tea1532ct-n1 NXP Semiconductors, tea1532ct-n1 Datasheet - Page 6

• Manufacturer Part Number: tea1532ct-n1
• Description: Greenchip Ii Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1532BT_TEA1532CT_1
Product data sheet
7.1 Start-up, mains enabling operation level and undervoltage lock out
7.2 Supply management
7.3 Oscillator
7.4 Cycle skipping
7.5 Current control mode
To prevent very high frequency operation at lower loads, the quasi-resonant operation
changes smoothly in fixed frequency Pulse Width Modulation (PWM) control.
In fixed frequency continuous conduction mode, which can be activated by grounding
pin DEM, the internal oscillator determines the start of the next converter stroke.
In both operating modes, a cycle skipping mode is activated at very low power (standby)
levels.
Refer to
voltage via pin DRAIN. Supply capacitor C
current source to a level of about 4 V or higher, depending on the drain voltage. Once the
drain voltage exceeds the V
start-up current source will continue charging capacitor C
see
passes the V
(green function). The IC supply is taken over by the auxiliary winding of the flyback
converter.
The moment the voltage on pin V
stops switching and performs a safe restart from the rectified mains voltage. In the safe
restart mode the driver output is disabled and pin V
All (internal) reference voltages are derived from a temperature compensated, on-chip
band gap circuit.
The fixed frequency of the oscillator is set by an internal current source and capacitor.
At very low power levels a cycle skipping mode activates. An internal control voltage
(V
this voltage increases to a higher value; see
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).
sense(max)
Figure
Figure 9
) lower than 25 mV will inhibit switch-on of the external power MOSFET until
1. The IC will activate the power converter as soon as the voltage on pin V
startup
and
level. At this moment the IC supply from the high voltage pin is stopped
Figure
Rev. 01 — 18 January 2007
mains(oper)(en)
10. Initially, the IC is self supplying from the rectified mains
CC
drops below V
TEA1532BT; TEA1532CT
(mains-dependent operation-enabling level), the
VCC
Figure
(at pin 1) is charged by the internal start-up
th(UVLO)
CC
5.
voltage is recharged via pin DRAIN.
VCC
GreenChip II SMPS control IC
(undervoltage lock out), the IC
(switch S1 will be opened);
© NXP B.V. 2007. All rights reserved.
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