SD4840

SD4840 SILAN | Alldatasheet

Document overview

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Technical content

SD4840/4841/4842/4843/4844 CURRENT MODE PWM CONTROLLER WITH BUILT-IN HIGH VOLTAGE MOSFET

DESCRIPTION

SD4840/4841/4842/4843/4844 is a current mode PWM controller with low standby power and low start current for power switch. In standby mode, the circuit enters burst mode to reduce the standby power dissipation. The switch frequency is 67KHz with ±2.5 KHz jitter frequency for low EMI. The stress on transformer during power on is reduced by the built- in 15ms soft start circuit to avoid the saturation of transformer. SD4840/4841/4842/4843/4844 includes under voltage lock-out, over voltage protection, leading edge blanking, over current protection and the temperature protection. The circuit will restart automatically until the system is normal after the protection is active.

FEATURES

HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 1 of 11

ORDERING INFORMATION

Part No. Package Marking SD4840P67K65 SD4840P67K65 SD4841P67K65 SD4841P67K65 SD4842P67K65 SD4842P67K65 SD4843P67K65 SD4843P67K65 SD4844P67K65 DIP-8-300-2.54 SD4844P67K65 Note: P denotes it is available in DIP8 package, 67k denotes 67KHz, and 65 denotes withstand voltage is 650V. * Lower start-up current (Typ.6μA) * Frequency jitter for low EMI * Overcurrent protection * Overvoltage protection * Undervoltage lockout * Built-in temperature protection * Built-in high voltage MOSFET * Auto restart mode * Built-in soft start * Burst mode operation * Cycle by cycle current limit

APPLICATIONS

• Switch power

SD4840/4841/4842/4843/4844 TYPICAL OUPUT POWER CAPABILITY 190~265VAC 85~265VAC Device Adapter Open Adapter Open SD4840P67K65 7W 9W 5W 7.2W SD4841P67K65 10W 14W 8W 12W SD4842P67K65 12W 17W 10W 14W SD4843P67K65 14W 19W 12W 15W SD4844P67K65 16W 21W 14W 18W BLOCK DIAGRAM HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 2 of 11 ABSOLUTE MAXIMUM RATING Characteristics Symbol Rating Unit Drain-Gate Voltage (RGS=1MΩ) VDGR 650 V Gate-Source (GND) Voltage VGS ±30 V SD4840P67K65 4 SD4841P67K65 6 SD4842P67K65 8 SD4843P67K65 11 Drain Current Pulse (note1) SD4844P67K65 IDM A + - + -

SD4840/4841/4842/4843/4844 HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 3 of 11 Characteristics Symbol Rating Unit SD4840P67K65 1 SD4841P67K65 1.5 SD4842P67K65 2 SD4843P67K65 3 Continuous Drain Current (Tamb=25°C) SD4844P67K65 ID A SD4840P67K65 15 SD4841P67K65 30 SD4842P67K65 68 SD4843P67K65 140 Signal Pulse Avalanche Energy(note 2) SD4844P67K65 EAS 200 mJ Power Supply Voltage VCC,MAX 21 V Analog Input Voltage VFB -0.3~ VSD V PD 1.5 W Total Power Dissipation Darting 0.017 W/°C Operating Junction Temperature TJ +160 °C Operating Temperature Tamb -25~ +85 °C Storage Temperature TSTG -55~+150 °C Note: 1. Pulse width is limited by maximum junction temperature. 2. L=51mH, starting Tj=25°C ELECTRICAL CHARACTERISTICS (sense MOSFET part, unless otherwise specified, Tamb=25°c) Characteristics Symbol Test conditions Min. Typ. Max. Unit Drain-Source Breakdown Voltage BVDSS VGS=0V, ID=50μA 650 -- -- V VDS=Max. VGS=0V -- -- 50 μA Zero Gate Voltage Drain Current IDSS VDS=0.8Max. VGS=0V Tamb=125°C -- -- 200 μA SD4840P67K65 -- 14.0 16.8 SD4841P67K65 -- 8.0 9.6 SD4842P67K65 -- 5.0 6.0 SD4843P67K65 -- 4.0 4.8 Static Drain- Source On Resistance SD4844P67K65 RDS(ON) VGS=10V, ID=0.5A -- 3.0 3.6 Ω SD4840P67K65 -- 210 -- SD4841P67K65 -- 250 -- SD4842P67K65 -- 550 -- SD4843P67K65 -- 640 -- Input Capacitance SD4844P67K65 Ciss VGS=0V, VDS=25V, f=1MHz -- 840 -- pF SD4840P67K65 -- 18 -- SD4841P67K65 -- 25 -- SD4842P67K65 -- 38 -- SD4843P67K65 -- 40 -- Output Capacitance SD4844P67K65 Coss VGS=0V, VDS=25V, f=1MHz -- 44 -- pF

