MAX5052BEUA ,22 V, 50 W, current-mode PWM controller with an error amplifier for isolated/nonisolated power supplyApplicationsUniversal Input AC Industrial PowerPin ConfigurationPower Supplies ConversionIsolated T ..
MAX5053AEUA ,10.8 V, 50 W, current-mode PWM controller with an error amplifier for isolated/nonisolated power supplyELECTRICAL CHARACTERISTICS(V = +12V (for MAX5052, V must first be brought up to 23.6V for startup), ..
MAX5053BEUA+ ,Current-Mode PWM Controllers with an Error Amplifier for Isolated/Nonisolated Power SuppliesFeaturesThe MAX5052/MAX5053 current-mode PWM controllers ♦ Available in a Tiny 8-Pin µMAX Packageco ..
MAX5053BEUA+T ,Current-Mode PWM Controllers with an Error Amplifier for Isolated/Nonisolated Power SuppliesELECTRICAL CHARACTERISTICS(V = +12V (for MAX5052, V must first be brought up to 23.6V for startup), ..
MAX5054AATA ,4A, 20ns, Dual MOSFET DriversApplications PART TEMP RANGEPACKAGE MARKPower MOSFET Switching Motor ControlMAX5054AATA -40°C to +1 ..
MAX5054AATA+T ,4A, 20ns, Dual MOSFET DriversApplicationsRANGE PACKAGE MARKPower MOSFET Switching Motor ControlMAX5054AATA+ -40°C to +125°C 8 TD ..
MAX9260GCB/V+T ,Gigabit Multimedia Serial Link with Spread Spectrum and Full-Duplex Control ChannelApplications Circuit appears at end of data sheet.For pricing, delivery, and ordering information, ..
MAX9310EUP ,1:5 Clock Driver with Selectable LVPECL Inputs and LVDS OutputsApplicationsData and Clock Drivers and BuffersCentral-Office Backplane Clock DistributionDSLAMBase ..
MAX9311ECJ ,1:10 Differential LVPECL/LVECL/HSTL Clock and Data DriversFeaturesThe MAX9311/MAX9313 are low-skew, 1-to-10 differen- +2.25V to +3.8V Differential HSTL/LVPE ..
MAX9311ECJ+ ,1:10 Differential LVPECL/LVECL/HSTL Clock and Data DriversApplicationsMAX9313ECJ -40°C to +85°C 32 LQFP (7mm ✕ 7mm)Precision Clock DistributionMAX9313EGJ* -4 ..
MAX9315EUP ,1:5 Differential LVPECL/LVECL/HSTL Clock and Data DriverELECTRICAL CHARACTERISTICS(V - V = 2.375V to 3.8V, outputs loaded with 50Ω ±1% to V - 2V, SEL = hig ..
MAX9315EUP+ ,1:5 Differential LVPECL/LVECL/HSTL Clock and Data DriverApplicationsOrdering InformationPrecision Clock DistributionPART TEMP. RANGE PIN-PACKAGELow-Jitter ..
MAX5052AEUA-MAX5052BEUA-MAX5053AEUA
22 V, 50 W, current-mode PWM controller with an error amplifier for isolated/nonisolated power supply
General DescriptionThe MAX5052/MAX5053 current-mode PWM controllers
contain all the control circuitry required for the design of
wide-input-voltage isolated and nonisolated power
supplies. The MAX5052 is well suited for universal input
(rectified 85VAC to 265VAC) or telecom (-36VDC to
-72VDC) power supplies. The MAX5053 is well suited for
low-input-voltage (10.8VDC to 24VDC) power supplies.
The MAX5052/MAX5053 contain an internal error ampli-
fier that regulates the tertiary winding output voltage.
This implements a primary-side regulated, isolated
power supply, eliminating the need for an optocoupler.
An input undervoltage lockout (UVLO) is provided for
programming the input-supply start voltage and to
ensure proper operation during brownout conditions.
The input-supply start voltage is externally programma-
ble with a voltage-divider. To shutdown the device, the
UVLO pin is pulled low. Internal digital soft-start
reduces output voltage overshoot. The internal thermal
shutdown circuit protects the device in the event the
junction temperature exceeds +130°C.
The MAX5052 has an internal bootstrap UVLO with
large hysteresis that requires a minimum voltage of
23.6V for startup. The MAX5053 does not have the
internal bootstrap UVLO and can be biased directly
from a minimum voltage of 10.8V.
