NCP1601A, NCP1601B Compact Fixed Frequency Discontinuous or Critical Conduction Voltage Mode Power Factor Correction Controller http://onsemi.com The NCP1601 is a controller designed for Power Factor Correction (PFC) boost circuits. The device operates in fixed-- frequency Discontinuous Conduction Mode (DCM) and variable-- frequency Critical Conduction Mode (CRM) and takes advantages from both operating modes. DCM limits the maximum switching frequency. It simplifies the front-- ended EMI filter design. CRM limits the maximum currents of the boost stage diode, MOSFET and inductor. It reduces the costs and improves the reliability of the circuit. This device substantially exhibits unity power factor while operating in DCM and CRM. The NCP1601 minimizes the required number of external components. It incorporates high safety protection features that make the NCP1601 suitable for robust and compact PFC stages. 8 Features 8 Near-- Unity Power Factor in DCM or CRM Voltage-- Mode Operation Low Startup and Shutdown Current Consumption Programmable Switching Frequency for DCM Synchronization Capability Overvoltage Protection (107% of Nominal Output Level) Undervoltage Protection or Shutdown (8% of Nominal Output Level) Programmable Overcurrent Protection Thermal Shutdown with Hysteresis (95/140C) Two VCC Undervoltage Lockout Hysteresis Options: 4.75 V for NCP1601A and 1.5 V for NCP1601B These are Pb-- Free Devices Typical Applications MARKING DIAGRAM 8 SOIC-- 8 D SUFFIX CASE 751 1 1 8 NCP1601x AWL YYWWG PDIP-- 8 N SUFFIX CASE 626 1 1 x A L, WL Y, YY W, WW G G = A or B = Assembly Location = Wafer Lot = Year = Work Week = Pb--Free Package = Pb--Free Package PIN CONNECTIONS FB 1 8 VCC Vcontrol 2 7 Drv Ramp 3 Electronic Light Ballast AC Adapters TV & Monitors Mid-- Power Applications 1601x ALYW G 6 GND CS 4 5 Osc (Top View) ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 16 of this data sheet. Semiconductor Components Industries, LLC, 2010 December, 2010 - Rev. 6 1 Publication Order Number: NCP1601A/D NCP1601A, NCP1601B AC Input EMI Filter Output 15 V FB VCC Vcontrol Drv Ramp GND CS Osc NCP1601X Figure 1. Typical Application Circuit L EMI Filter AC Input Output Voltage (Vout) Cfilter Cbulk RFB on RCS off IS IFB Vcontrol 1 FB / SD VCC Current Mirror 9V VCC V reg VCC(on) / 9 V + 96% I ref RS -- Reference Block C1 R3 1 C3 & Zero Current Detection (IS < 14 mA) Current Mirror R2 0 Shutdown / UVP (IFB < 8% Iref) 3.9 Vmax clamp Vton -+ PFC Modulation Ich Thermal Shutdown (95 / 140 C) Overcurrent Protection (IS > 203 mA) 9V Ramp 3 1 OR 0 Cramp 9V 45 mA Osc / Sync 5 COSC Ccontrol 9V R1 Internal Bias 4 I ref I FB Overvoltage Protection (IFB > 107% Iref) & CS + -- Regulation Block UVLO VCC Vcontrol Processing 300 k 8 18 V 2 94 mA 9V 0 1 + -- S 5 / 3.5 V & Q Drv S R delay Oscillator / Synchronization Block Figure 2. Functional Block Diagram http://onsemi.com 2 VCC R Q Output Driver 7 GND 6 NCP1601A, NCP1601B PIN FUNCTION DESCRIPTION Pin Symbol Function Function 1 FB Feedback / Shutdown This pin receives a current IFB which is proportional to the PFC circuit output voltage. The current is for the output regulation, output Overvoltage Protection (OVP), and output undervoltage protection (UVP). When IFB goes above 107% Iref, OVP is activated and the Drive Output is disabled. When IFB goes below 8% Iref, the device enters a low--current consumption shutdown mode. 2 Vcontrol Control The voltage of this pin Vcontrol directly controls the input impedance and hence the power factor of the circuit. This pin is connected to an external capacitor to limit the control voltage Vcontrol bandwidth typically below 20 Hz to achieve Power Factor Correction. 3 Ramp Ramp This pin is connected to an external capacitor to set a ramp signal. The capacitor value directly affects the input impedance of the PFC circuit and hence the maximum input power. 4 CS Current Sense This pin sources a current IS which depends on the inductor current and an offset voltage. The current is for Overcurrent Protection (OCP) and zero current detection. When IS is above 200 mA, OCP is activated and the Drive Output is disabled. When IS is below 14 mA, the circuit detects a zero current. This information is used by the on--time modulation arrangement and by the oscillator block. 5 Osc Oscillator / Synchronization In oscillator mode, this pin is connected to an external capacitor to set the oscillator frequency of the DCM operation. In synchronization mode, this pin is connected to an external driving signal. The positive edge of the drive output is synchronized to the negative edge of the external signal in DCM operation. If the inductor current is non--zero at the end of a switching period, the output drive is not allowed to turn on. CCM operation is prohibited. Instead, the circuit operates in CRM in this case. 6 GND The IC ground -- 7 Drv Drive Output This pin provides an output to an external MOSFET. 