L4981

L4981A STMICROELECTRONICS | Alldatasheet

Document overview

• Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 17

Technical content

CONTROL BOOST PWM UP TO 0.99P.F. LIMITLINE CURRENT DISTORTION TO < 5% UNIVERSAL INPUT MAINS FEED FORWARD LINE AND LOAD REGULA- TION AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY HIGH CURRENT BIPOLAR AND DMOS TO- TEM POLE OUTPUT LOW START-UP CURRENT (0.3mA TYP.) UNDER VOLTAGE LOCKOUT WITH HYS- TERESIS AND PROGRAMMABLE TURN ON THRESHOLD OVERVOLTAGE, OVERCURRENT PROTEC- TION PRECISE 2% ON CHIP REFERENCE EX- TERNALLY AVAILABLE SOFT START

DESCRIPTION

The L4981 I.C. provides the necessary features to achieve a very high power factor up to 0.99. Realized in BCD 60II technology this power factor corrector (PFC) pre-regulator contains all the con- trol functions for designing a high efficiency-mode power supply with sinusoidal line current con- sumption. The L4981 can be easily used in systems with mains voltages between 85V to 265V without any line switch. This new PFC offers the possibility to work at fixed frequency (L4981A) or modulated frequency (L4981B) optimizing the size of the in- September 1998 BLOCK DIAGRAM ORDERING NUMBERS: L4981X (DIP20) L4981XD (SO20) DIP20 SO20 MULTIPOWER BCD TECHNOLOGY

put filter; both the operating frequency modes working with an average current mode PWM con- troller, maintaining sinusoidal line current without slope compensation. Besides power MOSFET gate driver, precise volt- age reference (externally available), error ampli- fier, undervoltage lockout, current sense and the soft start are included. To limit the number of the external components, the device integrates pro- tections as overvoltage and overcurrent. The overcurrent level can be programmed using a simple resistor for L4981A. For a better precision and for L4981B an external divider must be used. ABSOLUTE MAXIMUM RATINGS Symbol Pin Parameter Value Unit VCC 19 Supply Voltage (ICC ≤50mA) (*) selflimit V IGDRV 20 Gate driv. output peak current (t = 1µs) SINK 2 Α . SOURCE 1.5 A VGDRV Gate driv. output voltage t = 0.1µs- 1 V Voltages at pins 3, 14, 7, 6, 12, 15 -0.3 to 9 V VVA-OUT 13 Error Amplifier Voltage -0.3 to 8.5 V IAC 4 AC Input Current 5 mA Voltages at pin 8, 9 -0.5 to 7 V VCA-OUT 5 Current Amplifier Volt. (Isource = -20mA; Isink = 20mA) -0.3 to 8.5 V VROSC 17 Voltage at pin 17 -0.3 to 3 V 11, 18 Voltage at pin 11, 18 -0.3 to 7 V ICOSC 18 Input Sink Current 15 mA IFREQ-MOD 16 Frequency Modulation Sink Current (L4981B) 5 mA V SYNC 16 Sync. Voltage (L4981A) -0.3 to 7 V V IPK 2 Voltage at pin 2 Voltage at Pin 2 t = 1µs -0.3 to 5.5 V V Ptot Power Dissipation at Tamb =7 0°C (DIP20) 1 W Power Dissipation at Tamb =7 0°C (SO20) 0.6 W Top Operating Ambient Temperature -40 to 125 °C Tstg StorageTemperature -55 to 150 °C (*) Maximum package power dissipation limits must be observed. PIN CONNECTIONS (Top views) L4981A L4981B L4981A - L4981B

Symbol Parameter DIP 20 SO 20 Unit R th j-amb Thermal Resistance Junction-ambient 80 120 °C/W PIN FUNCTIONS N. Name Description 1 P-GND Power ground. 2 IPK L4981A peak current limiting. A current limitation is obtained using a single resistor connected between Pin 2 and the sense resistor. To have a better precision another resistor between Pin 2 and a reference voltage (Pin 11) must be added. L4981B peak current limiting. A precise current limitation is obtained using two external resistor only. These resistors must be connected between the sense resistor, Pin 2 and the reference voltage. 3 OVP Overvoltage protection. At this input are compared an internal precise 5.1V (typ) voltage reference with a sample of the boost output voltage obtained via a resistive voltage divider in order to limit the maximum output peak voltage. 4 IAC Input for the AC current. An input current proportional to the rectified mains voltage generates, via a multiplier, the current reference for the current amplifier. 5 CA-OUT Current amplifier output. An external RC network determinates the loop gain.

