100
3A, 20V Schottky diode (SMA)
Diodes Incorporated B320A
250mA, 100V fast-switching diodes
(SOD-323)
Diodes Incorporated 1N4448HWS
100mA, 30V Schottky diodes
(SOD-523)
Central Semiconductor CMOSH-3
2.4µH, 20A inductor
Payton 50661 or
Coilcraft A9860-B* or
Pulse Engineering PA1494-242*
100V, 7.3A n-channel MOSFETs
(SO-8)
International Rectifier IRF7495
30V, 20A n-channel MOSFETs
(SO-8)
International Rectifier IRF7832
170mA, 100V n-channel MOSFET
(SOT23)
Fairchild BSS123
19.1kΩ ±0.1%, 25ppm resistors
(0603)
Panasonic ERA3EEB1912V
2.2kΩ ±5% resistor (0603)
DESIGNATION
R4
R5
R6
R7, R35
R8, R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
R19
R20, R36
R21
R22
R23, R24
R25
R26
R27
R28
R29
R30
R31
R32
R33
R34
R37, R38
R39
R40
QTY
1
1
1
2
2
1
1
1
1
1
1
1
1
1
1
2
1
1
2
1
1
1
1
1
1
1
1
1
1
2
1
1
DESCRIPTION
1MΩ ±1% resistor (0603)
38.3kΩ ±1% resistor (0603)
1MΩ ±1% resistor (0805)
0Ω ±5% resistors (0603)
8.2Ω ±5% resistors (0603)
20Ω ±5% resistor (1206)
360Ω ±5% resistor (0603)
34.8kΩ ±0.5%, 100ppm resistor
(0603)
Panasonic ERA3EKD3482V
47Ω ±5% resistor (1206)
270Ω ±5% resistor (0603)
31.6kΩ ±1% resistor (0603)
10.5kΩ ±1% resistor (0603)
0.027Ω ±1% 0.5W resistor (1206)
IRC LRF-1206-01-R027-F
4.7Ω ±5% resistor (1206)
475Ω ±1% resistor (0805)
0.004Ω ±1% resistors (1206)
IRC LRF-1206-01-R004-F
24.9kΩ ±1% resistor (0805)
15kΩ ±5% resistor (1206)
10Ω ±5% resistors (0805)
47.5kΩ ±1% resistor (0603)
0.002Ω ±5% resistor (2512)
IRC LRF-2512-01-R002-J
10Ω ±5% resistor (0603)
301Ω ±1% resistor (0805)
1Ω ±5% resistor (0603)
2kΩ ±1% resistor (0603)
220Ω ±5% resistor (0603)
698kΩ ±1% resistor (0805)
Panasonic ERJA6ENF6983V
604kΩ ±1% resistor (0805)
Panasonic ERJ6ENF6043V
220kΩ ±5% resistor (0603)
10Ω ±5% resistors (0603)
2kΩ ±5% resistor (1206)
32.4kΩ ±1% resistor (0603)
Evaluates: MAX5051/MAX5058
C35, C36
2
C38
1
C39
0
D1
1
D2, D3
D4
D5, D6, D8,
D10, D11
2
1
5
D7, D9
2
L1
1
N1, N2
2
N3, N4
2
N5
1
R1, R2
R3
2
1
_______________________________________________________________________________________
3
MAX5058 Evaluation Kit
Evaluates: MAX5051/MAX5058
Component List (continued)
DESIGNATION
T1
T2
QTY
1
1
DESCRIPTION
Planar transformer
Pulse Engineering PA0370
Drive transformer
Pulse Engineering PE-68386
Parallelable, clamped, two-switch
power-supply controller
MAXIM MAX5051AUI (28 TSSOP-EP)
High-voltage optocoupler
(Ultra-small flat-lead)
CEL/NEC PS2913-1-M
+VIN, -VIN,
ON/OFF
VOUT, SGND
None
U2
1
3
2
1
DESIGNATION
QTY
DESCRIPTION
Secondary-side synchronous rectifier
driver and feedback generator
controller
MAXIM MAX5058EUI (28-pin TSSOP-EP)
0.040in PC pins
0.062in PC pins
MAX5058 PC board
U3
1
U1
1
*Modifications
to the PC board traces are required to evaluate
this component.
Component Suppliers
SUPPLIER
CEL/NEC; California Eastern
Laboratories
Coilcraft
Cornell Dubilier
Diodes Inc
Fairchild
International Rectifier
IRC
Kemet
Murata
Panasonic
Payton Planar Magnetics Ltd.
Pulse Engineering
Taiyo Yuden
TDK
Vishay
PHONE
800-997-5227
847-639-6400
508-996-8564
805-446-4800
888-522-5372
310-322-3331
361-992-7900
864-963-6300
770-436-1300
714-373-7366
561-969-9585
858-674-8100
800-348-2496
847-803-6100
—
FAX
408-588-2213
847-639-1469
508-336-3830
805-446-4850
—
310-726-8721
361-992-3377
864-963-6322
770-436-3030
714-737-7323
561-989-9587
858-674-8262
847-925-0899
847-390-4405
—
www.cel.com
www.coilcraft.com
www.cornell-dubilier.com
www.diodes.com
www.fairchildsemi.com
www.irf.com
www.irctt.com
www.kemet.com
www.murata.com
www.panasonic.com
www.paytongroup.com
www.pulseeng.com
www.t-yuden.com
www.component.tdk.com
www.vishay.com
WEBSITE
Note:
Indicate that you are using the MAX5058 when contacting these component suppliers.