8 VCC Supply Voltage This pin is the positive supply of the device. The operating range is between 9 V and 18 V with UVLO start threshold 13.75 V for NCP1601A and 10.5 V for NCP1601B. http://onsemi.com 3 NCP1601A, NCP1601B MAXIMUM RATINGS Rating Symbol Value Unit FB, Vcontrol, Ramp, CS, Osc Pins (Pins 1--5) Maximum Voltage Range Maximum Current Vmax Imax --0.3 to +9 100 V mA Drive Output (Pin 7) Maximum Voltage Range Maximum Current Range (Note 2) Vmax Imax --0.3 to +18 --500 to +750 V mA Power Supply Voltage (Pin 8) Maximum Voltage Range Maximum Current Vmax Imax --0.3 to +18 100 V mA PD RθJA 800 100 mW C/W PD RθJA 450 178 mW C/W TJ --40 to +125 C Tstg --65 to +150 C Power Dissipation and Thermal Characteristics P suffix, Plastic Package, Case 626 Maximum Power Dissipation @ TA=70 C Thermal Resistance, Junction--to--Air D suffix, Plastic Package, Case 751 Maximum Power Dissipation @ TA=70 C Thermal Resistance, Junction--to--Air Operating Junction Temperature Range Storage Temperature Range Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. A. This device series contains ESD protection and exceeds the following tests: Pins 1--8: Human Body Model 2000 V per MIL--STD--883, Method 3015. Machine Model Method 200 V. B. This device contains Latchup protection and exceeds 100 mA per JEDEC Standard JESD78. 1. Guaranteed by design. http://onsemi.com 4 NCP1601A, NCP1601B ELECTRICAL CHARACTERISTICS (For typical values TJ = 25C. For min/max values, TJ = --40C to +125C, VCC = 15 V, Vcontrol = 100 nF, Ramp = 100 pF, Osc = 220 pF unless otherwise specified) Pin Symbol Min Typ Max Unit Oscillator Frequency (Osc = 220 pF to GND) 5 fosc 52 58 64 kHz Internal Capacitance of the Oscillator Pin 5 Cosc(int) -- 36 -- pF Maximum Oscillator Switching Frequency 5 fosc(max) -- 405 -- kHz Oscillator Discharge Current (Osc = 5.5 V) 5 Iodch 40 49 60 mA Oscillator Charge Current (Osc = 3 V) 5 Ioch 40 45 60 mA Comparator Lower Threshold (Osc = 220 pF to GND) (Note 3) 5 Vsync(L) 3.0 3.5 4.0 V Comparator Upper Threshold (Osc = 220 pF to GND) 5 Vsync(H) 4.5 5 5.5 V Synchronization Pulse Width for Detection 5 tsync(min) 500 -- -- ns Synchronization Propagation Delay 5 tsync(d) -- 371 -- ns ROH ROL 5 2 11.6 7.2 20 18 Ω Ω Characteristic OSCILLATOR GATE DRIVE Gate Drive Resistor Output High and Draw 100 mA out of Drv Pin (Isource = 100 mA) Output Low and Insert 100 mA into Drv Pin (Isink = 100 mA) 7 Gate Drive Rise Time from 1.5 V to 13.5 V (Drv = 1 nF to GND) 7 tr -- 53 -- ns Gate Drive Fall Time from 13.5 V to 1.5 V (Drv = 1 nF to GND) 7 tf -- 32 -- ns FEEDBACK / OVERVOLTAGE PROTECTION / UNDERVOLTAGE PROTECTION Reference Current 1 Iref 192 203 208 mA Regulation Block Ratio 1 IregL / Iref 95 96 97 % Vcontrol Pin Internal Resistor 2 Rcontrol -- 300 -- kΩ Maximum Control Voltage (IFB = 100 mA) 2 Vcontrol(max) 0.95 1.05 1.15 V Feedback Pin Voltage (IFB = 100 mA) 1 VFB1 -- 3 -- V Overvoltage Protection Current Ratio 1 IOVP / Iref 104 107 -- % Overvoltage Protection Current 1 IOVP -- 217 225 mA Undervoltage Protection Current Ratio 1 IUVP / Iref 4 8 15 % Current Sense Pin Offset Voltage (IS = 100 mA) 4 VS -- 4 -- mV Overcurrent Protection Level 4 IS(OCP) 190 203 210 mA Current Sense Pin Offset Voltage at Overcurrent Level 4 VS(OCP) 0 3.2 20 mV Zero Current Detection Level 4 IS(ZCD) 9 14 19 mA Current Sense Pin Offset Voltage at Zero Current Level 4 VS(ZCD) 0 7.5 20 mV Zero Current Sense Resistor (RS(ZCD) = VS(ZCD) / IS(ZCD)) 4 RS(ZCD) -- 0.536 1 kΩ Charging Current (Ramp = 0 V) 3 Ich 95 100 105 mA Maximum Power Resistance (Rpower = Vcontrol(max) / Ich) 3 Rpower 9.5 10.5 11.5 kΩ Internal Clamping of Voltage Vton -- Vton(max) -- 3.9 -- V Internal Capacitance of the Ramp Pin 3 Cramp(int) -- 20 -- pF Ramp Pin Sink Resistance (Osc = 0 V, Ramp = 1 mA sourcing) 3 Rramp -- 71.5 -- Ω Thermal Shutdown Threshold (Note 4) -- TSD 140 -- -- C Thermal Shutdown Hysteresis -- TH -- 45 -- C CURRENT SENSE RAMP THERMAL SHUTDOWN 2. Comparator lower threshold is also the synchronization threshold. 3. Guaranteed by design. http://onsemi.com 5 NCP1601A, NCP1601B ELECTRICAL CHARACTERISTICS (For typical values TJ = 25C. For min/max values, TJ = --40C to +125C, VCC = 15 V, Vcontrol = 100 nF, Ramp = 100 pF, Osc = 220 pF unless otherwise specified) Characteristic Pin Symbol Min Typ Max Unit Startup Threshold (UVLO) – NCP1601A Startup Threshold (UVLO) – NCP1601B 8 VCC(on) 12.5 9.6 13.75 10.5 15 11.4 V V Minimum Voltage for Operation After Turn--On 8 VCC(off) 8.25 9 9.75 V UVLO Hysteresis – NCP1601A UVLO Hysteresis – NCP1601B 8 VCC(H) 4 1 4.75 1.5 --- V V Power Supply Current: Startup (VCC = VCC(on) – 0.2 V) Operating (VCC = 15 V, Drv = open, Osc = 220 pF) Operating (VCC = 15 V, Drv = 1 nF to GND, Osc = 220 pF) Shutdown (VCC = 15 V, IFB = 0 A) 8 Istup ICC1 ICC2 Istdn ----- 17 2.7 3.7 24 40 5 5 50 mA mA mA mA SUPPLY SECTION TYPICAL CHARACTERISTICS 51 OSCILLATOR CHARGE & DISCHARGE CURRENT (mA) fOSC, OSCILLATOR FREQUENCY (kHz) 60 59 58 57 56 55 54 53 52 COSC = 220 pF 51 50 --50 --25 0 25 50 75 100 125 50 Iodch