6 LFF Load feedforward; this voltage input pin allows to modify the multiplier output current

proportionall y to the load, in order to give a faster response versus load transient. The best control is obtained working between 1.5V and 5.3V. If this function is not used, connect this pin to the voltage reference (pin = 11). 7 VRMS Input for proportional RMS line voltage. the VRMS input compesates the line voltage changes. Connecting a low pass filter between the rectified line and the pin 7, a DC voltage proportional to the input line RMS voltage is obtained. The best control is reached using input voltage between 1.5V and 5.5V. If this function is not used connect this pin to the voltage reference (pin = 11). 8 MULT-OUT Multiplier output. This pin common to the multiplier output and the current amplifier N.I. input is an high impedence input like I SENSE . The MULT-OUT pin must be taken not below -0.5V. 9I SENSE Current amplifier inverting input. Care must be taken to avoid this pin goes down -0.5V. 10 S-GND Signal ground. 11 V REF Output reference voltage (typ = 5.1V).Voltage refence at± 2% of accuracy externally available, it’s internally current limited and can deliver an output current up to 10mA. 12 SS A capacitor connected to ground defines the soft start time. An internal current generator delivering 100µA (typ) charges the external capacitor defining the soft start time constant. An internal MOS discharge, the external soft start capacitor both in overvoltage and UVLO conditions. 13 VA-OUT Error amplifier output, an RC network fixes the voltage loop gain characteristics. 14 VFEED Voltage error amplifier inverting input. This feedback input is connected via a voltage divider to the boost output voltage. 15 P-UVLO Programmable under voltage lock out threshold input. A voltage divider between supply voltage and GND can be connected in order to program the turn on threshold.

16 SYNC

(L4981A) This synchronization input/output pin is CMOS logic compatible. Operating as SYNC in, a rectangular wave must be applied at this pin. Opearting as SYNC out, a rectangular clock pulse train is available to synchronize other devices. FREQ-MOD (L4981B) Frequency modulation current input. An external resistor must be connected between pin 16 and the rectified line voltage in order to modulate the oscillator frequency. Connecting pin 16 to ground a fixed frequency imposed by ROSC and COSC is obtained. 17 R OSC An external resistor connected to ground fixes the constant charging current of COSC . 18 C OSC An external capacitor connected to GND fixes the switching frequency. 19 V CC Supply input voltage. 20 GDRV Output gate driver. Bipolar and DMOS transistors totem pole output stage can deliver peak current in excess 1A useful to drive MOSFET or IGBT power stages. L4981A - L4981B

