OB2201
High Performance Quasi-Resonant PWM Controller
Product Specification
GENERAL DESCRIPTION
FEATURES
TYPICAL APPLICATION
ght ACConfOB2201 is a high performance flyback Quasi-■ Multi-Mode Operation:
• At Full Loading, Fix Frequency (52KHz) Resonant (QR) controller optimized to achieve
CCM Operation @ Low Line and QR Mode high efficiency in the universal input range and full
Operation @ High Line Input loading range with effective system cost.
• Quasi-Resonant Operation at Normal At full loading, the IC operates in fix frequency
Load (52KHz) CCM mode in the low line input range
• Pulse Frequency Modulation (PFM) and operates in QR mode in high line input range.
Operation at Light Load In this way, high efficiency in the universal input
• Burst Mode at No Load range at full loading can be achieved.
■ Adaptive Frequency Shuffling and Slope At normal load condition, it operates in QR mode.
Compensation @ Fix Frequency CCM Mode To minimize switching loss, the maximum
switching frequency in QR mode is internally ■ Programmable OTP with latch Shutdown
■ Fixed 4ms Soft-start limited to 90 KHz. When the loading goes low, it
■ 2.5us Minimum Off Time operates in PFM mode for high power conversion
efficiency. When the load is very small, the IC ■ 12.5us Maximum On Time Limit
■ 55us Maximum Off Time Limit operates in ‘Extended Burst Mode’ to minimize the
■ 90KHz Maximum Frequency Limit standby power loss. As a result, high conversion
efficiency can be achieved in the whole loading ■ Internal Leading Edge Blanking
■ Output Over Voltage Protection range.
OB2201 offers comprehensive protection ■ 800mA Peak Current Sink/Source Capability coverage including Cycle-by-Cycle Current Limiting (OCP), VCC Under Voltage Lockout (UVLO), Output Over Voltage Protection (OVP),
Over Temperature Protection (OTP), Over Load APPLICATIONS
Protection (OLP), VCC Over Voltage Protection Offline AC/DC flyback converter for
(VCC OVP), VCC Clamp, and Gate Clamp. ■ Power Adaptor and Open-frame SMPS OB2201 also features protections against pin ■ Set-Top Box Power Supplies open and short conditions on selected pins. ■ NB/DVDOB2201 is offered in SOP-8 and DIP-8 packages.
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OB_DOC_DS_2201A1
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OB2201
High Performance Quasi-Resonant PWM Controller
GENERAL INFORMATION
Pin Configuration
The pin map of OB2201 in DIP8 and SOP8 package is shown as below. otherwise noted.
ConfidOB2201 X X X
enOrdering Information Part Number Description OB2201AP 8 Pin DIP, Pb free in Tube OB2201CP 8 Pin SOP, Pb free in Tube OB2201CPA 8 Pin SOP, Pb free in T&R Note: All Devices are offered in Pb-free Package if not
timaximum ratings” may cause permanent damage to the device. These are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute maximum-rated conditions for extended periods may affect device reliability.
al
Package Dissipation Rating Package RθJA (℃/W)
DIP8 90 SOP8 150
Absolute Maximum Ratings Parameter Value VCC Zener Clamp Voltage 29 V VCC Clamp Continuous 10 mA
Current
RI Input Voltage -0.3 to 7V FB Input Voltage -0.3 to 7V CS Input Voltage -0.3 to 7V DEM Input Voltage -0.7 to 7V RT Input Voltage -0.3 to 7V Maximum Operating Junction 150 ℃
Temperature TJ
Min/Max Storage Temperature
-55 to 150 ℃
Tstg
Lead Temperature (Soldering,
260 ℃
10secs)
Note: Stresses beyond those listed under “absolute
High Performance Qusi-Resonant
PWM controller
PackageA:DIP8C:SOP8
Package Pb freeBlank:NormalP:lead-free
ght to 万PackingBlank:TubeA: Tape/Reel
基
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OB2201
High Performance Quasi-Resonant PWM Controller
Marking Information
SOP8
DIP8
YWWOB2201CP sY: Year Code (0-9) WW: Week Code (1-52)C: SOP8P:lead-frees: internal code
YWWOB2201AP
Y: Year Code (0-9) WW: Week Code (1-52)A: DIP8P:lead-free
TERMINAL ASSIGNMENTS
Pin Num Pin Name
I/O
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A resistor connected between RI and GND sets the internal frequency
1 RI I and timer. The resistor is recommended to be set in the vicinity of 20K
Ohm.
