NCP43080DMNTWG

NCP43080 Synchronous Rectifier Controller The NCP43080 is a synchronous rectifier controller for switch mode power supplies. The controller enables high efficiency designs for flyback and quasi resonant flyback topologies. Externally adjustable minimum off−time and on−time blanking periods provides flexibility to drive various MOSFET package types and PCB layout. A reliable and noise less operation of the SR system is insured due to the Self Synchronization feature. The NCP43080 also utilizes Kelvin connection of the driver to the MOSFET to achieve high efficiency operation at full load and utilizes a light load detection architecture to achieve high efficiency at light load. The precise turn−off threshold, extremely low turn−off delay time and high sink current capability of the driver allow the maximum synchronous rectification MOSFET conduction time. The high accuracy driver and 5 V gate clamp make it ideally suited for directly driving GaN devices. Features • Self−Contained Control of Synchronous Rectifier in CCM, DCM and • • • • • • • • • • • • • • • QR for Flyback, Forward or LLC Applications Precise True Secondary Zero Current Detection Rugged Current Sense Pin (up to 150 V) Adjustable Minimum ON−Time Adjustable Minimum OFF-Time with Ringing Detection Adjustable Maximum ON−Time for CCM Controlling of Primary QR Controller Improved Robust Self Synchronization Capability 8 A / 4 A Peak Current Sink / Source Drive Capability Operating Voltage Range up to VCC = 35 V Automatic Light−load & Disable Mode Adaptive Gate Drive Clamp GaN Transistor Driving Capability (options A and C) Low Startup and Disable Current Consumption Maximum Operation Frequency up to 1 MHz SOIC-8 and DFN−8 (4x4) and WDFN8 (2x2) Packages These are Pb−Free Devices 8 1 SOIC−8 D SUFFIX CASE 751 MARKING DIAGRAMS 8 43080x ALYW G G 1 1 DFN8 MN SUFFIX CASE 488AF 43080x ALYWG G 1 WDFN8 MT SUFFIX CASE 511AT FxMG G 43080x = Specific Device Code x = A, B, C, D or Q Fx = Specific Device Code x = A or D A = Assembly Location L = Wafer Lot Y = Year W = Work Week M = Date Code G = Pb−Free Package (Note: Microdot may be in either location) ORDERING INFORMATION See detailed ordering and shipping information on page 33 of this data sheet. Typical Applications • • • • www.onsemi.com Notebook Adapters High Power Density AC/DC Power Supplies (Cell Phone Chargers) LCD TVs All SMPS with High Efficiency Requirements © Semiconductor Components Industries, LLC, 2016 February, 2017 − Rev. 0 1 Publication Order Number: NCP43080/D MIN_TON MIN_TOFF NCP43080 RTN D1 MIN_TON MIN_TOFF OK1 Figure 1. Typical Application Example − LLC Converter with Optional LLD +Vout + Vbulk TR1 R1 C1 C6 R7 C7 + C2 C5 R6 D3 R5 + VCC FLYBACK M2 D4 D6 C3 CONTROL GND CIRCUITRY FB C4 DRV M1 CS R2 R3 R4 D5 R8 OK1 Figure 2. Typical Application Example − DCM, CCM or QR Flyback Converter with optional LLD www.onsemi.com 2 NCP43080 +Vout + Vbulk TR1 R1 C1 + R3 R4 R9 VCC SIDE M2 D4 + PRIMARY C4 C10 R10 D3 ZCD C9 R11 C8 C2 D6 C3 GND FLYBACK CONTROLLER C7 DRV M1 R7 COMP CS R2 R6 R5 C5 R8 C6 Figure 3. Typical Application Example − Primary Side Flyback