TEA1761T GreenChip synchronous rectifier controller Rev. 02 — 25 April 2007 Product data sheet 1. General description The TEA1761T 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 TEA1761T is a controller IC dedicated for synchronous rectification on the secondary side of discontinuous conduction mode and quasi resonant flyback converters. Besides electronics for synchronous rectification, it also has integrated circuitry for output voltage and output current regulation. The TEA1761T is fabricated in a Silicon On Insulator (SOI) process. This NXP SOI process makes possible a wide range of operation. 2. Features 2.1 Distinctive features n n n n n n Combined synchronous rectification and primary feedback control functionality Wide supply voltage range (8.6 V to 38 V) High level of integration, resulting in a very low external component count Wide opto coupler output voltage range (3.5 V to 38 V) Accurate internal voltage reference for voltage control (within 1 %) High driver output voltage of 10 V to drive all MOSFET brands to the lowest RDSon 2.2 Green features n Low current consumption n High system efficiency from no load to full load 2.3 Protection features n Undervoltage protection n Internal over-temperature protection 3. Applications The TEA1761T is intended for adapters. The device can also be used in all other discontinuous conduction mode and quasi resonant flyback systems that demand a highly efficient and cost-effective solution. TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 4. Ordering information Table 1. Ordering information Type number TEA1761T/N2 Package Name Description Version SO8 plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 5. Block diagram VCC 8 6 OPTO 2.5 V 5 7 ISENSE 50 mV OVER TEMPERATURE PROTECTION SRSENSE VSENSE 1 control Q R DRIVER 4 TIMER 2 µs Q S 2.2 µs −310 mV 3 2 n.c. GND −12 mV −55 mV 014aaa056 Fig 1. TEA1761T block diagram TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 2 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 6. Pinning information 6.1 Pinning SRSENSE 1 GND 2 8 VCC 7 ISENSE TEA1761T n.c. 3 6 VSENSE DRIVER 4 5 OPTO 001aae772 Fig 2. Pin configuration for TEA1761T 6.2 Pin description Table 2. Pin description Symbol Pin Description SRSENSE 1 synchronous timing input GND 2 ground n.c. 3 not connected DRIVER 4 driver output for SR MOSFET OPTO 5 opto coupler driver output VSENSE 6 sense input for voltage control ISENSE 7 sense input for current control VCC 8 supply voltage 7. Functional description The TEA1761T is the controller for synchronous rectification to be used in discontinuous conduction mode and quasi resonant flyback converters. Besides controlling the SR MOSFET, the TEA1761T contains the voltage reference and amplifiers to regulate and control the output voltage and current of the power supply. 7.1 Start-up and undervoltage lock out The IC leaves the under-voltage lock-out state and activates the synchronous rectifier circuitry and also the voltage/current sense circuitry as soon as the voltage on the VCC pin is above 8.6 V (typical). As soon as the voltage drops below 8.1 V (typical), the under-voltage lock-out state is re-entered and the SR driver output is actively kept low and also the opto driver output is disabled. 7.2 Synchronous rectification After a negative voltage (−310 mV typical) is sensed on the SRSENSE pin, the driver output voltage is made high and the external MOSFET is switched on. As soon as the SRSENSE voltage rises to −55 mV, the driver output voltage is regulated to maintain the −55 mV on the SRSENSE pin. As soon as the SRSENSE voltage is above −12 mV, the TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 3 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller driver output is pulled to ground. After switch-on of the SR MOSFET, the input signal on the SRSENSE pin is blanked for 2 µs (typical). This will eliminate false switch-off due to high frequency ringing at the start of the secondary stroke. Because the driver output voltage is reduced as soon as the voltage on the SRSENSE pin is −55 mV, the external power switch can be switched off fast when the current through the switch reaches zero. With this zero-current switch off, no separate standby mode is needed to maintain high efficiency during no-load operation. The zero current is detected by sensing a −12 mV level on the SRSENSE pin. See Figure 3. VSRSENSE 0V −12 mV −55 mV −310 mV Primary current 0A Secondary current 0A VDRIVER 0V 014aaa057 Fig 3. Synchronous rectification signals If the secondary stroke of the flyback converter is shorter than 2 µs (typical), the driver output is disabled. This will guarantee stable operation for very low duty cycles. When the secondary stroke increases above 2.2 µs (typical) then the driver output is again enabled. 