Feedback input pin. PWM duty cycle is determined by voltage level into
2 FB I this pin and current-sense signal level at Pin 3.
3 CS I Current sense input. 4 GND P Ground for internal circuitry. 5 GATE O Totem-pole gate drive output for power MOSFET. 6 VCC P Chip DC power supply pin.
Transformer core demagnetization detection pin. This pin is also used for
7 DEM I output over voltage protection (OVP).
Over Temperature Protection pin. Connected through a NTC resistor to
8 RT I GND for over temperature latch shutdown.
Confidenti
als: internal code
to 万 s
基隆
OB2201
High Performance Quasi-Resonant PWM Controller
BLOCK DIAGRAM
1VDDInternal reference6UVLOPORRISoftDriverGATE5InternalsupplyRegulatorRT8OTPTimer,Logic,&Fault ManagementSQRQbValley detectorDEM7Load OVP to LEBMode selectionFB2OLPalti万CS3Adaptive Frequency Shuffling4GND4mS soft startupRECOMMENDED OPERATING CONDITION
Symbol VCC TA
Parameter
VCC Supply Voltage
Operating Ambient Temperature
Min 12 -20
Max 28 85
Unit V ℃
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OB2201
High Performance Quasi-Resonant PWM Controller
ELECTRICAL CHARACTERISTICS
(TA = 25℃, VCC=16V, RI=20Kohm if not otherwise noted) Symbol Parameter Test Conditions Min Typ Max Unit Supply Voltage Section (VCC Pin)
VCC Start up VCC =UVLO(OFF)-1.5V,
I_VCC_Startup - 5 15 uA Current Measure current into VCCOperation Current I_VCC_quiet FB3V - 2.0 4.0 mA without switching
Operation current FB3V, 1nF load at I_VCC_operation - 3.0 5.0 mA with switching GATE VCC Under UVLO(ON) Voltage Lockout 8.0 9.0 10.0 V Enter
VCC Under UVLO(OFF) 15 16 17 V Voltage Lockout Exit (Startup)
VCC Over Voltage
OVP(ON) 28 V Protection Enter VCC Zener Clamp
VCC_Clamp I_VCC = 5 mA 29 V
Voltage
Feedback Input Section (FB Pin) AVCS PWM Input Gain ΔVFB /ΔVcs - 3.5 - V/V
VFB_Open FB -- -- V Open Voltage 5.3
FB pin short circuit Short FB pin to GND, IFB_Short -- 1.5 - mA current measure current =Burst Mode on =VTH_BM_on - 0.8 - V threshold
Burst Mode off VTH_BM_off - 0.7 - V threshold
Power Limiting FB
VTH_PL - 4.4 - V Threshold Voltage
Power limiting TD_PL -- 80 -- ms Debounce Time
ZFB_IN Input Impedance - 4 - KohmCurrent Sense Input Section (CS Pin)
CS Input Leading T_blanking - 300 - ns Edge Blanking Time
Internal current VTH_OCP_zero_ontime Zero duty cycle 0.415 0.45 0.485V
limiting threshold
Internal current VTH_OCP_max Maximum duty cycle - 0.80 - V
limiting threshold
Flodback mode VTH_CS_min and burst mode 0.3 V CS peak
Over Current TD_OC CL=1nf at GATE, - 100 -- ns Detection and Control Delay
Demagnetization Detection Section (DEM Pin)
Demagnetization
VTH_DEM -- 75 -- mV comparator
threshold voltage
Negative clamp VDEM_clamp(neg) - -0.7 - V voltage
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=
OB2201
High Performance Quasi-Resonant PWM Controller
VDEM_clamp(pos) Tsupp TOUT TDEM_delay VTH_OVP T_OVP_delay Soft Start Section T_soft Timer Section RI_range
=Internal soft 4 ms startup
=Operating RI 14 20 26 Kohm
resistor range
V_RI_open RI open voltage 2.0 V
Burst mode Fburst switching RI20K - 22 - KHz frequency
Frequency high Fmax_QR_H RI20K 82 90 98 KHz clamp in QR mode
Frequency low Fmin_QR_L RI20K 47 52 57 KHz clamp in QR modeFmin_QR_L
+4 % frequency shuffling -4 △F（shuffle）/F
range
Ton_max Maximum on time RI20K 10 12.5 15 us Toff_max Maximum off time RI=20K 40 55 75 us
PFM mode frequency
G_PFM 90 - KHz/Vmodulation slope - versus control voltage
Over temperature Protection
Output current of I_RT RI20K 100 uA RT pin,
OTP threshold Vth_OTP 1.00 1.05 1.10 V voltage
RT pin open V_RT_open 3.5 V voltage
Latch Protection
VCC latch release
V_latch_release -- 6.3 -- V voltage
VCC current when
Ivdd(latch) VCCV_latch_release+1V- 45 - uA latch off
Gate Drive Output (GATE Pin) VOL Output Low Level Io = 100 mA (sink) - - 1 V VOH Output High Level Io = 100 mA (source) 7.5 - - V
Output Clamp VG_Clamp VCC20V - 16.5 - V Voltage Level
On Bri ©On-Bright Electronics Confidential Datasheet
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Suppression of the transformer ringing
-- 2.5 -- us at start of secondary stroke
=Timeout after last -- 5 -- us demag transistion Demag
- 250 - ns propagation delay Output OVP trigger
- 3.75 - V point
=Number of 4 - Cyclesubsequent cycles - to be true OVP
=万基隆
OB2201
High Performance Quasi-Resonant PWM Controller
Output Rising CL = 1nf
Time
Output Falling CL = 1nf
Time
- -
80 30
- -
ns ns
T_r T_f
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OB2201
