The MAX5058 evaluation kit (EV kit) is a fully assembled
and tested circuit board that contains a high-efficiency,
50W, isolated, synchronously rectified forward converter
in the industry-standard 1/8th brick pinout. The circuit
is configured for a +3.3V output voltage and provides
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 primary
side contributes to the overall efficiency improvement.
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-bycycle
current-limit protection. Additional steady-state
fault protection is provided by an integrating fault protection
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 capability,
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 storage
capacitor between the EV kit's +VIN and -VIN
input terminals before powering up or the MAX5058
EV kit may be damaged.