Richtek R7730GE Schematic [ru]

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Preliminary

R7730

Burst Triple-Mode PWM Flyback Controller

General Description

The R7730 is a high-performance, low cost, low startup current, current mode PWM controller with burst triplemode to support green mode power saving operation. The R7730 integrates functions of soft-start, Under VoItage Lockout (UVLO), Leading Edge Blanking (LEB), Over Temperature Protection (OTP), internal slope compensation. It provides the users a superior AC/DC power application of higher efficiency, low external component counts and lower cost solution.

To protect the external power MOSFET from being damaged by supply over voltage, the R7730 output driver is clamped at 12V. Furthermore, R7730 features fruitful protections like OLP (Over Load Protection) ,OVP (Over Voltage Protection) to eliminate the external protection circuits and provide reliable operation. R7730 is available in SOT-23-6 package.

Features

zVery Low Start-Up Current (<30uA)

z10/14V UVLO

zSoft Start Function

zCurrent Mode Control

zInternal Leading-Edge Blanking

zBuilt-in Slope Compensation

zBurst Triple-Mode PWM for Green-Mode

zCycle-by-Cycle Current Limiting

zFeedback Open Protection

zOutput Over Voltage Protection

zOver Temperature Protection

zOver Load Protection

zSoft Driving for Reducing EMI

zHigh Noise Immunity

zOpto Coupler Short Protection

zRoHS Compliant and Halogne Free

Applications

zAdaptor and Battery Charger

zATX Standby Power

zSet Top Boxes (STB)

zDVDand CD(R)

zTV/Monitor Standby Power

zPC Peripherals

Typical Application Circuit

AC Mains

VO+

 

(90V to 265V)

 

 

VO-

RT

VDD

 

R7730

COMP

 

GATE

GND

CS

DS7730-00 May 2008

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1

R7730

 

 

 

 

 

 

Preliminary

Ordering Information

 

 

 

 

 

 

 

R7730

 

 

 

 

 

 

Package Type

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E : SOT-23-6

 

 

 

 

 

 

 

Operating Temperature Range

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G : Green (Halogen Free with Commer-

 

 

 

 

 

 

 

cial Standard)

Note :

Richtek Green products are :

`RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes.

`100% matte tin (Sn) plating.

Marking Information

For marking information, contact our sales representative directly or through a Richtek distributor located in your area, otherwise visit our website for detail.

Pin Configurations

(TOP VIEW)

GATE VDD CS

6 5 4

1 2 3

GND COMP RT

SOT-23-6

Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark from left to right.

www.richtek.com

DS7730-00 May 2008

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Preliminary

R7730

Function Block Diagram

 

 

 

 

OVP +

VDD

 

 

 

 

POR

-

27V

 

 

Shutdown

OTP

 

 

 

 

Logic

 

 

+

 

 

 

 

 

 

 

Brown out

 

 

 

UVLO

-

14V/10V

sensing

 

 

 

 

 

 

COMP open

 

Counter

 

 

Bias &

 

 

 

 

sensing

 

 

 

 

Bandgap

OLP

 

 

Oscillator

 

 

Constant

SS

 

 

 

 

RT

 

 

Dmax

 

 

Power

 

 

 

 

 

 

 

 

 

 

 

Soft

 

 

 

 

S

 

Driver

 

 

 

 

 

 

 

 

 

-

 

Q

GATE

COMP

 

 

-

R

 

 

 

 

 

+

 

 

 

 

 

 

PWM

 

 

 

CS

Slope

comparator

 

 

 

 

 

 

 

 

Ramp

 

 

 

 

COMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Burst

 

VBURL

LEB

X3

 

 

Triple Mode

 

VBURH

 

 

 

 

VDD

 

 

 

 

 

 

 

 

 

 

 

 

GND

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

GND

Ground.

2

COMP

Comparator Input Pin. By connecting a photo-coupler to this pin, the peak

current set point is adjusted accordingly to the output power requirement.

 

 

3

RT

Set the switching frequency by connecting a resistor to GND.

4

CS

Primary Current Sense Pin.

5

VDD

IC Power Supply Pin.

6

GATE

Gate driver output to drive the external MOSFET.

DS7730-00 May 2008

www.richtek.com

3

R7730

Preliminary

Absolute Maximum Ratings

(Note 1)

z Supply Input Voltage, VDD -------------------------------------------------------------------------------------------

30V

z GATE Pin ----------------------------------------------------------------------------------------------------------------

20V

z FB, RT, COMP, CS Pin ----------------------------------------------------------------------------------------------

6.5V

z IDD -------------------------------------------------------------------------------------------------------------------------

10mA

z Power Dissipation, PD @ TA = 25°C

 

SOT-23-6 ----------------------------------------------------------------------------------------------------------------

0.4W

z Package Thermal Resistance (Note 4)

 

z SOT-23-6, θJA -----------------------------------------------------------------------------------------------------------

250°C/W

z Junction Temperature -------------------------------------------------------------------------------------------------

150°C

z Lead Temperature (Soldering, 10 sec.) ---------------------------------------------------------------------------

260°C

z Storage Temperature Range ----------------------------------------------------------------------------------------

−65°C to 150°C

z ESD Susceptibility (Note 2)

 

HBM (Human Body Mode) ------------------------------------------------------------------------------------------

4kV

MM (Machine Mode) --------------------------------------------------------------------------------------------------

250V

Recommended Operating Conditions (Note 3)

z Supply Input Voltage, VDD -------------------------------------------------------------------------------------------

12V to 25V

z Operating Frequency -------------------------------------------------------------------------------------------------

50k to 130kHz

z Junction Temperature Range ----------------------------------------------------------------------------------------

−40°C to 125°C

z Ambient Temperature Range ----------------------------------------------------------------------------------------

−40°C to 85°C

Electrical Characteristics

(VDD = 15V, RT = 100kΩ, TA = 25°C, unless otherwise specified)

Parameter

Symbol

Conditions

 

Min

Typ

Max

 

Unit

VDD Section

 

 

 

 

 

 

 

 

VDD Over Voltage Protection Level

VOVP

 

 

25.5

27

28.5

 

V

On Threshold Voltage

VTH_ON

 

 

13

14

15

 

V

 

 

 

 

 

 

 

 

 

VDD On/Off Hysteresis

VDD_hys

 

 

3

4

5

 

V

Start-up Current

IDD-ST

VDD = VTH_ON – 0.1V

 

--

20

30

 

uA

Operating Current

IDD-OP

VDD = 15V, RT = 100kΩ,

--

1.1

2.2

 

mA

GATE = Open, VCOMP

= 2.5V

 

 

 

 

 

 

 

 

VDD Hold-up Mode Hysteresis

VDD_hys

VCOMP < 1.6V

 

--

11.5

--

 

V

Ending Level

 

 

 

 

 

 

 

 

 

 

VDD Hold-up Mode Entry Level

VDD_Low

VCOMP < 1.6V

 

--

11

--

 

V

VDD Clamp Voltage

VDD_Clamp

 

 

--

29

--

 

V

Oscillator Section (RT pin)

 

 

 

 

 

 

 

 

Normal PWM Frequency

fOSC

RT = 100kΩ

 

60

65

70

 

kHz

Maximum Duty Cycle

DMAX

 

 

70

75

80

 

%

Frequency Variation Versus VDD

fDV

VVDD = 12V to 25V

 

--

--

2

 

%

Deviation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

To be continued

 

 

 

 

 

 

 

 

 

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DS7730-00

May 2008

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