TEA1533AP View Datasheet(PDF) - Philips Electronics

Part Name

Description

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TEA1533AP

GreenChip™II SMPS control IC

Philips Electronics 

Philips Semiconductors

GreenChipTMII SMPS control IC

Product specification

TEA1533P; TEA1533AP

handbook, full pagewidth

primary

stroke

secondary

stroke

drain

secondary

ringing

valley

secondary

stroke

oscillator

B

A

MGU235

A: Start of new cycle at lowest drain voltage.

B: Start of new cycle in a classical PWM system at high drain voltage.

Fig.8 Signals for valley switching.

OverCurrent Protection (OCP)

The cycle-by-cycle peak drain current limit circuit uses the

external source resistor to measure the current accurately.

This allows optimum size determination of the transformer

core (cost issue). The circuit is activated after the leading

edge blanking time, tleb. The OCP circuit limits the ‘sense’

voltage to an internal level.

OverPower Protection (OPP)

During the primary stroke, the rectified mains input voltage

is measured by sensing the current drawn from pin DEM.

This current is dependent on the mains voltage, according

to the following formula: IDEM ≈ R--V---D--a--Eu---xM-- ≈ N------×-R----VD----Em---M-a---i-n--s-

where: N = -N--N--a---pu---x

The current information is used to adjust the peak drain

current, which is measured via pin Isense. The internal

compensation is such that an almost mains independent

maximum output power can be realized.

The OPP curve is given in Fig.9.

2002 Aug 23

9

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