osc pin = 5.5 V 49 48 47 46 Ioch osc pin = 3 V 45 44 --50 --25 TJ, JUNCTION TEMPERATURE (C) 50 75 100 125 Figure 4. Oscillator Charge and Discharge Current vs. Temperature 5.5 18 16 Vsync(H) 5.0 GATE DRIVE RESISTANCE (Ω) OSCILLATOR COMPARATOR THRESHOLDS (V) 25 TJ, JUNCTION TEMPERATURE (C) Figure 3. Oscillator Frequency vs. Temperature 4.5 COSC = 220 pF 4.0 Vsync(L) 3.5 3 --50 0 --25 0 25 50 75 100 12 10 ROL 8 6 4 2 0 --50 125 ROH 14 TJ, JUNCTION TEMPERATURE (C) --25 0 25 50 75 100 TJ, JUNCTION TEMPERATURE (C) Figure 5. Oscillator Comparator Thresholds vs. Temperature Figure 6. Drive Output Resistance vs. Temperature http://onsemi.com 6 125 NCP1601A, NCP1601B TYPICAL CHARACTERISTICS 1.2 208 Vcontrol, CONTROL VOLTAGE (V) IREF, REFERENCE CURRENT (mA) 210 206 204 202 200 198 196 194 192 190 --50 0 --25 25 50 75 100 0.8 TJ = --40C 0.6 TJ = 25C 0.4 TJ = 125C 0.2 0 150 125 160 170 190 200 210 IFB, FEEDBACK CURRENT (mA) Figure 7. Reference Current vs. Temperature Figure 8. Regulation Block Transfer Function 220 MAXIMUM CONTROL VOLTAGE (V) 1.10 99 98 97 96 95 94 93 92 91 90 --50 0 --25 25 50 75 100 1.08 1.06 1.04 1.02 IFB = 100 mA 1.00 --50 125 --25 TJ, JUNCTION TEMPERATURE (C) OVERVOLTAGE PROTECTION RATIO (%) 5 TJ = 125C 3 TJ = --40C TJ = 25C 2 1 0 0 50 100 150 200 25 50 75 100 125 Figure 10. Maximum Control Voltage vs. Temperature 6 4 0 TJ, JUNCTION TEMPERATURE (C) Figure 9. Regulation Block Ratio vs. Temperature FEEDBACK PIN VOLTAGE (V) 180 TJ, JUNCTION TEMPERATURE (C) 100 REGULATION BLOCK RATIO (%) 1.0 250 110 109.5 109 108.5 108 107.5 107 106.5 106 105.5 105 --50 IFB, FEEDBACK PIN CURRENT (mA) --25 0 25 50 75 100 TJ, JUNCTION TEMPERATURE (C) Figure 11. Feedback Pin Voltage vs. Feedback Current Figure 12. Overvoltage Protection Ratio vs. Temperature http://onsemi.com 7 125 NCP1601A, NCP1601B TYPICAL CHARACTERISTICS UNDERVOLTAGE PROTECTION RATIO (%) OVERVOLTAGE THRESHOLD (mA) 220 218 216 214 212 210 208 206 204 202 200 --50 0 --25 25 50 75 100 125 10 9 8 7 6 5 4 3 2 1 0 --50 0 --25 TJ, JUNCTION TEMPERATURE (C) 100 125 10 CS PIN OFFSET VOLTAGE (mV) CS PIN OFFSET VOLTAGE (mV) 75 Figure 14. Undervoltage Protection Ratio vs. Temperature 120 100 80 60 40 TJ = 125 C TJ = 25 C 20 TJ = --40 C 0 100 50 150 200 9 8 VS(ZCD) 7 6 5 4 VS(OCP) 3 2 1 0 --50 250 IS, CS PIN CURRENT (mA) ZERO CURRENT DETECTION LEVEL (mA) 210 206 204 202 200 198 196 194 192 --25 0 25 50 75 0 25 50 75 100 125 Figure 16. CS Pin Offset Voltage at OCP, ZCD vs. Temperature 208 190 --50 --25 TJ, JUNCTION TEMPERATURE (C) Figure 15. CS Pin Offset Voltage vs. Current OVERCURRENT PROTECTION LEVEL (mA) 50 TJ, JUNCTION TEMPERATURE (C) Figure 13. Overvoltage Protection Threshold vs. Temperature 0 25 100 125 15.0 14.5 14.0 13.5 13.0 12.5 12.0 11.5 11.0 10.5 10.0 --50 TJ, JUNCTION TEMPERATURE (C) --25 0 25 50 75 100 TJ, JUNCTION TEMPERATURE (C) Figure 17. Overcurrent Protection Level vs. Temperature Figure 18. Zero Current Detection Level vs. Temperature http://onsemi.com 8 125 NCP1601A, NCP1601B 105 700 600 ICH, CHARGING CURRENT (mA) ZERO CURRENT SENSE RESISTOR (Ω) TYPICAL CHARACTERISTICS 500 400 300 200 100 0 --50 --25 0 25 50 75 100 104 103 102 101 100 97 96 --25 0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (C) TJ, JUNCTION TEMPERATURE (C) Figure 19. Zero Current Sense Resistor vs. Temperature Figure 20. Charging Current vs. Temperature VCC UNDERVOLTAGE LOCKOUT THRESHOLDS (V) 15 11.5 11.0 10.5 10.0 9.5 9.0 --50 --25 0 25 50 75 100 13 12 VCC(on) for NCP1601B 11 10 VCC(off) 9 --25 0 25 50 75 100 TJ, JUNCTION TEMPERATURE (C) TJ, JUNCTION TEMPERATURE (C) Figure 21. Maximum Power Resistance vs. Temperature Figure 22. Supply Voltage Undervoltage Lockout Thresholds vs. Temperature 125 4 35 30 25 Istdn 20 15 Istup 10 5 0 --50 VCC(on) for NCP1601A 14 8 --50 125 VCC SUPPLY CURRENT WITH 1.0 nF LOAD AND WITHOUT LOAD (mA) MAXIMUM POWER RESISTANCE (kΩ) 98 95 --50 125 12.0 VCC SUPPLY CURRENT IN STARTUP AND SHUTDOWN MODE (mA) 99 --25 0 25 50 75 100 125 3.8 3.6 ICC2, 1 nF Load 3.4 3.2 3 2.8 2.6 ICC1, No Load 2.4 2.2 2 --50 TJ, JUNCTION TEMPERATURE (C) VCC = 15 V, COSC = 220 pF --25 0 25 50 75 100 TJ, JUNCTION TEMPERATURE (C) Figure 23. Supply Current in Startup and Shutdown Mode vs. Temperature Figure 24. Supply Current vs. Temperature http://onsemi.com 9 125 NCP1601A, NCP1601B FUNCTIONAL DESCRIPTION Introduction conditions, CRM can be an alternative option which is without power factor degradation. On the other hand, the NCP1601 can be viewed as a CRM controller with a frequency clamp (maximum switching frequency limit) alternative option which is also without power factor degradation. In summary, the NCP1601 can cover both CRM and DCM without power factor degradation. Based on the selections of the boost inductor and the oscillator frequency, the circuit is capable of the following three applications. 1. “Mostly in CRM” with a frequency clamp set by the oscillator or synchronization frequency. 