Converter with optional LLD + Vbulk R18 TR1 R5 C1 C8 R13 R14 C2 C9 + R17 D3 D8 R12 C7 + VCC QR CONTROL CIRCUITRY ZCD C4 DRV FB CS M3 D4 D7 GND D1 R1 +Vout C5 M1 R15 R9 R10 R6 R7 R19 OK1 C3 M2 NCP43080Q D5 R16 R11 D6 TR2 C6 Figure 4. Typical Application Example − QR Converter − Capability to Force Primary into CCM Under Heavy Loads utilizing MAX−TON www.onsemi.com 3 NCP43080 PIN FUNCTION DESCRIPTION ver. A, B, C, D ver. Q Pin Name 1 1 VCC 2 2 MIN_TOFF Adjust the minimum off time period by connecting resistor to ground. 3 3 MIN_TON Adjust the minimum on time period by connecting resistor to ground. 4 4 LLD This input modulates the driver clamp level and/or turns the driver off during light load conditions. 5 − NC Leave this pin opened or tie it to ground. 6 6 CS Current sense pin detects if the current flows through the SR MOSFET and/or its body diode. Basic turn−off detection threshold is 0 mV. A resistor in series with this pin can decrease the turn off threshold if needed. 7 7 GND Ground connection for the SR MOSFET driver, VCC decoupling capacitor and for minimum on and off time adjust resistors and LLD input. GND pin should be wired directly to the SR MOSFET source terminal/soldering point using Kelvin connection. DFN8 exposed flag should be connected to GND 8 8 DRV Driver output for the SR MOSFET − 5 MAX_TON MIN_TON Description Supply voltage pin Adjust the maximum on time period by connecting resistor to ground. ELAPSED ADJ DISABLE Minimum ON time generator EN Disable detection & V DRV clamp modulation LLD V_DRV control VDD 100μA CS CS_ON CS detection DRIVER DRV Out DRV CS_OFF Control logic CS_RESET VDD RESET MIN_TOFF ADJ Minimum OFF time generator ELAPSED DISABLE EN VCC managment UVLO VCC GND NC Figure 5. Internal Circuit Architecture − NCP43080A, B, C, D www.onsemi.com 4 NCP43080 ELAPSED MIN_TON ADJ DISABLE Minimum ON time generator EN Disable detection & V DRV clamp modulation LLD V_DRV control VDD 100mA CS CS_ON CS detection DRIVER DRV Out DRV CS_OFF Control logic CS_RESET VDD RESET MIN_TOFF ADJ Minimum OFF time generator ELAPSED EN DISABLE VCC managment UVLO VCC ELAPSED MAX_TON ADJ Maximum ON time generator GND EN Figure 6. Internal Circuit Architecture − NCP43080Q (CCM QR) with MAX_TON www.onsemi.com 5 NCP43080 ABSOLUTE MAXIMUM RATINGS Rating Symbol Value Unit VCC −0.3 to 37.0 V VMIN_TON, VMIN_TOFF, VMAX_TON, VLLD −0.3 to VCC V Driver Output Voltage VDRV −0.3 to 17.0 V Current Sense Input Voltage VCS −4 to 150 V Current Sense Dynamic Input Voltage (tPW = 200 ns) VCS_DYN −10 to 150 V MIN_TON, MIN_TOFF, MAX_TON, LLD Input Current IMIN_TON, IMIN_TOFF, IMAX_TON, ILLD −10 to 10 mA Junction to Air Thermal Resistance, 1 oz 1 in2 Copper Area, SOIC8 RqJ−A_SOIC8 160 °C/W Junction to Air Thermal Resistance, 1 oz 1 in2 Copper Area, DFN8 RqJ−A_DFN8 80 °C/W RqJ−A_WDFN8 160 °C/W Maximum Junction Temperature TJMAX 150 °C Storage Temperature TSTG −60 to 150 °C ESD Capability, Human Body Model, Except Pin 6, per JESD22−A114E ESDHBM 2000 V ESD Capability, Human Body Model, Pin 6, per JESD22−A114E ESDHBM 1000 V ESD Capability, Machine Model, per JESD22−A115−A ESDMM 200 V ESD Capability, Charged Device Model, Except Pin 6, per JESD22−C101F ESDCDM 750 V ESD Capability, Charged Device Model, Pin 6, per JESD22−C101F ESDCDM 250 V Supply Voltage MIN_TON, MIN_TOFF, MAX_TON, LLD Input Voltage Junction to Air Thermal Resistance, 1 oz 1 in2 Copper Area, WDFN8 Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. 