LD7576/76H/76J/76K 12/5/2007 Green-Mode PWM Controller with High-Voltage Start-Up Circuit and Adjustable OLP Delay Time REV. 03 Features General Description The LD7576X series bring high performance, combines with z High-Voltage (500V) Startup Circuit highly integrated functions, protections and EMI-improve z Current Mode Control solution. It’s an ideal solution for those cost-sensitive system, z Non-Audible-Noise Green Mode Control reducing component count and overall system cost. z UVLO (Under Voltage Lockout) The LD7576X series features near-lossless high voltage z LEB (Leading-Edge Blanking) on CS Pin startup operation, z Internal Slope Compensation leading-edge blanking of the current sensing and internal z OVP (Over Voltage Protection) on Vcc slope compensation. circuit, green-mode power-saving They also consist with more z On-Chip OTP (Over Temperature Protection) protections of OLP (Over Load Protection), OVP (Over z OLP (Over Load Protection) Voltage Protection) and OTP (Over Temperature Protection) z Latch Mode Protection by CT pin z 500mA Driving Capability z Adjustable OLP delay time to prevent the circuit damage under abnormal conditions. The LD7576X series are available in DIP-8 and SOP-8 package. Applications Typical Application 1 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw z Switching AC/DC Adaptor and Battery Charger z Open Frame Switching Power Supply z LCD Monitor/TV Power LD7576/76H/76J/76K Pin Configuration HV NC VCC OUT SOP-8 & DIP-8 (TOP VIEW) 8 7 6 5 YY: WW: PP: TOP MARK 2 3 4 CS GND CT 1 COMP YYWWPP Year code Week code Production code Ordering Information Part number Protection/Frequency Package Top Mark Shipping LD7576 PS Auto-Recovery/65KHz SOP-8 PB Free LD7576PS 2500 /tape & reel LD7576 GS Auto-Recovery/65KHz SOP-8 Green Package LD7576GS 2500 /tape & reel LD7576 PN Auto-Recovery65KHz DIP-8 PB Free LD7576PN 3600 /tube /Carton LD7576J PS Auto-Recovery/100KHz SOP-8 PB Free LD7576JPS 2500 /tape & reel LD7576J GS Auto-Recovery/100KHz SOP-8 Green Package LD7576JGS 2500 /tape & reel LD7576J PN Auto-Recovery100KHz DIP-8 PB Free LD7576JPN 3600 /tube /Carton LD7576H PS Latch/65KHz SOP-8 PB Free LD7576HPS 2500 /tape & reel LD7576H GS Latch/65KHz SOP-8 Green Package LD7576HGS 2500 /tape & reel LD7576H PN Latch/65KHz DIP-8 PB Free LD7576HPN 3600 /tube /Carton LD7576K PS Latch/100KHz SOP-8 PB Free LD7576KPS 2500 /tape & reel LD7576K GS Latch/100KHz SOP-8 Green Package LD7576KGS 2500 /tape & reel LD7576K PN Latch/100KHz DIP-8 PB Free LD7576KPN 3600 /tube /Carton The LD7576 is ROHS compliant/ Green Package. Note: 1. Oscillating frequency: LD7576/76H: 65KHz (typ.), LD7576J/76K: 100KHz (typ.). 2. LD7576H/76K features Built-in latch-mode function of OVP on Vcc pin , OLP and On Chip OTP. 3. LD7576/76J features Built-in Auto-Recovery function of OVP on Vcc pin OLP and On Chip OTP. 2 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Pin Descriptions PIN NAME FUNCTION This pin is to program the frequency of the low frequency timer. 1 CT By connecting a capacitor to ground to set the OLP delay time. And this pin can be used for latch mode protection. By pulling this pin lower than 0.8 V, the controller will be entered latch mode until the AC power-on recycling. Voltage feedback pin (same as the COMP pin in UC384X), By connecting a 2 COMP photo-coupler to close the control loop and achieve the regulation. A high quality ceramic capacitor (X7R) is required for general applications (102pF at least). 3 CS Current sense pin, connect to sense the MOSFET current 4 GND Ground 5 OUT Gate drive output to drive the external MOSFET 6 VCC Supply voltage pin 7 NC Unconnected Pin Connect this pin to positive terminal of bulk capacitor to provide the startup current 8 HV for the controller. When Vcc voltage trips the UVLO(on), this HV loop will be off to save the power loss on the startup circuit. 