FAN100 datasheet(8/21 Pages) FAIRCHILD

Numer części	FAN100

Szczegółowy opis	Design and Application of Primary-Side Regulation (PSR) PWM Controller

Download	21 Pages

Scroll/Zoom	100%

Producent	FAIRCHILD [Fairchild Semiconductor]

Strona internetowa	http://www.fairchildsemi.com

Logo

8 / 21 page

AN-6067

APPLICATION NOTE

www.fairchildsemi.com

Rev. 1.0.1 • 1/26/10

8

Startup Circuitry

When the power is activated, the input voltage charges the

hold-up capacitor (C1) via the startup resistors, as shown in

Figure 20. As the voltage (VDD) reaches the startup voltage

threshold (VDD-ON), the PSR controller activates and drives

the entire power supply.

DD

V

GND

PSR

Controller

C1

D1

Vdc

IN

R

D_ON

T

Figure 20. Single-Step Circuit Connected to the

PSR Controller

The power-on delay is determined as follows:

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

⋅

−

⋅

−

⋅

−

=

−

IN

ST

DD

ac

ON

DD

IN

ON

D

R

I

V

C

R

T

2

1

ln

1

_

(2)

where I

DD-ST is the startup current of the PSR controller.

Due to the low startup current, a large RIN value, such as

1.5M

Ω can be used. With a hold-up capacitor of 4.7µF, the

power-on delay TD_ON is less than 3s for a 90VAC input.

If a shorter startup time is required, a two-step startup

circuit, as shown in Figure 21, is recommended. In this

circuit, a smaller C1 capacitor can be used to decrease

startup time without a need for a smaller startup resistor

(RIN) and increase the power dissipation on the RIN resistor.

The energy supporting the PSR controller after startup is

mainly from a larger capacitor C2.

DD

V

GND

PSR

Controller

C1

Vdc

IN

R

D_ON

T

C2

Figure 21. Two Steps of Providing Power to the

PSR Controller

The maximum power dissipation of RIN is:

(

)

IN

dc

IN

DD

dc

MAX

R

V

R

V

P

IN

2

max

,

2

max

,

≅

−

=

(3)

where Vdc,max is the maximum rectified input voltage.

Take a wide-ranging input (90VAC~264VAC) as an example,

Vdc =100V~380V:

mW

P

MAX

RIN

96

10

5

.

1

380

6

2

,

≅

×

=

(4)

Built-in Slope Compensation

The sensed voltage across the current sense resistor is used

for peak-current-mode control and cycle-by-cycle current

limiting. Within every switching cycle, the PSR controller

produces a positively sloped, synchronized ramp signal. The

built-in slope compensation function improves power supply

stability and prevents peak-current-mode control from

causing sub-harmonic oscillations.

Leading Edge Blanking (LEB)

Each time the MOSFET is powered on, a spike, induced by

the diode reverse recovery and by the output capacitances of

the MOSFET and diode, appears on the sensed signal. To

avoid premature termination of the MOSEFT, a leading-

edge blanking time is introduced in the PSR controller.

During the blanking period, the current-limit comparator is

disabled and unable to switch off the gate driver.

Under-Voltage Lockout (UVLO)

The power-on and off thresholds of the PSR controller are

fixed at 16V/5V. During startup, the hold-up capacitor must

be charged to 16V through the startup resistor to enable PSR

controller. The hold-up capacitor continues to supply VDD

until power can be delivered from the auxiliary winding of

the main transformer (VDD must not drop below 5V during

this startup process). This UVLO hysteresis window ensures

that the hold-up capacitor can adequately supply VDD during

startup.

VDD Over-Voltage Protection (OVP)

VDD over-voltage protection prevents damage due to over-

voltage conditions. When VDD exceeds 28V due to abnormal

conditions, PWM output is turned off. Over-voltage

conditions are usually caused by open feedback loops.

Over-Temperature Protection (OTP)

The PSR controller has a built-in temperature sensing circuit

to shut down the PWM output if the junction temperature

exceeds 145°C. When the PWM output shuts down, the VDD

voltage gradually drops to the UVLO voltage. Some of the

internal circuits shut down and VDD gradually starts

Podobny numer części - FAN100

Producent	Numer części	Arkusz danych	Szczegółowy opis
Fairchild Semiconductor	FAN100	513Kb / 14P	Primary-Side-Control PWM Controller
	FAN100	517Kb / 16P	Primary-Side-Control PWM Controller
	FAN100MY	513Kb / 14P	Primary-Side-Control PWM Controller
	FAN100MY	517Kb / 16P	Primary-Side-Control PWM Controller
	FAN100	517Kb / 16P	Primary-Side-Control PWM Controller

More results

Podobny opis - FAN100

Producent	Numer części	Arkusz danych	Szczegółowy opis
Fairchild Semiconductor	FAN103	667Kb / 16P	Primary-Side-Regulation PWM Controller (PWM-PSR)
ON Semiconductor	FL663	406Kb / 15P	Primary-Side-Regulation PWM Controller June 2015 Rev. 1.0
Fairchild Semiconductor	FAN103	952Kb / 16P	Primary-Side-Regulation PWM Controller
List of Unclassifed Man...	DP2525	490Kb / 11P	Low Cost Primary Side Regulation(PSR) PWM Power Switch Rev.2.0
ON Semiconductor	FL7740	657Kb / 16P	Constant-Voltage Primary-Side-Regulation PWM Controller April 2017 - Rev. P0
	FL6630	453Kb / 14P	Single-Stage Primary-Side-Regulation PWM Controller May 2015 Rev. 1.0
	FL7740	344Kb / 14P	Constant-Voltage Primary-Side-Regulation PWM Controller February 2018 - Rev. 3
	FL7734	380Kb / 14P	Single-Stage Primary-Side-Regulation PWM Controller November 2014 Rev. 1.0
	FL7730	896Kb / 15P	Single-Stage Primary-Side-Regulation PWM Controller October 2012 Rev. 1.0.8
	FAN1080M6X	415Kb / 19P	Offline Primary-Side-Regulation (PSR) Quasi-Resonant Valley Switch Controller June, 2019 ??Rev. 2

More results

FAN100 Arkusz danych(PDF) 8 Page - Fairchild Semiconductor

FAN100 Arkusz danych(HTML) 8 Page - Fairchild Semiconductor

Podobny numer części - FAN100

Podobny opis - FAN100

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Arkusz danych Pobierz

Link URL