2. “Mostly in fixed-- frequency mode DCM” and only run in CRM at high load and low line. 3. “Fixed-- frequency DCM” only. The NCP1601 is a Power Factor Correction (PFC) boost controller designed to operate in Discontinuous Conduction Mode (DCM) and Critical Conduction Mode (CRM). The fixed-- frequency nature of DCM limits the maximum switching frequency. It limits the possible conducted and radiated EMI noise that may pollute surrounding systems. NCP1601 offers the simplest solution to PFC including fewer external circuit components and simple voltage-- mode feedback. The diode turn-- off switching loss is negligible and hence there is no need to use a low reverse-- recovery time trr diode. On the other hand, the CRM feature is added to limit the maximum current stress to twice of the average current. The NCP1601 incorporates high safety protection features and combines the advantages of DCM and CRM so that the NCP1601 is suitable for robust and compact PFC stages. The NCP1601 provides the following protection features: 1. Overvoltage Protection (OVP) is activated and the output drive goes low when the output voltage exceeds 107% of the nominal regulation level which is a user-- defined value. The circuit automatically resumes operation when the output voltage becomes lower than 107%. 2. Undervoltage Protection (UVP) is activated and the device is shut down when the output voltage goes below 8% of the nominal regulation level. The circuit automatically resumes operation when the output voltage goes above 8% of the nominal regulation level. This feature also provides output open-- loop protection and external shutdown feature. 3. Overcurrent Protection (OCP) is activated and the output device goes low when the inductor current exceeds a user-- defined value. The operation automatically resumes when the inductor current becomes lower than this user-- defined value at the next clock cycle. 4. Thermal Shutdown (TSD) is activated and the output drive is disabled when the junction temperature exceeds 140C. The operation resumes when the junction temperature falls down by typical 45C. Current Inductor current, IL Input current, Iin time DCM Critical Mode DCM Figure 25. Operating Modes DCM needs higher peak inductor current comparing to CRM in the same averaged input current. Hence, CRM is generally preferred at around the sinusoidal peak for lower the maximum current stress but DCM is also preferred at the non-- peak region to avoid excessive switching frequencies. Because of the variable-- frequency feature of the CRM and constant-- frequency feature of DCM, switching frequency is the maximum in the DCM region and hence the minimum switching frequency will be found at the moment of the sinusoidal peak. DCM PFC Circuit A DCM/CRM PFC boost converter is shown in Figure 26. Input voltage is a rectified 50 or 60 Hz sinusoidal signal. The MOSFET is switching at a high frequency (typically around 100 kHz) so that the inductor current IL basically consists of high--frequency and low--frequency components. Filter capacitor Cfilter is an essential and very small value capacitor in order to eliminate the high-- frequency content of the DCM inductor current IL. This filter capacitor cannot The NCP1601 is available in two versions. The NCP1601A has a typical 4.75 V undervoltage lockout (UVLO) hysteresis, while NCP1601B has a typical 1.5 V UVLO hysteresis. It allows the use of different VCC biasing schemes. Operating Modes of NCP1601 The NCP1601 is a PFC driver primarily designed to operate in fixed-- frequency DCM. In the most stressful http://onsemi.com 10 NCP1601A, NCP1601B be too bulky because it can pollute the power factor by distorting the rectified sinusoidal input voltage. Iin IL Power factor is corrected when the input impedance Zin in (eq.3) are constant or slowly varying. The MOSFET on time t 1 or PFC modulation duty is generated by a feedback signal Vton and a ramp. The PFC modulation circuit and timing diagram are shown in Figure 28. A relationship in (eq.4) is obtained. L Vout Vin Cfilter Cbulk t1 = Figure 26. DCM/CRM PFC Boost Converter Cramp Vton Ich PFC Modulation + -- Ramp PFC Methodology NCP1601 uses a proprietary PFC methodology particularly designed for both DCM and CRM operation. The PFC methodology is described in this section. 