SD4840/4841/4842/4843/4844 HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 4 of 11 Characteristics Symbol Test conditions Min. Typ. Max. Unit SD4840P67K65 -- 8 -- SD4841P67K65 -- 10 -- SD4842P67K65 -- 17 -- SD4843P67K65 -- 30 -- Reverse Transfer Capacitance SD4844P67K65 Crss VGS=0V, VDS=25V, f=1MHz -- 40 -- pF SD4840P67K65 -- 10 -- SD4841P67K65 -- 12 -- SD4842P67K65 -- 20 -- SD4843P67K65 -- 33 -- Turn On Delay Time SD4844P67K65 td(ON) VDD=0.5BVDSS, ID=25mA -- 40 -- nS SD4840P67K65 -- 3 -- SD4841P67K65 -- 4 -- SD4842P67K65 -- 15 -- SD4843P67K65 -- 19 -- Rise Time SD4844P67K65 tr VDD=0.5BVDSS, ID=25mA -- 25 -- nS SD4840P67K65 -- 27 -- SD4841P67K65 -- 30 -- SD4842P67K65 -- 55 -- SD4843P67K65 -- 70 -- Turn Off Delay Time SD4844P67K65 td(OFF) VDD=0.5BVDSS, ID=25mA -- 90 -- nS SD4840P67K65 -- 8 -- SD4841P67K65 -- 10 -- SD4842P67K65 -- 25 -- SD4843P67K65 -- 32 -- Fall Time SD4844P67K65 tf VDD=0.5BVDSS, ID=25mA -- 42 -- nS ELECTRICAL CHARACTERISTICS (unless otherwise specified, Tamb=25°c) Characteristics Symbol Test conditions Min. Typ. Max. Unit Undervoltage Section Start Threshold Voltage Vstart 11 12 13 V Stop Threshold Voltage Vstop 7 8 9 V Oscillator Section Oscillate Frequency FOSC 61 67 73 KHz Frequency Jitter FMOD ±1.5 ±2.0 ±2.5 KHz Frequency Change With Temperature Maximum Duty Cycle Dmax 72 77 82 % Feedback Section Feedback Source Current IFB 0V≤VFB≤3V 0.7 0.9 1.1 mA Shutdown Feedback Voltage VSD 5.5 6.0 6.5 V Shutdown Delay Current Idelay 5V≤VFB≤VSD 3.5 5.0 6.5 μA

SD4840/4841/4842/4843/4844 HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 5 of 11 Characteristics Symbol Test conditions Min. Typ. Max. Unit Built-in Soft Start Time ts VFB=4V 10 15 20 ms Current Limit SD4840P67K65 0.53 0.60 0.67 SD4841P67K65 0.67 0.75 0.83 SD4842P67K65 0.80 0.90 1.00 SD4843P67K65 1.10 1.20 1.30 Peak Current Limit SD4844P67K65 Iover Max. inductor current 1.35 1.50 1.65 A Burst mode Burst Mode High Voltage VBURH 0.4 0.5 0.6 V Burst Mode Low Voltage VBURL 0.25 0.35 0.45 V Protection Section Overvoltage Protection Vovp 18 19 -- V Thermal Shutdown Tsd 125 140 -- °C Leading-edge Blanking Time TLEB 200 -- -- ns Total Standby Current Start Current Istart VCC=11V -- 6 20 μA Supply Current (Control Part) Iop VCC=12V 1 3 5 mA PIN CONFIGURATION PIN DESCRIPTION Pin No. Pin Name I/O Function description 1 SGND - Ground for control part. 2 PGND - MOSFET Ground. 3 VCC - Power supply pin. 4 FB I/O Feedback input pin. 5 NC - Not connected. 6,7,8 Drain O Drain pins.

SD4840/4841/4842/4843/4844 FUNCTION DESCRIPTION SD4840/4841/4842/4843/4844 is designed for off-line SMPS, consisting of high voltage MOSFET, optimized gate driver and current mode PWM controller which includes frequency oscillator and various protections such as undervoltage lockout, overvoltage protection, overcurrent protection and overtemperature protection. Frequency jitter generated from oscillator is used to lower EMI and built-in soft start is used for reducing transformer stress when the circuit is powered on. Burst mode is adopted during light load to lower standby power dissipation, and function of lead edge blanking eliminates the MOSFET error shutdown caused by interference through minimizing MOSFET turning on time. Few peripheral components are needed for higher efficiency and higher reliability and it is suitable for flyback converter and forward converter. 1. Under Voltage Lockout and Self-Start At the beginning, the capacitor connected to pin VCC is charged via start resistor by high voltage AC and the circuit start to work if voltage at Vcc is 12V. The output is shutdown if there is any protection during normal operation and Vcc is decreased because of powering of auxiliary winding. The whole control circuit is shutdown if voltage at Vcc is 8V below to lower current dissipation and the capacitor is recharged for restarting. 2. Built-In Soft Start Circuit In order to decrease transformer stress and to prevent its saturation during power on, it is recommended to increase peak current value of primary winding slowly by increasing feedback voltage slowly. After about 15ms, the soft start is completed and it has no effect on normal operation. HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 6 of 11