ELECTRICAL CHARACTERISTICS (Unless otherwise specified VCC = 18V, COSC = 1nF, R OSC = 24KΩ ,C SS =1 µF, VCA-OUT = 3.5V, VISENSE = 0V, VLFF =V REF ,IAC = 100µA, VRMS = 1V, VFEED = GND, VIPK = 1V, VOVP = 1V, TJ =2 5°C Symbol Prameter Test Condition Min. Typ. Max. Unit ERROR AMPLIFIER SECTION VIO Input Offset Voltage –25 °C<T J <8 5°C ±8m V IIB Input Bias Current V FEED = 0V -500 -50 500 nA Open Loop Gain 70 100 dB V13H Output High voltage V FEED = 4.7V IVA-OUT = -0.5mA 5.5 6.5 7.5 V V13L Output Low Voltage V FEED = 5.5V IVA-OUT = 0.5mA 0.4 1 V -I13 Output Source Current V FEED = 4.7V; VVA-OUT = 3.5V 2 10 mA I13 Output Sink Current V FEED = 5.5V; VVA-OUT = 3.5V 4 20 mA REFERENCE SECTION Vref Reference Output Voltage –25 °C<T J <8 5°C 4.97 5.1 5.23 V Tj=2 5°CI ref= 0 5.01 5.1 5.19 V Δ Vref Load Regulation 1mA ≤ Iref ≤ 10mA –25°C<T J <8 5°C 31 5 m V Δ Vref Line Regulation 12V ≤ VCC ≤ 19V –25°C<T J <8 5°C 31 0 m V Iref sc Short Circuit Current V ref= 0 V 2 03 05 0 m A OSCILLATOR SECTION fosc Initial Accuracy T j=2 5°C 85 100 115 KHz Frequency Stability 12V ≤ VCC ≤ 19V –25°C<T J <8 5°C 80 100 120 KHz Vsvp Ramp Valley to Peak 4.7 5 5.3 V I18C Charge Current V COSC = 3.5V 0.45 0.55 0.65 mA I18D Discharge Current V COSC = 3.5V 11.5 mA V 18 Ramp Valley Voltage 0.9 1.15 1.4 V SYNC SECTION (Only forL4981A ) tW Output Pulse Width 50% Amplitude 0.3 0.8 µs I16 Sink Current with Low Output Voltage VSYNC = 0.4V VCOSC =0 V 0.4 0.8 mA -I16 Source Current with High Output Voltage VSYNC = 4.5V VCOSC = 6.7V 16 m A V16L Low Input Voltage 0.9 V V16H High Input Voltage 3.5 V td Pulse for Synchronization 800 ns FREQUENCY MODULATION FUNCTION (Only forL4981B ) f18max Maximum Oscillation Frequency VFREQ-MOD = 0V (Pin 16) Ifreq= 0 85 100 115 KHz f18min Minimum Oscillator Frequency IFREQ-MOD = 360µA (Pin 16) VVRMS = 4V (Pin 7)

74 KHz

IFREQ-MOD = 180µA (Pin 16) VVRMS = 2V (Pin 7)

76 KHz

ISS Soft Start Source Current V SS = 3V 60 100 140 µA V12sat Output Saturation Voltage V 3 = 6V, ISS = 2mA 0.1 0.25 V L4981A - L4981B

ELECTRICAL CHARACTERISTICS (continued) Symbol Parameter Test Condition Min. Typ. Max. Unit SUPPLY VOLTAGE VCC Operating Supply Voltage 19.5 V OVER VOLTAGE PROTECTION COMPARATOR Vthr Rising Threshold Voltage V ref -20mV

5.1 V ref

+20mV V V3Hys Hysteresis 180 250 320 mV I3 Input Bias Current 0.05 1 µA td Propagation delay to output V OVP =V thr+100mV 1 2 µs OVER CURRENT PROTECTION COMPARATOR V th Threshold Voltage ±30 mV td Propagation delay to Output V OCP =V thr-0.2V 0.4 0.9 µs Iipk Current Source Generator V IPK = -0.1V only for L4981A 65 85 105 µA IL Leakage Current V IPK = -0.1V only for L4981B 5 µA CURRENT AMPLIFIER SECTION Voffset Input Offset Voltage V MULT OUT =V SENSE = 3.5V ±2m V I9bias Input Bias Current V SENSE = 0V -500 50 500 nA Open Loop Gain 1.1V ≤ VCA OUT ≤ 6V 70 100 dB SVR Supply Voltage Rejection 12V ≤ VCC ≤ 19V VMULT OUT = 3.5V VSENSE = 3.5V 68 90 dB V5H Output High Voltage V MULT OUT = 200mV ICA OUT = -0.5mA, VIAC =0 V 6.2 V V 5L Output Low Voltage V MULT OUT = -200mV ICA OUT = 0.5mA, VIAC =0 V 0.9 V -I5 Output Source Current V MULT OUT = 200mV, VIAC = 0V, VCA-OUT = 3.5V 21 0 m A I5 Output Sink Current 2 10 mA OUTPUT SECTION V20L Output Voltage Low I SINK = 250mA 0.5 0.8 V V20H Output Voltage High I SOURCE = 250mA VCC = 15V 11.5 12.5 V tr Output Voltage Rise Time C OUT = 1nF 50 150 ns tf Output Voltage Fall Time C OUT = 1nF 30 100 ns VGDRV Voltage Clamp I SOURCE = 0mA 13 16 19 V TOTAL STANDBY CURRENT SECTION I19start Supply Current before start up VCC = 14V 0.3 0.5 mA I19on Supply Current after turn on V IAC =0 V ,VCOSC =0 , Pin17 = Open 81 2 m A I19 Operating Supply Current Pin20 = 1nF 12 16 mA VCC Zener Voltage (*) 20 25 30 V UNDER VOLTAGE LOCKOUT SECTION Vth ON Turn on Threshold 14.5 15.5 16.5 V Vth OFF Turn off Threshold 9 10 11 V Programmable Turn-on Threshold Pin 15 to VCC = 220K Pin15 to GND = 33K 10.6 12 13.4 V LOAD FEED FORWARD ILFF Bias Current V 6 = 1.6V 70 140 µA V6 = 5.3V 200 300 µA VI Input Voltage Range 1.6 5.3 V (*) Maximum package power dissipation limits must be observed. L4981A - L4981B

