TEA1733T_TEA1733LT_1

© NXP B.V. 2009. All rights reserved.

Objective data sheet

Rev. 01 — 26 October 2009

5 of 17

NXP Semiconductors

TEA1733T; TEA1733LT

GreenChip SMPS control IC

When the voltage on pin VCC drops below the UVLO level during normal operation, the

controller stops switching and enters Restart mode. In Restart mode the driver output is

disabled and the VCC pin voltage is recharged via the resistor to the rectified mains.

7.3 Supply management

All internal reference voltages are derived from a temperature compensated on-chip band

gap circuit. Internal reference currents are derived from a trimmed and temperature

compensated current reference circuit.

7.4 Input voltage detection (VINSENSE pin)

In a typical application the mains input voltage can be detected by the VINSENSE pin. As

(typically 0.93 V), switching is inhibited.

switching and performs a restart.

If the pin is left open or disconnected, the pin is pulled up by the internal 20 nA (typ.)

trigger a restart protection.

An internal clamp of 5.2 V (typ.) protects this pin from excessive voltages.

7.5 Protection input (PROTECT PIN)

The pin PROTECT is a general purpose input pin, which can be used to switch off the

converter (latched protection). The converter is stopped as soon as the voltage on this pin

A current of 32

µA (typ.) is flowing out of the chip when the pin voltage is V

A current of 107

µA (typ.) is flowing into the chip when the pin voltage is V

Fig 4.

Start-up sequence, normal operation and restart sequence

014aaa929

starting

converter

charging VCC

capacitor

normal

operation

protection

(power down)

soft start

ISENSE

VINSENSE

PROTECT

OPTIMER

Output voltage

restart

soft start

4.5 V

1.2 V