3 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Block Diagram ∑ 4 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Absolute Maximum Ratings Supply Voltage VCC 30V High-Voltage Pin, HV -0.3V~600V COMP, CT, CS -0.3 ~7V Junction Temperature 150°C Operating Ambient Temperature -40°C to 85°C Storage Temperature Range -65°C to 150°C Package Thermal Resistance (SOP-8) 160°C/W Package Thermal Resistance (DIP-8) 100°C/W Power Dissipation (SOP-8, at Ambient Temperature = 85°C) 400mW Power Dissipation (DIP-8, at Ambient Temperature = 85°C) 650mW Lead temperature (Soldering, 10sec) 260°C ESD Voltage Protection, Human Body Model (except HV Pin) 3KV ESD Voltage Protection, Machine Model 300V Gate Output Current 500mA Caution: Stresses beyond the ratings specified in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Recommended Operating Conditions Item Min. Max. Unit Supply Voltage VCC 11 25 V VCC Capacitor 10 47 μF 0.047 0.1 μF 1 100 nF CT Value COMP Pin Capacitor 5 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Electrical Characteristics o (TA = +25 C unless otherwise stated, VCC=15.0V) PARAMETER CONDITIONS MIN TYP MAX UNITS 0.5 1.0 1.5 mA 35 μA 100 μA High-Voltage Supply (HV Pin) High-Voltage Current Source Vcc< UVLO(on),HV=500V Off-State Leakage Current Vcc> UVLO(off),HV=500V Supply Voltage (VCC Pin) Startup Current VCOMP=0V 2.7 3.5 mA VCOMP=3V 3.1 4.0 mA Operating Current OLP tripped 0.5 mA (with 1nF load on OUT pin) OVP tripped 0.6 mA OTP tripped 0.5 mA Latch Protection 2.0 mA UVLO (off) 9.0 10.0 11.0 V UVLO (on) 15.0 16.0 17.0 V OVP Level 26.5 28.0 29.5 V 2.2 mA Voltage Feedback (COMP Pin) Short Circuit Current VCOMP=0V 1.3 Open Loop Voltage COMP pin open 5.6 V 2.35 V Green Mode Threshold VCOMP Current Sensing (CS Pin) Maximum Input Voltage 0.80 Leading Edge Blanking Time 0.85 0.90 230 Input impedance nS 1 Delay to Output V MΩ 100 nS Oscillator for Switching Frequency Frequency Green Mode Frequency Trembling Frequency LD7576/76H 61.0 65.0 69.0 KHz LD7576J/76K 94.0 100.0 106.0 KHz LD7576/76H 20 KHz LD7576J/76K 32 KHz LD7576/76H ± 4.0 KHz LD7576J/76K ± 6.0 KHz Temp. Stability (-40°C ~105°C) 5 % Voltage Stability (VCC=11V-25V) 1 % 6 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Electrical Characteristics o (TA = +25 C unless otherwise stated, VCC=15.0V) PARAMETER CONDITIONS MIN TYP MAX UNITS Low Frequency Timer (CT Pin) Low Frequency Period CT=0.047μF 4.7 mS Temp. Stability (-40°C ~105°C) 5 % Voltage Stability (VCC=11V-25V) 1 % Output Low Level VCC=15V, Io=20mA 1 V Output High Level VCC=15V, Io=20mA Rising Time Load Capacitance=1000pF 50 160 nS Falling Time Load Capacitance=1000pF 30 60 nS Gate Drive Output (OUT Pin) 8 V OLP (Over Load Protection) OLP Trip Level 5.0 V CT=0.1μF 110 mS CT=0.047μF 45 mS OTP Level 140 °C OTP Hysteresis 30 °C OLP Delay Time OTP (Over Temperature) Latch Protection CT Pin Trip Level for Latch Protection Low Activated 0.8 Timer for Power-on Verification 250 De-Latch Vcc Level 7.2 7 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw 8 V mS 8.8 V LD7576/76H/76J/76K Typical Performance Characteristics 1.5 0.86 1.3 VCS (off) (V) HV Current Source (mA) 0.88 1.1 0.84 0.82 0.9 0.80 0.7 -40 0 40 80 0.78 120 125 -40 Temperature (°C) 12 17.2 11.2 UVLO (off) (V) UVLO (on) (V) 18.0 16.4 15.6 120 125 10.4 9.6 8 -40 0 40 80 120 125 -40 Temperature (°C) Fig. 3 UVLO (on) vs. Temperature 0 40 80 120 125 Temperature (°C) Fig. 4 UVLO (off ) vs. Temperature 70 24 68 22 Frequency (KHz) Frequency (KHz) 80 8.8 14.8 66 64 20 18 16 62 60 40 Temperature (°C) Fig. 2 VCS (off) vs. Temperature Fig. 1 HV Current Source vs. Temperature (HV=500V, Vcc=0V) 14.0 0 -40 0 14 40 80 120 125 -40 December 2007 80 120 125 Fig. 6 Green Mode Frequency vs. Temperature 8 LD7576-DS-03 40 Temperature (°C) Temperature (°C) Fig. 5 Frequency vs. Temperature Leadtrend Technology Corporation 0 www.leadtrend.com.tw LD7576/76H/76J/76K 25 Green mode frequency (KHz) 70 Frequency (KHz) 68 66 64 62 12 14 16 18 20 22 24 19 17 14 16 18 20 22 Vcc (V) Fig. 7 Frequency vs. Vcc Fig. 8 Green mode frequency vs. Vcc 85 35 80 30 75 70 24 25 25 20 15 60 10 -40 0 40 80 120 125 -40 0 40 80 Temperature (°C) Temperature (°C) Fig. 9 Max Duty vs. Temperature