1. This device meets latch−up tests defined by JEDEC Standard JESD78D Class I. RECOMMENDED OPERATING CONDITIONS Parameter Symbol Maximum Operating Input Voltage Min Max 35 V −40 125 °C VCC Operating Junction Temperature TJ Unit Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability. ELECTRICAL CHARACTERISTICS −40°C ≤ TJ ≤ 125°C; VCC = 12 V; CDRV = 0 nF; RMIN_TON = RMIN_TOFF = 10 kW; VLLD = 0 V; VCS = −1 to +4 V; fCS = 100 kHz, DCCS = 50%, unless otherwise noted. Typical values are at TJ = +25°C Parameter Test Conditions Symbol Min Typ Max Unit VCC rising VCCON 8.3 8.8 9.3 V VCC falling VCCOFF 7.3 7.8 8.3 SUPPLY SECTION VCC UVLO (ver. B & C) VCC UVLO Hysteresis (ver. B & C) VCC UVLO (ver. A, D & Q) VCCHYS V VCC rising VCCON 4.20 4.45 4.80 VCC falling VCCOFF 3.70 3.95 4.20 VCC UVLO Hysteresis (ver. A, D & Q) Start−up Delay 1.0 VCC rising from 0 to VCCON + 1 V @ tr = 10 ms www.onsemi.com 6 VCCHYS 0.5 tSTART_DEL 75 V V 125 ms NCP43080 ELECTRICAL CHARACTERISTICS −40°C ≤ TJ ≤ 125°C; VCC = 12 V; CDRV = 0 nF; RMIN_TON = RMIN_TOFF = 10 kW; VLLD = 0 V; VCS = −1 to +4 V; fCS = 100 kHz, DCCS = 50%, unless otherwise noted. Typical values are at TJ = +25°C Parameter Test Conditions Symbol Min Typ Max Unit ICC 3.0 4.0 5.6 mA B, D, Q 3.5 4.5 6.0 A, C 4.5 6.0 7.5 B, D, Q 7.7 9.0 10.7 A, C 20 25 30 B, D, Q 40 50 60 1.0 2.0 2.5 mA 75 125 mA 55 75 mA SUPPLY SECTION Current Consumption, RMIN_TON = RMIN_TOFF = 0 kW CDRV = 0 nF, fSW = 500 kHz A, C CDRV = 1 nF, fSW = 500 kHz CDRV = 10 nF, fSW = 500 kHz Current Consumption No switching, VCS = 0 V, RMIN_TON = RMIN_TOFF = 0 kW ICC Current Consumption below UVLO No switching, VCC = VCCOFF – 0.1 V, VCS = 0 V ICC_UVLO Current Consumption in Disable Mode VLLD = VCC − 0.1 V, VCS = 0 V ICC_DIS 30 DRIVER OUTPUT Output Voltage Rise−Time CDRV = 10 nF, 10% to 90% VDRVMAX tr 40 55 ns Output Voltage Fall−Time CDRV = 10 nF, 90% to 10% VDRVMAX tf 20 35 ns RDRV_SOURCE 1.2 W Driver Source Resistance Driver Sink Resistance Output Peak Source Current Output Peak Sink Current Maximum Driver Output Voltage VCC = 35 V, CDRV > 1 nF, VLLD = 0 V, (ver. B, D and Q) RDRV_SINK 0.5 W IDRV_SOURCE 4 A IDRV_SINK 8 A VDRVMAX VCC = 35 V, CDRV > 1 nF, VLLD = 0 V, (ver. A, C) Minimum Driver Output Voltage VCC = VCCOFF + 200 mV, VLLD = 0 V, (ver. B) VDRVMIN VCC = VCCOFF + 200 mV, VLLD = 0 V, (ver. C) VCC = VCCOFF + 200 mV, VLLD = 0 V Minimum Driver Output Voltage VLLD = VCC − VLLDREC V VDRVLLDMIN V 9.0 9.5 10.5 4.3 4.7 5.5 7.2 7.8 8.5 4.2 4.7 5.3 3.6 4.0 4.4 0.0 0.4 1.2 V V CS INPUT Total Propagation Delay From CS to DRV Output On VCS goes down from 4 to −1 V, tf_CS = 5 ns tPD_ON 35 60 ns Total Propagation Delay From CS to DRV Output Off VCS goes up from −1 to 4 V, tr_CS = 5 ns tPD_OFF 12 23 ns CS Bias Current VCS = −20 mV Turn On CS Threshold Voltage Turn