FA5332P

FA5331P(M)/FA5332P(M) FA5331P(M)/FA5332P(M) s Description FA5331P(M) and FA5332P(M) are control ICs for a power factor correction system. These ICs use the average current control system to ensure stable operation. With this system, a power factor of 99% or better can be achieved. FA5331P(M) is a 1st generation IC and FA5332P(M) is 2nd generation IC which light-load characteristics are improved. Bipolar IC For Power Factor Correction s Dimensions, mm SOP-16 16 9 5.5 7.8±0.3 • Drive circuit for connecting a power MOS-FET(Io =±1.5A) • Pulse-by-pulse overcurrent and overvoltage limiting function • Output ON/OFF control function by external signals • External synchronizing signal terminal for synchronous operation with other circuits • Undervoltage malfunction prevention function • Low standby current (90µ A typical) for simple start-up circuit • 16-pin package (DIP/SOP) • ±2% accuracy reference voltage for setting DC output and overvoltage protection [FA5332P(M) only] • When there is a possibility of light-load operation, FA5332P(M) is suitable. 10.06 +0.1 1 8 0.20 –0.05 s Features 0~10˚ 0.7 0.40±0.1 1.27±0.2 DIP-16 FA5331P 16 9 s Block diagram 1 0.81 19.4 1.5 8 3.1min 4.3max 0.2min 3.4 6.5 0.3 –0 7.6 +0.1 5 .0 2.54±0.25 0.5±0.1 0~15 ˚ 0~1 5˚ FA5332P 16 9 1 0.71 19.2 1.3 8 2.54min 5.06max Pin No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin symbol IFB IIN– VDET OVP VFB VIN– GND OUT VC VCC CS ON/OFF REF SYNC CT IDET 0.51min Current error amplifier output Inverting input to current error amplifier Multiplier input Overvoltage protection input Voltage error amplifier output Inverting input to voltage error amplifier Ground Output Power supply to output circuit Power supply Soft-start Output ON/OFF control input Reference voltage Oscillator synchronization input Oscillator timing capacitor and resistor Non-inverting input to current error amplifier 2.54±0.25 3.6 Description 6.3 –0.0 0.25 7.62 0~1 5˚ 0.48±0.1 0~15 ˚ 1 2.0 +0.1 5 FA5331P(M)/FA5332P(M) s Absolute maximum ratings Item Supply voltage Output current Input voltage Symbol Rating FA5331P(M) FA5332P(M) 30 ±1.5 –0.3 to +5.3 V A V Unit VCC, VC 30 IO ±1.5 VSYNC, VON/OFF, VVIN– –0.3 to +5.3 VVDET, VOVP VIDET Pd Topr Tstg –10.0 to +5.3 850 (DIP-16) –30 to +85 –40 to +150 *1 650 (SOP-16) * 2 –10.0 to +5.3 850 (DIP-16) –30 to +85 –40 to +150 *1 650 (SOP-16) * 2 V mW °C °C Notes: *1 Derating factor Ta > 25° C: 6.8mW/° C (on PC board) *2 Derating factor Ta > 25° C: 5.2mW/° C (on PC board) Total power dissipation (Ta=25° C) Operating temperature Storage temperature s Recommended operating conditions Item Supply voltage IDET terminal input voltage VDET terminal input voltage VDET terminal peak input voltage Oscillator timing capacitance Oscillator timing resistance Symbol FA5331P(M) Min. Max. 28 0 2.0 2.0 – – 220 100 10 –1.0 0 0.65 – – 10 0 FA5332P(M) Min. 10 –1.0 0 0.65 330 10 15 0 Max. 28 0 2.4 2.4 1000 75 150 27 V V V V pF kΩ kHz Ω Unit VCC, VC VIDET VVDET VPVDET CT RT Oscillation frequency fOSC Noise filter resistance connected to IDET terminal Rn s Electrical characteristics (Ta=25°C, CT=470pF, RT=22kΩ, VCC=VC=18V) Oscillator section Item Oscillation frequency Frequency variation 1 (due to supply voltage change) Frequency variation 1 (due to temperature change) Output peak voltage Synchronizing input peak voltage Symbol Test condition FA5331P(M) Min. Typ. 75 1 5 3.55 SYNC terminal voltage 1.5 1.5 68 82 FA5332P(M) Max. Min. 68 Typ. 75 1 5 3.55 Max. 82 3 8 kHz % % V V Unit fOSC fdV fdT VOSC VSYNC CT=470pF