DATASHEET SEARCH SITE | WWW.ALLDATASHEET.COM

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 11

Technical content

Features

 Frequency shuffling technology for improved EMC performance  Audio noise free operation  Extended burst mode control for improved efficiency and minimum standby power design  External programmable PWM switching  Internal synchronized slope compensation  Low VDD startup current and low operating current  Leading edge blanking on current sense input  Good protection coverage with auto self-recovery (UVLO/OVP/OCP/OLP)  Package: SOT-23-6

Applications

 Battery charger  Power adapter  Set-top box power supplies Figure 1. Package Type

Figure 2. Pin Configuration

1 GND Ground

5 VDD Chip DC power supply pin

6 GATE Totem-pole gate drive output for the power MOSFET

Table 1. Pin Description

Figure 3. Functional Block Diagram

December, 2013 Rev. 1.1 4/11 ©2013 Shaoxing Devechip Microelectronics Co., Ltd. www.sdc-semi.com Current Mode PWM Controller SDC4565

Ordering Information

SOT-23-6: J E1: Pb-free G1: Halogen-free TR: Tape Reel X X - X Package Temperature Range Part Number Marking ID Packing Type Pb-free Halogen-free Pb-free Halogen-free SOT-23-6 -40℃~85℃ SDC4565JTR-E1 SDC4565JTR-G1 4565 4565G Tape Reel SDC CONFIDENTIAL DOCUMENT

Table 2. Absolute Maximum Ratings Table 3. Recommended Operating Conditions

December, 2013 Rev. 1.1 6/11 ©2013 Shaoxing Devechip Microelectronics Co., Ltd. www.sdc-semi.com Current Mode PWM Controller SDC4565 Electrical Characteristics (Ta=25°C, unless otherwise specified) Parameter Symbol Condition Min Typ Max Unit Supply Voltage (VDD) VDD start up current ISTARTUP VDD =12.5V, RI=100k, Measure Leakage current into VDD - 3 20 uA Operation current IDD VDD=16V, RI=100k, VFB=3V - 1.4 - mA VDD under voltage lockout enter VUVLO(ON) - 7.2 8.2 9.2 V VDD under voltage lockout exit (recovery) VUVLO(OFF) - 13.5 14.5 15.5 V VDD zener clamp voltage VDD_CLAMP IVDD=10mA 30 32 34 V Feedback Input Section(FB Pin) FB open loop voltage VFB_OPEN - - 4.8 - V FB pin short circuit current IFB_SHORT Short FB pin to GND and Measure Current - 0.8 - mA Zero duty cycle fb threshold voltage zero VTH_0D VDD=16V, RI=100k - - 0.85 V Power limiting FB threshold voltage VTH_PL - - 3.7 - V Power limiting debounce time tD_PL - - 35 - ms Maximum duty cycle DCMAX VDD=16V, RI=100k, FB=3V, CS=0 70 80 90 % Current Sense Input(Sense Pin) Leading edge blanking time tBLANKING RI=100k - 300 - ns Over current detection and control delay tD_OC VDD=16V, CS>VTH_OC, FB=3.3V - 75 - ns Over current threshold voltage at zero duty cycle VTH_OC FB=3.3V, RI=100k 0.70 0.75 0.81 V Oscillator Normal oscillation frequency fOSC RI=100k 60 65 70 kHz Frequency temperature stability Δf TEMP VDD =16V,RI=100k, Frequency voltage stability ΔfVDD VDD= 12V~25V,RI=100k - 5 - % SDC CONFIDENTIAL DOCUMENT

