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TPS92311

1A 100V

20Q

0.1 PF

ZCD

LED+

LED-

6 ± 7

LED

AUX

OUT

SWSW

GND

ZCD

VIN

ISNS

GND

COMP

MODE1

DLY

MODE2

NC NC

*Optional

ZCD

VCC

COMP

ISNS

DLY

TPS92311

www.ti.com

SNVS811B –MAY 2012–REVISED MAY 2013

Off-Line Primary Side Sensing Converter with PFC

Check for Samples: TPS92311

FEATURES

DESCRIPTION

The TPS92311 is an off-line converter specifically

• Integrated 600V Power MOSFET With Superior

designed to drive high power LEDs for lighting

Avalanche Energy Capability

applications. Features include an integrated 3.75Ω

• Regulates LED Current Without Secondary

600V power MOSFET, adaptive constant on-time

Side Sensing

control, quasi-resonant switching, and capable of

operating in various topologies via mode selection

• Adaptive ON-Time Control With Inherent PFC

pins. The TPS92311 is ideally suited for driving 8W

• Critical-Conduction-Mode (CRM) With Zero-

LED loads and below. Power Factor Correction is

Current Detection (ZCD) for Valley Switching

inherent if the TPS92311 is operated in the constant

• Programmable Switch Turn ON Delay

on-time mode with an adaptive algorithm. Resonant

switching allows for a reduced EMI signature and

• Programmable Constant ON-Time (COT) and

increased system efficiency. Low external parts count

Peak Current Control

is realized with its simplified and high level of

• Over-Temperature Protection

integration. The control algorithm of TPS92311

adjusts the on time with reference to the primary side

APPLICATIONS

inductor peak current and secondary side inductor

discharge time dynamically, the response time of

• LED Lamps: A19 (E26/27, E14), PAR30/38,

which is set by an external capacitor. Other

GU10

supervisory features of the TPS92311 include cycle-

• Solid State Lighting

by-cycle primary side inductor current limit, VCC

under-voltage lockout, output over-voltage protection

and thermal shutdown. The TPS92311 is available in

16–pin narrow SOIC package.

Typical Application

Figure 1. Typical Application

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (23 pages)

