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FSDH321, FSDL321

2

Internal Block Diagram

Figure 2. Functional Block Diagram of FSDx321

8V/12V

2

6,7,8

1

3

Vref

Internal

Bias

S

Q

Q

R

OSC

Vcc

Vcc

I

DELAY

I

FB

V

SD

TSD

Vovp

Vcc

Vocp

S

Q

Q

R

R

2.5R

Vcc good

Vcc

Drain

Vfb

GND

AOCP

Gate

driver

5

Vstr

I

CH

Vcc good

V

BURL

/V

BURH

LEB

PWM

+

-

4

Ipk

Freq.

Modulation

V

BURH

Vcc

I

BUR(pk)

Burst

Normal

Soft

Start

Summary of Contents for FPS FSDH0265RN

Page 1: ...e Lock Out UVLO protection Leading Edge Blanking LEB an optimized gate turn on turn off driver Thermal Shut Down TSD protection Abnormal Over Cur rent Protection AOCP and temperature compensated preci sion current sources for loop compensation and fault protection circuitry When compared to a discrete MOSFET and controller or RCC switching converter solution the FSDx321 devices reduce total compon...

Page 2: ...agram of FSDx321 8V 12V 2 6 7 8 1 3 Vref Internal Bias S Q Q R OSC Vcc Vcc IDELAY IFB VSD TSD Vovp Vcc Vocp S Q Q R R 2 5R Vcc good Vcc Drain Vfb GND AOCP Gate driver 5 Vstr ICH Vcc good VBURL VBURH LEB PWM 4 Ipk Freq Modulation VBURH Vcc IBUR pk Burst Normal Soft Start ...

Page 3: ...using an internal 5uA current source This time delay prevents false triggering under transient conditions but still allows the protection mechanism to operate under true overload conditions 4 Ipk This pin adjusts the peak current limit of the Sense FET The feedback 0 9mA current source is diverted to the parallel combination of an internal 2 8kΩ resistor and any external resistor to GND on this pi...

Page 4: ... and 51 10 DIP Characteristic Symbol Value Unit Drain Pin Voltage VDRAIN 650 V Vstr Pin Voltage VSTR 650 V Drain Gate Voltage VDG 650 V Gate Source Voltage VGS 20 V Drain Current Pulsed 1 IDM 1 5 A Continuous Drain Current Tc 25 ID 0 7 A Continuous Drain Current Tc 100 ID 0 32 A Single Pulsed Avalanche Energy 2 EAS 10 mJ Supply Voltage VCC 20 V Feedback Voltage Range VFB 0 3 to VCC V Total Power D...

Page 5: ...quency fOSC FSDH321 90 100 110 KHz Switching Frequency Modulation fMOD 2 5 3 0 3 5 KHz Switching Frequency fOSC FSDL321 45 50 55 KHz Switching Frequency Modulation fMOD 1 0 1 5 2 0 KHz Switching Frequency Variation 2 fOSC 25 C Ta 85 C 5 10 Maximum Duty Cycle DMAX FSDH321 62 67 72 FSDL321 71 77 83 UVLO Threshold Voltage VSTART VFB GND 11 12 13 V VSTOP VFB GND 7 8 9 V Feedback Source Current IFB VFB...

Page 6: ...icable Programmable of default current limit Smaller transformer Allows power limiting constant over load power Allows use of larger device for lower losses and higher efficiency Frequency Modulation not applicable 3 0KHz 100KHz 1 5KHz 50KHz Reduces conducted EMI Burst Mode Operation Built into controller Built into controller same for both devices Improves light load efficiency Reduces power cons...

Page 7: ...0 100 150 Temp Normalized Frequency Modulation FMOD vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Maximum Duty Cycle DMAX vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Operating Supply Current IOP vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Start Threshold Voltage VSTART vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0...

Page 8: ...60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Peak Current Limit ILIM vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Start Up Charging Current ICH vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Burst Peak Current IBUR pk vs Ta 0 00 0 20 0 40 0 60 0 80 1 00 1 20 50 0 50 100 150 Temp Normalized Over Voltage Protection VOVP vs Ta ...