High Performance Quasi-Resonant PWM Controller
CHARACTERIZATION PLOTS
Iop_n vs Vdd54321041220Vdd(V)28Istartup(uA) vs Temperature(℃)9.0Istartup(uA)8.07.06.05.0-400Ivdd(mA)UVLO(ON)(V) vs Temperature(℃)UVLO(OFF)(V) vs Temperature(℃)16.20UVLO(OFF)(V)16.0515.9015.7515.60UVLO(ON)(V)9.008.808.60-4004080120ential-4004080120Temperature(℃)Vth_load_OVP(V) vsTemperature(℃)-4004080120Temperature(℃)Fmin_QR_L vs RI90.080.070.060.050.040.030.01216202428329.20F_QR_clamp_l(KHz)nfF_QR_clamp_l(KHz) vsTemperature(℃)53.5052.0050.5049.00idTemperature(℃)Vth_load_OVP(V)Co3.903.853.803.75ght -4004080120Temperature(℃)On BriI_RT(uA) vs Temperature(℃)101.5100.098.5-4004080120Temperature(℃)Fmin_QR_L(KHz)103.0I_RT(uA) ©On-Bright Electronics Confidential Datasheet
OB_DOC_DS_2201A1
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OB2201
High Performance Quasi-Resonant PWM Controller
modulation) mode for high power conversion efficiency. In PFM mode, the “ON” time in a switching cycle is fixed and the system modulates the frequency according to the load conditions. Generally, in flyback converter, the decreasing of load results in voltage level decreasing at FB pin. The controller monitors the voltage level at FB and control the switching frequency. However, the valley switching characteristic is still preserved in PFM mode. That is, when load decreases, the system automatically skip more and more valleys and the switching frequency is thus reduced. In such way, a smooth frequency foldback is realized and high power conversion efficiency is achieved.
■ At zero load or very light load conditions (VFB Quasi-Resonant (QR) converter typically features lower EMI and higher power conversion efficiency compared to conventional hard-switched converter with a fixed switching frequency. OB2201 is a highly integrated QR controller optimized for offline flyback converter applications. The built-in advanced energy saving with high level protection features provide cost effective solutions for energy efficient power supplies. z Startup Current and Start up Control Startup current of OB2201 is designed to be very low so that VCC could be charged up above UVLO(OFF) threshold level and device starts up quickly. A large value startup resistor can therefore be used to minimize the power loss yet reliable startup in application. For a typical AC/DC adaptor with universal input range design, a 2MΩ, 1/8 W startup resistor could be used together with a VCC capacitor to provide a fast startup and yet low power dissipation design solution. z Operating Current The operating current of OB2201 is as low as 3mA. Good efficiency is achieved by the low operating current together with extended burst mode control schemes at No/light load conditions. z Multi-Mode Operation for High Efficiency OB2201 is a multi-mode QR controller. The controller changes the mode of operation according to FB voltage, which reflects the line and load conditions. ■ At full load conditions (FB>Vth3, Figure 1), there are two situations: firstly, if the system input is in low line input range, the IC operates in fix frequency (52KHz @ RI=20K Ohm) CCM mode. Thus, small size transformer can be used with high power conversion efficiency. Secondly, if the system input is in high line input range, the IC operates in QR mode. In this way, high power conversion efficiency can be achieved in the universal input range when system is at full loading conditions. ■ At normal operating conditions (Vth2 z Internal frequency and timer setting A resistor connected between RI and GND sets the constant current source to charge/discharge the internal cap and thus the internal frequency and timer is determined. It is recommended that the resistor is set to be in the vicinity of 20K Ohm. z Demagnetization Detection ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 9 - to Figure 1 万基隆 OB2201 High Performance Quasi-Resonant PWM Controller become rather high without limiting. To meet EMI limit and to achieve high efficiency at light loading conditions, the maximum switching frequency in OB2201 is internally limited to 90KHz. z Ringing Suppression Timer A ringing suppression timer Tsupp is implemented in OB2201. In normal operation, Tsupp starts when CS reaches the feedback voltage FB, the external power switch is set to off state. During Tsupp, the external power switch remains in off state and can not be turned on again. The ringing