Fig. 10 VCC OVP vs. Temperature 6.0 6.5 5.5 6.0 5.0 OLP (V) 7.0 5.5 5.0 4.5 12 Vcc (V) 65 VCOMP (V) 21 15 11 25 VCC OVP (V) Max Duty (%) 60 11 23 120 125 4.5 4.0 -40 0 40 80 3.5 120 125 -40 0 Temperature (°C) Fig. 11 VCOMP open loop voltage vs. Temperature Fig. 12 9 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw 40 80 Temperature (°C) OLP-Trip Level vs. Temperature 120 125 LD7576/76H/76J/76K Application Information will be enabled to supply 1mA current. Meanwhile, the Vcc Operation Overview supply current is as low as 100μA that most of the HV As long as the green power requirement becomes a trend current is adopted to charge the Vcc capacitor. and the power saving is getting more and more important for the switching power supplies and switching adaptors, the same no matter under low-line or high-line conditions. traditional PWM controllers are not able to support such new As the Vcc voltage rises higher than UVLO(on) to power on requirements. Furthermore, the cost and size limitation force the LD7576X series and further to deliver the gate drive the PWM controllers need to be powerful to integrate more functions to reduce the external part counts. By using such configuration, the turn-on delay time will be almost signal, the high-voltage current source will be disabled and The LD7576X the supply current is provided from the auxiliary winding of series are ideal for these applications to provide an easy the transformer. Therefore, it would eliminate the power and cost effective solution; its detailed features are loss on the startup circuit and perform highly power saving. described as below. An UVLO comparator is embedded to detect the voltage on the Vcc pin to ensure the supply voltage enough to power Internal High-Voltage Startup Circuit and on the LD7576X series PWM controller and in addition to Under Voltage Lockout (UVLO) drive the power MOSFET. As shown in Fig. 14, a hysteresis is provided to prevent the shutdown from the voltage dip during startup. The turn-on and turn-off threshold level are set at 16V and 10.0V, respectively. Vcc UVLO(on) UVLO(off) t HV Current 1mA Fig. 13 ~ 0mA (off) The traditional circuit provides the startup current through a t startup resistor to power up the PWM controller. However, it consumes too significant power to meet the current power Vcc current Operating Current (Supply from Auxiliary Winding) saving requirement. In most cases, startup resistors carry large resistance. And larger resistance takes longer startup Startup Current (<100uA) time. To achieve the optimized topology, as shown in figure 13, LD7576X series are implemented with a high-voltage Fig. 14 startup circuit for such requirement. During the startup, a high-voltage current source sinks current from the bulk Current Sensing, Leading-Edge Blanking and capacitor to provide the startup current as well as charge the the Negative Spike on CS Pin Vcc capacitor C1. During the startup transient, the Vcc The typical current mode PWM controller feedbacks both drops lower than the UVLO threshold so the current source current signal and voltage signal to close the control loop 10 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K and achieve regulation. The LD7576X series detects the primary MOSFET current from the CS pin, which is not only for the peak current mode control but also for the pulse-by-pulse current limit. The maximum voltage threshold of the current sensing pin is set at 0.85V. Thus the MOSFET peak current can be calculated as: 0.85 V IPEAK(MAX) = RS 230ns blanking time VCC A 230nS leading-edge blanking (LEB) time is provided in the OUT input of CS pin to prevent false-triggering from the current spike. In the low power applications, if the total pulse width LD7576X of the turn-on spikes is less than 230nS and the negative spike on the CS pin does not exceed -0.3V, the R-C filter (as CS shown in figure15) can be eliminated. GND However, the total pulse width of the turn-on spike is related to the output power, circuit design and PCB layout. It