3 closed when output low Cramp (eq.4) Ich Turns off MOSFET Vton Inductor Current Vton ramp output Ipk Figure 28. PFC Modulation Circuit and Timing Diagram t1 t2 The charging current Ich is constant 100 mA current and the ramp capacitor Cramp is constant for a particular design. Hence, according to (eq.4) the MOSFET on time t1 is proportional to Vton. In order to protect the PFC modulation comparator, the maximum voltage of Vton is limited to internal clamp Vton(max) (3.9 V typical) and the ramp pin (Pin 3) is with a 9 V ESD Zener diode. The 3.9 V maximum limit of this Vton indirectly limits the maximum on time. time t3 T Figure 27. Inductor Current in DCM As shown in Figure 27, the inductor current IL of each switching cycle starts from zero in DCM. CRM is a special case of DCM when t3 = 0. When the PFC boost converter MOSFET is on, the inductor current IL increases from zero to Ipk for a time duration t1 with inductance L and input voltage Vin. (eq.1) is formulated. Ipk Vin = L t1 closed when zero current R1 R2 (eq.1) The input filter capacitor Cfilter and the front-- ended EMI filter absorb the high-- frequency component of inductor current. It makes the input current Iin a low-- frequency signal. C1 Vcontrol 2 -+ R3 C3 Ccontrol Ipk (t1 + t2) Iin = 2T for DCM (eq.2a) Ipk Iin = 2 for CRM (eq.2b) Figure 29. Vcontrol Processing Circuit The Vcontrol processing circuit generates Vton from control voltage Vcontrol and time information of zero inductor current. The circuit in Figure 29 makes (eq.5) where the value of resistor R1 is much higher than the value of resistor R2 (R1 >> R2). From (eq.1) and (eq.2), the input impedance Zin is formulated. V 2TL for DCM Zin = in = Iin t1(t1 + t2) (eq.3a) V 2L Zin = in = t1 Iin (eq.3b) for CRM Vton Vton = http://onsemi.com 11 T Vcontrol t1 + t2 for DCM (eq.5a) NCP1601A, NCP1601B Vton = Vcontrol for CRM (eq.5b) Rpower = It is noted that Vton is always greater than or equal to Vcontrol (i.e., Vton Vcontrol). In summary, the input impedance Zin in (eq.6) is obtained from (eq.1)-- (eq.5) 2 L Ich V Zin = in = Iin Cramp Vcontrol Pin(max) = Control voltage Vcontrol comes from the PFC output voltage Vout which is a slowly varying signal. The bandwidth of Vcontrol can be additionally limited by inserting an external capacitor Ccontrol to the Vcontrol pin (Pin 2) in Figure 28. The internal 300 kΩ resistor and the capacitor Ccontrol create a low-- pass filter which has a bandwidth fcontrol in (eq.7). It is generally recommended to limit the bandwidth below 20 Hz to achieve power factor correction. Typical value of Ccontrol is 0.1 mF. 300k Iac(max) = Vcontrol 2L ηVac2CrampRpower Pin(max) 2L Vac = VacCrampRpower 2L V − VFB1 V IFB = out ≈ out RFB RFB (eq.10a) (eq.10b) (eq.11) (eq.12) where RFB is the feedback resistor connected between the FB pin (Pin 1) and the output voltage referring to Figure 2. Then, the feedback current IFB represents the output voltage Vout and will be used in the output voltage regulation, Undervoltage Protection (UVP), and Overvoltage Protection (OVP). 2 Output Voltage Regulation Feedback current IFB, which presents output voltage Vout, is regulated with a reference current (Iref = 203 mA typical) as shown in Figure 31. Figure 30. Vcontrol Low--Pass Filtering Vreg Maximum Power 1.05 V Input and output power (Pin and Pout) are derived in (eq.8) when the circuit efficiency η is obtained or assumed. The variable Vac stands for the RMS input voltage. Vac2CrampVcontrol Pout = η Pin = (eq.9) The output voltage Vout of the PFC circuit is sensed as a feedback current IFB flowing into the FB pin (Pin 1) of the device. The FB pin voltage VFB1 is typically less than 5 V referring to Figure 11. It is much lower than Vout which is typically 400 V. Therefore, VFB1 is generally neglected. (eq.7) Ccontrol V 2 Pin = ac = Zin = 10.5 kΩ Output Feedback Vcontrol Processing Circuit Regulation Block 1.05 V 100 mA The maximum input current Iac(max) to deliver the maximum input power Pin(max) is also derived in (eq.11). The suffix ac stands for RMS value. Vreg Iref IFB = Vac2CrampRpower Pout(max) = If the bandwidth of Vcontrol is much less than the 50 or 60 Hz line frequency, the input impedance Zin is slowly varying or roughly constant. Then, the power factor correction is achieved in DCM and CRM. 96% Iref Ich It means that the maximum input and output power (Pin(max) and Pout(max)) are limited to 10% variation. (eq.6) 1 Ccontrol > 2π300kΩ fcontrol Vcontrol(max) 2LIch ηVac2CrampVcontrol 2LIch 96% Iref Iref IFB Figure 31. Regulation Block (eq.8a) When IFB is lower than 96% of Iref, the Vreg which is the output of the regulation block is as high as Vcontrol(max) (1.05 V typical) that gives the maximum value on Vton. As a result, it gives the maximum MOSFET on time and Vout increases. When IFB is higher than Iref, the Vreg becomes 0 V that gives no MOSFET on time and Vout decreases. As a result, the output voltage Vout is regulated around the range between 96% and 100% of the nominal value of RFB Iref. Based on (eq.8) for a particular power level, the Vcontrol is inversely proportional to Vac2. Hence, in high Vac condition Vcontrol is lower. It means that IFB or output (eq.8b) From (eq.8), control voltage Vcontrol controls the amount of output power, input power, or input impedance. The maximum value of the control voltage Vcontrol is 1.05 V (i.e., Vcontrol(max) = 1.05 V). A parameter called maximum power resistor Rpower (10.5 kΩ typical) is defined in (eq.9) and restricted to have a maximum 10% variation (i.e., 9.5 kΩ Rpower 11.5 kΩ) for defining the maximum power in an application. http://onsemi.com 12 NCP1601A, NCP1601B voltage is higher based on the regulation block characteristic