T 13 14 R12 C11 R13 MOS D5 R17 R11 R3 R5 C3 R4 C4 R16 C6 C10 R2 R10 R1 R9 11121710189582 FUSE Vi Vo=400V D93IN029B 85VAC -265VAC R S R21 Figure 9A:L4981A Power Factor Corrector (200W) C1 470nF 400V C2 100µF 450V C3 2.2nF C4 1nF C5 100µF 25V C6 1µF 16V C7 220nF 63V C8 220nF 63V C9 330nF C10 1µF 16V C11 270pF 400V C12 8.2nF 100V D1 STTA506D D2, D3 1N4148 D4 18V 1/2W D5 BYT11-600 MOS STH/STW15NA50 FUSE = 4A/250V R S 0.07(3 x .22) 1/2W 5% R1 820kΩ 1/4W 1% R2 10kΩ 1/4W 1% R3 1.8kΩ 1/4W 5% R4 1.8kΩ 1/4W 5% R5 18kΩ 1/4W 5% R6 1.2MΩ 1/4W 5% R7 360kΩ 1/4W 5% R8 33kΩ 1/4W 5% R9 1.8MΩ 1/4W 1% R10 21kΩ 1/4W 1% R11 402Ω 1/4W 1% R12 120kΩ 1/4W 5% R13 27Ω 1/4W 5% R14 1M Ω 1/4W 1% R15 120kΩ 1/2W 5% R16 30kΩ 1/4W 5% R17 1.8kΩ 4W 1% R21 5.1kΩ 1/4W 1% BRIDGE = 4 x P600M PART LIST T= primary: 88 turns of 12 x 32 AWG (0.2mm) secondary: 9 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1,6mm for a total primary inductance of 0.9mH f SW = 80kHz PO = 200W VOUT = 400V Irms max = 2.53A VOVP = 442V IPK max = 6.2A L4981A - L4981B

T 13 14 R12 C11 R13 MOS D5 R17 R11 R3 R5 C3 R4 C4 R16 C6 C10 R2 R10 R1 R9 11121710189582 FUSE Vi Vo=400V D95IN220 85VAC -265VAC R S R21 R22 Figure 9B:L4981B Power Factor Corrector (200W) C1 470nF 400V C2 100µF 450V C3 2.2nF C4 1.1nF C5 100µF 25V C6 1µF 16V C7 220nF 63V C8 220nF 63V C9 330nF C10 1µF 16V C11 270pF 400V C12 8.2nF 100V D1 STTA506D D2, D3 1N4148 D4 18V 1/2W D5 BYT11-600 MOS STH/STW15NA50 FUSE = 4A/250V R S 0.07(3 x .22) 1/2W 5% R1 820kΩ 1/4W 1% R2 10kΩ 1/4W 1% R3 1.8kΩ 1/4W 5% R4 1.8kΩ 1/4W 5% R5 18kΩ 1/4W 5% R6 1.2MΩ 1/4W 5% R7 360kΩ 1/4W 5% R8 33kΩ 1/4W 5% R9 1.8MΩ 1/4W 1% R10 21kΩ 1/4W 1% R11 402Ω 1/4W 1% R12 120kΩ 1/4W 5% R13 27Ω 1/4W 5% R14 1M Ω 1/4W 1% R15 120kΩ 1/2W 5% R16 24kΩ 1/4W 5% R17 1.8kΩ 4W 1% R21 5.1kΩ 1/4W 1% R22 1.1MΩ 1/4W 1% BRIDGE = 4 x P600M PART LIST T= primary: 88 turns of 12 x 32 AWG (0.2mm) secondary: 9 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1,6mm for a total primary inductance of 0.9mH f SW = 80 to 92kHz PO = 200W VOUT = 400V Irms max = 2.53A VOVP = 442V IPK max = 6.2A L4981A - L4981B

