Datasheet TOP242, TOP243, TOP244, TOP245, TOP246, TOP247, TOP248, TOP249, TOP250 (Power Integrations) - 10
| Manufacturer | Power Integrations |
| Description | Extended Power, Design Flexible, EcoSmart, Integrated Off-Line Switcher |
| Pages / Page | 54 / 10 — TOP242-250. Bandgap Reference. LINE-SENSE (L) Pin Operation (Y, R and F … |
| File Format / Size | PDF / 4.0 Mb |
| Document Language | English |
TOP242-250. Bandgap Reference. LINE-SENSE (L) Pin Operation (Y, R and F Packages). High-Voltage Bias Current Source
Model Line for this Datasheet
- TOP247F TOP247F-TL TOP247FN TOP247FN-TL TOP247G TOP247G-TL TOP247GN TOP247GN-TL TOP247P TOP247P-TL TOP247PN TOP247PN-TL TOP247R TOP247R-TL TOP247RN TOP247RN-TL TOP247Y TOP247Y-TL TOP247YN TOP247YN-TL
- TOP248F TOP248F-TL TOP248FN TOP248FN-TL TOP248G TOP248G-TL TOP248GN TOP248GN-TL TOP248P TOP248P-TL TOP248PN TOP248PN-TL TOP248R TOP248R-TL TOP248RN TOP248RN-TL TOP248Y TOP248Y-TL TOP248YN TOP248YN-TL
Text Version of Document
TOP242-250
resumes providing automatic recovery. A large hysteresis of 132 kHz (Figure 13), which is suited for most applications. 70 °C (typical) is provided to prevent overheating of the PC For other cases that may benefit from lower switching board due to a continuous fault condition. V is regulated frequency such as noise sensitive video applications, a C in hysteretic mode and a 4.8 V to 5.8 V (typical) sawtooth 66 kHz switching frequency (half frequency) can be waveform is present on the CONTROL pin while in thermal selected by shorting the FREQUENCY pin to the CONTROL shutdown. pin (Figure 14). In addition, an example circuit shown in Figure 15 may be used to lower the switching frequency
Bandgap Reference
from 132 kHz in normal operation to 66 kHz in standby All critical TOPSwitch-GX internal voltages are derived mode for very low standby power consumption. from a temperature-compensated bandgap reference. This reference is also used to generate a temperature-
LINE-SENSE (L) Pin Operation (Y, R and F Packages)
compensated current reference, which is trimmed to When current is fed into the LINE-SENSE pin, it works as a accurately set the switching frequency, MOSFET gate voltage source of approximately 2.6 V up to a maximum drive current, current limit, and the line OV/UV thresholds. current of +400 µA (typical). At +400 µA, this pin turns into TOPSwitch-GX has improved circuitry to maintain all of the a constant current sink. Refer to Figure 12a. In addition, a above critical parameters within very tight absolute and comparator with a threshold of 1 V is connected at the temperature tolerances. pin and is used to detect when the pin is shorted to the SOURCE pin.
High-Voltage Bias Current Source
This current source biases TOPSwitch-GX from the DRAIN There are a total of four functions available through the pin and charges the CONTROL pin external capacitance use of the LINE-SENSE pin: OV, UV, line feed-forward during start-up or hysteretic operation. Hysteretic operation with DC reduction, and remote ON/OFF. Connecting MAX occurs during auto-restart, remote OFF and over-temp- the LINE-SENSE pin to the SOURCE pin disables all erature shutdown. In this mode of operation, the current four functions. The LINE-SENSE pin is typically used for source is switched on and off with an effective duty cycle of line sensing by connecting a resistor from this pin to the approximately 35%. This duty cycle is determined by the rectified DC high voltage bus to implement OV, UV and ratio of CONTROL pin charge (I ) and discharge currents DC reduction with line voltage. In this mode, the value C MAX (I and I ). This current source is turned off during normal of the resistor determines the line OV/UV thresholds, and CD1 CD2 operation when the output MOSFET is switching. The effect the DC is reduced linearly with rectified DC high voltage MAX of the current source switching will be seen on the DRAIN starting from just above the UV threshold. The pin can voltage waveform as small disturbances and is normal. also be used as a remote ON/OFF and a synchronization input. Refer to Table 2 for possible combinations of the
Using Feature Pins
functions with example circuits shown in Figure 16 through
FREQUENCY (F) Pin Operation
Figure 40. A description of specific functions in terms of The FREQUENCY pin is a digital input pin available in the the LINE-SENSE pin I/V characteristic is shown in Figure Y, R or F package only. Shorting the FREQUENCY pin to 11 (right hand side). The horizontal axis represents LINE- SOURCE pin selects the nominal switching frequency of SENSE pin current with positive polarity indicating currents
LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE*
Figure Number t 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Three Terminal Operation 3 Undervoltage 3 3 3 3 3 Overvoltage 3 3 3 3 3 Line Feed-Forward (DC ) 3 3 3 3 MAX Overload Power Limiting 3 External Current Limit 3 3 3 3 3 3 Remote ON/OFF 3 3 3 3 3 3 3 *This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible. Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations.
