Voltage Mode PWM

The SG3525A series of pulse width modulator integrated circuits are designed to offer improved performance and lowered external parts count when used in designing all types of switching power supplies. The on-chip + 5.1 V reference is trimmed to ±1 % and the input common-mode range of the error amplifier includes the reference voltage eliminating external resistors. A sync input to the oscillator allows multiple units to be slaved or a single unit to be synchronized to an external system clock. A single resistor between the CT and the discharge terminals provide a wide range of dead time ad- justment.These devices also feature built-in soft-start circuitry with only an external timing capacitor required. A shutdown terminal controls both the soft-start circuity and the output stages, providing instantaneous turn off through the PWM latch with pulsed shutdown,as well as soft-start recycle with longer shutdown commands. These functions are also controlled by an undervoltage lockout which keeps the outputs off and the soft-start capacitor discharged for sub-normal input voltages. This lockout circuitry includes approximately 500 mV of hysteresis for jitter-free operation. Another feature of these PWM circuits is a latch following the comparator. Once a PWM pulses has been terminated for any reason,the outputs will remain off for the duration of the period. The latch is reset with each clock pulse. The output stages are totem-pole designs capable of sourcing or sinking in excess of 200 mA. The SG3525A output stage features NOR logic, giving a LOW output for an OFF state.

Key Features

  • DUAL SOURCE/SINK OUTPUT DRIVERS
  • LATCHING PWM TO PREVENT MULTIPLE PULSES
  • PULSE-BY-PULSE SHUTDOWN
  • INTERNAL SOFT-START
  • 8 TO 35 V OPERATION
  • 100 Hz TO 500 KHz OSCILLATOR RANGE
  • 5.1 V REFERENCE TRIMMED TO ± 1 %
  • ADJUSTABLE DEADTIME CONTROL
  • INPUT UNDERVOLTAGE LOCKOUT WITH HYSTERESIS
  • SEPARATE OSCILLATOR SYNC TERMINAL

Circuit Diagram

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Design

Technical Documentation

Product Specifications
Description Version Size
DS0901 DS0901: REGULATING PULSE WIDTH MODULATORS 4.0 934 KB
Application Notes
Description Version Size
AN250 AN250: A second-generation IC switch mode controller optimized for high frequency power MOS drive 1.2 835 KB

Presentations & Training Material

Presentations
Description Version Size
Primary side regulation controllers portfolio 1 MB

Publications and Collaterals

Brochures
Description Version Size
Brochure Power management guide 05.2016 4 MB
Support & Community



Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
SG3525AN PDIP 16 Tube Active - - NEC EAR99 MALAYSIA MORE INFO DISTRIBUTOR AVAILABILITY
SG3525AP013TR SO-16 Tape And Reel Active - - NEC EAR99 CHINA MORE INFO DISTRIBUTOR AVAILABILITY
SG3525AP SO-16 Tube Active - - NEC EAR99 CHINA MORE INFO DISTRIBUTOR AVAILABILITY
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(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
SG3525AN ActivePDIP 16IndustrialEcopack2 (**) 0 0
SG3525AP013TR ActiveSO-16IndustrialEcopack2 (**) 0 0
SG3525AP ActiveSO-16IndustrialEcopack2 (**) 0 0
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(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.

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