PAGE 1
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 Off-Line Primary Side Sensing Converter with PFC Check for Samples: TPS92311 FEATURES DESCRIPTION • The TPS92311 is an off-line converter specifically designed to drive high power LEDs for lighting applications. Features include an integrated 3.75Ω 600V power MOSFET, adaptive constant on-time control, quasi-resonant switching, and capable of operating in various topologies via mode selection pins.
PAGE 2
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Connection Diagram Top View SW 1 16 SW SW 2 15 SW NC 3 14 NC ZCD 4 13 ISNS GND 5 12 GND VIN 6 11 MODE1 NC 7 10 MODE2 COMP 8 9 DLY Figure 2.
PAGE 3
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. Absolute Maximum Ratings (1) (2) SW to GND -0.3V to 600V VCC to GND -0.3V to 40V DLY, COMP, ZCD to GND -0.3V to 7V ISNS to GND -0.3V to 7V MODE1 to GND -0.3V to 7V MODE2 to GND -0.3V to 7V SW FET Drain Current Peak 1.
PAGE 4
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Electrical Characteristics VCC = 18V unless otherwise indicated. Typicals and limits appearing in plain type apply for TA = TJ = +25°C. Limits appearing in boldface type apply over the full Operating Temperature Range. Data sheet minimum and maximum specification limits are specified by design, test or statistical analysis. Symbol Min Typ (1) Max Units VCC Turn on threshold 23.4 / 23 25.6 27.8 / 29 V VCCTurn off threshold 11.1 / 10.
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TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 Electrical Characteristics (continued) VCC = 18V unless otherwise indicated. Typicals and limits appearing in plain type apply for TA = TJ = +25°C. Limits appearing in boldface type apply over the full Operating Temperature Range. Data sheet minimum and maximum specification limits are specified by design, test or statistical analysis.
PAGE 6
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics All curves taken at VCC=18V with configuration in typical application for driving seven power LEDs with ILED=350mA shown in this datasheet. TA=25°C, unless otherwise specified. 15.0 VCC-UVLO vs Temperature VCC Startup Voltage vs Temperature 28 VCCSTARTUP VOLTAGE (V) 14.5 VCC-UVLO(V) 14.0 13.5 13.0 12.5 12.0 11.5 11.0 -50 80 27 26 25 24 23 22 -25 0 25 50 75 TEMPERATURE (°C) Figure 3.
PAGE 7
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 Typical Performance Characteristics (continued) All curves taken at VCC=18V with configuration in typical application for driving seven power LEDs with ILED=350mA shown in this datasheet. TA=25°C, unless otherwise specified. 1.50 VZCD-ARM vs Temperature 0.80 1.45 0.75 0.70 1.35 VZCD-TRIG(V) VZCD-ARM(V) 1.40 1.30 1.25 1.20 1.15 0.60 0.56 0.45 1.05 -25 0 25 50 75 TEMPERATURE (°C) Figure 9. 0.
PAGE 8
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Simplified Internal Block Diagram SW VCC VC1 SW VREF SW BIAS & VRef SW UVLO MODE1 MODE Decode ISNS TSD MODE2 ZC ZCD LEB GND ON VTRIG/VARM CONTROL iLimit LEB OCP OVP TON TON Peak Hold VONpk VC1 TON Control COMP IREF GND D UVLO DRV COMP OFT ZC DELAY VONpk ON IDLY V/I DLY Figure 14. Simplified Block Diagram APPLICATION INFORMATION The TPS92311 is an off-line convertor specifically designed to drive LEDs.
PAGE 9
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 The setting of the delay time, tDLY will be described in a separate paragraph. During steady state operation, the duration of the on-period tON can be determined with two different modes: the Constant On-Time (COT) mode and the Peak Current Mode (PCM), which are configured by setting the MODE1 and MODE2 pins. For the COT mode, tON is generated by comparing an internal generated saw-tooth waveform with the voltage on the COMP pin (VCOMP).
PAGE 10
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Startup Bias and UVLO During startup, the TPS92311 is powered from the AC line through R1 and D1 (Figure 1). In the startup state, most of the internal circuits of the TPS92311 are shut down in order to minimize internal quiescent current. When VCC reaches the rising threshold of the VCC-UVLO (typically 25.6V), the TPS92311 is operating in a low switching frequency mode, where tON and tOFF are fixed to 1.5μs and 72μs.
PAGE 11
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 Zero Crossing Detection To minimized the switching loss of the internal power MOSFET, a zero crossing detection circuit is embedded in the TPS92311. VLAUX is AC voltage coupled from VSW by means of the transformer, with the lower part of the waveform clipped by DZCD. VLAUX is fed back to the ZCD pin to detect a zero crossing point through a resistor divider network which consists of R2 and R3.
PAGE 12
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com 60 RDLY(k ) 50 40 30 20 10 0 0 400 800 1200 1600 DELAY TIME (ns) 2000 Figure 18. Delay Time Setting Protection Features OUTPUT OPEN CIRCUIT PROTECTION If the LED string is disconnected from the output of the TPS92311, The output voltage (VLED) increases and thus VZCD-PEAK increases. When VZCD-PEAK is greater than VZCD-OVP for 3 continues switching cycles, the Over Voltage Protection (OVP) feature is triggered.
PAGE 13
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 VSW Steady state Low freq state Low freq state t VCC 25.6V 13V t VZCD VZCD-OVP VZCD-ARM t VLED t Figure 19. Output Short Circuit waveforms OVER CURRENT PROTECTION Over Current Protection (OCP) limits the drain current of internal MOSFET and prevents inductor / transformer saturation. When VISNS reaches a threshold, the OCP is triggered and the internal MOSFET will turn off immediately. The threshold is typically 3.4V and 0.
PAGE 14
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com Steady state Startup state Low Freq state VSW OV state Steady state Disconnect LED Reconnect LED Steady state Startup state Startup state Startup state Low Freq state VCC 25.6V 13V VZCD VZCD-OVP VZCD-ARM VLED ILED Steady state Force output short circuit Steady state Figure 20.
PAGE 15
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 DESIGN EXAMPLE The following design example illustrates the procedures to calculate the external component values for the TPS92311 isolated single stage fly-back LED driver with PFC. Design Specifications: Input voltage range, VAC_RMS = 85VAC – 132VAC Nominal input voltage, VAC_RMS(NOM) = 110VAC Number of LED in serial =7 LED current, ILED = 350mA Forward voltage drop of single LED = 3.
PAGE 16
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com In operation, the voltage at the switching node, VSW must be small than the internal MOSFET maximum rated voltage VQ1(MAX) , For reason of safety, 10% safety margin is recommended. Hence, 90% of VQ1(MAX) is used in the following equation.
PAGE 17
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 Calculate The Current Sensing Resistor After the primary inductance and transformer turn ratio is determined, the current sensing resistor, RISNS can be calculated. The resistance for RISNS is governed by the output current and transformer turn ratio, the equation in below can be used. where • VREF is fixed to 0.14V internally. (14) Transformer turn ratio, NP : NS is 3.8 : 1 and ILED = 0.
PAGE 18
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com In this design example, open circuit AUX winding OVP voltage threshold is set to 30V. Assume the current through the AUX winding is 0.4mA typical. As a result, R2 is 66kΩ and R3 is 11kΩ. Also, for suppressing high frequency noise at the ZCD pin, a 15pF capacitor connects the ZCD pin to ground is recommended.
PAGE 19
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 VOS VSN VMOS_BV n u VLED VAC_PEAK Vsw Figure 24. Snubber Waveform where • n is the turn ratio of the transformer. (17) (18) At the same time, sum of the snubber clamp voltage and VAC peak voltage (VAC_PEAK) must be smaller than the MOSFET breakdown voltage (VMOS_BV). By re-arranging terms, equation in below can be used. (19) In here, snubber clamp voltage, VSN = 250V is recommended.
PAGE 20
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com PCB Layout Considerations The performance of any switching power supplies depend as much upon the layout of the PCB as the component selection. Good layout practices are important when constructing the PCB. The layout must be as neat and compact as possible, and all external components must be as close as possible to their associated pins.
PAGE 21
TPS92311 www.ti.com SNVS811B – MAY 2012 – REVISED MAY 2013 L1 3.3 mH 0.5A 600V 0.5A D1 C1 0.1 PF CIN 0.1 PF R1a 100 k: NP:NAUX = 1:1 LP = LS 90-135 VAC VR1 R1b 100 k: CAC 47 nF D2 0.1A 600V R4 20Q T1 RAC LAUX COUT 6-7 LED 470 PF R2 68 k: 22: 1W 35V* R3 11 k: CZCD 15 pF D3 1A 600V SCR* 6k* DZCD CUSU4148 * Optional for short circuit protection 10 F 3.3 F CVCC CCOMP SW SW SW SW NC NC ZCD ISNS GND GND MODE1 VIN NC MODE2 DLY COMP TPS92311 RISNS 0.4Ÿ RDLY 6.34k Figure 26.
PAGE 22
TPS92311 SNVS811B – MAY 2012 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision A (May 2013) to Revision B • 22 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
PAGE 23
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