General description

The TEA1738(L) is a low cost Switched Mode Power Supply (SMPS) controller IC

intended for flyback topologies. The TEA1738(L) operates in peak current and frequency

control mode. Frequency jitter has been implemented to reduce ElectroMagnetic

Interference (EMI). Slope compensation is integrated for Continuous Conduction Mode

(CCM) operation.

The TEA1738(L) IC includes OverPower Protection (OPP). This enables the controller to

operate under overpower situations for a limited amount of time.

Two pins, VINSENSE and PROTECT, are reserved for protection purposes. Input

UnderVoltage Protection (UVP), output OverVoltage Protection (OVP) and

OverTemperature Protection (OTP) can be implemented using a minimal number of

external components.

At low power levels the primary peak current is set to 25 of the maximum peak current

and the switching frequency is reduced to limit switching losses. The combination of fixed

frequency operation at high output power and frequency reduction at low output power

provides high efficiency over the total load range.

The TEA1738(L) enables low cost, highly efficient and reliable supplies for power

requirements up to 75 W to be designed easily and with a minimum number of external

components.

Features

SMPS controller IC enabling low-cost applications

Large input voltage range (12 V to 30 V)

Integrated OverVoltage Protection (OVP) on pin VCC

Very low supply current during start-up and restart (10 μA typical)

Low supply current during normal operation (0.55 mA typical without load)

Overpower or high/low line compensation

Adjustable overpower time-out

Adjustable overpower restart timer

Fixed switching frequency with frequency jitter to reduce EMI

Frequency reduction at medium power operation to maintain high efficiency

Frequency reduction with fixed minimum peak current at low power to maintain high

efficiency at low output power levels

Frequency increase at peak power operation

Slope compensation for CCM operation

Low and adjustable OverCurrent Protection (OCP) trip level

Adjustable soft start

Two protection inputs (e.g. for input UVP and OTP)

IC overtemperature protection