General description

The TEA1752LT is the third generation of green Switched Mode Power Supply (SMPS)

controller ICs. The TEA1752LT combines a controller for Power Factor Correction (PFC)

and a flyback controller. Its high level of integration allows the design of a cost-effective

power supply with a very low number of external components.

The special built-in green functions provide high efficiency at all power levels. This

efficiency applies to quasi-resonant operation at high-power levels, quasi-resonant

operation with valley skipping, as well as reduced frequency operation at lower power

levels. At low-power levels, the PFC switches off to maintain high efficiency.

During low-power conditions, the flyback controller switches to frequency reduction mode

and limits the peak current to an adjustable minimum value. This mode ensures high

efficiency at low-power and good standby power performance while minimizing audible

noise from the transformer.

The TEA1752LT is a Multi-Chip Module, (MCM), containing 2 chips. The proprietary

high-voltage BCD800 process which makes direct start-up possible from the rectified

universal mains voltage in an effective and green way. The second low voltage

Silicon On Insulator (SOI) is used for accurate, high-speed protection functions and

control.

The TEA1752LT enables the design of highly efficient and reliable supplies with power

requirements of up to 250 W with a minimum number of external components.

Remark: All values provided throughout the running text, are typical values unless

otherwise stated.

Features and benefits

Distinctive features

Integrated PFC and flyback controller

Universal mains supply operation (70 V AC to 276 V AC)

Dual boost PFC with accurate maximum output voltage (NXP patented)

High level of integration, resulting in a very low external component count and a

cost-effective design

Adjustable PFC switch-off delay

Green features

On-chip start-up current source

PFC green features

Valley/zero voltage switching for minimum switching losses (NXP patented)

Frequency limitation to reduce switching losses

PFC is switched off when a low load is detected at the flyback output

Flyback green features

Valley switching for minimum switching losses (NXP patented)

Frequency reduction with adjustable minimum peak current at low-power operation to

maintain high efficiency at low output power levels

Protection features

Safe restart mode for system fault conditions

Continuous mode protection with demagnetization detection for both converters (NXP

patented)

UnderVoltage Protection (UVP) (foldback during overload)

Accurate OverVoltage Protection (OVP) for both converters (adjustable for flyback

converter)

Mains voltage independent OverPower Protection (OPP)

Open control loop protection for both converters. The open-loop protection on the

flyback converter is latched

OverTemperature Protection (OTP)

Low and adjustable OverCurrent Protection (OCP) trip level for both converters

General-purpose input for latched protection, for system OverTemperature Protection

(OTP) for example