suppression time is necessary in applications where the transformer has a large leakage inductance, particularly at low output voltages or startup. In OB2201, the ringing suppression timer Tsupp is set to 2.5us internally. z OCP Compensation The variation of max output power in QR system can be rather large if no compensation is provided. The OCP threshold value is self adjusted lower at higher AC voltage. This OCP threshold slope adjustment helps to compensate the increased output power limit at higher AC voltage. In OB2201, a proprietary OCP compensation block is integrated and no external components are needed. The OCP threshold in OB2201 is a function of the switching ON time. For the ON time less than 12.5us, the OCP threshold changes linearly from 0.45V to 0.8V. For the ON time larger than 12.5us, the OCP threshold is clamped to 0.8V, as shown in Figure 3. (Note: RI=20K conditions) 1/2πLpCd, where Lp is the primary self inductance of the transformer and Cd is the capacitance on the drain node. Figure 2 The typical detection level is fixed at 75mV at the DEM pin. Demagnetization is recognized by detection of a possible “valley” when the voltage at DEM is below 75mV in falling edge. DEM detection is suppressed during the ringing suppression time Tsupp (please refer to “Ringing Suppression Timer” section). z Current Sensing and Leading Edge Blanking Cycle-by-Cycle current limiting is offered in OB2201. The switch current is detected by a sense resistor into the CS pin. An internal leading edge blanking circuit chops off the sense voltage spike at initial MOSFET on state, the QR current limit comparator is disabled and cannot turn off the external MOSFET during the blanking period. z Maximum and Minimum On-Time The minimum on-time of the system is determined by the LEB time (typical 300ns, RI=20K). The IC limits the on-time to a maximum time of 12.5uS. z Maximum Frequency Clamp According to the QR operation principle, the switching frequency is inversely proportional to the output power. Therefore, when the output power decreases, the switching frequency can On Bright ConfidentialAdaptive Frequency Shuffling and Slope Compensation In OB2201, when the fix frequency CCM mode is touched, the frequency shuffling and slope compensation will be automatically added to the system to improve the EMI performance and current loop stability. The magnitude of shuffling z ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 10 - to Figure 3 万基The transformer core demagnetization is detected by monitoring the voltage activity on the auxiliary windings through DEM pin. This voltage features a flyback polarity. A new cycle starts when the power switch is activated. After the on time (determined by the CS voltage and FB), the switch is off and the flyback stroke starts. After the flyback stroke, the drain voltage shows an oscillation with a frequency of approximately 隆 OB2201 High Performance Quasi-Resonant PWM Controller on soft start. It resumes operation once the fault disappears. Auxiliary windingOB2201R18R2DEMPlateauSampling3.75VLasts for 4 subsequent cycles YesTrue OVPOn B If the sampled plateau voltage exceeds the OVP trip level (3.75V), an internal counter starts counting subsequent OVP events. If OVP events are detected in successive 4 cycles, the controller assumes a true OVP and it enters a latch off mode and stops all switching operations. The counter has been added to prevent incorrect OVP detection which might occur during ESD or lightning events. If the output voltage exceeds the OVP trip level less than 4 successive cycles, the internal counter will be cleared and no fault is asserted. z Over Load Protection When over load (for example, short circuit) occurs, the feedback current of photo coupler is below minimum value, FB pin voltage approaches its floating pin voltage, then a fault is detected. If this fault is present for more than 80ms, the controller enters an auto-recovery soft burst mode. All pulses are stopped, VCC will drops below UVLO and the controller will try to restart with the power right ConfidFigure 4 ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 11 - enti z Pin Floating and Short Protection OB2201 provides pin floating protection for RI, CS, FB, DEM, etc., and RI pin short protection. In cases when the pin are floating or RI pin is shorted to ground, Gate switching is disabled, thus protect the power system. z External latch