7.3 SMPS output voltage and current regulation The output voltage of the flyback Switched Mode Power Supply (SMPS) can be controlled by sensing the output voltage via pin VSENSE. The feedback loop via the primary controller can regulate the output voltage of the switched mode power supply by regulating the voltage on pin VSENSE, to 2.5 V. Also the output current of the flyback SMPS can be controlled or limited. The voltage on pin ISENSE is regulated or limited to 50 mV above the voltage on pin GND. TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 4 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 7.4 Opto output The opto output is intended to drive an opto coupler (see Figure 5). The opto output has an open-drain output configuration. The maximum sink current is internally limited to 5 mA (typical). The output is linearly controlled via the VSENSE and ISENSE input pins. An over-temperature situation will switch the opto output to its maximum sink current. During start-up (VCC < Vstartup) and undervoltage lock-out the output is disabled. 7.5 Supply management All (internal) reference voltages are derived from a temperature compensated, on-chip band gap circuit. The reference voltage is trimmed to an accuracy within 1 %. 7.6 OverTemperature Protection (OTP) The IC provides an accurate internal overtemperature protection of 150 °C (typical). The IC will maximize the current of pin OPTO as soon as the internal temperature limit is reached. The opto signal can be used on the primary side of the flyback controller to activate the SMPS protection or limit the output power. As soon as the overtemperature condition is solved, normal operation will resume. 7.7 Driver The driver circuit to the gate of the external power MOSFET has a source capability of typically 250 mA and a sink capability of typically 2.7 A. This permits fast turn-on and turn-off of the power MOSFET for efficient operation. The output voltage of the driver is limited to 10 V (typical). This high output voltage will drive all MOSFET brands to the minimum on-state resistance. During start-up conditions (VCC < Vstartup) and undervoltage lock-out the driver output voltage is actively pulled low. TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 5 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 8. Limiting values Table 3. Limiting values 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. Symbol Parameter Conditions Min Max Unit VCC supply voltage continuous −0.4 +38 V VOPTO voltage on pin OPTO continuous −0.4 +38 V VSRSENSE voltage on pin SRSENSE continuous - 120 V VVSENSE voltage on pin VSENSE continuous −0.4 +5 V VISENSE voltage on pin ISENSE −0.4 +5 V Voltages Currents IOPTO current on pin OPTO IDRIVER current on pin DRIVER ISRSENSE current on pin SRSENSE duty cycle < 10 % - 12 mA −0.8 +3 A −3 - mA General Tamb < 80 °C Ptot total power dissipation - 0.45 W Tstg storage temperature −55 +150 °C Tj junction temperature −20 +150 °C ESD VESD electrostatic discharge voltage class 2 human body model [1] - 2000 V machine model [2] - 200 V - 500 V charged device model [1] Equivalent to discharging a 100 pF capacitor through a 1.5 kΩ series resistor. [2] Equivalent to discharging a 200 pF capacitor through a 0.75 µH coil and a 10 Ω resistor. 9. Thermal characteristics Table 4. Thermal characteristics Symbol Parameter Conditions Typ Unit Rth(j-a) thermal resistance from junction to ambient in free air 150 K/W The graph in Figure 4 shows the relationship between junction temperature and VSENSE voltage. TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 6 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 001aae779 2600 regulated VSENSE voltage (mV) 2520 2480 2440 2400 −50 0 50 100 150 junction temperature (°C) Fig 4. Typical regulated VSENSE voltage versus junction temperature 10. Characteristics Table 5. Characteristics Tamb = 25 °C; VCC = 20 V; all voltages are measured with respect to ground (pin 2); currents