RT=22kΩ VCC=10 to 30V Ta=–30 to +85° C Voltage error amplifier section Item Symbol Test condition FA5331P(M) Min. Reference voltage Input bias current Open-loop voltage gain Output voltage Typ. 1.54 FA5332P(M) Max. Min. 1.60 Typ. Max. nA dB 3.8 50 –900 200 V mV µA Unit Vr IBE AVE VOE+ VOE– IOE+ 1.48 80 No load 3.5 1.519 1.550 1.581 V –500 –50 80 3.5 –500 –50 3.8 50 200 Output source current VOE=0V –900 2 FA5331P(M)/FA5332P(M) Current error amplifier section Item Input threshold voltage Input bias current Open-loop voltage gain Output voltage Output source curent Symbol Test condition FA5331P(M) Min. Typ. FA5332P(M) Max. Min. 0 Typ. 30 Max. 60 mV Unit VTH IDET IBC AVC VOC+ VOC– IOC+ VDET=0V – – – VFB= Vr, Rn=30Ω IDET=0V –350 –230 80 No load 3.5 3.8 50 200 –900 –350 –250 –150 µA 80 3.5 3.8 50 –900 200 dB V mV µA VIFB=0V Reference voltage section Item Output voltage Voltage variation 1 (by supply voltage variation) Voltage variation 2 (by load change) Symbol Test condition FA5331P(M) Min. Typ. 5.0 4.8 5.2 25 2 2 FA5332P(M) Max. Min. 4.8 Typ. 5.0 Max. 5.2 25 5 V mV mV Unit VREF VRDV VRDT VCC=10 to 30V IOR=0.1 to 2mA Multiplier section Item Symbol Test condition FA5331P(M) Min. VDET terminal input voltage VFB terminal input voltage Output current Output voltage coefficient Typ. FA5332P(M) Max. Min. 2.0 3.5 –65 –1.0 0 1.5 –65 –1.0 Typ. Max. 2.4 3.5 V V µA – Unit VMVDET VMVFB IM K 0 1.5 VIIN–=0V Pulse width modulation circuit section Item Maximum duty cycle Symbol Test condition FA5331P(M) Min. Typ. 92 89 95 FA5332P(M) Max. Min. 89 Typ. 92 Max. 95 % Unit DMAX Output circuit section Item Output voltage Symbol Test condition FA5331P(M) Min. Typ. 1.3 15.5 16.5 1.8 15.5 FA5332P(M) Max. Min. Typ. 1.3 16.5 Max. 1.8 V V Unit VOL VOH tr tr IO=100mA IO=–100mA VCC=18V No load No load Rise time Fall time 300 200 300 200 ns ns Soft-start circuit section Item Input threshold voltage Symbol Test condition Duty cycle=0% Duty cycle=DMAX CS terminal=0V FA5331P(M) Min. Typ. 0.1 3.55 –10 FA5332P(M) Max. Min. Typ. 0.1 3.55 –10 Max. V V µA Unit VTHCSO VTHCSM ICHG Charge current 3 FA5331P(M)/FA5332P(M) Overvoltage protection circuit section Item Input threshold voltage Input threshold voltage/reference voltage(VTHOVP/ Vr) Delay time Symbol Test condition OVP terminal voltage FA5331P(M) Min. Typ. 1.64 – 200 1.56 – 1.72 – FA5332P(M) Max. Min. Typ. Max. Unit VTHOVP 1.617 1.650 1.683 V 1.044 1.065 1.086 – 200 ns TPDOVP Overcurrent limiting circuit section Item Symbol Test condition FA5331P(M) Min. Input threshold voltage Delay time Typ. FA5332P(M) Max. Min. Typ. Max. Unit VTHOCP TPDOCP IDET terminal voltage –1.25 –1.15 –1.05 –1.20 –1.10 –1.00 V 200 200 ns Output ON/OFF circuit section Item Symbol Test condition FA5331P(M) Min. Threshold voltage Typ. – – 60 – FA5332P(M) Max. Min. – 3.5 – 120 – 3.7 2.8 1.5 – 10 Typ. Max. 4.3 3.4 2.8 – 40 V V V µA µA Unit VTHONOFF Ta=–30°C Ta=+25° C Ta=+85° C – 2.0 – Input current at ON ITHON ON/OFF terminal voltage=3.5V ON/OFF terminal voltage=VTHONOFF Undervoltage lockout circuit section Item Symbol Test condition FA5331P(M) Min. OFF to ON threshold voltage ON to OFF threshold voltage Voltage hysteresis Typ. 15.3 8.3 7.0 FA5332P(M) Max. Min. 16.3 9.0 14.6 7.6 Typ. 15.3 8.3 7.0 Max. 16.0 9.0 V V V Unit VTHUON ITHUOFF VUHYS 14.3 7.6 Overall device Item Standby current Operating-state supply current OFF-state supply current Symbol Test condition FA5331P(M) Min. Typ. 90 10 Pin 12=0V 1.1 140 15 1.8 FA5332P(M) Max. Min. Typ. 90 10 1.1 Max. 140 15 1.8 µA mA mA Unit