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UCC28740-Q1

ACTIVE

Automotive ultra low standby, flyback controller with integrated HV startup and optocoupler feedback

Product details

Topology Flyback Control mode Secondary-side regulation Switching frequency (max) (kHz) 100 Features Automotive qualified, Current limiting, DCM, Error amplifier, Green mode, High voltage startup, High-voltage startup, Input line monitor, Leading edge blanking, Light load efficiency, Light-load efficiency, Low power, Overcurrent protection, SSR, Secondary-side regulated, Soft start, Valley switching UVLO thresholds on/off (V) 21/7.75 Operating temperature range (°C) -40 to 125 Rating Automotive Gate drive (typ) (A) 0.025 TI functional safety category Functional Safety-Capable
Topology Flyback Control mode Secondary-side regulation Switching frequency (max) (kHz) 100 Features Automotive qualified, Current limiting, DCM, Error amplifier, Green mode, High voltage startup, High-voltage startup, Input line monitor, Leading edge blanking, Light load efficiency, Light-load efficiency, Low power, Overcurrent protection, SSR, Secondary-side regulated, Soft start, Valley switching UVLO thresholds on/off (V) 21/7.75 Operating temperature range (°C) -40 to 125 Rating Automotive Gate drive (typ) (A) 0.025 TI functional safety category Functional Safety-Capable
SOIC (D) 7 29.4 mm² 4.9 x 6
  • Qualified for automotive applications
  • AEC-Q100 qualified with the following results:
    • Device temperature grade 1: -40.C to +125.C
    • Device HBM classification level 2: ±2 kV
    • Device CDM classification level C4B: ±750 V
  • Funcitonal Safety-Capable
  • Less than 10-mW no-load power capability
  • Enables ±1% voltage regulation and ±5% current regulation across line and load
  • 700-V startup switch
  • 100-kHz maximum switching frequency enables high-power-density charger designs
  • Resonant-ring valley-switching operation for highest overall efficiency
  • Frequency dithering to ease EMI compliance
  • Clamped gate-drive output for MOSFET
  • Overvoltage, low-line, and over current protection functions
  • Create a custom design using the UCC28740-Q1 with the WEBENCH Power Designer
  • Qualified for automotive applications
  • AEC-Q100 qualified with the following results:
    • Device temperature grade 1: -40.C to +125.C
    • Device HBM classification level 2: ±2 kV
    • Device CDM classification level C4B: ±750 V
  • Funcitonal Safety-Capable
  • Less than 10-mW no-load power capability
  • Enables ±1% voltage regulation and ±5% current regulation across line and load
  • 700-V startup switch
  • 100-kHz maximum switching frequency enables high-power-density charger designs
  • Resonant-ring valley-switching operation for highest overall efficiency
  • Frequency dithering to ease EMI compliance
  • Clamped gate-drive output for MOSFET
  • Overvoltage, low-line, and over current protection functions
  • Create a custom design using the UCC28740-Q1 with the WEBENCH Power Designer

The UCC28740-Q1 isolated-flyback power-supply controller regulates the output using an optical coupler to provide fast transient response to large-load steps.

An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response.

Control algorithms in the UCC28740-Q1 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power.

The UCC28740-Q1 isolated-flyback power-supply controller regulates the output using an optical coupler to provide fast transient response to large-load steps.

An internal 700-V startup switch, dynamically controlled operating states, and a tailored modulation profile support ultra-low standby power without sacrificing startup time or output transient response.

Control algorithms in the UCC28740-Q1 allow operating efficiencies to meet or exceed applicable standards. The drive output interfaces to a MOSFET power switch. Discontinuous conduction mode (DCM) with valley-switching reduces switching losses. Modulation of switching frequency and primary current-peak amplitude (FM and AM) keeps the conversion efficiency high across the entire load and line ranges.

The controller has a maximum switching frequency of 100 kHz and always maintains control of the peak-primary current in the transformer. Protection features keep primary and secondary component stresses in check. A minimum switching frequency of 170 Hz facilitates the achievement of less than 10-mW no-load power.

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Technical documentation

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Type Title Date
* Data sheet UCC28740-Q1 Ultra Low Standby, Flyback Controller for Automotive, with Integrated HV Startup and Optocoupler Feedback datasheet (Rev. C) PDF | HTML 08 Dec 2020
Application note Designing a Robust Traction Inverter Redundant Power Supply From 800 V Battery (Rev. C) PDF | HTML 16 Feb 2023
Functional safety information UCC28740-Q1 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA PDF | HTML 11 Nov 2020
Application note Minimize Standby Consumption for UCC287XX Family 01 Aug 2019
Analog Design Journal Agency requirements for stand-by power consumption w/ offline and PoL converters 26 Jan 2016

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

UCC28740EVM-525 — UCC28740EVM-525 Evaluation Module

The UCC28740EVM-525 evaluation module is a 10W off-line discontinuous mode (DCM) flyback converter that provides constant-voltage (CV) and constant-current (CC) output regulation. It uses optical coupler feedback for tight voltage regulation and improved the transient response to large load steps (...)

User guide: PDF
Not available on TI.com
Simulation model

UCC28740 SIMPLIS Transient Model (Rev. A)

SLUM672A.ZIP (122 KB) - SIMPLIS Model
Calculation tool

UCC28740 Design Calculator (Rev. B)

SLUC487B.ZIP (317 KB)
Reference designs

PMP41009 — 350-V to 1000-V DC input, 56-W flyback isolated power supply reference design

This reference design provides isolated 14-V and 56-W outputs with a quasi-resonant flyback topology. The power supply can be powered from the 350-V to 1000-V DC input. This design uses cascode MOSFETs and flyback controller UCC28740-Q1. The line and load regulation are regulated to within ±1% (...)
Test report: PDF
Reference designs

TIDA-010071 — SAE J1772-compliant electric vehicle service equipment reference design for level 1 and 2 EV charger

This reference design highlights an ultra-low standby isolated AC/DC auxiliary power stage followed by converters and linear regulators, a comparator-based control pilot interface to meet the SAE J1772 standard, an  efficient relay and contactor drive and isolated line voltage sensing across (...)
Design guide: PDF
Schematic: PDF
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SOIC (D) 7 View options

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