Quick Start
Required Equipment
•
±36V
to
±72V
power supply capable of providing up
to 3A
• Voltmeter
• A fan to provide at least 100LFM airflow for extended
operation at 15A
4
• 100µF, 100V bulk storage capacitor to be connected
to the input terminals of the EV kit
The MAX5058 EV kit is fully assembled and tested.
Follow these steps to verify board operation.
Do not
turn on the power supply until all connections are
completed.
_______________________________________________________________________________________
MAX5058 Evaluation Kit
No Load Output
1) Connect a voltmeter to the VOUT and SGND pins to
measure the output voltage.
2) Connect the positive terminal of a 36V to 72V power
supply to the +VIN terminal. Connect the power
supply’s ground to the -VIN terminal.
3) Turn on the power supply above 36V and verify that
the voltmeter reads +3.3V.
Note:
For improved voltage regulation at the load, con-
nect a 22-gauge twisted-pair cable from the VS+ and
VS- terminals of the MAX5058 EV kit, to the load posi-
tive and ground terminals, respectively. Connect the
VOUT and SGND terminals to the load with power
cables sized to carry the full load current, up to 15A.
The planar surface-mount transformer features a bias
winding that, along with diode D5, current-limiting resis-
tor R18, and reservoir capacitor C21, powers the
MAX5051 once the input voltage is stable. Upon initial
input voltage application, bootstrap resistor R22 and
capacitor C21 enable the MAX5051 to startup within
approximately 70ms. No reset windings are required on
the transformer with a clamped two-transistor power
topology, simplifying transformer design and maximizing
the available copper window in the transformer. When
both external primary-side transistors turn off, Schottky
diodes D2 and D3 recover the magnetic energy stored in
the core and feed it back to the input supply. The trans-
former provides galvanic isolation up to 500V.
On the transformer’s secondary side, the MAX5058
built-in error amplifier, reference voltage source, and
feedback resistors R1 and R2 provide voltage feed-
back to the primary side through optocoupler U2.
Resistor R12 sets the reference voltage for the
MAX5058 to 1.657V. Margin-up/down capability
enables an increase or decrease in the output voltage
by 5% and is configurable by replacing resistors R32
and R33. On the primary side, the MAX5051 receives
the voltage-feedback signal from biasing resistor R3
and compensation resistor/capacitor networks R11/C17
and C24 connected to optocoupler U2.
Pulse transformer T2 provides a galvanically isolated
signal to the MAX5058 secondary-side synchronous
rectifier driver circuit from the MAX5051 PWM primary-
side signal. This look-ahead signal avoids large current
spikes resulting from a shorted transformer secondary
when the freewheeling synchronous rectifier (N4) and
primary-side MOSFETs concurrently conduct.
The MAX5051 controller switches at a 250kHz frequency
set by resistor R21 and capacitor C1. The duty cycle is
varied to control energy transfer to the output. The
maximum duty cycle is 50% for the EV kit’s synchro-
nously rectified forward converter design and is limited
by the MAX5051.
The MAX5058 EV kit features output-voltage soft-start,
thus eliminating any output-voltage overshoots. Soft-
start allows the output voltage to slowly ramp up in a
controlled manner within approximately 3ms. Capacitor
C5 sets the soft-start time. The brownout UVLO thresh-
old voltage is set by resistors R5 and R6. This prevents
the power supply from operating below the minimum
input supply voltage.
Multiple MAX5058 EV kits can be easily paralleled for
increased power capabilities when high output current
is required. Parallel-connected resistors R20 and R36
facilitate current sharing when multiple MAX5058 EV
5
Evaluates: MAX5051/MAX5058
Detailed Description
The MAX5058 EV kit is a 50W, isolated, synchronously
rectified forward converter that provides +3.3V at up to
15A output. The circuit can be powered from a
±36V
to
±72V
DC source.
The user must supply an additional
100µF bulk storage capacitor between the +VIN and
-VIN input terminals before powering up or the
MAX5058 EV kit may be damaged.
This capacitor
should be rated for 100V and be able to carry 1.5A of
ripple current. Lower ripple-current-rated capacitors
should be acceptable for short-term operation.
The 50W forward converter achieves high efficiency by
using a clamped two-transistor power topology at the
primary input and synchronous rectifiers on the sec-
ondary output side. A MAX5051 parallelable, clamped,
two-switch, power-supply controller IC switches the two
primary-side, 100V-rated transistors, N1 and N2. A
MAX5058 secondary-side synchronous rectifier driver
and feedback generator controller IC drives two sur-
face-mount SO-8 n-channel 30V-rated MOSFETs con-
figured as synchronous rectifiers on the secondary
side. MOSFET N3 provides secondary-side rectification
and MOSFET N4 synchronously rectifies the current
flowing through freewheeling diode D4.
The PC board footprint is minimized by using surface-
mount SO-8 n-channel MOSFETs on the primary side.
Cycle-by-cycle current limiting protects the converter
against short circuits at the output. For a continuous
short circuit at the output, the MAX5051’s fault integra-
tion feature provides hiccup fault protection, thus greatly
minimizing excessive temperature rise. Current-sense
resistor R17 senses the current through the primary of
transformer T1 and both primary-side transistors N1 and
N2 are turned off when the trip level of 154mV (typ) is
reached. The programmable integrating fault protection
allows transient overload conditions to be ignored and is
configured by resistor R4 and capacitor C7.
_______________________________________________________________________________________
Microchip MCU
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