Richtek R7735AGE, R7735AGN, R7735GGE, R7735GGN, R7735HGE, R7735HGN, R7735LGE, R7735LGN, R7735RGE, R7735RGN Schematics

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®

R7735

High Performance Enhanced Quadruple Mode PWM

Flyback Controller

General Description

R7735 series is the successor of R7732/3 and fully compatible with most of SOT-23-6 / DIP-8 product so far in the market. It has enhanced quadruple mode PWM controller and owns excellent green power performance, especially under light load and no load conditions. It focuses on "easy to design" in different applications and it will save both design effort and external components.

Besides the general features shown in the Features section, R7735 covers wide protection options, such as internal Over Load Protection (OLP) and Over Voltage Protection (OVP) to eliminate the external protection circuits. Moreover, it also features Secondary Rectifier Short Protection (SRSP) and CS pin open protection. This protection will make the PSU design for reliability and safety easier.

R7735 is designed for power supply such as NB adaptor which is a very cost effective and compact design. The precise external OVP and Over Temperature Protection (OTP) can be implemented by very simple circuit. The start-up resistors can also be replaced by bleeding resistors to save power loss and component count.

Ordering Information

R7735

(B)* (* : See Version Table)

Package Type

E : SOT-23-6

N : DIP-8 (R7735G Only)

Lead Plating System

G : Green (Halogen Free and Pb Free)

R7735 Version (Refer to Version Table)

Note :

Richtek 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.

Features

zNo Load Input Power Under 100mW

zAccurate Over Load Protection

zUVLO 9V/14V

zSoft Start Function

zCurrent Mode Control

zBuilt-in Slope Compensation

zInternal Leading Edge Blanking

zPWM Quadruple Mode for Green-Mode

zExcellent Green Power Performance

zCycle-by-Cycle Current Limit

zInternal Over Voltage Protection

zSecondary Rectifier Short Protection

zOpto-Coupler Short Protection

zFeedback Open-Loop Protection

zCS Pin Open Protection

zBuilt-in Jittering Frequency

zBuilt-in PRO Pin for External Arbitrary OVP/OTP

zSoft Driving for EMI Noise

zHigh Noise Immunity

zRoHS Compliant and Halogen Free

Application

zSwitching AC/DC Adaptor

zDVD Open Frame Power Supply

zSet-Top Box (STB)

zATX Standby Power

zTV/Monitor Standby Power

zPC Peripherals

zNB Adaptor

Marking Information

For marking information, contact our sales representative directly or through a Richtek distributor located in your area.

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

R7735-03 September 2012

www.richtek.com

 

1

R7735

Pin Configurations

(TOP VIEW)

 

 

 

 

 

 

 

 

 

GND COMP NC

PRO

GATE VDD CS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

8

7

 

 

6

 

5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6

5

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

3

 

 

 

 

 

 

2

 

 

3

 

4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND COMP PRO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SOT-23-6

GATE VDD

NC

 

CS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DIP-8

 

 

 

 

 

R7735 Version Table

Version

R7735G

R7735R

R7735L

R7735A

R7735H

Frequency

65kHz

65kHz

65kHz

65kHz

100kHz

OLP Delay Time

56ms

56ms

56ms

28ms

36ms

Internal OVP(27V)

Auto Recovery

Auto Recovery

Latch

Latch

Auto Recovery

 

 

 

 

 

 

OLP & SRSP

Auto Recovery

Auto Recovery

Auto Recovery

Latch

Auto Recovery

 

 

 

 

 

 

PRO Pin High

Latch

Auto Recovery

Latch

Latch

Auto Recovery

PRO Pin Low

Auto Recovery

Latch

Latch

Latch

Latch

*: VSRSP_TH : Secondary Rectifier Short Protection (SRSP) triggered threshold. R7735XGE : VSRSP_TH = 1.7V, X = G/R/L/A

R7735HGE(B) : VSRSP_TH = 2.6V

Typical Application Circuit

AC Mains (90V to 265V)

PRO

VDD

GATE

 

 

R7735

 

COMP

 

CS

 

GND

 

NTC

 

 

Vo+

+

+

Vo-

#

 

# : See Application Information

 

 

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

R7735-03 September 2012

2

 

R7735

Functional Pin Description

Pin No.

Pin Name

Pin Function

 

 

SOT-23-6

DIP-8

 

 

 

 

 

 

1

8

GND

Ground.

 

 

 

 

2

7

COMP

Voltage Feedback. By connecting an opto-coupler to close control loop

and achieve the regulation.