The 262kHz switching frequency is internally trimmed to
±12% accuracy; this allows the optimization of the
magnetic and filter components resulting in compact,
cost-effective power supplies. The MAX5052A/
MAX5053A are offered with a 50% maximum duty-cycle
limit. The MAX5052B/MAX5053B are offered with a 75%
maximum duty-cycle limit. These devices are available
in 8-pin µMAX packages and operate over the -40°C to
+85°C temperature range.
Applications
FeaturesAvailable in a Tiny 8-Pin µMAX PackageCurrent-Mode Control50W Output PowerUniversal Offline Input Voltage Range
Rectified 85VAC to 265VAC (MAX5052)VINDirectly Driven from 10.8V to 24V Input
(MAX5053)Digital Soft-StartProgrammable Input Startup VoltageInternal Bootstrap UVLO with Large Hysteresis
(MAX5052)Internal Error Amplifier with 1% Accurate
ReferenceThermal Shutdown45µA (typ) Startup Supply Current1.4mA (typ) Operating Supply CurrentFixed Switching Frequency of 262kHz ±12%50% Maximum Duty-Cycle Limit
(MAX5052A/MAX5053A)75% Maximum Duty-Cycle Limit
(MAX5052B/MAX5053B)60ns Cycle-by-Cycle Current-Limit Response Time
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
Ordering Information19-2590; Rev 1; 11/03
Functional Diagram/Typical Operating Circuit/Selector
Pin Configuration
Warning:The MAX5052/MAX5053 are designed to work with
high voltages. Exercise caution.
Universal Input AC
Power Supplies
Isolated Telecom Power
Supplies
Networking Systems
Computer Systems/
Servers
Industrial Power
Conversion
Isolated Keep-Alive
Circuits
12V Boost Regulators
12V SEPIC Regulators
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VIN= +12V (for MAX5052, VINmust first be brought up to 23.6V for startup), 10nF bypass capacitors at VINand VCC, CNDRV= 0,
VUVLO= +1.4V, VFB= +1.0V, VCOMP= floating, VCS= 0V, typical values are measured at TA= +25°C, TA= -40°C to + 85°C, unless
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VINto GND.............................................................-0.3V to +30V
VCCto GND............................................................-0.3V to +13V
FB, COMP, UVLO, CS to GND.................................-0.3V to +6V
NDRV to GND.............................................-0.3V to (VCC+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C)..............362mW
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range ............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s).................................+300°C
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
Note 1:All devices are 100% tested at TA= +85°C. All limits over temperature are guaranteed by characterization.
Note 2:VREFis measured with FB connected to the COMP pin (see Functional Diagram).
Note 3:The MAX5052 is intended for use in universal input power supplies. The internal clamp circuit is used to prevent the boot-
strap capacitor (C1 in Figure 1) from charging to a voltage beyond the absolute maximum rating of the device when
EN/UVLO is low. The maximum current to VIN(hence to clamp) when UVLO is low (device in shutdown) must be externally
limited to 2mA, max. Clamp currents higher than 2mA may result in clamp voltage higher than 30V, thus exceeding the
absolute maximum rating for VIN. For the MAX5053, do not exceed the 24V maximum operating voltage of the device.
ELECTRICAL CHARACTERISTICS (continued)(VIN= +12V (for MAX5052, VINmust first be brought up to 23.6V for startup), 10nF bypass capacitors at VINand VCC, CNDRV= 0,
VUVLO= +1.4V, VFB= +1.0V, VCOMP= floating, VCS= 0V, typical values are measured at TA= +25°C, TA= -40°C to + 85°C, unless
otherwise noted.) (Note 1)
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
Typical Operating Characteristics(UVLO = +1.4V, VFB= +1V, VCOMP= floating, VCS= 0V, TA= +25°C, unless otherwise noted.)
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
Typical Operating Characteristics (continued)(UVLO = +1.4V, VFB= +1V, VCOMP= floating, VCS= 0V, TA= +25°C, unless otherwise noted.)
MAX5052/MAX5053
Detailed DescriptionThe MAX5052/MAX5053 are current-mode PWM con-
trollers that have been specifically designed for use in
isolated and nonisolated power-supply applications. A
bootstrap UVLO with a large hysteresis (11.9V), very
low startup current, and low operating current result in
efficient universal-input power supplies. In addition to
the internal bootstrap UVLO, these devices also offer
programmable input startup voltage programmed
through the UVLO/EN pin. This feature is useful in pre-
venting the power supply from entering a brownout
condition, in case the input voltage drops below its
minimum value. This is important since switching power
supplies increases their input supply current as the
input voltage drops in order to keep the output power
constant. The MAX5052 is well suited for universal input
(rectified 85VAC to 265VAC) or telecom (-36VDC to
-72VDC) power supplies. The MAX5053 is well suited for
low-input-voltage (10.8VDC to 24VDC) power supplies.
