TEA1733T Ver la hoja de datos (PDF) - NXP Semiconductors.

Número de pieza

componentes Descripción

Fabricante

TEA1733T

GreenChip SMPS control IC

NXP Semiconductors. 

NXP Semiconductors

2

1.7

IISENSE

(μA)

TEA1733T

GreenChip SMPS control IC

0.68 1

2

3

4

VVINSENSE (V)

014aaa933

Fig 8. Overpower compensation using pins VINSENSE and ISENSE

7.11 Soft start-up (ISENSE pin)

To prevent audible noise during start-up or a restart condition, a soft start is made. Before

the converter starts, the soft start capacitor C6 (see Figure 3) on the ISENSE pin is

charged. When the converter starts switching, the primary peak current slowly increases

as the soft start capacitor discharges through the soft start resistor (R6, see Figure 3).

The soft start time constant is set by the soft start capacitor value chosen. The soft start

resistor value must also be taken into account, but this value is typically defined by the

overpower compensation (see Section 7.10).

7.12 Low power operation

In low power operation switching losses are reduced by lowering the switching frequency.

The converter switching frequency is reduced and the peak current is set to 25 % of the

maximum peak current (see Figure 6 and Figure 9).

fsw

(kHz)

switching

frequency

Fig 9. Frequency control

1

2

VCTRL (V)

014aaa934

7.13 Driver (DRIVER pin)

The driver circuit to the gate of the power MOSFET has a current sourcing capability of

typically 300 mA and a current sink capability of typically 750 mA. This allows for a fast

turn-on and turn-off of the power MOSFET for efficient operation.

TEA1733T

Product data sheet

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

Rev. 7 — 11 July 2013

© NXP B.V. 2013. All rights reserved.

9 of 21

Share Link: