UC3825

ACTIVE

Ehanced 30V, 1.5A double ended PWM controller with 9.2V/8.4V UVLO and 85% duty cycle , 0C to 70C

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Product details

Parameters

Topology Boost, Flyback, Forward, Half-Bridge, Push-Pull Control method Current, Feedforward, Voltage VCC (Min) (V) 9.2 VCC (Max) (V) 12 Duty cycle (Max) (%) 85 UVLO thresholds on/off (V) 9.2/8.4 Frequency (Max) (kHz) 1000 Operating temperature range (C) 0 to 70 Gate drive (Typ) (A) 1.5 Features Adjustable Switching Frequency, Current Limiting, Error Amplifier, Multi-topology, Programmable Max Duty Cycle, Soft Start, Synchronization Pin Rating Catalog open-in-new Find other PWM controllers & resonant controllers

Package | Pins | Size

PDIP (N) 16 181 mm² 19.3 x 9.4 SOIC (DW) 16 77 mm² 10.3 x 7.5 open-in-new Find other PWM controllers & resonant controllers

Features

  • Compatible with Voltage or Current Mode Topologies
  • Practical Operation Switching Frequencies to 1MHz
  • 50ns Propagation Delay to Output
  • High Current Dual Totem Pole Outputs (1.5A Peak)
  • Wide Bandwidth Error Amplifier
  • Fully Latched Logic with Double Pulse Suppression
  • Pulse-by-Pulse Current Limiting
  • Soft Start / Max. Duty Cycle Control
  • Under-Voltage Lockout with Hysteresis
  • Low Start Up Current (1.1mA)
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Description

The UC1825 family of PWM control ICs is optimized for high frequency switched mode power supply applications. Particular care was given to minimizing propagation delays through the comparators and logic circuitry while maximizing bandwidth and slew rate of the error amplifier. This controller is designed for use in either current-mode or voltage mode systems with the capability for input voltage feed-forward.

Protection circuitry includes a current limit comparator with a 1V threshold, a TTL compatible shutdown port, and a soft start pin which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free operation and prohibit multiple pulses at an output. An under-voltage lockout section with 800mV of hysteresis assures low start up current. During under-voltage lockout, the outputs are high impedance.

These devices feature totem pole outputs designed to source and sink high peak currents from capacitive loads, such as the gate of a power MOSFET. The on state is designed as a high level.

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Technical documentation

= Top documentation for this product selected by TI
No results found. Please clear your search and try again. View all 4
Type Title Date
* Datasheet High Speed PWM Controller datasheet (Rev. A) Feb. 24, 2004
Selection guides Power Management Guide 2018 (Rev. R) Jun. 25, 2018
Application notes Current Doubler Rectifier Offers Ripple Current Cancellation Sep. 21, 2004
Application notes U-110 1.5 Mhz Current Mode IC Controlled 50-Watt Power Supply Sep. 05, 1999

Design & development

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Design tools & simulation

SIMULATION MODELS Download
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SLUM654.ZIP (6 KB) - TINA-TI Spice Model
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CAD/CAE symbols

Package Pins Download
PDIP (N) 16 View options
SOIC (DW) 16 View options

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