TEA1530AT Просмотр технического описания (PDF) - Philips Electronics

Номер в каталоге

Компоненты Описание

производитель

TEA1530AT

GreenChip™II SMPS control IC

Philips Electronics 

Philips Semiconductors

TEA1530AT

GreenChip™II SMPS control IC

7.1 Start-up, mains enabling operation level and undervoltage lock out

Refer to Figure 8 and Figure 9. Initially, the IC is self supplying from the rectified mains

voltage via pin DRAIN. Supply capacitor CVCC (at pin 1) is charged by the internal start-up

current source to a level of about 4 V or higher, depending on the drain voltage. Once the

drain voltage exceeds the Vm (mains-dependent operation-enabling level), the start-up

current source will continue charging capacitor CVCC (switch S1 will be opened); see

Figure 1. The IC will activate the power converter as soon as the voltage on pin VCC

passes the Vstart level. At this moment the IC supply from the high voltage pin is stopped

(green function). The IC supply is taken over by the auxiliary winding of the flyback

converter.

The moment the voltage on pin VCC drops below VUVLO (undervoltage lock out), the IC

stops switching and performs a safe restart from the rectified mains voltage. In the safe

restart mode the driver output is disabled and pin VCC voltage is recharged via pin DRAIN.

7.2 Supply management

All (internal) reference voltages are derived from a temperature compensated, on-chip

band gap circuit.

7.3 Current control mode

Current control mode is used for its good line regulation behavior.

The primary current is sensed across an external resistor and compared with the internal

control voltage. The driver output is latched in the logic, preventing multiple switch-on.

The internal control voltage is inversely proportional to the external pin CTRL voltage, with

an offset of 1.5 V. This means that a voltage range from 1 V to approximately 1.5 V on

pin CTRL will result in an internal control voltage range from 0.5 V to 0 V (a high external

control voltage results in a low duty cycle).

Vsense(max) (V)

coa016

0.52 V

Cycle

skip

active

25 mV

1V

(typ)

1.5 V

(typ) VCTRL (V)

Fig 5. The Vsense(max) voltage as a function of VCTRL

7.4 Oscillator

The fixed frequency of the oscillator is set by an internal current source and capacitor.

Objective data sheet

Rev. 01 — 18 May 2005

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

5 of 22

Share Link: