VIPER22ADIP-E

VIPer22ADIP - E VIPer22AS - E Low Power OFF-Line SMPS Primary Switcher Features ■ ■ ■ ■ ■ ■ Fixed 60kHZ Switching Frequency 9V to 38V Wide Range VDD Voltage Current Mode Control Auxiliary Undervoltage Lockout with Hysteresis High Voltage Start-up Current Source Overtemperature, Overcurrent and Overvoltage Protection with Auto-Restart SO-8 DIP-8 Description The VIPer22A-E combines a dedicated current mode PWM controller with a high voltage Power MOSFET on the same silicon chip. Typical applications cover off line power supplies for battery charger adapters, standby power supplies for TV or monitors, auxiliary supplies for motor control, etc. The internal control circuit offers the following benefits: – Large input voltage range on the VDD pin accommodates changes in auxiliary supply voltage. This feature is well adapted to battery charger adapter configurations. – Automatic burst mode in low load condition. – Overvoltage protection in HICCUP mode. DRAIN Typical Power Capability Mains type European (195 - 265 Vac) US / Wide range (85 - 265 Vac) SO-8 12W 7W DIP-8 20W 12W Block diagram ON/OFF REGULATOR 60kHz OSCILLATOR INTERNAL SUPPLY OVERTEMP. DETECTOR R1 S FF PWM LATCH Q R2 R3 R4 VDD 8/14.5V _ BLANKING + OVERVOLTAGE LATCH Q + _ 0.23 V + 42V _ S R FF 230 Ω 1 kΩ FB SOURCE February 2006 Rev1 1/20 www.st.com 20 Contents VIPer22ADIP/ VIPer22AS - E Contents 1 Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 1.2 Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Thermal Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 3 4 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pin Connections and Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1 4.2 4.3 4.4 4.5 Rectangular U-I Output Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Wide Range of VDD Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Feedback Pin Principle of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Startup sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Overvoltage threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 5 6 7 8 Operation pictures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Mechanical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2/20 Rev1 VIPer22ADIP/ VIPer22AS - E Electrical Data 1 1.1 Electrical Data Maximum Ratings Stressing the device above the rating listed in the “Absolute Maximum Ratings” table may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents. Table 1. Symbol VDS(sw) VDS(st) ID VDD IFB VESD TJ TC Tstg Absolute Maximum Rating Parameter Switching drain source voltage (TJ = 25 ... 125°C) (1) Start-up drain source voltage (TJ = 25 ... 125°C) Continuous drain current Supply voltage Feedback current Electrostatic discharge: Machine model (R = 0Ω; C = 200pF) Charged device model Junction operating temperature Case operating temperature Storage Temperature (2) Value -0.3 ... 730 -0.3 ... 400 Internally limited 0 ... 50 3 200 1.5 Internally limited -40 to 150 -55 to 150 Unit V V A V mA V kV °C °C °C 1. This parameter applies when the start-up current source is OFF. This is the case when the VDD voltage has reached VDDon and remains above VDDoff. 2. This parameter applies when the start up current source is on. This is the case when the VDD voltage has not yet reached VDDon or has fallen below V DDoff. 1.2 Thermal Data Table 2. Symbol RthJC RthJA Thermal Data Parameter Thermal Resistance Junction - Case Thermal Resistance Junction - Ambient (1) Max Max SO-8 25 55 DIP-8 15 45 Unit °C/W °C/W 1. When mounted on a standard single-sided FR4 board with 200 mm 2 of Cu (at least 35 µm thick) connected to all DRAIN pins. Rev1 3/20 Electrical Characteristics VIPer22ADIP/ VIPer22AS - E 2 Electrical Characteristics TJ = 25°C, VDD = 18V, unless otherwise specified Table 3. Symbol BVDSS IDSS rDS(on) tf tr COSS Power section Parameter D rain-source voltage OFF State drain current Static drain-source ON state resistance Fall time R ise time D rain capacitance Test conditions ID = 1mA; VFB = 2V VDS = 500V; VFB = 2V; TJ = 125°C ID = 0.4A ID = 0.4A; TJ = 100°C ID = 0.2A; VIN = 300V (1) (See Figure 8 on page 12) ID = 0.4A; VIN = 300V (1) (See Figure 8 on page 12) VDS = 25V 15 Min. 730 0.1 17 31 Typ. Max. Unit V mA Ω ns ns pF 100 50 40 1. On clamped inductive load Table 4. Symbol IDDch Supply section Parameter Start-up charging current Start-up charging current in thermal shutdown Operating supply current not switching Operating supply current switching Restart duty-cycle VDD Undervoltage shutdown threshold VDD Start-up threshold VDD Threshold hysteresis VDD Overvoltage threshold Test conditions VDS = 100V; VDD = 0V ...VDDon (See Figure 9 on page 12) VDD = 5V; VDS = 100V TJ > TSD - THYST IFB = 2mA IFB = 0.5mA; ID = 50mA (1) (See Figure 10 on page 12) (See Figure 9, Figure 10 on page 12) (See Figure 9, Figure 10 on page 12)) (See Figure 9 on page 12) 7 13 5.8 38 0 Min. Typ. -1 Max. Unit mA IDDoff mA IDD0 IDD1 DRST VDDoff VDDon VDDhyst VDDovp 3 4.5 16 8 14.5 6.5 42 5 mA mA % 9 16 7.2 46 V V V V 1. These test conditions obtained with a resistive load are leading to the maximum conduction time of the device. 