in Figure 31. On the other hand, the Vcontrol in the low Vac condition is much higher than the high Vac condition. In order to not over-- design the circuit in the application, the Vcontrol in the low Vac condition is usually very closed to Vcontrol(max). It makes the output voltage be almost 96% of the nominal value of RFB Iref in low Vac condition while the output voltage is almost 100% of the nominal value RFB Iref in high Vac condition. The feedback resistor RFB consists of two or three high precision resistors in order to set the nominal Vout precisely and safety purpose. The regulation block output Vreg is connected to control voltage Vcontrol through an internal resistor Rcontrol (300 kΩ typical) for the low-- pass filter in Figure 30. The Vcontrol and the time information of zero current are collected in the Vcontrol processing circuit to generate Vton which is then compared to a ramp signal to generate the MOSFET on time t1 for power factor correction. IL RS IS RCS IL CS + NCP1601 Gnd VS -- Figure 32. Current Sensing Inductor current IL passes through RCS and creates a negative voltage. This voltage is measured by a current IS flowing out of the CS pin (Pin 4). The CS pin has an offset voltage VS. This offset voltage is studied in the setting of zero inductor current IL(ZCD) and the maximum inductor current IL(OCP) (i.e., overcurrent protection threshold). A typical variation of offset voltage VS versus sense current IS is shown in Figure 15. Higher the value of the offset voltage at low current region creates lower the zero current threshold for better accuracy. Based on Figure 32, (eq.13) is derived. Overvoltage Protection (OVP) When the feedback current IFB is higher than 107% of the reference current Iref (i.e., the output voltage Vout is higher than 107% of its nominal value), the Drive Output pin (Pin 7) of the device goes low for protection and the switch of the Vcontrol processing circuit is kept off. The circuit automatically resumes operation when the output voltage is lower than 107%. The maximum OVP threshold is limited to 225 mA which corresponds to 225 mA 1.95 MΩ + 5 V = 443.75 V when RFB = 1.95 MΩ (1.8 MΩ + 150 kΩ) and VFB1 = 5 V (for the worst case referring to Figure 11). Hence, it is generally recommended to use 450 V rating output capacitor to allow some design margin. VS − RS IS = --RCS IL (eq.13) Zero Current Detection (ZCD) The device recognizes zero inductor current when the CS pin (Pin 4) sense current IS is lower than IS(ZCD) (14 mA typical). The offset voltage of the CS pin in this condition is VS(ZCD) (7.5 mV typical). It is illustrated in Figure 33. The inductor current IL(ZCD) at the ZCD condition is derived in (eq.14). IL(ZCD) = RSIS(ZCD) − VS(ZCD) RCS (eq.14) It is obvious that the IL(ZCD) is not always zero. In order to make it reasonably close to zero, the settings of RS and RCS are crucial. Undervoltage Protection (UVP) When the feedback current IFB is lower than 8% of the reference current Iref (i.e., the output voltage Vout is lower than 8% of its nominal value), the device is shut down and consumes lower than 50 mA. In normal situation of boost converter configuration, the output voltage Vout is always higher than the input voltage Vin and the feedback current IFB is always higher than 8% of the reference current Iref. It enables the NCP1601 to operate. Hence, UVP happens when the output voltage is abnormally undervoltage, the FB pin (Pin 1) is opened, or the FB pin (Pin 1) is manually pulled low. VS RS > RS(ZCD) Operating ZCD point RS = RS(ZCD) Ideal ZCD point VS(ZCD) Current Sense The device senses the inductor current IL by the current sense scheme in Figure 32. This scheme has the advantages of: (1) the inrush current limitation by the resistor RCS, and (2) the overcurrent protection and zero current detection implemented in the same pin. IS IS(ZCD) Figure 33. CS Pin Characteristic when IL = 0 http://onsemi.com 13 NCP1601A, NCP1601B Based on the CS pin (Pin 4) characteristics in Figure 15, Figure 33 is studied. When the inductor current is exactly zero (i.e., IL(ZCD) = 0), the ideal ZCD point in the Figure is reached where RS is RS(ZCD) (536 Ω typical). Considering the tolerance, the actual sense resistor RS is needed to be higher than the ideal value of RS(ZCD) to ensure that zero current signal is generated when sense current is smaller than the ZCD threshold (i.e., IS < IS(ZCD)). That is, RS > RS(ZCD) = VS(ZCD) When overcurrent protection threshold is reached, the Drive Output of the device goes low. Oscillator / Synchronization Block Oscillator Clock 45 mA Osc 5 94 mA (eq.15) IS(ZCD) 0 The higher value of RS makes the longer distance between the operating and ideal ZCD points in Figure 33. Hence, RS has to be as low as possible. The best recommended value of RS is therefore the maximum of RS(ZCD) which is 1 kΩ. Now that the RS is set at a particular value which is greater than RS(ZCD). From (eq.13), the operating lines in (eq.16) with