ICCST ICCOP ICCOFF VCC=14V 4 FA5331P(M)/FA5332P(M) s Description of each circuit 1. Oscillator section This section outputs sawtooth waves oscillating between 0.15 and 3.55V using the capacitor charge and discharge characteristics. Figure 1 shows how to connect the required external components to this circuit. The oscillation frequency is determined by the CT and RT values. The relationship between the CT and RT values is shown in characteristic curves. Pin 14 (SYNC) is a synchronizing input terminal whose threshold voltage is about 1V. As Fig. 1 shows, input rectangular synchronizing signal waves to pin 14 through an RC circuit. Set the free-running frequency about 10% lower than the synchronizing signal frequency. Connect a clamp diode (D1) to prevent an unwanted current inside the IC. 2. Voltage error amplifier and overvoltage limiting circuit The voltage error amplifier forms a voltage feedback loop to keep the output voltage stable. The positive input terminal of this amplifier is connected to the reference voltage (Vr). Fig. 2 shows how to connect the required external components to this circuit. The output voltage (Vo) is as follows: ............................................................................... (1) Vo = R1 + R2 • Vr R1 FA5331: Vr=1.54V(typ.) FA5332: Vr=1.55V(typ.) 13 REF RT 15 CT CT OSC R 14 Csy D1 SYNC Fig. 1 Oscillator Vo C1 R2 5 R4 6 R3 R1 ER.AMP _ A1 + Vr MUL Connect a resistor and a capacitor in parallel across error amplifier output pin 5 and error amplifier negative input pin 6 to set the voltage gain (Av). The Av value is as follows: Av = R4 R3 ( 1 + jω C1 • R4 ) ............................... (2) 4 Vp OVP C1 F.F Error amplifier cutoff frequency (fc) is as follows: fc = 1 2π C1 • R4 ................................................. (3) Fig. 2 Voltage error amplifier and overvoltage limiting circuit If 100 or 120Hz ripples appear at the error amplifier output, the active filter does not operate stably. To ensure stable operation, set the fc value to about 1Hz. An overvoltage detection comparator (C1) is built in to limit the voltage if the output voltage exceeds the design value. The reference input voltage (Vp) is as follows: Vp = α • Vr ............................................................. (4) α =1.065 The connections shown in Fig. 2 limit the output voltage to α times the design value. 5 FA5331P(M)/FA5332P(M) 3. Current error amplifier and overcurrent limiting circuit The current error amplifier forms a current loop to change the input circuit current into sinusoidal waves. As Fig. 3 shows, the multiplier output is connected to pin 2 (IIN –) through a resistor (RA) to input the reference current signal. Pin 16 (IDET) is a current input terminal. Design the circuit so that the voltage at pin 16 will be within the range from 0 (GND potential) to –1.0V. Connect a phase correction resistor and capacitors across pin 1 (amplifier output) and pin 2. See Fig. 4 for the expected gain characteristics of the circuit shown in Fig. 3. Here, Z= p= 1 .................................................. (5) 2π R5 • C3 1 2π R5 • C C2 • C3 C2 + C3 MUL Vm 1 C3 C2 2 10k RA CURR.AMP _ A2 + RC 16 4 5k Rn Cn C2 Vocp Current detection OPC F.F 15k RB VREF 5V R5 PWM comparator ............................................. (6) C= Fig. 3 Current error amplifier and overcurrent limiting circuit The voltage gain (G1) between Z and P of the circuit (gain between pins 16 and 1) is given as follows: G1 = 20 • log10 { 0.75 ( R5 + 1) } RA .................... (7) Voltage