TEA1733MT Ver la hoja de datos (PDF) - NXP Semiconductors.

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Fabricante

TEA1733MT

GreenChip SMPS control IC

NXP Semiconductors. 

NXP Semiconductors

TEA1733MT

GreenChip SMPS control IC

VCC

ISENSE

VINSENSE

PROTECT

OPTIMER

soft start

Vstartup

Vth(UVLO)

soft start

Vdet(H)(VINSENSE)

Vdet(H)(PROTECT)

Vdet(L)(PROTECT)

4.5 V

1.2 V

VO

charging VCC

capacitor

starting

converter

normal

operation

(power down)

protection

restart

014aaa929

Fig 4. Start-up sequence, normal operation and restart sequence

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

controller stops switching. A VCC undervoltage causes the TEA1733MT to be latched in

the off-state.

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.

Switching will not take place until the voltage on VINSENSE has reached the

Vstart(VINSENSE) voltage (typically 0.94 V).

When the VINSENSE voltage drops below Vdet(L)(VINSENSE) (typically 0.72 V) or exceeds

Vdet(H)(VINSENSE) (typically 3.52 V), the converter stops switching and performs a restart.

If pin VINSENSE is left open or disconnected, the pin is pulled up by the internal 20 nA

(typical) current source to reach the Vdet(H)(VINSENSE) level. This triggers a restart

protection.

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

7.5 Protection input (PROTECT pin)

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

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

pulled above Vdet(H)(PROTECT) (typically 0.8 V) or below Vdet(L)(PROTECT) (typically 0.5 V). A

current of 32 μA (typical) flows out of the chip when the pin voltage is at the

Vdet(L)(PROTECT) level. A current of 107 μA (typical) flows into the chip when the pin voltage

is at the Vdet(H)(PROTECT) level.

TEA1733MT

Preliminary data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 1 — 4 February 2011

© NXP B.V. 2011. All rights reserved.

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