different inductor currents IL of (eq.13) are studied. VS = RS − RCSIL Discontinuous mode time The NCP1601 is a DCM / CRM PFC controller. In order to keep the operation in DCM or CRM only, the Drive Output cannot turn on as long as there is some inductor current flowing through the circuit. Hence, the zero current signal is provided to the oscillator / synchronization block in Figure 35. An input comparator monitors the Osc pin (Pin 5) voltage and generates a clock signal. The negative edge of the clock signal is stored in a RS latch. When zero current is detected, the RS latch will be reset and a set signal is sent to the output drive latch which turns on the MOSFET in the PFC boost circuit. Figure 36 illustrates a typical timing diagram of the oscillator block. Oscillator Mode Operating ZCD point The Osc pin (Pin 5) is connected to an external capacitor Cosc. When the voltage of this pin is above Vsync(H) (5 V typical), the pin sinks a current Iodch (94 – 45 = 49 mA typical) and the external capacitor Cosc discharges. When the voltage reaches Vsync(L) (3.5 V typical), the pin sources a current Ioch (45 mA typical) and the external capacitor Cosc is charged. It is noted that there is a typical 300 ns propagation delay and the 3.5 V and 5 V threshold conditions are measured on 220 pF Cosc capacitor. Hence, the actual oscillator hysteresis is a slightly smaller. Figure 34. CS Pin Characteristic with Different Inductor Current It is noted in Figure 34 and (eq.16) that when the (RCS IL) term is smaller the error or distance between the lines to the line IL = 0 is smaller. Therefore, the value of the current sense resistor RCS is also recommended to be as small as possible to minimize the error in the zero current detection. Overcurrent Protection (OCP) Osc pin voltage Overcurrent protection is reached when IS is higher than IS(OCP) (200 mA typical). The offset voltage of the CS pin is VS(OCP) (3.2 mV typical) in this condition. That is RCS Critical mode Figure 36. Oscillator Block Timing Diagram IL > IL(ZCD) RSIS(OCP) − VS(OCP) delay inductor current IS IL(OCP) = R clock latch (latch output) Best ZCD point IS(ZCD) Turn on MOSFET clock edge (latch set signal) (eq.16) VS(ZCD) 1 & clock VS IL = IL(ZCD) 5 V/3.5 V S Q Figure 35. Oscillator / Synchronization Block These operating lines are added in Figure 33 to formulate Figure 34. When the inductor current IL is lower than IL(ZCD), the sense current IS is lower than IS(ZCD) and hence the zero current signal is generated. IL = 0 + -- Zero Current 5V 3.5 V Osc clock Clock edge (eq.17) Drive output (DCM) Figure 37. Oscillator Mode Timing Diagram in DCM http://onsemi.com 14 NCP1601A, NCP1601B There is an internal capacitance Cosc(int) (36 pF typical) in the oscillator pin and the oscillator frequency is to fosc(max) (405 kHz typical) when the Osc pin is opened. Hence, the oscillator switching frequency can be formulated in (eq.18) and represented in Figure 38. Cosc = 36 pF ⋅ 405 kHz fosc − 36 pF signal turns to 3.5 V. A timing diagram of synchronization mode is summarized in Figure 39. Osc Clock (eq.18) Clock Edge 700 C osc , Oscillator Capacitor (pF) 5V 3.5 V Sync Signal Drive Output (DCM) 600 500 Figure 39. Synchronization Mode Timing Diagram in DCM 400 VCC Undervoltage Lockout (UVLO) 300 There are two UVLO options. The device typically starts to operate when the supply voltage VCC exceeds 13.75 V for NCP1601A and 10.5 V for NCP1601B. It turns off when the supply voltage VCC goes below 9 V. An 18 V internal ESD Zener diode is connected to the VCC pin (Pin 8). Hence, the operating range is 9 V to 18 V. The 4.75 V UVLO hysteresis option of the NCP1601A and 14 mA low startup current make the self-- supply design easier. The 1.5 V UVLO hysteresis option of NCP1601B makes it more flexible to match with the second-- stage PWM controller biasing VCC supply voltage. 200 100 0 0 50 100 150 f osc , Oscillator Frequency (kHz) 200 Figure 38. Osc Pin Frequency Setting Synchronization Mode The Osc pin (Pin 5) receives an external digital signal with level high defined to be higher than Vsync(H) (5 V typical) and level low defined to be lower than Vsync(L) (3.5 V typical). An internal 9 V ESD Zener diode is connected to the Osc pin and hence the maximum synchronization voltage is 9 V. The circuit recognizes a synchronization frequency by the time difference between two falling edge instants when the synchronization signal across the 3.5 V threshold points. The actual synchronization threshold point is a slightly higher than the 3.5 V threshold point. The minimum synchronization pulse width is 500 ns. There is a typical 350 ns propagation delay from synchronization threshold point to the moment of output goes high and there is also a typical 300 ns propagation delay from the synchronization threshold point to the moment of crossing 3.5 V. Hence, the output goes high apparently when the sync Thermal Shutdown An internal thermal circuitry disables the circuit gate drive