TEA1731LTS

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© NXP B.V. 2012. All rights reserved.

Product data sheet

Rev. 2 — 16 August 2012

4 of 19

NXP Semiconductors

TEA1731LTS

GreenChip SMPS control IC

7.

Functional description

7.1 General control

The TEA1731LTS contains a controller for a flyback circuit. A typical configuration is

shown in Figure 3.

7.2 Start-up and UnderVoltage LockOut (UVLO)

Initially, the capacitor on the VCC pin, C3, is charged from the high-voltage mains via

resistor R1.

level and then starts switching. In a typical application, the auxiliary winding of the

transformer takes over the supply voltage (see Figure 4).

If a protection is triggered, the controller stops switching. Depending on the protection

triggered, it either causes a restart or latches the converter to an off-state.

A restart protection disables the switching of the IC. The supply voltage of the IC drops to

the UVLO level. When the UVLO level is reached, the IC switches to Power-down mode,

where it consumes a low supply current (10

A typical). The switching recommences

When a latched protection is triggered, the TEA1731LTS immediately enters Power-down

mode. The VCC pin is clamped to a voltage just above the latch protection reset voltage

Fig 3.

TEA1731LTS typical configuration

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