MAX8540
Synchronizable, High-Frequency Current- and Voltage-Mode PWM Controllers for Isolated Supplies
Versatile, High-Frequency PWM Controllers Reduce Isolated DC-DC Converter Size and Cost
Top
Overview
Features and Benefits
- 200kHz to 1MHz Adjustable Switching Frequency
- Synchronization to External Clock
- Programmable, Constant Maximum Volt-Second Simplifies Transformer Design
- Programmable Hiccup/Skip Cycles or Latch-Mode Protection
- Clean Startups with High-Capacitance Loads
- Programmable Under/Overvoltage Protection
- Current-Mode, Adjustable Slope Compensation (MAX8540)
- Voltage-Mode, Adjustable Ramp Magnitude (MAX8541)
- 10mA, 5V Regulator
- 75mV to 1.25mV Adjustable Current Limit Reduces External Components
- Internal Gate Driver for Low-Power Applications
- External Gate Driver for High-Power Applications
Product Details
The MAX8540/MAX8541 pulse-width-modulated (PWM) controllers for forward/flyback isolated DC-to-DC converters provide maximum flexibility to power-supply designers and reduce external component count. These controllers allow common PC board layout for current-mode (MAX8540) and voltage-mode (MAX8541) designs.
Both controllers feature adjustable switching frequency and external synchronization from 200kHz to 1MHz. Active-high and active-low enable, undervoltage protection (UVP), and overvoltage protection (OVP) reduce external component count.
Maximum duty cycle is adjustable, and the feed-forward function scales the maximum duty cycle with input voltage to limit the maximum volt-seconds applied to the transformer primary. The MAX8540 allows the user to select the value of slope compensation to further optimize magnetics design. The MAX8541 features user-adjustable ramp magnitude for the PWM comparator.
A cycle-by-cycle current-limit function controls the peak primary current during overload and short circuit. Both controllers can be set to latch off or to hiccup when a short circuit is detected. The number of current-limited cycles to initiate the hiccup mode and number of cycles skipped are user selectable to allow startup with high-capacitance loads and protect the converter against sustained short circuits.
The MAX8540/MAX8541 feature 9Ω internal gate drivers for low-power applications and are compatible with external gate drivers for high-power applications. Both devices are available in the space-saving 16-pin QSOP package.
The MAX8541 EV kit evaluates the MAX8540 and the MAX8541 to speed designs. Design examples are also available in application notes: 50W Voltage-Mode Forward Converter Design with the MAX8541 and 50W Current-Mode Forward Converter Design with the MAX8540.
Applications
- Cell Phone Base Stations
- High-Performance Offline AC/DC Converters
- Isolated DC-to-DC Modules (Bricks)
- Telecom and Network Systems
Product Categories
Product Lifecycle
Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
Design Resources
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Support & Discussions
Sample & Buy
Ordering FAQs
See our Ordering FAQs for answers to questions about online orders, payment options and more.
Buy Now Pricing
(**) Displayed Buy Now Price and Price Range is based on small quantity orders.
List Pricing
(*)The 1Ku list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.
Lead Times
Please see the latest communication from our CCO regarding lead times.
Sampling
Selecting the Sample button above will redirect to the third-party ADI Sample Site. The part selected will carry over to your cart on this site once logged in. Please create a new account there if you have never used the site before. Contact SampleSupport@analog.com with any questions regarding this Sample Site.