IL34262 Power Factor Controllers The are active power factor controllers specifically designed for use as a preconverter in electronic ballast and in off-line power converter applications. These integrated circuits feature an internal startup timer for stand-alone applications, a one quadrant multiplier for near unity power factor, zero current detector to ensure critical conduction operation, transconductance error amplifier, quickstart circuit for enhanced startup, trimmed internal bandgap reference, current sensing comparator, and a totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of an overvoltage comparator to eliminate runaway output voltage due to load removal, input undervoltage lockout with hysteresis, cycle-bycycle current limiting, multiplier output clamp that limits maximum peak switch current, an RS latch for single pulse metering, and a drive output high state clamp for MOSFET gate protection. These devices are available in dual-in-line and surface mount plastic packages. Features * Overvoltage Comparator Eliminates Runaway Output Voltage * Internal Startup Timer * One Quadrant Multiplier * Zero Current Detector 8 * Trimmed 2% Internal Bandgap Reference 1 * Totem Pole Output with High State Clamp * Undervoltage Lockout with 6.0 V of Hysteresis * Low Startup and Operating Current * Supersedes Functionality of SG3561 andTDA4817 Figure 1. Package and pin connection Figure 2. Simplified Block Diagram Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 MAXIMUM RATINGS Rating Symbol Value Unit Total Power Supply and Zener Current (Icc + Iz) 30 mA Output Current, Source or Sink lo 500 mA Current Sense, Multiplier, and Voltage Feedback Inputs Vin -1.0 to +10 V 50 mA Zero Current Detect Input High State Forward Current Low hn State Reverse Current -10 Power Dissipation and Thermal Characteristics P Suffix, Plastic Package, Case 626 Maximum Power Dissipation @ TA = 70C PD 800 mW Thermal Resistance, Junction-to-Air RJA 100 C/W Maximum Power Dissipation @ TA = 70C PD 450 mW Thermal Resistance, Junction-to-Air RJA 178 0 Operating Junction Temperature TJ +150 C Operating Ambient Temperature TA 0 to + 85 C Storage Temperature Tstg -65 to +150 C D Suffix, Plastic Package, Case 751 C/W ELECTRICAL CHARACTERISTICS (\/cc =12 V, for typical values TA = 25C, for min/max values TA is the operating ambient temperature range that applies unless otherwise noted.) Test list Position # Symbol Min Typ Max Voltage Feedback Input Threshold TA=25C TA = Tlow to Thigh (Vcc = 12 V to 28 V) Line Regulation (VCC = 12 V to 28 V, TA = 25C) Input Bias Current (VFB = 0 V) Transconductance (TA = 25C) 2 3 35 4 36 VFB 2.465 2.44 -- -- 80 2.5 -- 1.0 -0.1 100 2.535 2.54 10 -0.5 130 Output Current Source (VFB = 2.3 V) Sink (VFB = 2.7 V) 25 26 lo -- -- 10 10 -- -- 7 8 VOH(ea) VOL(ea) 5.8 -- 6.4 1.7 -- 2.4 Unit ERROR AMPLIFIER V Regline IIB gm mV A mho A Output Voltage Swing High State (VFB = 2.3 V) Low State (VFB = 2.7 V) OVERVOLTAGE COMPARATOR Voltage Feedback Input Threshold MULTIPLIER Input Bias Current, Pin 3 (VFB = 0 V) Input Threshold, Pin 2 V 9 VFB(OV) 1.065VFB 1.08VFB 1.095VFB V 5 14 IIB Vth(M) -- 1.05VOL(EA) -0.1 1.2VOL(EA) -0.5 -- A V Dynamic Input Voltage Range Multiplier Input (Pin 3) Compensation (Pin 2) 33 34 Vpin3 Vpin2 0 to 3.5 -- -- V Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by 0 to 2.5 Vth(M) to Vth(M) to (Vth(M)+1.0) (Vth(M)+ 1.5) IL34262 Multiplier Gain (Vpin 3 = 0.5 V, Vpin 2 = Vth(M) + 1.0 V) (Note 4) 15 K Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by 0.43 0.65 0.87 1/V IL34262 ELECTRICAL CHARACTERISTICS ZERO CURRENT DETECTOR Input Threshold Voltage (Vjn Increasing) Hysteresis (Vin Decreasing) Input Clamp Voltage High State (IDET = + 3.0 mA) High State (IDET = - 3.0 mA) CURRENT SENSE COMPARATOR Input Bias Current (Vpin 4 = 0 V) Input Offset Voltage (Vpm 2 = 1.1 V, Vpm 3 = 0 V) Maximum Current Sense Input Threshold (Note 5) Delay to Output DRIVE OUTPUT Output