Off CS Threshold Voltage Guaranteed by Design Turn Off Timer Reset Threshold Voltage CS Leakage Current VCS = 150 V ICS −105 −100 −95 mA −75 −40 mV 0 mV 0.6 V 0.4 mA VTH_CS_ON −120 VTH_CS_OFF −1 VTH_CS_RESET 0.4 0.5 ICS_LEAKAGE MINIMUM tON and tOFF ADJUST Minimum tON time RMIN_TON = 0 W tON_MIN 25 56 75 ns Minimum tOFF time RMIN_TOFF = 0 W tOFF_MIN 160 245 290 ns Minimum tON time RMIN_TON = 10 kW tON_MIN 0.92 1.00 1.08 ms Minimum tOFF time RMIN_TOFF = 10 kW tOFF_MIN 0.92 1.00 1.08 ms Minimum tON time RMIN_TON = 50 kW tON_MIN 4.62 5.00 5.38 ms Minimum tOFF time RMIN_TOFF = 50 kW tOFF_MIN 4.62 5.00 5.38 ms www.onsemi.com 7 NCP43080 ELECTRICAL CHARACTERISTICS −40°C ≤ TJ ≤ 125°C; VCC = 12 V; CDRV = 0 nF; RMIN_TON = RMIN_TOFF = 10 kW; VLLD = 0 V; VCS = −1 to +4 V; fCS = 100 kHz, DCCS = 50%, unless otherwise noted. Typical values are at TJ = +25°C Parameter Test Conditions Symbol Min Typ Max Unit MAXIMUM tON ADJUST Maximum tON Time VMAX_TON = 3 V tON_MAX 4.3 4.8 5.3 ms Maximum tON Time VMAX_TON = 0.3 V tON_MAX 41 48 55 ms Maximum tON Output Current VMAX_TON = 0.3 V, VCS = 0 V IMAX_TON −105 −100 −95 mA Disable Threshold VLLD_DIS = VCC − VLLD VLLD_DIS 0.8 0.9 1.0 V Recovery Threshold VLLD_REC = VCC − VLLD VLLD_REC 0.9 1.0 1.1 V LLD INPUT Disable Hysteresis Disable Time Hysteresis Disable to Normal, Normal to Disable Disable Recovery Time 0.1 V tLLD_DISH 45 ms tLLD_DIS_REC 6.0 fLPLLD 6 Low Pass Filter Frequency Driver Voltage Clamp Threshold VLLD_DISH VDRV = VDRVMAX, VLLDMAX = VCC − VLLD VLLDMAX 12.5 16.0 ms 10 13 kHz 2.0 V Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. TYPICAL CHARACTERISTICS 4.7 9.3 4.6 9.1 VCCON 4.4 8.7 4.3 8.5 4.2 4.1 VCCOFF 4.0 VCCON 8.9 VCC (V) VCC (V) 4.5 8.3 8.1 VCCOFF 7.9 3.9 7.7 3.8 7.5 7.3 −40 −20 3.7 −40 −20 0 20 40 60 TJ (°C) 80 100 120 Figure 7. VCCON and VCCOFF Levels, ver. A, D, Q 0 20 40 60 TJ (°C) 80 100 Figure 8. VCCON and VCCOFF Levels, ver. B, C www.onsemi.com 8 120 NCP43080 TYPICAL CHARACTERISTICS 6 TJ = 55°C TJ = 25°C 120 TJ = 85°C TJ = 125°C 5 100 ICC_UVLO (mA) ICC (mA) 4 TJ = 0°C 3 TJ = −20°C TJ = −40°C 2 1 80 60 40 20 0 0 5 10 15 20 25 30 0 −40 35 −20 0 20 60 80 100 VCC (V) TJ (°C) Figure 9. Current Consumption, CDRV = 0 nF, fCS = 500 kHz, ver. D Figure 10. Current Consumption, VCC = VCCOFF − 0.1 V, VCS = 0 V, ver. D 30 120 60 CDRV = 10 nF CDRV = 10 nF 50 20 40 ICC (mA) 25 15 10 30 20 CDRV = 1 nF 5 CDRV = 1 nF 10 CDRV = 0 nF CDRV = 0 nF 0 −40 −20 0 20 40 60 80 100 0 −40 −20 120 0 20 40 60 80 100 120 TJ (°C) TJ (°C) Figure 11. Current Consumption, VCC = 12 V, VCS = −1 to 4 V, fCS = 500 kHz, ver. A Figure 12. Current Consumption, VCC = 12 V, VCS = −1 to 4 V, fCS = 500 kHz, ver. D 70 65 ICC_DIS (mA) ICC (mA) 40 60 55 50 45 40 −40 −20 0 20 40 60 80 100 120 TJ (°C) Figure 13. Current Consumption in Disable, VCC = 12 V, VCS = 0 V, VLLD = VCC − 0.1 V www.onsemi.com 9 NCP43080 TYPICAL CHARACTERISTICS 0 −90 −92 −0.2 −94 −0.4 −98 ICS (mA) ICS (mA) −96 −100 −102 −104 TJ = 125°C TJ = 85°C TJ = 55°C TJ = 25°C TJ = 0°C TJ = −20°C TJ = −40°C −0.6 −0.8 −1.0 −106 −108 −110 −40 −1.2 −20 0 20 40 60 80 100 −1.4 −1.0 −0.8 −0.6 −0.4 −0.2 120 0.4 0.6 VCS (V) Figure 14. CS Current, VCS = −20 mV Figure 15. CS Current, VCC = 12 V 2.5 −50 VTH_CS_ON (mV) −30 2.0 ICC (mA) 0.2 TJ (°C) 3.0 TJ = 125°C TJ = 85°C TJ = 55°C TJ = 25°C TJ = 0°C TJ = −20°C TJ = −40°C 1.5 1.0 0.5 0 −4 0 −3 −2 0.8 1.0 −70 −90 −110 −130 −1 0 1 2 3 −150 −40 −20 4 0 20 40 60 80 100 VCS (V) TJ (°C) Figure 16. Supply Current vs. CS Voltage, VCC = 12 V Figure 17. CS Turn−on Threshold 1.0 120 0.60 VTH_CS_RESET (V) VTH_CS_OFF (mV) 0.5 0 −0.5 −1.0 0.55 0.50 0.45 −1.5 −2.0 −40 −20 0 20 40 60 80 100 0.40 −40 120 −20 0 20 40 60 80 TJ (°C) TJ (°C) Figure 18. CS Turn−off Threshold Figure 19. CS Reset Threshold www.onsemi.com 10 100 120 NCP43080 0.80 200 0.75 180 0.70 160 0.65 140 ICS_LEAKAGE (nA) VTH_CS_RESET (V) TYPICAL CHARACTERISTICS 0.60 0.55 0.50 0.45 80 60 0.40 40 0.35 0.30 20 0 −40 0 5 10 15 20 25 30 35 −20 0 20 40 60 80 100 VCC (V) TJ (°C) Figure 20. CS Reset Threshold Figure 21. CS Leakage, VCS = 150 V 60 24 55 22 120 20 50 18 tPD_OFF (ns) tPD_ON (ns) 120 100 45 40 35 16 14 12 10 30 8 25 6 −20 0 20 40 60 80 100 4 −40 120 −20 0 20 40 60 80 100 120 TJ (°C) TJ (°C) Figure 22. Propagation Delay from CS to DRV Output On Figure 23. Propagation Delay from CS to DRV Output Off 75 1.08 70 1.06 65 1.04 tMIN_TON (ms) tMIN_TON (ns) 20 −40 60 55 50 1.02 1.00 0.98 45 0.96 40 0.94 35 −40 −20 0 20 40 60 80 100 0.92 −40 120 −20 0 20 40 60 80 100 120 TJ (°C) TJ (°C) Figure 24. Minimum On−time RMIN_TON = 0 W Figure 25. Minimum On−time RMIN_TON = 10 kW www.onsemi.com 11 NCP43080 TYPICAL CHARACTERISTICS 5.4 290 5.3 280 270 tMIN_TOFF (ns) tMIN_TON (ms) 5.2 5.1 5.0 4.9 240 230 210 4.7 4.6 −40 −20 0 20 40 60 80 100 200 190 −40 120 −20 0 20 40 60 80 100 120 TJ (°C) TJ (°C) Figure 26. Minimum On−time RMIN_TON = 50 kW Figure 27. Minimum Off−time RMIN_TOFF = 0 W 1.08 5.4 1.06 5.3 1.04 5.2 tMIN_TOFF (ms) tMIN_TOFF (ms) 250 220 4.8 1.02 1.00 0.98 5.1 5.0 4.9 0.96 4.8 0.94 4.7 0.92 −40 −20 0 20 40 60 80 100 4.6 −40 120 −20 0 20 40 60 80 100 TJ (°C) TJ (°C) Figure 28. Minimum Off−time RMIN_TOFF = 10 kW Figure 29. Minimum Off−time RMIN_TOFF = 50 kW 1.04 1.08 1.03 1.06 1.02 1.04 tMIN_TOFF (ms) tMIN_TON (ms) 260 1.01 1.00 0.98 120 1.02 1.00 0.98 0.96 0.96 0.94 0.94 092 0.92 0 5 10 15 20 25 30 0 35 5 10 15 20 25 30 VCC (V) VCC (V) Figure 30. Minimum On−time RMIN_TON = 10 kW Figure 31. Minimum Off−time RMIN_TOFF = 10 kW www.onsemi.com 12 35 NCP43080 TYPICAL CHARACTERISTICS 5.5 10.4 VCC = 12 V, CDRV = 0 nF VCC = 12 V, CDRV = 1 nF VCC = 12 V, CDRV = 10 nF VCC = 35 V, CDRV = 0 nF VCC = 35 V, CDRV = 1 nF VCC = 35 V, CDRV = 10 nF VDRV (V) 10.0 9.8 5.1 VDRV (V) 10.2 VCC = 12 V, CDRV = 0 nF VCC = 12 V, CDRV = 1 nF VCC = 12 V, CDRV = 10 nF VCC = 35 V, CDRV = 0 nF VCC = 35 V, CDRV = 1 nF VCC = 35 V, CDRV = 10 nF 5.3 9.6 4.9 4.7 9.4 4.5 9.2 9.0 −40 −20 0 20 40 60 80 4.3 −40 −20 120 100 20 40 60 80 100 120 TJ (°C) TJ (°C) Figure 32. Driver and Output Voltage, ver. B, D and Q Figure 33. Driver Output Voltage, ver. A and C 50 5.3 TJ = 125°C TJ = 85°C TJ = 55°C TJ = 25°C 45 40 TJ = 0°C TJ = −20°C TJ = −40°C 5.2 5.1 tMAX_TON (ms) 35 30 25 20 5.0 4.9 4.8 4.7 15 4.6 10 4.5 5 0 4.4 0 0.5 1.0 1.5 2.0 2.5 4.3 −40 3.0 −20 0 20 40 60 80 100 120 VMAX_TON (V) TJ (°C) Figure 34. Maximum On−time, ver. Q Figure 35. Maximum On−time, VMAX_TON = 3 V, ver. Q 55 53 51 tMAX_TON (ms) tMAX_TON (ms) 0 49 47 45 43 41 −40 −20 0 20 40 60 80 100 TJ (°C) Figure 36. Maximum On−time, VMAX_TON = 0.3 V, ver. Q www.onsemi.com 13 120 NCP43080 APPLICATION INFORMATION General description An extremely fast turn−off comparator, implemented on the current sense pin, allows for NCP43080 implementation in CCM applications without any additional components or external triggering. An output driver features capability to keep SR transistor closed even when there is no supply voltage for NCP43080. SR transistor drain voltage goes up and down during SMPS operation and this is transferred through drain gate capacitance to gate and may turn on transistor. NCP43080 uses this pulsing voltage at SR transistor gate (DRV pin) and uses it internally to provide enough supply to activate internal driver sink transistor. DRV voltage is pulled low (not to zero) thanks to this feature and eliminate the risk of turned on SR transistor before enough VCC is applied to NCP43080. Some IC versions include a MAX_TON circuit that helps a quasi resonant (QR) controller to work in CCM mode when a heavy load is present like in the example of a printer’s motor starting up. Finally, the NCP43080 features a special pin (LLD) that can be used to reduce gate driver voltage clamp according to application load conditions. This feature helps to reduce issues with transition from disabled driver to full driver output voltage and back. Disable state can be also activated through this pin to decrease power consumption in no load conditions. If the LLD feature is not wanted then the LLD pin can be tied to GND. The NCP43080 is designed to operate either as a standalone IC or as a companion IC to a primary side controller to help achieve efficient synchronous rectification in switch mode power supplies. This controller features a high current gate driver along with high−speed logic circuitry to provide appropriately timed drive signals to a synchronous rectification MOSFET. With its novel architecture, the NCP43080 has enough versatility to keep the synchronous rectification system efficient under any operating mode. The NCP43080 works from an available voltage with range from 4 V (A, D & Q options) or 8 V (B & C options) to 35 V (typical). The wide VCC range allows direct connection to the SMPS output voltage of most adapters such as notebooks, cell phone chargers and LCD TV adapters. Precise turn-off threshold of the current sense comparator together with an accurate offset current source allows the user to adjust for any required turn-off current threshold of the SR MOSFET switch using a single resistor. Compared to other SR controllers that provide turn-off thresholds in the range of −10 mV to −5 mV, the NCP43080 offers a turn-off threshold of 0 mV. When using a low RDS(on) SR (1 mW) MOSFET our competition, with a −10 mV turn off, will turn off with 10 A still flowing through the SR FET, while our 0 mV turn off turns off the FET at 0 A; significantly reducing