Page 9: ...ction circuits are fully inte grated inside the IC without external components the reliability is improved without increasing cost Once a fault condition occurs switching is terminated and the Sense FET remains off This causes Vcc to fall When Vcc reaches the UVLO stop voltage VSTOP 8V the protection is reset and the internal high voltage current source charges the Vcc capacitor via the Vstr pin W...

Page 10: ...T within 350ns after it is activated Figure 7 Abnormal Over Current Protection AOCP 4 4 Over Voltage Protection OVP In the event of a mal function in the secondary side feedback circuit or an open feedback loop caused by a soldering defect the current through the opto coupler transistor becomes almost zero refer to Figure 5 Then VFB climbs up in a similar manner to the over load situation forcing ...

Page 11: ...witching continues until the feedback voltage drops below VBURL 350mV At this point switching stops and the output voltages start to drop at a rate dependent on the standby current load This causes the feedback voltage to rise Once it passes VBURH 500mV switching resumes The feedback voltage then falls and the process repeats Burst mode operation alternately enables and disables switching of the p...

Page 12: ... pin forms a parallel resistance with the 2 8kΩ when the internal diodes are biased by the main current source of 900uA Figure 13 Peak Current Limit Adjustment For example FSDx321 has a typical Sense FET peak current limit ILIM of 0 7A ILIM can be adjusted to 0 5A by insert ing Rx between the Ipk pin and the ground The value of the Rx can be estimated by the following equations 0 7A 0 5A 2 8kΩ XkΩ...

Page 13: ...efficiency as well as lower audible noise Adjusting Sound Frequency Moving the fundamental frequency of noise out of 2 4 kHz range is the third method Generally humans are more sensi tive to noise in the range of 2 4 kHz When the fundamental frequency of noise is located in this range one perceives the noise as louder although the noise intensity level is identical Refer to Figure 14 Equal Loudnes...

Page 14: ...he pule by pulse peak current limit level ILIM is set to default value 0 7A by floating the Ipk pin 4 R102 and C101 clamp the DRAIN voltage of MOSFET below 650V under all conditions 1 Schematic Application Output power Input voltage Output voltage Max current PC Auxiliary Power Supply 10W DC 140 375V 5 0V 2 0A 10W PC Auxiliary Power Circuit T1 EE1625 7 10 D201 SB360 C201 1000uF 16V C203 470uF 16V ...

Page 15: ...ation Polyester Tape t 0 050m m 3Layers N 5V 10 7 0 55φ 1 12 Solenoid w inding Insulation Polyester Tape t 0 050m m 3Layers N M V cc 4 6 0 20φ 1 40 Solenoid w inding Insulation Polyester Tape t 0 050m m 3Layers N P 2 2 1 0 15φ 1 80 Solenoid w inding Insulation Polyester Tape t 0 050m m 3Layers N a 5 6 0 20φ 1 34 Solenoid w inding O uter Insulation P olyester Tape t 0 050m m 3Layers P in S p e c R ...

Page 16: ...1 4W D103 1N4937 PN Ultra Fast R203 2K 1 4W D201 SB360 Schottky R204 2K 1 4W ZD1 1N4746A 18V Zener ZD2 1N4746A 18V Zener Capacitor C101 10nF 630V Film IC C102 47uF 50V Electrolytic IC101 FSDH321 FPS C103 10uF 50V Electrolytic IC201 KA431 TL431 Voltage reference C104 22nF 50V Film IC301 H11A817A Opto Coupler C201 1000uF 16V Electrolytic C202 100nF 50V Ceramic C203 1uF 100V Electrolytic C204 470uF 1...

Page 17: ...FSDH321 FSDL321 17 Package Dimensions 8DIP ...

Page 18: ...FSDH321 FSDL321 18 Package Dimensions Continued 8LSOP ...

Page 19: ...9 Ordering Information Product Number Package Marking Code BVDSS fOSC RDS ON FSDH321 8DIP DH321 650V 100KHz 14Ω FSDL321 8DIP DL321 650V 50KHz 14Ω FSDH321L 8LSOP DH321 650V 100KHz 14Ω FSDL321L 8LSOP DL321 650V 50KHz 14Ω ...

Page 20: ...ructions for use provided in the labeling can be reasonably expected to result in a significant injury of the user 2 A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness www fairchildsemi com DISCLAIMER FAIRCHILD SEMICONDUCTOR RE...

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