 

 

 

 

 

 

 

3

5

PRO

For External Arbitrary OVP or OTP.

 

 

 

 

4

4

CS

Primary Current Sense.

 

 

 

 

5

2

VDD

Power Supply.

 

 

 

 

6

1

GATE

Gate Drive Output to Drive the External MOSFET.

 

 

 

 

--

3, 6

NC

No Internal Connection.

 

 

 

 

Function Block Diagram

 

 

 

 

 

 

 

VDD

 

VL_TH

Auto

Auto

 

 

 

IBIAS

 

+

 

 

 

 

-

Recovery

Recovery

OVP

+

 

PRO

 

27V

 

 

+

Latch

Latch

 

-

 

 

-

 

 

 

 

VH_TH

 

 

 

 

 

 

Secondary Rectifier Short

 

 

 

 

 

 

 

POR

 

 

VSRSP_TH

-

& CS Open Protection

Shutdown

 

 

 

+

 

 

Logic

UVLO

 

 

 

 

 

 

 

+

 

 

 

Brownout

 

 

 

9V/14V

 

 

Sensing

 

 

 

-

 

COMP Open

 

Counter

 

 

Bias &

 

 

 

 

 

 

 

Sensing

 

 

 

Bandgap

 

 

OLP

 

Oscillator

 

 

 

 

 

 

 

 

 

 

Constant

SS

Dmax

 

 

 

 

 

 

 

 

 

 

 

 

Power

 

 

 

 

Soft Driver

 

 

 

 

 

S

 

 

 

 

 

 

 

 

 

 

 

 

-

 

Q

GATE

COMP

 

 

 

-

R

 

 

 

 

 

 

+

 

 

 

 

 

 

 

PWM

 

 

 

CS

 

 

Slope

Comparator

 

 

 

 

 

 

 

 

 

 

 

Ramp

 

 

 

VCOMP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Quadruple Mode

 

VBURL

 

 

 

 

 

 

VBURH

 

LEB

X3

 

 

 

 

 

 

 

 

 

VDD

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND

 

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

 

R7735-03 September 2012

www.richtek.com

3

R7735

Absolute Maximum Ratings (Note 1)

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

−0.3V to 30V

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

−0.3V to 16.5V

z PRO, COMP, CS Pin ------------------------------------------------------------------------------------------------------

−0.3V to 6.5V

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

10mA

z Power Dissipation, PD @ TA = 25°C

 

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

0.400W

DIP-8--------------------------------------------------------------------------------------------------------------------------

0.714W

z Package Thermal Resistance (Note 2)

 

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

250°C/W

DIP-8, θJA --------------------------------------------------------------------------------------------------------------------

140°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 3)

 

HBM (Human Body Model) -----------------------------------------------------------------------------------------------

3kV

MM (Machine Model) ------------------------------------------------------------------------------------------------------

250V

Recommended Operating Conditions

(Note 4)

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

12V to 25V

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

−40°C to 125°C

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

−40°C to 85°C

Electrical Characteristics

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

 

Parameter

Symbol

Test Conditions

Min

Typ

 

Max

 

Unit

 

VDD Section

 

 

 

 

 

 

 

 

 

 

 

VDD Over Voltage Protection Level

VOVP

 

 

 

26

27

 

28

 

V

 

VDD Zener Clamp

VZ

 

 

 

29

--

 

--

 

V

 

On Threshold Voltage

VTH_ON

 

 

 

13

14

 

15

 

V

 

Off Threshold Voltage

VTH_OFF

 

 

 

8.5

9

 

9.5

 

V

 

VDD Holdup Mode Entry Point

VDD_LOW

VCOMP < 1.6V

 

 

9.5

10

 

10.5

 

V

 

VDD Holdup Mode Ending Point

VDD_HIGH

VCOMP < 1.6V

 

 

10

10.5

 

11

 

V

 

Latch-off Voltage

VLH

 

 

 

4.5

5.5

 

6.5

 

V

 

Latched Reset Voltage

VLH_RST

 

 

 

4

5

 

6

 

V

 

Start-up Current

IDD_ST

VDD = VTH_ON – 0.2V,

 

1

5

 

10

 

μA

 

TA= −40ºC to 100ºC

(Note 5)

 

 

 

 

 

 

 

 

 

 

 

 

Operating Supply Current

IDD_OP

VDD= 15V, VCOMP = 2.5V,

0.55

0.9

 

1.6

 

mA

 