gain (dB) Ensure an adequate phase margin by selecting C1 and C2 so that the p/z ratio is about 10. The current error amplifier output is used as an input to the comparator for PWM. The overcurrent detection comparator (C2) limits an overcurrent. The threshold voltage for overcurrent detection at pin 16 is –1.15V for FA5331 and –1.10V for FA5332. Connect noise filters Rn and Cn to prevent the voltage at pin 16 from fluctuating due to noise, causing the comparator to malfunction. For Rn, select a resistor of up to 100 Ω for FA5331 and up to 27Ω for FA5332. (See P64, 4. No-load operation ) 4. Comparator for PWM Figure 5 shows the comparator for PWM. When the oscillator output (Va) is smaller than the current error amplifier output (Vc), the comparator output is high and the output ON signal is generated at pin 8. Pin 11 (CS) is a terminal for soft start. This terminal charges capacitor C4 with the internal constant current (10µA) for a soft start. Priority is given to Vb and Vc whichever is lower. 5. Multiplier The multiplier generates a reference current signal. Input a fully rectified sinusoidal signal voltage into pin 3 (VDET). Design the circuit to keep the peak voltage at pin 3 within a range from 0.65V to 2V for FA5331 and 0.65V to 2.4V for FA5332. The multiplier output voltage (Vm) is roughly given as follows (see Fig. 6): Vm = 1.25 – (Ve –1.55) • Vs .................................... (8) As Fig. 3 shows Vm is internally connected to pin 2 (IIN–) of the current error amplifier A2 through a 10kΩ resistor. (See the characteristic curve, page 66 for the input and output characteristics of the multiplier.) G1 Z P Frequency Fig. 4 Voltage gain-frequency CURR.AMP(A2) output Vc Oscillator output Va CS C4 C3 11 Vb PWM comparator 10µA Fig. 5 PWM comparator VIN ER.AMP(A1) output R7 Ve Vm MUL 3 Vs R6 Fig. 6 Multiplier 6 FA5331P(M)/FA5332P(M) 6. ON/OFF control input circuit Figure 7 shows the ON/OFF control input circuit. If pin 12 is set to the high level (enable), this IC outputs pulses from the OUT pin. If pin 12 is set to the low level (disable), the internal bias power (reference voltage) goes off and the IC current consumption becomes about 1/10 that of its ON state. The output level of pin 11 (CS for soft start) also goes low. 7. Output circuit As Fig. 8 shows, pin 9 is configured as the high power terminal (VC), independent of the IC power terminal (VCC). This pin allows an independent drive resistance when the power MOSFET is ON and OFF. If the drive resistances in the ON and OFF states are Rg (on) and Rg (off), the following formulas can be used to determine the total gate resistance Rg: Rg (on) = Rg1 + Rg2 ............................................. (9) Rg (off) = Rg2 ..................................................... (10) VCC ON/OFF 12 10µA Vcc 1k 100k Fig. 7 ON/OFF control input circuit In the standby state, the output level of pin 8 is held low. If the potential at the drain terminal of the power MOSFET fluctuates, the gate-drain capacitance may drive the IC output voltage at pin 8 to below 0. Once the voltage at pin 8 reaches –0.6V, an unwanted current flows in the IC and a large abnormal current flows in the output circuit when the output transistor is turned on. To prevent this, connect a Schottky diode across the gate and source of the power MOSFET. 