MAX5058 Datasheet, PDF (1/25 Pages) Maxim Integrated Products – Parallelable Secondary-Side Synchronous Rectifier Driver and Feedback-Generator Controller ICs

19-3045; Rev 0; 10/03
Parallelable Secondary-Side Synchronous Rectifier
Driver and Feedback-Generator Controller ICs
General Description
The MAX5058/MAX5059 enable secondary-side syn-
chronous rectification in isolated power supplies using
widely available power MOSFETs. These devices facili-
tate the commutation of the secondary-side MOSFETs by
providing a clean gate-drive signal that is synchronized
to the power MOSFET switching in the primary side of
the isolation transformer. The MAX5058/MAX5059 com-
plement the MAX5051 and MAX5042/MAX5043 primary-
side PWM ICs and enable the design of high-efficiency
synchronously rectified isolated power supplies.
Simultaneous conduction of the primary side and the
freewheeling synchronous rectifier MOSFET is avoided
by having a look-ahead signal (before the primary-side
MOSFETs turn ON), thus eliminating large current spikes
resulting from a shorted transformer secondary.
An on-board error amplifier with a versatile current ref-
erence output enables virtually unlimited possibilities in
reference-voltage generation. Reference voltage for the
error amplifier is generated by connecting an appropri-
ate resistor to this output.
Low on-resistance margining MOSFETs integrated on-
chip allow for implementation of a margining circuit
without the use of external switches. The MAX5058 pro-
vides a 5V LDO output for logic-level MOSFETs while
the MAX5059 provides a 10V LDO output for conven-
tional 10V MOSFETs.
The MAX5058/MAX5059 are designed to enable paral-
leling of multiple power supplies for accurate current
sharing using a simple 2-wire, differential, current-share
bus. Parallelability enables expansion of the power
capabilities and simplifies thermal management in high-
output-current applications. When used in conjunction
with the MAX5051, the primaries can also be synchro-
nized and operated 180 degrees out of phase.
The MAX5058/MAX5059 are available in a 28-pin ther-
mally enhanced TSSOP package and operate over a
wide -40°C to +125°C temperature range.
Warning: The MAX5058/MAX5059 are designed to
work in circuits that contain high voltages. Exercise
caution.
Applications
Isolated Telecom Power Supplies
Isolated Networking Power Supplies
±48V Power-Supply Modules
Industrial Power Supplies
±48V/±12V Server Power Supplies
Features
o Clean Drive Waveforms for Synchronous
MOSFETs
o Utilization of a Look-Ahead Signal from the
Primary for Proper Turn-On/Turn-Off Times
o Synchronous Rectifier Drivers Capable of
Sourcing and Sinking Up to 2A Peak Current
o Internal Gate-Voltage Regulator for 5V (MAX5058)
or 10V (MAX5059) Gate-Drive Voltage
o Internal Error Amplifier
o Accurate Differential Current-Share/Force Circuit
Allows Paralleling of Several Power Supplies for
High Output Current
o Internal Remote Voltage-Sense Amplifier
o Flexible Reference-Voltage Generation
o Output Voltage Regulation Down to 0.5V
o Low Quiescent Current Consumption of 2.5mA
o Integrated Digital Output Margining Circuit Saves
External Parts and Board Space
o 30ns Propagation Delay Time from Pulse Input
to Output
o Automatic Detection of Discontinuous Current
Conduction and Turn-Off of the Freewheeling
MOSFET
o High Efficiency at Low Output Currents and
Reverse-Current Protection
o Open-Drain Overtemperature Warning Flag
o 28-Pin Thermally Enhanced TSSOP Package
Ordering Information
PART
TEMP RANGE
MAX5058AUI
MAX5058EUI
MAX5059AUI
MAX5059EUI
-40°C to +125°C
-40°C to +85°C
-40°C to +125°C
-40°C to +85°C
*EP = Exposed paddle.
PIN-
PACKAGE
28 TSSOP-EP*
28 TSSOP-EP*
28 TSSOP-EP*
28 TSSOP-EP*
V_REG
(V)
5
5
10
10
Pin Configuration appears at end of data sheet.
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