4/20 Rev1 VIPer22ADIP/ VIPer22AS - E Electrical Characteristics Table 5. Symbol FOSC Oscillation section Parameter Oscillator frequency total variation Test conditions VDD = VDDoff ... 35V; TJ = 0 ... 100°C Min. 54 Typ. 60 Max. 66 Unit kHz Table 6. Symbol G ID IDlim IFBsd RFB td tb tONmin PWM Comparator section Parameter IFB to ID current gain Peak current limitation IFB Shutdown current FB Pin input impedance Current sense delay to turn-OFF Blanking time Minimum Turn-ON time Test Conditions (See Figure 11 on page 13) VFB = 0V (See Figure 11 on page 13) (See Figure 11 on page 13) ID = 0mA (See Figure 11 on page 13) ID = 0.4A 0.56 Min. Typ. 560 0.7 0.9 1.2 200 500 700 0.84 A mA kΩ ns ns ns Max. Unit Table 7. Symbol TSD THYST Overtemperature section Parameter Thermal shutdown temperature Thermal shutdown hysteresis Test Conditions (See Figure 12 on page 13) (See Figure 12 on page 13) Min. 140 Typ. 170 40 Max. Unit °C °C Table 8. Typical Power Capability (1) Mains type SO-8 12W 7W DIP-8 20W 12W European (195 - 265 Vac) US / Wide range (85 - 265 Vac) 1. Above power capabilities are given under adequate thermal conditions Rev1 5/20 Pin Connections and Function VIPer22ADIP/ VIPer22AS - E 3 Pin Connections and Function Figure 1. Pin connection SOURCE SOURCE FB VDD 1 2 3 4 8 7 6 5 DRAIN DRAIN DRAIN DRAIN SOURCE SOURCE FB VDD 1 2 3 4 8 7 6 5 DRAIN DRAIN DRAIN DRAIN SO-8 DIP-8 Figure 2. Current and voltage conventions I DD ID I FB FB VDD CONTROL DRAIN VDD VFB VIPer22A VD SOURCE Table 9. Pin Name Pin function Pin Function Power supply of the control circuits. Also provides a charging current during start up thanks to a high voltage current source connected to the drain. For this purpose, an hysteresis comparator monitors the VDD voltage and provides two thresholds: - VDDon: Voltage value (typically 14.5V) at which the device starts switching and turns off the start up current source. - VDDoff: Voltage value (typically 8V) at which the device stops switching and turns on the start up current source. Power MOSFET source and circuit ground reference. Power MOSFET drain. Also used by the internal high voltage current source during start up phase for charging the external VDD capacitor. Feedback input. The useful voltage range extends from 0V to 1V, and defines the peak drain MOSFET current. The current limitation, which corresponds to the maximum drain current, is obtained for a FB pin shorted to the SOURCE pin. VDD SOURCE DRAIN FB 6/20 Rev1 VIPer22ADIP/ VIPer22AS - E Operations 4 4.1 Operations Rectangular U-I Output Characteristics Figure 3. Rectangular U-I output characteristics for battery charger DCOUT R1 C2 D1 T1 D2 C1 F1 AC IN C3 T2 + D4 C4 ISO1 U1 VDD D3 DRAIN C5 C6 FB CONTROL SOURCE VIPerX2A C7 R2 D5 U2 R3 Vcc Vref R4 R5 C10 C8 + GND + - C9 R6 R7 R10 R8 TSM101 R9 GND A complete regulation scheme can achieve combined and accurate output characteristics. Figure 3. presents a secondary feedback through an optocoupler driven by a TSM101. This device offers two operational amplifiers and a voltage reference, thus allowing the regulation of both output voltage and current. An integrated OR function performs the combination of the two resulting error signals, leading to a dual voltage and current limitation, known as a rectangular output characteristic. This type of power supply is especially useful for battery chargers where the output is mainly used in current mode, in order to deliver a defined charging rate. The accurate voltage regulation is also convenient for Li-ion batteries which require both modes of operation. 4.2 Wide Range of VDD Voltage The VDD pin voltage range extends from 9V to 38V. This feature offers a great flexibility in design to achieve various behaviors. In Figure 3 on page 7 a forward configuration has been chosen to supply the device with two benefits: Rev1 7/20 Operations ■ VIPer22ADIP/ VIPer22AS - E As soon as the device starts switching, it immediately receives some energy from the auxiliary winding. C5 can be therefore reduced and a small ceramic chip (100nF) is sufficient to insure the filtering function. The total start up time from the switch on of input voltage to output voltage presence is dramatically decreased. The output current characteristic can be maintained even with very low or zero output voltage. Since the TSM101 is also supplied in forward mode, it keeps the current regulation up whatever the output voltage is.The VDD pin voltage may vary as much as the input voltage, that is to say with a ratio of about 4 for a wide range application. ■ 4.3 Feedback Pin Principle