Voltage (VCC = 12 V) Low State (Isink = 20 mA) (Isink = 200 mA) High State (Isource = 20 mA) (Isource = 200 mA) Test list Position # Symbol Min Typ Max Unit 10 11 Vth VH 1.33 100 1.6 200 1.87 300 V mV 16 17 VIH VIL 6.1 0.3 6.7 0.7 -- 1.0 6 12 IIB VIO -- -- -0.15 9.0 -1.0 25 ?A mV 13 Vth(max) 1.3 1.5 1.8 V 38 tPHL(in/out) -- 200 400 ns 27 28 29 30 VOL -- -- 9.8 7.8 0.3 2.4 10.3 8.4 -- -- 0.8 3.3 V V VOH Output Voltage (VCC = 30 V) High State (Isource = 20 mA, C L = 15 pF) Output Voltage Rise Time (CL 1.0 nF) Output Voltage Fall Time (CL 1.0 nF) 31 VO(max) 14 16 18 V 41 39 tr tf -- -- 50 50 120 120 ns ns Output Voltage with UVLO Activated (Vcc = 7.0 V,l Sink= 1.0mA) RESTART TIMER Restart Time Delay UNDERVOLTAGE LOCKOUT Startup Threshold (VCC Increasing) Minimum Operating Voltage After Turn-On (VCC Decreasing) Hysteresis TOTAL DEVICE 32 VO(UVLO) -- 0.1 0.5 V 40 tDLY 200 620 -- s 19 20 Vth(on) VShutdown 11.5 7.0 13 8.0 14.5 9.0 V V 21 VH 3.8 5.0 6.2 V 22 23 37 24 ICC -- 30 0.4 12 20 -- mA VZ 0.25 6.5 9.0 36 Power Supply Current Startup (Vcc = 7.0 V) Operating Dynamic Operating (50 kHz, CL = 1.0 nF) Power Supply Zener Voltage (Ice = 25 mA) Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by V IL34262 Figure 3. Current Sense Input Threshold versus Multiplier Input. Figure 4. Current Sense Input Threshold versus Multiplier Input, Expanded View Figure 5. Voltage Feedback Input Threshold Change versus Temperature. Figure 4. Overvoltage Comparator Input Threshold versus Temperature. Figure 7. Error Amp Transconductance and Phase versus Frequency Figure 8. Quickstart Charge Current versus Temperature Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 Figure 9. Restart Timer Delay versus Temperature Figure 10. Zero Current Detector Input Threshold Voltage versus Temperature . . Figure 11. Output Saturation Voltage versus Load Current Figure 12. Supply Current versus Supply Voltage Figure 13. Undervoltage Lockout Thresholds versus Temperature Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 APPLICATIONS INFORMATION The application circuits shown in Figures 14, 15 and 16 reveal that few external components are required for a complete power factor preconverter. Each circuit is a peak detecting current-mode boost converter that operates in critical conduction mode with a fixed on-time and variable off-time. A major benefit of critical conduction operation is that the current loop is inherently stable, thus eliminating the need for ramp compensation. The application in Figure 14 operates over an input voltage range of 90 Vac to 138 Vac and provides an output power of 80 W (230 V at 350 mA) with an associated power factor of approximately 0.998 at nominal line. Figures 15 and 16 are universal input preconverter examples that operate over a continuous input voltage range of 90 Vac to 268 Vac. Figure 15 provides an output power of 175 W (400 V at 440 mA) while Figure 16 provides 450 W (400 V at 1.125 A). Both circuits have an observed worst-case power factor of approximately 0.989. Table 3. Design Equations Notes Calculate the maximum required output power. Calculated at the minimum required ac line voltage for output regulation. Let the efficiency ? = 0.92 for low line operation. Let the switching cycle t = 40 ?s for universal input (85 to 265 Vac) operation and 20 ?s for fixed input (92 to 138 Vac, or 184 to 276 Vac) operation. Calculation Required Converter Output Power Peak Inductor Current Inductance In theory the on-time ton is constant. In practice ton tends to increase at the ac line zero crossings due to the charge on capacitor C5. Let Vac = Vac(LL) for initial ton and toff calculations. The off-time toff is greatest at the peak of the ac line voltage and approaches zero at the ac line zero crossings. Theta (?) represents the angle of the ac line voltage. The minimum switching frequency occurs at the peak of the ac line voltage. As the ac line voltage traverses from peak to