is strongly recommended to add a small R-C filter (as shown in Can be removed if the negative spike is not over spec. (-0.3V). figure 16) for higher power application to avoid the CS pin from being damaged by the negative turn-on spike. Fig. 15 Output Stage and Maximum Duty-Cycle An output stage of a CMOS buffer, with typical 500mA driving capability, is incorporated to drive a power MOSFET directly. And the maximum duty-cycle of LD7576X series are limited to 75% to avoid the transformer saturation. Voltage Feedback Loop The voltage feedback signal is provided from the TL431 on the secondary side through the photo-coupler to the COMP pin of LD7576X series. The input stage of LD7576X series, like the UC384X, is with 2 diodes voltage offset to feed the voltage divider with 1/3 ratio, that is, 1 V+ (PWM COMPARATOR ) = × ( VCOMP − 2VF ) 3 A pull-high resistor is embedded internally to optimize the external circuit. Generally, an external capacitor in parallel to photo-coupler is required in application. Fig. 16 Oscillator and Switching Frequency The switching frequency of LD7576X series are fixed at 65KHz and 100KHz internally to provide the optimized 11 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K operations in consideration of the EMI performance, thermal generate longer OLP delay time. The recommended CT treatment, component sizes and transformer design. value will be 0.1μF when OLP delay time is for around 110mS and 0.047μF for around 55mS. A divide-2 counter is implemented to reduce the average Internal Slope Compensation power under OLP behavior. A fundamental issue of current mode control is the stability the output is latched off and the divide-2 counter starts to problem when its duty-cycle is operated for more than 50%. count the number of UVLO(off). To stabilize the control loop, the slope compensation is output is recovered to switching again. ramp signal from the RT/CT pin through a coupling In LD7576X series, the internal The latch will be released when the 2nd UVLO(off) point started to counted then the needed in the traditional UC384X design by injecting the capacitor. Whenever OLP is activated, With the protection mechanism, the average input power will slope be minimized, so that the component temperature and compensation circuit has been implemented to simplify the stress can be controlled within the safe operating area. external circuit design. Over Load Protection (OLP) - Latch mode On/Off Control By pulling COMP pin lower than 1.2V will disable the gate Other than LD7576/76J, the LD7576H/76K features latch output pin of LD7576X series immediately. The off mode mode of smart OLP protection. Figure 18 shows the can be released when the pull-low signal is removed. waveform under fault condition. The feedback system will force the voltage loop toward the saturation and thus pull Dual-Oscillator Green-Mode Operation the voltage high on COMP pin (VCOMP). When the VCOMP There are many different topologies has been implemented ramps up to the OLP threshold of 5.0V and stays for longer in different chips for the green-mode or power saving than OLP delay time, the protection will be activated and requirements such as “burst-mode control”, “skipping-cycle then latch off the gate output to stop switching of the power mode”, “variable off-time control “…etc. The basic operation circuit. The delay time is to prevent the false-triggering from theory of all these approaches intended to reduce the power-on, turn-off transient and peak load condition. As switching cycles under light-load or no-load condition either by skipping some switching pulses or reduce the switching soon as the over load condition is removed, the controller frequency. will be kept latched until the Vcc drops lower than 8V. It is By using LD proprietary dual-oscillator technique, the necessary to start another AC power-on recycling to get the green-mode frequency can be well controlled and further to output back. avoid the generation of audible noise. Over Load Protection (OLP) - Auto Recovery To protect the circuit from being damaged during over load condition and short or open loop condition, the LD7576X series were implemented with smart OLP function. LD7576/76J features auto recovery function of it, see figure 17 for the waveform. In the example of the fault condition, the feedback system will force the voltage loop toward the saturation and then pull the voltage high on COMP pin (VCOMP). When the VCOMP ramps up to the OLP threshold of 5V and stays for longer than the OLP delay time, the protection will be activate and then turn off the gate output to stop the switching of power circuit. The OLP delay time, set by CT pin, is to prevent the false triggering from the power-on and turn-off transient. Higher CT value will 12 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K VCC OVP (Over Voltage Protection) on Vcc - Auto UVLO(on) Recovery UVLO(off) The maximum VGS ratings of the power MOSFETs are mostly for 30V. To prevent the VGS enter fault condition, OLP 2nd UVLO(off) OLP Counter Reset LD7576X series are implemented with OVP function on Vcc. t Whenever the Vcc voltage is higher than the OVP threshold, COMP the output gate drive circuit will be shutdown simultaneously OLP Delay Time and the switching of the power MOSFET is disabled until the 5.0V next UVLO(on). The Vcc OVP functions of LD7576/76J are auto-recoverable. OLP trip Level t If the OVP condition, usually caused by open-loop of feedback, is not released, the Vcc will tripped the OVP level OUT again and re-shutdown the output. The Vcc works in hiccup mode. Figure 19 shows its operation. Switching Non-Switching Switching Otherwise, when the OVP condition is removed, the Vcc level will be resumed and the output will automatically return t to the normal operation. Fig. 17 COMP OVP (Over Voltage Protection) on Vcc - Latch OLP Delay Time mode 5.0V As similar behavior like OLP latch-mode, whenever the OLP trip Level voltage on the Vcc pin is higher than the OVP threshold, the t output gate drive circuit will be shutdown simultaneous to VCC latch off the switching of the power MOSFET. As soon as UVLO(on) the voltage on Vcc pin drops below OVP threshold and UVLO(off) starts AC-recycling again, it will recover to normal operation. PDR(8V) Figure 20 shows its operation. Latch Released t AC input Voltage AC Off AC On( Recycle) t OUT Switching Non- Switching Switching t Fig. 18 Fig. 19 13 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Fig. 21 Fig. 20 Pull-Low Resistor on the Gate Pin of MOSFET The LD7576X series consist with an anti-floating resistor on the OUT pin to protect the output from abnormally operation i = Cgd ⋅ or false triggering of MOSFET. Even so, we still recommend adding an external one on the MOSFET gate terminal to provide more protection in case of disconnection of gate resistor RG during power-on. In such single-fault condition, as show in figure 22, the resistor R8 can provide a discharge path to avoid the MOSFET from being false-triggered by the current through the gate-to-drain capacitor CGD. Therefore, the MOSFET is always pulled low and placed in the off-state whenever the gate resistor is disconnected or opened in any case. Fig. 22 14 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw dVbulk dt LD7576/76H/76J/76K output will be disabled until the chip is cooled down below Protection Resistor on the Hi-V Path the hysteresis window. In some other Hi-V process and design, there may be a parasitic SCR caused around HV pin, Vcc and GND. As shown in figure 23, a small negative spike on the HV pin On-Chip OTP – Latch - Mode may trigger this parasitic SCR and cause latchup between Vcc and GND. As similar behavior like OLP and OVP on Vcc latch-mode, It will intend to damage the chip because of an the equivalent short-circuit induced by such latchup behavior. circuit are embedded with the trip OTP level, it shutdowns the output gate drive circuit Figure 24 shows the equivalent circuit of LD7576X series of Hi-V structure. OTP controller. When the chip temperature