Table 4. Electrical Characteristics

December, 2013 Rev. 1.1 8/11 ©2013 Shaoxing Devechip Microelectronics Co., Ltd. www.sdc-semi.com Current Mode PWM Controller SDC4565 Function Description The SDC4565 is a highly integrated PWM controller IC optimized for offline flyback converter applications in sub 60W power range. The extended burst mode control greatly reduces the standby power consumption and helps the design easily meet the international power conservation requirements. Startup Current and Start up Control Startup current of SDC4565 is designed to be very low so that VDD could be charged up above UVLO threshold level and device starts up quickly. A large value startup resistor can therefore be used to minimize the power loss yet provides reliable startup in application. Operating Current The operating current of SDC4565 is low at 1.4mA. Good efficiency is achieved with SDC4565 low operating current together with extended burst mode control features. Frequency shuffling for EMI improvement The frequency shuffling /jittering (switching frequency modulation) is implemented in SDC4565. The oscillation frequency is modulated with a random source so that the tone energy is spread out. The spread spectrum minimizes the conduction band EMI and therefore reduces system design challenge. Extended Burst Mode Operation Under zero load or light load condition, meet of the power dissipation in a switching mode power supply is from switching loss on the MOSFET transistor, the core loss of the transformer and the loss on the snubber circuit. The magnitude of power loss is in proportion to the number of switching events withi n a fixed period of time, Reducing switching frequence leads to the reduction on power loss and thus conserves the energy. SDC4565 self adjusts the switching mode according to the loading condition. Under no load to light/medium load condition, the FB input drops below burst mode threshold level, device enters burst mode control. The gate drive output switches only when VDD voltage drops below a preset level and FB input is active to output an on state, otherwise the gate drive remains at off state to minim ize the switching loss and reduces the standby power consumption to the greatest extend. The frequency control also eliminates the audio noise at any loading conditions. Oscillator Operation A resistor connected between RI and GND sets the constant current source to charge/discharge the internal cap and t hus the PWM oscillator frequency is determined. The relationship between RI and switching frequency follows the below equation within the specified RI in kΩ range at nominal loading operational condition. )()(RI 6500f kHzkosc Ω= Current Sensing and Leading Edge Blanking Cycle-by-cycle current limiting is offered in SDC4565 current mode PWM control. The switch current is detected by a sense resistor into the sense pin. An internal leading edge blanking circuit chops off the sense voltage spike at initial MOSFET on state due to snubber diode reverse recovery so that the external RC filtering on sense input is no longer required. The current limit comparator is disabled and thus cannot turn off the external MOSFET during the blanking period. PWM duty cycle is determined by the current sense input voltage and the FB input voltage. Internal Synchronized Slope Compensation Built-in slope compensation circuit adds voltage ramp onto the current sense input voltage for PWM generation. This greatly improves the close loop stability at CCM and SDC CONFIDENTIAL DOCUMENT

while too strong gate drive output compromises the EMI. higher than expected VDD input. clamp, under voltage lockout on VDD (UVLO). Figure 4. Typical Application

December, 2013 Rev. 1.1 10/11 ©2013 Shaoxing Devechip Microelectronics Co., Ltd. www.sdc-semi.com Current Mode PWM Controller SDC4565 Package Dimension SOT-23-6 Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 1.050 1.250 0.041 0.049 A1 0.000 0.100 0000 0.004 A2 1.050 1.150 0.041 0.045 b 0.300 0.500 0.012 0.020 c 0.100 0.200 0.004 0.008 D 2.820 3.020 0.111 0.119 E 1.500 1.700 0.059 0.067 E1 2.650 2.950 0.104 0.116 e 0.950(BSC) 0.037(BSC) e1 1.800 2.000 0.071 0.079 L 0.300 0.600 0.012 0.024 θ 0° 8° 0° 8° SDC CONFIDENTIAL DOCUMENT

December, 2013 Rev. 1.1 11/11 ©2013 Shaoxing Devechip Microelectronics Co., Ltd. www.sdc-semi.com Current Mode PWM Controller SDC4565 Shaoxing Devechip Microelectronics Co., Ltd. http://www.sdc-semi.com/ IMPORTANT NOTICE Information in this document is provided solely in connection with Shaoxing Devechip Microelectronics Co., Ltd. (abbr. SDC) products. SDC reserves the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at anytime, without notice . SDC does not assume any responsibility for use of any its products for any particular purpose, nor does SDC assume any liability arising out of the application or use of any its products or circuits. SDC does not convey any license under its patent rights or other rights nor the rights of others. © 2013 Devechip Microelectronics - All rights reserved Contact us: Headquarters of Shaoxing Address: Tian Mu Road, No13, Shaoxing city, Zhejiang province, China Zip code: 312000 Tel: (86) 0575-8861 6750 Fax: (86) 0575-8862 2882 Shenzhen Branch Address: 22A, Shangbu building, Nan Yuan Road, No.68, Futian District, Shenzhen city, Guangdong province, China Zip code: 518031 Tel: (86) 0755-8366 1155 Fax: (86) 0755-8301 8528 SDC CONFIDENTIAL DOCUMENT