and then keeps the power switch off when the junction temperature exceeds 140C. The output stage is then enabled once the temperature drops below typically 95C (i.e., 45C hysteresis). The thermal shutdown is provided to prevent possible device failures that could result from an accidental overheating. Output Drive The output stage of the device is designed for direct drive of power MOSFET. It is capable of up to - 500 mA and +750 mA peak drive current and has a typical rise and fall time of 53 and 32 ns with a 1.0 nF load. Table 1. Power Factor Controller Test Data Vin (Vac) Pin (W) Vout (V) Iout (mA) PF THD (%) Efficiency (%) 90 143.4 327 400 0.998 4 91.2 110 161.1 373 400 0.997 6 92.6 130 160.5 378 400 0.996 6 94.2 150 160.9 382 400 0.993 7 95.0 180 161.6 386 400 0.990 6 95.5 190 161.7 387 400 0.986 8 95.7 210 162.0 389 400 0.980 8 96.0 230 162.2 391 400 0.973 9 96.4 250 162.8 393 400 0.959 16 96.6 http://onsemi.com 15 NCP1601A, NCP1601B KBP06 3.15 A Fuse Input 90 Vac to 260 Vac 100 nF 450 mH / 4.5 A 1 mF 1 mF MUR460 680 k 68 mF 450 V Output 390 V 680 k SPP11N60S5 SPF47283900 0.1 560 k Vcc 2.2 k NCP1601B 56 1N4934 1.5 nF 68 nF 1.5 nF 220 pF 10 k Figure 40. 130 W Power Factor Correction Circuit ORDERING INFORMATION Package Shipping† NCP1601APG PDIP--8 (Pb--Free) 50 Units / Rail NCP1601ADR2G SOIC--8 (Pb--Free) 2500 Units / Tape & Reel NCP1601BPG PDIP--8 (Pb--Free) 50 Units / Rail NCP1601BDR2G SOIC--8 (Pb--Free) 2500 Units / Tape & Reel Device †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. http://onsemi.com 16 NCP1601A, NCP1601B Appendix I – Summary of Equations in NCP1601 Boost PFC Description Boost converter Critical Mode (CRM) t + t2 Vout = 1 t2 Vin t + t2 Vout = 1 t2 Vin → Vout − Vin = t → Vout − Vin = t Ipk Iin = 2 t + t2 Ipk Iin = 1 2 T Vton = Vcontrol Vton = t1 1 + t2 Vout Input current averaged by filter capacitor Voltage for on time Vton MOSFET on--time t1 Discontinuous Mode (DCM) LIpk t1 = , or Vin t1 = CrampVcontrol Ich → t1 is constant for unity PFC → Vcontrol is constant for unity PFC Switching period Minimum Inductor for CRM t1 + t2 = V CrampVcontrol Vout , or − V Ich out in t1 + t2 = V LIpk Vout out − Vin Vin Zin = Input power Pin = Control voltage Vcontrol VoutVout− Vin T CrampIchVcontrol Vac2CrampVcontrol Same as CRM 2LIch Pin_max = Cramp > Vctrl = Same as CRM 2LIch Same as CRM Vac2Cramp 2LIch Same as CRM Pin ⋅ 2LIch Vac2 Same as CRM 2LIchPin CrampVac2 http://onsemi.com 17 − Vin CrampVcontrol VoutVout T Ich T CrampVcontrol t1 + t2 = , or t1 Ich Same as CRM ηVac2CrampVcontrol t1 = → t1 (t1 + t2) is constant for unity PFC → Vcontrol is constant for unity PFC Same as CRM Pout = ηPin = Minimum ramp capacitor when Vcontrol = 1 V LIpk t1 = , or Vin 2LIch CrampVcontrol Output power Maximum input power when Vcontrol = 1 V T V t1 + t2 control t1 + t2 = V − Vin Vin 1 L > L(CRM) = out Vout Ipk f Input impedance t1 1 + t2 Vout NCP1601A, NCP1601B PACKAGE DIMENSIONS SOIC--8 D SUFFIX CASE 751--07 ISSUE AJ - X-- NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSION A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.15 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.127 (0.005) TOTAL IN EXCESS OF THE D DIMENSION AT MAXIMUM MATERIAL CONDITION. 6. 751--01 THRU 751--06 ARE OBSOLETE. NEW STANDARD IS 751--07. A 8 5 S B 1 0.25 (0.010) M Y M 4 - Y-- K G C N DIM A B C D G H J K M N S X 45 _ SEATING PLANE - Z-- 0.10 (0.004) H D 0.25 (0.010) M Z Y S X M J S SOLDERING FOOTPRINT* 1.52 0.060 7.0 0.275 4.0 0.155 0.6 0.024 1.270 0.050 SCALE 6:1 mm inches *For additional information on our Pb--Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. http://onsemi.com 18 MILLIMETERS MIN MAX 4.80 5.00 3.80 4.00 1.35 1.75 0.33 0.51 1.27 BSC 0.10 0.25 0.19 0.25 0.40 1.27 0 _ 8 _ 0.25 0.50 5.80 6.20 INCHES MIN MAX 0.189 0.197 0.150 0.157 0.053 0.069 0.013 0.020 0.050 BSC 0.004 0.010 0.007 0.010 0.016 0.050 0 _ 8 _ 0.010 0.020 0.228 0.244 NCP1601A, NCP1601B PACKAGE DIMENSIONS 8 LEAD PDIP CASE 626--05 ISSUE M D A D1 8 E 5 E1 1 4 NOTE 5 F c E2 TOP VIEW END VIEW NOTE 3 e/2 A NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994. 2. CONTROLLING DIMENSION: INCHES. 3. DIMENSION E IS MEASURED WITH THE LEADS RESTRAINED PARALLEL AT WIDTH E2. 4. DIMENSION E1 DOES NOT INCLUDE MOLD FLASH. 5. ROUNDED CORNERS OPTIONAL. DIM A A1 b C D D1 E E1 E2 E3 e L INCHES NOM MAX -- -- -- -- 0.210 -- -- -- --- -- -- -0.018 0.022 0.010 0.014 0.365 0.400 -- -- -- --- -- -- -0.310 0.325 0.250 0.280 0.300 BSC -- -- -- --- -- -- -- 0.430 0.100 BSC 0.115 0.130 0.150 MIN -- -- -- -0.015 0.014 0.008 0.355 0.005 0.300 0.240 MILLIMETERS MIN NOM MAX -- -- -- --- -- -- -5.33 0.38 -- -- -- --- -- -- -0.35 0.46 0.56 0.20 0.25 0.36 9.02 9.27 10.02 0.13 -- -- -- --- -- -- -7.62 7.87 8.26 6.10 6.35 7.11 7.62 BSC -- -- -- --- -- -- -- 10.92 2.54 BSC 2.92 3.30 3.81 L A1 C SEATING PLANE E3 e 8X SIDE VIEW b 0.010 M C A END VIEW ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. 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