SD4840/4841/4842/4843/4844 3. Frequency Jitter The oscillation frequency is kept changed for low EMI and decreasing radiation on one frequency. The oscillation frequency changes within a very small range to simplify EMI design. The rule of frequency changing: change from 65KHz to 69KHz. 4. Light Load Mode Working in this mode to reduce power dissipation. It works normally when FB is 500mV above and during 350mV<FB <500mV, there are two different conditions: when FB changes from low to high, there is no action for switch and it is the same with condition of FB lower than 350mV; the other is that FB changes form high to low, comparison value is increased for increasing turning on time to decrease switch loss. For this mode, during FB changes form high to low, the output voltage increases (increasing speed is decided by load) because of the high comparison value to decrease FB until it is 350mV below; when FB <350mV, there is no action for switch and output voltage decrease (decreasing speed is also decided by load) to increase FB. This is repeated to decrease action of switch for lower power dissipation. 5. Leading Edge Blanking For this current-controlled circuit, there is pulse peak current during the transient of switch turning on and there is an error operation if the current is sampled during this time. And leading edge blanking is adopted to eliminate this error operation. The output of PWM comparator is used for controlling shutdown after the leading edge blanking if there is any output drive. HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 7 of 11

SD4840/4841/4842/4843/4844 HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 8 of 11 6. Over Voltage Protection The output is shutdown if voltage at Vcc exceeds the threshold and this state is kept until the circuit is powered on reset. 7. Overload Protection FB voltage increase if there is overload and the output is shutdown when FB voltage is up to the feedback shutdown voltage. This state is kept until the circuit is powered on reset. 8. Peak Current Limit Cycle By Cycle During each cycle, the peak current value is decided by the comparison value of the comparator, which will not exceed the peak current limited value to guarantee the current on MOSFET will not be more than the rating current. The output power will not increase if the current reaches the peak value to limit the max. output power. The output voltage decreases and FB voltage increases if there is overload and corresponding protection occurs. 9. Abnormal Over Current Protection That secondary diode is short, or the transformer is short will cause this event. At this time, once it is over current in spite of the leading edge blanking (L.E.B) time, protection will begin after 350nS, and is active for every cycle. When the voltage on the current sense resistor is 1.6V, this protection will occur and the output is shut down. This state is kept until the under voltage occurs, and the circuit will start. 10. Thermal Shutdown If the circuit is over temperature, the over temperature protection will shut down the output to prevent the circuit from damage. This state is kept until the under voltage occurs, and the circuit will start.

SD4840/4841/4842/4843/4844 TYPICAL APPLICATION CIRCUIT Note: 1. The circuit and parameters are for reference only, please set the parameters of the real application circuit based on the real test. 2. Better not to place VCC winding as inner coil. HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 9 of 11

SD4840/4841/4842/4843/4844 PACKAGE OUTLINE DIP-8-300-2.54 UNIT: mm MOS DEVICES OPERATE NOTES: Electrostatic charges may exist in many things. Please ta ke following preventive measures to prevent effectively the MOS electric circuit as a result of the damage which is caused by discharge: z The operator must put on wrist strap which should be earthed to against electrostatic. z Equipment cases should be earthed.  z All tools used during assembly, including soldering tools and solder baths, must be earthed. z MOS devices should be packed in antistatic/conductive containers for transportation. Note：Silan reserves the right to make changes without notice in this specification for the improvement of the design and performance. Silan will supply the best possible product for customers. HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 10 of 1 1

SD4840/4841/4842/4843/4844 HANGZHOU SILAN MICROELECTRONICS CO.,LTD REV:1.2 2008.12.17 Http: //www.silan.com.cn Page 11 of 1 1 Attachment

Revision History

2008.07.07 1.0 Original 2008.11.06 1.1 Modify the “BLOCK DIAGRAM” and “FUNCTION DESCRIPTION” 2008.12.17 1.2 Add the note for “TYPICAL APPLICATION CIRCUIT”