Figure 19:200W Evaluation Board Circuit. T= primary: 75 turns of litz wire 20 x 32 AWG (0.2mm) secondary: 8 turns of # 27AWG (0.15mm) core: B1ET3411A THOMSON - CSF gap: 1.4mm for a total primary inductance of 0.7mH f sw = 100kHz; VO = 400V; P O = 200W NOTE: Start Up Circuit Usually the VCC capacitor (C11 in fig. 19)can be charged by a resistor drawing current from the rectified mains. In the evaluation board instead the start up circuit composed by (Q2+R19+R15+Dz) has been designed to perform a fast and effective supply in all the conditions. Once that the L4981A/B has started, the reference voltage available at pin 6 by R20 and Q3, ensures Q2 to be turned off. Programmable Under voltage Lockout The PCB allows to insert a couple of resistor (R22, R23) to modify the threshold input voltage. Please refer to fig. 16 and table1. L4981A - L4981B

Figure 20:P.C. Board and Component Layout of Evaluation Board Circuit (1:1 scale). L4981A - L4981B

The evaluation board has been designed using: a faster not dissipative start-up circuit, a diode (D2) to speed-up the MOS start-off time and (even if a single resistor can be used) an external divider to improve the precision of the overcurrent thresh- old. Further there is a possibility to change the input threshold voltage using an external divider (R23 and R22) and if an inrush current problem arises a NTC resistor can be used. The PFC demoboard performances has been evaluated testing the following parameters: PF (power factor), A-THD (percentage of current total harmonic distortion), H3..H9 (percentage of current’s n th harmonic amplitude),ΔVo (output voltage ripple), Vo (output voltage),η (efficiency). The test configuration, equipments and results are: AC POWER SOURCE LARCET /3KW PM1200 AC POWER ANALYSER EMI FILTER PFC L4981 DEMO LOAD D94IN057 Vi fP i PF A-THD H3 H5 H7 H9 V O Δ VO PO η EMI/RFI FILTER The harmonic content measurement has been done using an EMI/RFI filter interposed between the AC source and the demoboard under test, while the efficiency has been calculated without the filter contribution. D94IN052 T1 T2 C LINE PFC EARTH where: T1 = 1mH C1 = 0.33 µF, 630V T2 = 27mH C2 = 2.2nF, 630V L4981A - L4981B

SO20 PACKAGE MECHANICAL DATA DIM. mm inch A 2.35 2.65 0.093 0.104 A1 0.1 0.3 0.004 0.012 B 0.33 0.51 0.013 0.020 C 0.23 0.32 0.009 0.013 D 12.6 13 0.496 0.512 E 7.4 7.6 0.291 0.299 e 1.27 0.050 H 10 10.65 0.394 0.419 h 0.25 0.75 0.010 0.030 L 0.4 1.27 0.016 0.050 K 0 (min.)8 (max.) 11 0 1120 A eB D E L K H A1 C SO20MEC hx4 5° L4981A - L4981B

DIP20 PACKAGE MECHANICAL DATA DIM. mm inch a1 0.254 0.010 B 1.39 1.65 0.055 0.065 b 0.45 0.018 b1 0.25 0.010 D 25.4 1.000 E 8.5 0.335 e 2.54 0.100 e3 22.86 0.900 F 7.1 0.280 I 3.93 0.155 L 3.3 0.130 Z 1.34 0.053 L4981A - L4981B

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics  1998 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. L4981A - L4981B