trip point By externally forcing a level on pin RT (e.g.., with a signal coming from a temperature sensor) less than 1.05V, OB2201 can be permanently latched-off. To resume normal operation, VCC voltage should go below 6V (typical), which implies to unplug the SMPS from the mains. z Gate Drive The Gate pin is connected to the gate of an external QR power switch with 0.8A capability. An internal 16.5V clamp is added for MOSFET gate protection at high VCC voltage. When VCC voltage drops below UVLO(ON), the Gate pin is internally pull low to maintain the off state. alWith 20K Ohm RI selected, an internal 100uA current flows through the NTC resistors. The voltage at RT pin becomes lower at high temperature. The internal OTP circuit is triggered and shuts down the MOSFET when the sensed input voltage is lower than 1.05V. OTP is a latched shutdown. to lies in the range of ±4% of 52K Hz. When the system leaves fix frequency CCM mode, the frequency shuffling and slope compensation will automatically disappear. z Output Over Voltage Protection (OVP) An output over voltage protection (OVP) is implemented by sensing the auxiliary winding voltage at DEM pin during the flyback phase. The auxiliary winding voltage is a well-defined replica of the output voltage. The OVP works by sampling the plateau voltage at DEM pin during the flyback phase. Internal 2.5us delay (plateau sensing) guarantees a clean plateau, provided that the leakage inductance ringing has been fully damped. Over Temperature Protection with latch shutdown A NTC resistor in series with a regular resistor should be connected between RT and GND for temperature sensing and protection. NTC resistor value becomes lower when the ambient temperature rises. A resistor between RI and GND sets internal reference current and the timer. The relationship between RT source current and RI resistor fellows below equation: I_RT = 100*z 20K ( uA ), RI 万基隆 OB2201 High Performance Quasi-Resonant PWM Controller PACKAGE MECHANICAL DATA 8-Pin Plastic DIP Confidential to Dimensions In Inches Min Max 0.146 0.21 0.015 0.125 0.142 0.014 0.026 0.06 (BSC) 0.008 0.014 0.354 0.4 0.244 0.260 0.288 0.312 0.1 (BSC) 0.115 0.15 0.323 0.375 Symbol Dimensions In Millimeters Min Max A 3.710 5.334 A1 0.381 A2 3.175 3.600 B 0.350 0.650 B1 1.524 (BSC) C 0.200 0.360 D 9.000 10.160 E 6.200 6.600 E1 7.320 7.920 e 2.540 (BSC) L 2.921 3.810 E2 8.200 9.525 On Bright ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 12 - 万基隆 OB2201 High Performance Quasi-Resonant PWM Controller 8-Pin Plastic SOP Confidential to On Bri ght Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 1.350 1.750 0.053 0.069 A1 0.050 0.250 0.002 0.010 A2 1.250 1.650 0.049 0.065 b 0.310 0.510 0.012 0.020 c 0.170 0.250 0.006 0.010 D 4.700 5.150 0.185 0.203 E 3.800 4.000 0.150 0.157 E1 5.800 6.200 0.228 0.244 e 1.270 (BSC) 0.05 (BSC) L 0.400 1.270 0.016 0.050 θ 0º 8º 0º 8º ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 13 - 万基隆 OB2201 High Performance Quasi-Resonant PWM Controller IMPORTANT NOTICE RIGHT TO MAKE CHANGES On-Bright Electronics Corp. reserves the right to make corrections, modifications, enhancements, improvements and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. WARRANTY INFORMATION On-Bright Electronics Corp. warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with its standard warranty. Testing and other quality control techniques are used to the extent it deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. On-Bright Electronics Corp. assumes no liability for application assistance or customer product design. Customers are responsible for their products and applications using On-Bright’s components, data sheet and application notes. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. LIFE SUPPORT On-Bright Electronics Corp.’s products are not designed to be used as components in devices intended to support or sustain human life. On-bright Electronics Corp. will not be held liable for any damages or claims resulting from the use of its products in medical applications. MILITARY On-Bright Electronics Corp.’s products are not designed for use in military applications. On-Bright Electronics Corp. will not be held liable for any damages or claims resulting from the use of its products in military applications. On Bri ©On-Bright Electronics Confidential Datasheet OB_DOC_DS_2201A1 - 14 - ght Conf idential to 万基隆 因篇幅问题不能全部显示，请点此查看更多更全内容