Power supplies designed with the MAX5052 use a
high-value startup resistor, R1, that charges a reservoir
capacitor, C1 (see Figure 1). During this initial period,
while the voltage is less than the internal bootstrap
UVLO threshold, the device typically consumes only
45µA of quiescent current. This low startup current and
the large bootstrap UVLO hysteresis helps to minimize
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
Typical Operating Characteristics (continued)(UVLO = +1.4V, VFB= +1V, VCOMP= floating, VCS= 0V, TA= +25°C, unless otherwise noted.)
the power dissipation across R1 even at the high end of
the universal AC input voltage (265VAC).
The MAX5052/MAX5053 include a cycle-by-cycle cur-
rent limit that turns off the gate drive to the external
MOSFET during an overcurrent condition. When using
the MAX5052 in the bootstrapped mode (if the power-
supply output is shorted), the tertiary winding voltage
drops below the 10V threshold causing the UVLO to
turn off the gate drive to the external power MOSFET.
This reinitiates a startup sequence with soft-start.
MAX5052/MAX5053
Undervoltage Lockout The MAX5052/MAX5053 have an input voltage
UVLO/EN pin. The threshold for this UVLO is 1.28V.
Before any operation can commence, the voltage on
this pin has to exceed 1.28V. The UVLO circuit keeps
the CPWM comparator, ILIM comparator, oscillator,
and output driver shut down to reduce current con-
sumption (see the Functional Diagram).
Use this UVLO function to program the input-supply
start voltage. For example, a reasonable start voltage
for a 36V to 72V telecom range might be set at 34V.
Calculate the divider resistor values, R2 and R3 (see
Figure 1) by using the following formulas:
The value of R3 is calculated to minimize the voltage-
drop error across R2 as a result of the input bias cur-
rent of the UVLO/EN pin. VULR2= 1.28V, IUVLO= 50nA
(max). VINis the value of the input-supply voltage
where the power supply must start.
where IUVLOis the UVLO/EN pin input current (50nA),
and VULR2is the UVLO/EN wake-up threshold.
MAX5052 Bootstrap
Undervoltage Lockout In addition to the externally programmable UVLO func-
tion offered in both the MAX5052 and MAX5053, the
MAX5052 has an additional internal bootstrap UVLO
that is very useful when designing high-voltage power
supplies (see the Functional Diagram). This allows the
device to bootstrap itself during initial power-up. The
MAX5052 attempts to start when VINexceeds the boot-
strap UVLO threshold of 21.6V.
During startup, the UVLO circuit keeps the CPWM com-
parator, ILIM comparator, oscillator, and output driver
shut down to reduce current consumption. Once VIN
reaches 21.6V, the UVLO circuit turns on both the CPWM
and ILIM comparators, as well as the oscillator, and
allows the output driver to switch. If VINdrops below
9.7V, the UVLO circuit will shut down the CPWM com-
parator, ILIM comparator, oscillator, and output driver
returning the MAX5052/MAX5053 to the startup mode.
MAX5052 Startup OperationNormally VINis derived from a tertiary winding of the
transformer. However, at startup there is no energy
delivered through the transformer, hence, a special
bootstrap sequence is required. Figure 2 shows the
voltages on VINand VCCduring startup. Initially, both
VINand VCCare 0V. After the line voltage is applied,
C1 charges through the startup resistor, R1, to an inter-
mediate voltage. At this point, the internal regulator
begins charging C2 (see Figure 1). The MAX5052 uses
only 45µA of the current supplied by R1, and the
remaining input current charges C1 and C2. The charg-
ing of C2 stops when the VCCvoltage reaches approxi-
mately 9.5V, while the voltage across C1 continues
rising until it reaches the wake-up level of 21.6V. Once
VINexceeds the bootstrap UVLO threshold, NDRV
begins switching the MOSFET and transfers energy to
the secondary and tertiary outputs. If the voltage on the
tertiary output builds to higher than 9.9V (the bootstrap
UVLO lower threshold), then startup has been accom-
plished and sustained operation commences.
MAX5052/MAX5053
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power SuppliesFigure 1. Nonisolated Power Supply with Programmable Input-
Supply Start Voltage