GATE pin open

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Latch-off Operating Current

IDD_LH

TA= −40ºC to 100ºC

(Note 5)

2

--

 

8

 

μA

 

 

 

 

 

 

 

 

 

 

 

 

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

 

www.richtek.com

 

 

 

 

R7735-03

September 2012

4

 

 

 

 

 

 

 

 

 

 

R7735

 

Parameter

Symbol

Test Conditions

Min

Typ

Max

 

Unit

 

Oscillator Section

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Normal PWM Frequency

fOSC

R7735G/R/L/A

 

60

65

70

 

kHz

 

 

 

 

 

 

 

 

R7735H

 

92

100

108

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Frequency Reduction Mode

fFR_MIN

R7735G/R/L/A

 

18

22

--

 

kHz

 

Minimum Frequency

R7735H

 

--

25

--

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Maximum Duty Cycle

DCYMAX

 

 

70

75

80

 

%

 

PWM Frequency Jitter Range

f

 

 

--

±6

--

 

%

 

 

 

 

 

 

 

 

 

 

 

PWM Frequency Jitter Period

TJIT

For 65kHz

 

--

4

--

 

ms

 

Frequency Variation Versus

fDV

VDD= 12V to 25V

--

--

2

 

%

 

VDD Deviation

 

 

 

 

 

 

 

 

 

 

 

Frequency Variation Versus

fDT

TA= −30°C to 105°C

--

--

5

 

%

 

Temperature Deviation

(Note 5)

 

 

 

 

 

 

 

 

 

 

 

COMP Input Section

 

 

 

 

 

 

 

 

 

Open-Loop Voltage

VCOMP_OP

COMP pin Open

5.5

5.75

6

 

V

 

COMP Open-Loop Protection

 

R7735G/R/L

 

45

56

65

 

 

 

TOLP

 

 

 

 

 

 

 

 

R7735A

 

22

28

34

 

ms

 

Delay Time

 

 

 

 

 

R7735H

 

30

36

42

 

 

 

 

 

 

 

 

 

 

 

 

 

Short Circuit Current

IZERO

VCOMP= 0V

 

0.15

0.29

0.45

 

mA

 

Frequency Reduction Mode Entry

VFR_ET

 

 

2.85

3

3.15

 

V

 

Voltage

 

 

 

 

 

 

 

 

 

 

 

 

 

Frequency Reduction Mode

VFR_ED

R7735G/R/L/A

 

2.75

2.9

3.05

 

V

 

Ending Voltage

R7735H

 

2.65

2.8

2.95

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Current Sense Section

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Initial Peak Current Limitation

VCS_TH

 

 

0.68

0.7

0.72

 

V

 

Offset

 

 

 

 

Maximum Clamping Current Limit

VCS(MAX)

 

 

1.05

1.1

1.15

 

V

 

Leading Edge Blanking Time

tLEB

(Note 6)

 

150

250

350

 

ns

 

Internal Propagation Delay Time

tPD

(Note 6)

 

--

100

--

 

ns

 

Minimum On Time

tON(MIN)

 

 

250

350

450

 

ns

 

GATE Section

 

 

 

 

 

 

 

 

 

Rising Time

tR

VDD= 15V, CL= 1nF

60

125

140

 

ns

 

Falling Time

tF

VDD= 15V, CL= 1nF

25

40

65

 

ns

 

GATE Output Clamping Voltage

VCLAMP

VDD= 25V

 

12.1

14

15.9

 

V

 

PRO Interface Section

 

 

 

 

 

 

 

 

 

Pull Low Threshold

VL_TH

 

 

0.47

0.5

0.53

 

V

 

Pull High Threshold

VH_TH

 

 

3.5

3.8

4.1

 

V

 

Internal Bias Current

IBIAS

 

 

90

100

110

 

μA

 

Pull High Sinking Current

ISINK

(Note 7)

 

0.7

--

1.4

 

mA

 

 

 

 

 

 

 

 

 

 

 

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

 

 

R7735-03 September 2012

 

 

 

 

 

www.richtek.com

 

 

 

 

 

 

 

 

 

5

R7735

Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability.

Note 2. θJA is measured at TA = 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3. Note 3. Devices are ESD sensitive. Handling precaution is recommended.

Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. Guaranteed by design.

Note 6. Leading edge blanking time and internal propagation delay time are guaranteed by design.

Note 7. The sourcing current of PRO pin must be limited below 5mA. Otherwise it may cause permanent damage to the device.

Copyright ©2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

R7735-03 September 2012

6

 

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