are positive when flowing into the IC; unless otherwise specified. Symbol Parameter Conditions Min Typ Max 8.6 8.85 Unit Supply voltage management (pin VCC) Vstartup start-up voltage Vhys hysteresis voltage 8.35 ICC(oper) operating supply current VCC = 8 V (VCC < Vstartup) [1] under normal operation; no load on pin DRIVER 0.5 V V - 1 - mA - 1.4 - mA Synchronous rectification sense input (pin SRSENSE) Vact(drv) driver activation voltage −340 −310 −280 mV Vreg(drv) driver regulation voltage −65 −55 −45 mV Vdeact(drv) driver deactivation voltage td(act)(drv) driver activation delay time tact(sr)(min) minimum synchronous rectification active time −12 mV - 125 - ns Short time 1.5 2 2.5 µs Long time 1.7 2.2 2.7 µs −0.3 −0.25 −0.2 A voltage on pin DRIVER = 2 V 1 1.4 - A voltage on pin DRIVER = 9.5 V 2.2 2.7 - A - 10 12 V Driver (pin DRIVER) Isource source current VCC = 15 V; voltage on pin DRIVER = 2 V Isink sink current VCC = 15 V; Vo(max) maximum output voltage VCC = 15 V TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 7 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller Table 5. Characteristics …continued Tamb = 25 °C; VCC = 20 V; all voltages are measured with respect to ground (pin 2); currents are positive when flowing into the IC; unless otherwise specified. Symbol Parameter Conditions Min Typ Max Unit Opto output (pin OPTO) IO(max) maximum output current VOPTO > 5 V 4 5 12 mA VO(min) minimum output voltage - - 3.5 V IOPTO = 4 mA Voltage sense (pin VSENSE) Vreg(VSENSE) regulation voltage on pin See Figure 4 VSENSE 2.475 2.5 2.525 V II(VSENSE) input current on pin VSENSE VVSENSE = Vreg(VSENSE) −100 0 +100 nA gm transconductance VVSENSE to IOPTO - 40 - A/V GB gain bandwidth product RL = 1 kΩ 1 MHz Current sense (pin ISENSE) Vreg(ISENSE) regulation voltage on pin ISENSE 46 50 54 mV II(reg)(ISENSE) regulation input current on pin ISENSE VISENSE = Vreg(ISENSE) −200 −100 0 nA gm transconductance VISENSE to IOPTO - 15 - A/V GB gain bandwidth product RL = 1 kΩ 1 - - MHz Temperature protection Tpl(max) maximum protection level temperature 140 150 - °C Tpl(hys) protection level hysteresis temperature - 12 - °C [1] The VCC stop voltage is Vstartup − Vhys. 11. Application information A switched mode power supply with the TEA1761T 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 TEA1761T. The output voltage and/or current is also controlled by the TEA1761T via the opto coupler connection to the primary side. See Figure 5. The output voltage is set by resistors Rfb1 and Rfb2. The output current is controlled by the resistor Risense. The timing for the synchronous rectifier switch is derived from the voltage sensed on the SRSENSE pin. The resistor in the SRSENSE connection is needed to protect the TEA1761T from excessive voltages. The SRSENSE resistor should typically be 1 kΩ. Higher values might impair correct timing, lower values may not provide sufficient protection. TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 8 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller Vout Ropto Rfb1 OPTO TR Vin Cfb VCC OPTO Rsrsense Qprim PRIMARY SIDE CONTROLLER SRSENSE VSENSE Cout TEA1761T Qsec Rfb2 DRIVER GND ISENSE Risense 001aae775 Fig 5. Application example TEA1761T 12. Test information 12.1 Quality information The General Quality Specification for Integrated Circuits, SNW-FQ-611 is applicable. TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 9 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 13. Package outline SO8: plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 D E A X c y HE v M A Z 5 8 Q A2 A (A 3) A1 pin 1 index θ Lp 1 L 4 e detail X w M bp 0 2.5 5 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT A max. A1 A2 A3 bp c D (1) E (2) e HE L Lp Q v w y Z (1) mm 1.75 0.25 0.10 1.45 1.25 0.25 0.49 0.36 0.25 0.19 5.0 4.8 4.0 3.8 1.27 6.2 5.8 1.05 1.0 0.4 0.7 0.6 0.25 0.25 0.1 0.7 0.3 inches 0.069 0.010 0.057 0.004 0.049 0.01 0.019 0.0100 0.014 0.0075 0.20 0.19 0.16 0.15 0.05 0.01 0.01 0.004 0.028 0.012 0.244 0.039 0.028 0.041 0.228 0.016 0.024 θ 8o o 0 Notes 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. 2. Plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC SOT96-1 076E03 MS-012 JEITA EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-18 Fig 6. Package outline SOT96-1 (SO8) TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 10 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 14. Revision history Table 6. Revision history Document ID Release date Data sheet status Change notice Supersedes TEA1761T_2 20070425 Product data sheet - TEA1761T_1 Modifications: TEA1761T_1 • • • • • Updated limiting values for VSRSENSE in Table 3. • Legal texts have been adapted to the new company name where appropriate. Updated characteristic values for Isource and Isink in Table 5. Added footnote [1] to Table 5. Soldering section removed. The format of this data sheet has been redesigned to comply with the new identity guidelines of NXP Semiconductors. 20060331 Objective data sheet TEA1761T_2 Product data sheet - - © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 11 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 15. Legal information 15.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term ‘short data sheet’ is explained in section “Definitions”. [3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL http://www.nxp.com. 15.2 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. Short data sheet — A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail. 15.3 Disclaimers General — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. 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. This document supersedes and replaces all information supplied prior to the publication hereof. Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of a NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) may cause permanent damage to the device. Limiting values are stress ratings only and operation of the device at these or any other conditions above those given in the Characteristics sections of this document is not implied. Exposure to limiting values for extended periods may affect device reliability. Terms and conditions of sale — NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms, including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by NXP Semiconductors. In case of any inconsistency or conflict between information in this document and such terms and conditions, the latter will prevail. No offer to sell or license — Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights. 15.4 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. GreenChip — is a trademark of NXP B.V. 16. Contact information For additional information, please visit: http://www.nxp.com For sales office addresses, send an email to: [email protected] TEA1761T_2 Product data sheet © NXP B.V. 2007. All rights reserved. Rev. 02 — 25 April 2007 12 of 13 TEA1761T NXP Semiconductors GreenChip synchronous rectifier controller 17. Contents 1 2 2.1 2.2 2.3 3 4 5 6 6.1 6.2 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 8 9 10 11 12 12.1 13 14 15 15.1 15.2 15.3 15.4 16 17 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Distinctive features . . . . . . . . . . . . . . . . . . . . . . 1 Green features . . . . . . . . . . . . . . . . . . . . . . . . . 1 Protection features . . . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Pinning information . . . . . . . . . . . . . . . . . . . . . . 3 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3 Functional description . . . . . . . . . . . . . . . . . . . 3 Start-up and undervoltage lock out. . . . . . . . . . 3 Synchronous rectification . . . . . . . . . . . . . . . . . 3 SMPS output voltage and current regulation . . 4 Opto output . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Supply management. . . . . . . . . . . . . . . . . . . . . 5 OverTemperature Protection (OTP) . . . . . . . . . 5 Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 6 Thermal characteristics. . . . . . . . . . . . . . . . . . . 6 Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Application information. . . . . . . . . . . . . . . . . . . 8 Test information . . . . . . . . . . . . . . . . . . . . . . . . . 9 Quality information . . . . . . . . . . . . . . . . . . . . . . 9 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 11 Legal information. . . . . . . . . . . . . . . . . . . . . . . 12 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 12 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Contact information. . . . . . . . . . . . . . . . . . . . . 12 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2007. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] Date of release: 25 April 2007 Document identifier: TEA1761T_2