the turn-off current threshold and improving efficiency. Many of the competitor parts maintain a drain source voltage across the MOSFET causing the SR MOSFET to operate in the linear region to reduce turn−off time. Thanks to the 8 A sink current of the NCP43080 significantly reduces turn off time allowing for a minimal drain source voltage to be utilized and efficiency maximized. To overcome false triggering issues after turn-on and turn−off events, the NCP43080 provides adjustable minimum on-time and off-time blanking periods. Blanking times can be adjusted independently of IC VCC using external resistors connected to GND. If needed, blanking periods can be modulated using additional components. Current Sense Input Figure 37 shows the internal connection of the CS circuitry on the current sense input. When the voltage on the secondary winding of the SMPS reverses, the body diode of M1 starts to conduct current and the voltage of M1’s drain drops approximately to −1 V. The CS pin sources current of 100 mA that creates a voltage drop on the RSHIFT_CS resistor (resistor is optional, we recommend shorting this resistor). Once the voltage on the CS pin is lower than VTH_CS_ON threshold, M1 is turned−on. Because of parasitic impedances, significant ringing can occur in the application. To overcome false sudden turn−off due to mentioned ringing, the minimum conduction time of the SR MOSFET is activated. Minimum conduction time can be adjusted using the RMIN_TON resistor. www.onsemi.com 14 NCP43080 Figure 37. Current Sensing Circuitry Functionality Figure 38). Therefore the turn−off current depends on MOSFET RDSON. The −0.5 mV threshold provides an optimum switching period usage while keeping enough time margin for the gate turn-off. The RSHIFT_CS resistor provides the designer with the possibility to modify (increase) the actual turn−on and turn−off secondary current thresholds. To ensure proper switching, the min_tOFF timer is reset, when the VDS of the MOSFET rings and falls down past the VTH_CS_RESET. The minimum off−time needs to expire before another drive pulse can be initiated. Minimum off−time timer is started again when VDS rises above VTH_CS_RESET. The SR MOSFET is turned-off as soon as the voltage on the CS pin is higher than VTH_CS_OFF (typically −0.5 mV minus any voltage dropped on the optional RSHIFT_CS). For the same ringing reason, a minimum off-time timer is asserted once the VCS goes above VTH_CS_RESET. The minimum off-time can be externally adjusted using RMIN_TOFF resistor. The minimum off−time generator can be re−triggered by MIN_TOFF reset comparator if some spurious ringing occurs on the CS input after SR MOSFET turn−off event. This feature significantly simplifies SR system implementation in flyback converters. In an LLC converter the SR MOSFET M1 channel conducts while secondary side current is decreasing (refer to www.onsemi.com 15 NCP43080 VDS = VCS ISEC V TH_CS _RESET – (RSHIFT _CS*ICS ) VTH_CS_OFF – (RSHIFT _CS*ICS ) VTH_CS _ON – (RSHIFT _CS*ICS ) VDRV Turn−on delay Turn −off delay Min ON−time tMIN_TON Min t OFF timer was stopped here because of VCS