MAX5052 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – Current-Mode PWM Controllers with an Error Amplifier for Isolated/Nonisolated Power Supplies

19-2590; Rev 1; 11/03
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Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
General Description
The 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.
Universal Input AC
Power Supplies
Isolated Telecom Power
Supplies
Networking Systems
Computer Systems/
Servers
Applications
Industrial Power
Conversion
Isolated Keep-Alive
Circuits
12V Boost Regulators
12V SEPIC Regulators
Features
♦ Available in a Tiny 8-Pin µMAX Package
♦ Current-Mode Control
♦ 50W Output Power
♦ Universal Offline Input Voltage Range
Rectified 85VAC to 265VAC (MAX5052)
♦ V_IN Directly Driven from 10.8V to 24V Input
(MAX5053)
♦ Digital Soft-Start
♦ Programmable Input Startup Voltage
♦ Internal Bootstrap UVLO with Large Hysteresis
(MAX5052)
♦ Internal Error Amplifier with 1% Accurate
Reference
♦ Thermal Shutdown
♦ 45µA (typ) Startup Supply Current
♦ 1.4mA (typ) Operating Supply Current
♦ Fixed 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
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
MAX5052AEUA
-40°C to +85°C 8 µMAX
MAX5052BEUA
-40°C to +85°C 8 µMAX
MAX5053AEUA
-40°C to +85°C 8 µMAX
MAX5053BEUA
-40°C to +85°C 8 µMAX
Warning: The MAX5052/MAX5053 are designed to work with
high voltages. Exercise caution.
Pin Configuration
TOP VIEW
UVLO/EN 1
FB 2
COMP 3
CS 4
MAX5052
MAX5053
8 V_IN
7 V_CC
6 NDRV
5 GND
Functional Diagram/Typical Operating Circuit/Selector
Guide appear at end of data sheet.
µMAX
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