10 Rg1 9 Rg2 8 + Cv Pin7 GND 7 Schottky diode Fig. 8 Output circuit 7 FA5331P(M)/FA5332P(M) s Design advice 1. Start circuit Figure 9 shows a sample start circuit. Since the IC current while the Vcc pin voltage rises from 0V to VTHON is as small as 90µA (typ.), the power loss in resistor RA is small. If an additional winding is prepared in the voltage step-up inductor (L), power to the control circuit can be supplied from this circuit. However, the voltage must be stabilized by a regulator circuit (REG) to prevent an excess rise of the IC supply voltage (Vcc). Use fast or ultra-fast rectifier diodes for the rectifier circuit (DB1) of the winding for high-frequency operation. 2. Current sensing resistor The current sensing resistor (Rs) detects the current in the inductor. Rs is used to make the input current sinusoidal. The current in the inductor produces a negative voltage across Rs. The voltage is input to IC pin 16 (IDET). Determine the value of Rs so that the peak voltage of the IDET pin is –1V. Rs = Vin √2 • Pin .................................................. (11) DB1 L Io AC input Vcc REG 16 RS FA5331/FA5332 7 10 CA C RA Fig. 9 Start circuit Vin: Minimum AC input voltage (effective value) [V] Pin: Maximum input power [W] Example: FA5332 When Vin is 85V and Pin is 300W, the formulas of (11) and (12) can be calculated as: Rs = ip = And, R6 = 0.65 [ V ] R6 + R7 If R6 is set to 2.7kΩ to satisfy these formulas, R7 becomes 480k Ω. √ 2 • 85 • Example: When Vin is 85V, Vo is 385V, and γ is 0.2, the formula of (14) can be calculated as: L≥ 2.48 ! 104 [ H ] ......................................... (15) fs • Pin 85 = 0.2 [ Ω ] √ 2 • 300 1.10 0.2 = 5.5 [ A ] Since the threshold voltage of the overcurrent limiting circuit (pin 16) is –1.15V for FA5311 for and –1.10V for FA5332, the peak input current limit (ip) is determined by: FA5331: ip= 1.15 ............................................................................. (12) Rs FA5332: ip= 1.10 Rs 3. Voltage step-up type converter Figure 9 shows the basic circuit of a voltage step-up type converter which is used as a power factor correction. (a) Output voltage For stable operation, set the output voltage to be 10V or more over the peak value of the maximum input voltage. When using this IC for an active filter, set the output voltage (Vo) as follows: Vo ≥ √ 2 • Vin + 10V ............................................ (13) Vin: Maximum AC input voltage [V] (effective value of sinusoidal wave) (b) Voltage step-up inductor When using a voltage step-up converter in continuous current mode, the ratio of inductor current ripple to the input peak current is set to about 20%. Determine the inductance as follows: 2 L ≥ Vin ( Vo – √ 2 • Vin ) γ • fs • Pin • Vo (c) Smoothing capacitor When a voltage step-up converter is used in a power factor correction circuit, the input current waveform is regulated to be in-phase with the input voltage waveform. Therefore, ripple noise of twice the input line frequency appears at the output. The output voltage (υo) is represented as: ................................ (14) υo = Vo – Io • Sin 2 ωo t 2 • ωo •C ................... (16) Vin: Minimum AC input voltage (effective value) [V] γ : Ratio of inductor current ripple (peak to peak value) to the input peak current (about 0.2) fs: Switching frequency [Hz] Pin: Converter’s maximum input power [W] Vo: Average output voltage Io: Output current ωo : 2π fo (fo: Input power frequency, 50 or 60Hz) C: Smoothing capacitor value As the characteristic curves on page 66 show, the peak voltage at pin 3 should be at least 0.65V, even when the AC input voltage is minimal. Considering this, determine R6 and R7 shown in Fig. 6. Therefore, the