tea1791t/n1

Manufacturer Part Numbertea1791t/n1
DescriptionGreenchip Synchronous Recti?er Controller
ManufacturerNXP Semiconductors
tea1791t/n1 datasheet
 
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TEA1791T
GreenChip synchronous rectifier controller
Rev. 01 — 3 February 2009
1. General description
The TEA1791T is a member of the new generation of Synchronous Rectifier (SR)
controller ICs for switched mode power supplies. Its high level of integration allows the
design of a cost-effective power supply with a very low number of external components.
The TEA1791T is a controller IC dedicated for synchronous rectification on the secondary
side of discontinuous conduction mode and quasi-resonant flyback converters.
The TEA1791T is fabricated in a Silicon On Insulator (SOI) process.
2. Features
2.1 Distinctive features
I
Accurate synchronous rectification functionality
I
Wide supply voltage range (8.5 V to 38 V)
I
High level of integration, resulting in a very low external component count
I
High driver output voltage of 10 V to drive all MOSFET brands to the lowest R
2.2 Green features
I
Low current consumption
I
High system efficiency from no load to full load
2.3 Protection features
I
Undervoltage protection
3. Applications
I
The TEA1791T is intended for adapters. The device can also be used in all other
discontinuous conduction mode systems and quasi-resonant flyback systems that
demand a highly efficient and cost-effective solution.
4. Ordering information
Table 1.
Ordering information
Type number
Package
Name
TEA1791T/N1
SO8
Description
plastic small outline package; 8 leads; body width 3.9 mm
Product data sheet
DSon
Version
SOT96-1

tea1791t/n1 Summary of contents

  • Page 1

    ... The TEA1791T is intended for adapters. The device can also be used in all other discontinuous conduction mode systems and quasi-resonant flyback systems that demand a highly efficient and cost-effective solution. 4. Ordering information Table 1. Ordering information Type number Package Name TEA1791T/N1 SO8 Description plastic small outline package; 8 leads; body width 3.9 mm Product data sheet DSon Version SOT96-1 ...

  • Page 2

    ... NXP Semiconductors 5. Block diagram SRSENSE Fig 1. 6. Pinning information 6.1 Pinning Fig 2. 6.2 Pin description Table 2. Symbol SRSENSE GND n.c. DRIVER n.c n.c. n. TEA1791T_1 Product data sheet 1 control Q TIMER DRIVER Q 2 n.c. Block diagram SRSENSE 1 2 GND n.c. 3 DRIVER 4 Pin configuration Pin description ...

  • Page 3

    ... NXP Semiconductors 7. Functional description 7.1 Introduction The TEA1791T is the controller for synchronous rectification to be used in discontinuous conduction mode and quasi-resonant flyback converters. 7.2 Start-up and UnderVoltage LockOut (UVLO) The IC leaves the undervoltage lockout state and activates the synchronous rectifier circuitry as soon as the voltage on the V drops below 8 ...

  • Page 4

    ... NXP Semiconductors V SRSENSE Primary Secondary V DRIVER Fig 3. If the secondary stroke of the flyback converter is shorter than 2 s (typ), the driver output is disabled. This will guarantee stable operation for very low duty cycles. When the secondary stroke increases above 2.2 s (typ), the driver output is again enabled. ...

  • Page 5

    ... NXP Semiconductors 8. Limiting values Table 3. In accordance with the Absolute Maximum Rating System (IEC 60134). All voltages are measured with respect to ground (pin 2); positive currents flow into the chip. The voltage ratings are valid provided other ratings are not violated; current ratings are valid provided the other ratings are not violated ...

  • Page 6

    ... NXP Semiconductors 10. Characteristics Table 5. Characteristics all voltages are measured with respect to ground (pin 2); currents are positive when flowing into the amb CC IC; unless otherwise specified. Symbol Parameter Supply voltage management (pin V V start-up voltage startup V hysteresis voltage ...

  • Page 7

    ... NXP Semiconductors 11. Application information A switched mode power supply with the TEA1791T consists of a primary side discontinuous conduction mode flyback controller, a transformer, and an output stage with a feedback circuit. In the output stage a MOSFET (Qsec) is used for low conduction losses. The MOSFET is controlled by the TEA1791T. ...

  • Page 8

    ... NXP Semiconductors 12. Package outline SO8: plastic small outline package; 8 leads; body width 3 pin 1 index 1 DIMENSIONS (inch dimensions are derived from the original mm dimensions) A UNIT max. 0.25 1.45 mm 1.75 0.25 0.10 1.25 0.010 0.057 inches 0.069 0.01 0.004 0.049 Notes 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. ...

  • Page 9

    ... NXP Semiconductors 13. Revision history Table 6. Revision history Document ID Release date TEA1791T_1 20090203 TEA1791T_1 Product data sheet GreenChip synchronous rectifier controller Data sheet status Change notice Product data sheet - Rev. 01 — 3 February 2009 TEA1791T Supersedes - © NXP B.V. 2009. All rights reserved. ...

  • Page 10

    ... Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice ...

  • Page 11

    ... NXP Semiconductors 16. Contents 1 General description . . . . . . . . . . . . . . . . . . . . . . 1 2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.1 Distinctive features . . . . . . . . . . . . . . . . . . . . . . 1 2.2 Green features . . . . . . . . . . . . . . . . . . . . . . . . . 1 2.3 Protection features . . . . . . . . . . . . . . . . . . . . . . 1 3 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 Ordering information . . . . . . . . . . . . . . . . . . . . . 1 5 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6 Pinning information . . . . . . . . . . . . . . . . . . . . . . 2 6.1 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 2 7 Functional description . . . . . . . . . . . . . . . . . . . 3 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 7.2 Start-up and UnderVoltage LockOut (UVLO 7.3 Synchronous rectification . . . . . . . . . . . . . . . . . 3 7.4 Supply management ...