zero, toff approaches zero producing an increase in switching frequency. Set the current sense threshold V CS to 1.0 V for universal input (85 Vac to 265 Vac) operation and to 0.5 V for fixed input (92 Vac to 138 Vac, or 184 Vac to 276 Vac) operation. Note that V CS must be <1.4 V. Set the multiplier input voltage V M to 3.0 V at High line. Empirically adjust V M for the lowest distortion over the ac line voltage range while guaranteeing startup at minimum line. Switch On-Time The IIB R1 error term can be minimized with a divider current in excess of 50 ? A . Converter Output Voltage The calculated peak-to-peak ripple must be less than 16% of the average dc output voltage to prevent false tripping of the Overvoltage Comparator. Refer to the Overvoltage Comparator text. ESR is the equivalent series resistance of C3 The bandwidth is typically set to 20 Hz. When operating at high ac line, the value of C1 may need to be increased. (See Figure 17) Converter Output Peak to Peak Ripple Voltage Switch Off-Time Formula P O =V I L(pk) = O IO 2 2P O cVac (LL) Vo 2 t - Vac (LL) c Vac (LL) 2 Lp = 2 VoPo 2PoLp ton = c Vac 2 ton Vo toff = -1 2 Vac | Sin e | Switching Frequency Peak Switch Current Multiplier Input Voltage Error Amplifier Bandwidth The following converter characteristics must be chosen: VO -- Desired output voltage Vac -- AC RMS line voltage I O -- Desired out put current Vac (LL) -- AC RMS low line voltage ? VO -- Converter output peak -to-peak ripple voltage Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by 1 ton + toff f = R7 = VM = Vcs IL(pk) Vac 2 R5 + 1 R3 R2 Vo = Vref + 1 - IIBR1 R1 AVo(P - P) = Io ( ) 2 1 + ESR2 2 fac C3 BW = gm 2 C1 IL34262 IL34262 Figure 14. 80 W Power Factor Controller Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 IL34262 Figure 15. 175 W Universal Input Power Factor Controller Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 IL34262 Figure 16. 450 W Universal Input Power Factor Controller Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 Figure 17. Error Amp Compensation The Error Amp output is a high impedance node and is susceptible to noise pickup. To minimize pickup, compensation capacitor C1 must be connected as close to Pin 2 as possible with a short, heavy ground returning directly to Pin 6. When operating at high ac line, the voltage at Pin 2 may approach the lower threshold of the Multiplier, ? ? 2.0 V. If there is excessive ripple on Pin 2, the Multiplier will be driven into cut-off causing circuit instability, high distortion and poor power factor. This problem can be eliminated by increasing the value of C1. . Figure 18. Current Waveform Spike Suppression A narrow turn-on spike is usually present on the leading edge of the current waveform and can cause circuit instability. The IL34262 provides an internal RC filter with a time constant of 220 ns. An additional external RC filter may be required in universal input applications that are above 200 W. It is suggested that the external filter be placed directly at the Current Sense Input and have a time constant that approximates the spike duration. Figure 19. Negative Current Waveform Spike Suppression A negative turn-off spike can be observed on the trailing edge of the current waveform. This spike is due to the parasitic inductance of resistor R7, and if it is excessive, it can cause circuit instability. The addition of Shottky diode D1 can effectively clamp the negative spike. The addition of the external RC filter shown in Figure 18 may provide sufficient spike attenuation. Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by IL34262 Figure 20. Bonding diagram of Il34262 Chip size 2,1x2,1mm2 Chip holder size 2,9x2,9mm2 Chip contact pads 04, 12, 13, 14, 15 are not to be wired. Korzhenevsky 12, Minsk, 220064, Republic of Belarus Fax: +375 (17) 278 28 22, Phone: +375 (17) 278 07 11, 277 24 70, 277 24 61, 277 69 16 E-mail: belms@belms.belpak.minsk.by URL: www.bms.by