peak-to-peak value of the output ripple voltage Vrp is given by: Io ..................................................... (17) ω oC Using formula (17), determine the necessary C value. Vrp = 8 FA5331P(M)/FA5332P(M) 4. No-load operation The following condition should be meet to prevent from overvoltage and audible noise during no-load or light-load operation. For FA5331 (Fig.10) 0.85• ≤ ROFST(kΩ)≤ where, = (3.5•103–0.26•Rn)•12 42+0.26•Rn 13 REF ROFST C3 Rx R5 C2 2 IIN– FA5331 1 IFB and, Rn ≤ 100Ω and, RX: don’t connect. •You must not connect RX which reduces DC gain of current error amplifier. •You can connect R5 which is series with capacitor C3. For FA5332 (Fig.11) Rn ≤ 27Ω and, RX: don’t connect. •You must not connect RX which reduces DC gain of current error amplifier. •You can connect R5 which is series with capacitor C3. •If you connect ROFST, dead time of AC input current will extend. 5. How to prevent from intermittent switching of low frequency An intermittent switching, which frequency is lower than 10Hz, occurs in some applications. In this case, it is possible to prevent from this intermittent switching to reduce feedback gain by decreasing the resistance of R4. (See Fig. 2) You must check the effect thoroughly because this intermittent switching depends on load, temperature and input condition. Current detection Rn 16 IDET Cn Fig.10 13 REF ROFST C3 Rx R5 C2 2 IIN– FA5332 1 IFB Current detection Rn 16 IDET Cn Fig.11 9 FA5331P(M)/FA5332P(M) s Characteristic curves (Ta = 25°C) Oscillation frequency (fOSC ) vs. timing resistor resistance (R T) FA5331 FA5332 200 100 fosc [kHz] 50 CT=330pF CT=470pF 20 CT=680pF 10 10 20 50 100 RT [kΩ] Oscillation frequency (fOSC ) vs. ambient temperature (Ta) FA5331 FA5332 78 77 76 75 fosc [kHz] 74 73 72 71 70 69 68 –40 Vcc=18V CT=470pF RT=22kΩ –20 0 20 40 60 80 100 Ta [˚C] Output duty cycle vs. CS terminal voltage (VCS ) ON/OFF control terminal current vs. ON/OFF control terminal voltage 10 FA5331P(M)/FA5332P(M) IIN– terminal voltage vs. VDET terminal voltage Multiplier I/O FA5331 FA5332 1.4 VFB=1.5V 1.2 IIN– terminal voltage [V] IIN– terminal voltage [V] VFB=1.6V 1.0 VFB=1.7V 0.8 0.6 V 2.5 B= V VF VF VF 0.4 0.2 0 0 VFB=2.0V B= 3.5 V 3.0 0.8 B= 0.4 1.2 1.6 2 2.4 VDET terminal voltage [V] IDET terminal voltage vs. IIN– terminal voltage Normal operation FA5331 0 FA5332 0 IDET terminal voltage [V] IDET terminal voltage [V] –0.5 0.5 –1.0 1.0 –1.5 0 0.5 1.0 1.5 1.5 0 0.5 1.0 1.5 IIN– terminal voltage [V] IIN– terminal voltage [V] H-level output voltage (VOH) vs. output source current (ISOURCE) L-level output voltage(VOL) vs. output sink current (ISINK) 11 FA5331P(M)/FA5332P(M) Overcurrent limiting threshold voltage vs. ambient temperature (Ta) FA5331 FA5332 –1.08 Overcurrent limiting threshold voltage [V] –1.09 Vcc=18V –1.1 –1.11 –1.12 –1.13 –40 –20 0 20 40 60 80 100 Ta [˚C] OVP terminal threshold voltage vs. ambient temperature (Ta) FA5331 FA5332 1.67 Vcc=18V OVP terminal threshold voltage [V] 1.66 1.65 1.64 1.63 1.62 1.61 –40 –20 0 20 40 60 80 100 Ta [˚C] Supply current (ICC ) vs. supply voltage (VCC) Normal operation Supply current (ICC ) vs. supply voltage (VCC) OFF mode 12 FA5331P(M)/FA5332P(M) s Application circuit Example of FA5331 application circuit Example of FA5332 application circuit Parts tolerances characteristics are not defined in the circuit design sample shown above. When designing an actual circuit for a product, you must determine parts tolerances and characteristics for safe and economical operation. 13