rises higher than the Leadtrend’s proprietary of Hi-V technology will eliminate parasitic SCR in LD7576X series. internal LD7576H/76K to provide the worst-case protection for this simultaneously to latch off the switching of the power So MOSFET. It won’t recover unless the chip is cooled down that LD7576X series are more capable to sustain negative below the OTP threshold and recycle again. voltage than similar products. However, a 10KΩ resistor is recommended to be added on the Hi-V path to play as a current limit resistor whenever a negative voltage is applied. Latch-Mode Protection The latch-mode protection in LD7576 series will be enabled by pulling the CT pin voltage below 0.8V. the operation. Figure 26 shows When the latch-mode is tripped, LD7576 series will shutdown the gate output and then latch-off the power supply. Unless the controllers re-plug and re-start to drop VCC below 8V, the gate output mode will remain latched. The detailed operation is depicted as figure 26. Fig. 23 Fig. 24 On-Chip OTP An internal OTP circuit is embedded inside the LD7576/76J to provide the worst-case protection for this controller. When Fig. 26 the chip temperature rises higher than the trip OTP level, the 15 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Reference Application Circuit --- 10W (5V/2A) Adapter L F1 R1A R1B Z1 CX1 FL1 IC1 CT HV 1 8 2 3 5 CS R9 OUT D1A~D1D C1 VCC 6 4 GND LD7576 COMP D2 C2 R7 R6 R4A R4B R8 D4 C4 RS1 T1 Q1 RS2 R51B R51A CR51 IC2 C51 C52 R56A ZD51 R54 L51 C55 R55 R56B R52 R53 C54 16 AC input N NTC1 CT C5 photocoupler CY1 IC5 December 2007 LD7576-DS-03 www.leadtrend.com.tw Leadtrend Technology Corporation LD7576/76H/76J/76K BOM P/N Component Value P/N Original Component Value Note R1A N/A C1 22μF, 400V L-tec R1B N/A C2 22μF, 50V L-tec R4A 39KΩ, 1206 C4 1000pF, 1000V, 1206 Holystone R4B 39KΩ, 1206 C5 0.01μF, 16V, 0805 R6 2.2Ω, 1206 C51 1000pF, 50V, 0805 R7 10Ω, 1206 C52 1000μF, 10V L-tec R8 10KΩ, 1206 C54 470μF, 10V L-tec R9 10KΩ, 1206 C55 0.022μF, 16V, 0805 RS1 2.7Ω, 1206, 1% CT 0.047μF, 10V, 0805 X5R RS2 2.7Ω, 1206, 1% CX1 0.1μF X-cap R51A 100Ω, 1206 CY1 2200pF Y-cap R51B 100Ω, 1206 D1A 1N4007 R52 2.49KΩ, 0805, 1% D1B 1N4007 R53 2.49KΩ, 0805, 1% D1C 1N4007 R54 100Ω, 0805 D1D 1N4007 R55 1KΩ, 0805 D2 PS102R R56A 2.7KΩ, 1206 D4 1N4007 R56B N/A Q1 2N60B NTC1 5Ω, 3A 08SP005 CR51 SB540 FL1 20mH UU9.8 ZD51 6V2C T1 EI-22 IC1 LD7576PS L51 2.7μH IC2 EL817B IC51 TL431 17 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw F1 250V, 1A Z1 N/A 600V, 2A SOP-8 1% LD7576/76H/76J/76K Package Information SOP-8 Dimensions in Millimeters Dimensions in Inch Symbols MIN MAX MIN MAX A 4.801 5.004 0.189 0.197 B 3.810 3.988 0.150 0.157 C 1.346 1.753 0.053 0.069 D 0.330 0.508 0.013 0.020 F 1.194 1.346 0.047 0.053 H 0.178 0.229 0.007 0.009 I 0.102 0.254 0.004 0.010 J 5.791 6.198 0.228 0.244 M 0.406 1.270 0.016 0.050 θ 0° 8° 0° 8° 18 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Package Information DIP-8 Dimension in Millimeters Dimensions in Inches Symbol Min Max Min Max A 9.017 10.160 0.355 0.400 B 6.096 7.112 0.240 0.280 C ----- 5.334 ------ 0.210 D 0.356 0.584 0.014 0.023 E 1.143 1.778 0.045 0.070 F 2.337 2.743 0.092 0.108 I 2.921 3.556 0.115 0.140 J 7.366 8.255 0.29 0.325 L 0.381 ------ 0.015 -------- Important Notice Leadtrend Technology Corp. reserves the right to make changes or corrections to its products at any time without notice. Customers should verify the datasheets are current and complete before placing order. 19 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw LD7576/76H/76J/76K Revision History Rev. Date Change Notice 00 3/30/07 Original Specification. 01 4/23/07 Oscillator for Switching Frequency updated 02 6/21/07 Electrical Characteristics updated 03 11/30/2007 1. Features: Adjustable OLP delay time 2. Detailed Description for COMP pin capacitor. 3. Electrical Characteristics/ Low Frequency Timer 4. Green package option. 5. Block Diagram revision. 20 Leadtrend Technology Corporation LD7576-DS-03 December 2007 www.leadtrend.com.tw