of Operation A feedback pin controls the operation of the device. Unlike conventional PWM control circuits which use a voltage input (the inverted input of an operational amplifier), the FB pin is sensitive to current. Figure 4. presents the internal current mode structure. Figure 4. Internal current control structure The Power MOSFET delivers a sense current Is which is proportional to the main current Id. R2 receives this current and the current coming from the FB pin. The voltage across R2 is then compared to a fixed reference voltage of about 0.23V. The MOSFET is switched off when the following equation is reached: R 2 ⋅ ( I S + IFB ) = 0.23V 8/20 Rev1 VIPer22ADIP/ VIPer22AS - E By extracting IS: 0.23V I S = --------------- – I FB R2 Operations Using the current sense ratio of the MOSFET GID: ⎠ ⎞ by the IFBsd 0.23V I D = G I D ⋅ I S = G I D ⋅ --------------- – I FB R2 ⎝ ⎛ The current limitation is obtained with the FB pin shorted to ground (V FB = 0V). This leads to a negative current sourced by this pin, and expressed by: 0.23V I FB = – --------------R1 By reporting this expression in the previous one, it is possible to obtain the drain current limitation IDlim: ⎠ ⎞ 1 1 IDlim = G I D ⋅ 0.23V ⋅ ------ + -----R2 R1 ⎝ ⎛ In a real application, the FB pin is driven with an optocoupler as shown on Figure 4. which acts as a pull up. So, it is not possible to really short this pin to ground and the above drain current value is not achievable. Nevertheless, the capacitor C is averaging the voltage on the FB pin, and when the optocoupler is off (start up or short circuit), it can be assumed that the corresponding voltage is very close to 0V. For low drain currents, the formula (1) is valid as long as IFB satisfies IFB < IFBsd, where IFBsd is an internal threshold of the VIPer22A. If IFB exceeds this threshold the device will stop switching. This is represented on Figure 11 on page 13, and IFBsd value is specified in the PWM COMPARATOR SECTION. Actually, as soon as the drain current is about 12% of Idlim, that is to say 85 mA, the device will enter a burst mode operation by missing switching cycles. This is especially important when the converter is lightly loaded. Figure 5. IFB Transfer function IDpeak IDlim Part masked threshold 1 t ⋅V ON m in IN -- ----- ----- ----- ---- ---- ---- ---- ---- --L 85mA 2 t ⋅V ON m in IN -- ----- ----- ----- ---- ---- ---- ---- ---- --L IFB 0 IFBsd It is then possible to build the total DC transfer function between ID and IFB as shown on Figure 5 on page 9. This figure also takes into account the internal blanking time and its associated minimum turn on time. This imposes a minimum drain current under which the device is no more able to control it in a linear way. This drain current depends on the primary inductance value of the transformer and the input voltage. Two cases may occur, depending on the value of this current versus the fixed 85mA value, as described above. Rev1 9/20 Operations VIPer22ADIP/ VIPer22AS - E 4.4 Startup sequence Figure 6. Startup sequence This device includes a high voltage start up current source connected on the drain of the device. As soon as a voltage is applied on the input of the converter, this start up current source is activated as long as V DD is lower than VDDon. When reaching VDDon, the start up current source is switched OFF and the device begins to operate by turning on and off its main power MOSFET. As the FB pin does not receive any current from the optocoupler, the device operates at full current capacity and the output voltage rises until reaching the regulation point where the secondary loop begins to send a current in the optocoupler. At this point, the converter enters a regulated operation where the FB pin receives the amount of current needed to deliver the right power on secondary side. This sequence is shown in Figure 6. Note that during the real starting phase tss, the device consumes some energy from the V DD capacitor, waiting for the auxiliary winding to provide a continuous supply. If the value of this capacitor is too low, the start up phase is terminated before receiving any energy from the auxiliary winding and the converter never starts up. This is illustrated also in the same figure in dashed lines. 10/20 Rev1 VIPer22ADIP/ VIPer22AS - E Operations 4.5 Overvoltage threshold An overvoltage detector on the VDD pin allows the VIPer22A to reset itself when VDD exceeds VDDovp. This is illustrated in Figure 7. w hich shows the whole sequence of an overvoltage event. Note that this event is only latched for the time needed by VDD to reach VDDoff, and then the device resumes normal operation automatically. Figure 7. Overvoltage Sequence VDD VDDovp VDDon VDDoff t VDS t Rev1 11/20 Operation pictures VIPer22ADIP/ VIPer22AS - E 5 Operation pictures Figure 8. ID Rise and Fall time C C