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Rev. R 10/20 www.power.com
resumes providing automatic recovery. A large hysteresis of 132 kHz (Figure 13), which is suited for most applications. 70 °C (typical) is provided to prevent overheating of the PC For other cases that may benefit from lower switching board due to a continuous fault condition. V is regulated frequency such as noise sensitive video applications, a C in hysteretic mode and a 4.8 V to 5.8 V (typical) sawtooth 66 kHz switching frequency (half frequency) can be waveform is present on the CONTROL pin while in thermal selected by shorting the FREQUENCY pin to the CONTROL shutdown. pin (Figure 14). In addition, an example circuit shown in Figure 15 may be used to lower the switching frequency
Bandgap Reference
from 132 kHz in normal operation to 66 kHz in standby All critical TOPSwitch-GX internal voltages are derived mode for very low standby power consumption. from a temperature-compensated bandgap reference. This reference is also used to generate a temperature-
LINE-SENSE (L) Pin Operation (Y, R and F Packages)
compensated current reference, which is trimmed to When current is fed into the LINE-SENSE pin, it works as a accurately set the switching frequency, MOSFET gate voltage source of approximately 2.6 V up to a maximum drive current, current limit, and the line OV/UV thresholds. current of +400 µA (typical). At +400 µA, this pin turns into TOPSwitch-GX has improved circuitry to maintain all of the a constant current sink. Refer to Figure 12a. In addition, a above critical parameters within very tight absolute and comparator with a threshold of 1 V is connected at the temperature tolerances. pin and is used to detect when the pin is shorted to the SOURCE pin.
High-Voltage Bias Current Source
This current source biases TOPSwitch-GX from the DRAIN There are a total of four functions available through the pin and charges the CONTROL pin external capacitance use of the LINE-SENSE pin: OV, UV, line feed-forward during start-up or hysteretic operation. Hysteretic operation with DC reduction, and remote ON/OFF. Connecting MAX occurs during auto-restart, remote OFF and over-temp- the LINE-SENSE pin to the SOURCE pin disables all erature shutdown. In this mode of operation, the current four functions. The LINE-SENSE pin is typically used for source is switched on and off with an effective duty cycle of line sensing by connecting a resistor from this pin to the approximately 35%. This duty cycle is determined by the rectified DC high voltage bus to implement OV, UV and ratio of CONTROL pin charge (I ) and discharge currents DC reduction with line voltage. In this mode, the value C MAX (I and I ). This current source is turned off during normal of the resistor determines the line OV/UV thresholds, and CD1 CD2 operation when the output MOSFET is switching. The effect the DC is reduced linearly with rectified DC high voltage MAX of the current source switching will be seen on the DRAIN starting from just above the UV threshold. The pin can voltage waveform as small disturbances and is normal. also be used as a remote ON/OFF and a synchronization input. Refer to Table 2 for possible combinations of the
Using Feature Pins
functions with example circuits shown in Figure 16 through
FREQUENCY (F) Pin Operation
Figure 40. A description of specific functions in terms of The FREQUENCY pin is a digital input pin available in the the LINE-SENSE pin I/V characteristic is shown in Figure Y, R or F package only. Shorting the FREQUENCY pin to 11 (right hand side). The horizontal axis represents LINE- SOURCE pin selects the nominal switching frequency of SENSE pin current with positive polarity indicating currents
LINE-SENSE AND EXTERNAL CURRENT LIMIT PIN TABLE*
Figure Number t 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Three Terminal Operation 3 Undervoltage 3 3 3 3 3 Overvoltage 3 3 3 3 3 Line Feed-Forward (DC ) 3 3 3 3 MAX Overload Power Limiting 3 External Current Limit 3 3 3 3 3 3 Remote ON/OFF 3 3 3 3 3 3 3 *This table is only a partial list of many LINE-SENSE and EXTERNAL CURRENT LIMIT pin configurations that are possible. Table 2. Typical LINE-SENSE and EXTERNAL CURRENT LIMIT Pin Configurations.
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Rev. R 10/20 www.power.com
