Datasheet TEA1501 (NXP) - 5

Philips Semiconductors TEA1501 GreenChip SMPS controller IC
The Burst mode operates by switching at high frequency until VAUX reaches its regulation level of 20 V. The TEA1501 stops switching until the time period set by the burst oscillator has expired. At the start of the next burst period the TEA1501 starts switching at high frequency and repeats the cycle again. To guarantee a stable operation in a Burst mode controlled system a VAUX slope compensation circuit is integrated in the TEA1501. The TEA1501 delivers a constant voltage to the secondary load until a burst duty cycle of 40 % is reached.
7.1.4 Data transfer
The TEA1501 has a data transfer function which makes communication from the isolated secondary side to the non-isolated primary side of the transformer possible, without using an opto-coupler. This communication function is activated by increasing the secondary load. With this data transfer function a main power supply can be switched on and off by the system of the TEA1501. The power delivered to the secondary and auxiliary winding is proportional to the number of primary current pulses per burst period, provided that the converter operates in Discontinuous conduction mode. During each burst period the number of primary current pulses is counted. A threshold (Ndata) of 56 pulses is integrated. The clamp level on the OOD pin is set to data-on level from data-off level in case the Ndata threshold is passed. This data-on clamp level can be sensed by the on/off input of a main supply control IC of the GreenChip family. The data-on clamp level is maintained until a burst appears with a number of pulses below the Ndata threshold. TEA1501_2 © Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet Rev. 02 — 31 March 2006 5 of 21
Document Outline 1. General description 2. Features 2.1 Distinctive features 2.2 Green features 2.3 Protection features 3. Quick reference data 4. Ordering information 5. Block diagram 6. Pinning information 6.1 Pinning 6.2 Pin description 7. Functional description 7.1 System operation 7.1.1 On/off 7.1.2 Start-up 7.1.3 Operation 7.1.4 Data transfer 7.2 Waveforms in the Off mode, Start-up mode and Operation mode 7.3 Circuit block description 7.3.1 On/off/data section 7.3.2 VAUX management 7.3.3 Start-up current source 7.3.4 Reference block 7.3.5 Temperature protection 7.3.6 Switch oscillator 7.3.7 Burst oscillator 7.3.8 Gate driver 7.3.9 Power switch 7.3.10 Primary current comparator 7.3.11 Leading edge blanking 7.3.12 Modulator 7.3.13 Counter 7.3.14 Supply current tracking 7.4 Design Equations 7.4.1 Primary peak current 7.4.1.1 Minimum value of RSOURCE 7.4.2 Switch oscillator 7.4.2.1 Range of RREF values 7.4.3 Leading edge blanking 7.4.4 Burst oscillator 7.4.4.1 Minimum value of CBURST 8. Limiting values 9. Thermal characteristics 10. Characteristics 11. Test information 11.1 Quality information 12. Package outline 13. Soldering 13.1 Introduction to soldering surface mount packages 13.2 Reflow soldering 13.3 Wave soldering 13.4 Manual soldering 13.5 Package related soldering information 14. Revision history 15. Legal information 15.1 Data sheet status 15.2 Definitions 15.3 Disclaimers 15.4 Trademarks 16. Contact information 17. Contents