HT7A6003 EMI-Improved Green Mode PWM Controller with Integrated Protections Feature General Description • Frequency jitter for restraining EMI HT7A6003 is an advanced, highly integration OffLine PWM Controller. This device provides many protection functions with ultra low power circuit design, and is optimized for restraining EMI. By integrated a Non-Audible Noise Green Mode Control Scheme and optimizing for the Energy Star 2.0 spec., the Power Supply Unit (PSU) implemented using the HT7A6003 can satisfy the “Energy Star NoLoad Mode” Stand-by Power standard, which is less than 0.3W within all Nameplate Output Power Range of 0~250W. This device also integrated various protection functions such as Short-Circuit Protection (SCP, which can also be used for Over-Load Protection, OLP), Cycle-by-Cycle Current Limiting, Over Voltage Protection (OVP), and Soft-Start function for reducing inrush current during system initialization and preventing device burn-out. • Integrated Soft-Start function • Very low operating current and start-up current (<20mA) for satisfying Energy-Star 2.0 "No-Load Mode" (Stand-by) power standard • ±5% trimmed oscillator for precise frequency • Programmable switching frequency • Non-audible-noise Green Mode Control • LEB (Leading-Edge Blanking) on CS pin • Internal slope compensation • Cycle-by-Cycle current limiting • Short-Circuit-Protection(SCP) for Short-Circuit and Over-Load condition • Over-Voltage-Protection(OVP) on VCC Pin • 8-Pin SOP package The HT7A6003 also integrates Leading-Edge Blanking and Slope Compensation for minimizing external components cost and system complexity. Applications • Switching AC-DC adaptor • Open frames switching power supply • UPS • LCD TV Application Circuits EMI Filter Flyback Converter VOUT 10k RT HT7A6003 GND Current Sense GD CS VCC COMP VREF 0.1uF FOD817 Voltage Sense GND 95k TL431 25k Rev. 1.00 1 May 27, 2011 HT7A6003 Block Diagram Pin Assignment VREF VCC UVLO Soft-Start 14V / 8V Driver Stage Green Mode OSC RT COMP VCC Internal Bias & Vref 32V OVP S GD Q GND R Frequency Jitter 8 2 7 3 6 4 5 VREF VCC GD GND HT7A6003 8 SOP-A Slop Compensation PWM 2R COMP NC CS RT 1 R OCP CS SCP LEB 350nS 1V Pin Description Pin No. Pin Name Description 1 COMP 2 N.C No connection 3 CS A voltage proportional to inductor current is connected to this input. The PWM generator uses this voltage information to terminate the output switch conduction. 4 RT The oscillator frequency is programmed by connecting a resistor RT between this pin and ground. A maximum frequency of 500kHz is possible. 5 GND 6 GD 7 VCC Positive Supply. 8 VREF Reference output. Voltage Feedback Pin. Connected to a Photo-Coupler for close-loop control. Combined control circuitry and power ground. Power MOSFET gate driver output. Absolute Maximum Ratings Supply Voltage VCC�������������������������������������������������������������������������������������������������������������������������������� -0.3V~30.0V COMP, RT, CS Pins����������������������������������������������������������������������������������������������������������������������������������� -0.3V~5.5V Junction Temperature������������������������������������������������������������������������������������������������������������������������������������������ 150°C Operating Ambient Temperature��������������������������������������������������������������������������������������������������������������� -40°C~85°C Storage Temperature Range�������������������������������������������������������������������������������������������������������������������� -65°C~150°C Package Thermal Resistance (8-Pin SOP)����������������������������������������������������������������������������������������������������� 160°C/W ESD Protection: Human Body Model��������������������������������������������������������������������������������������������������������������������������������������3kV Machine Model�������������������������������������������������������������������������������������������������������������������������������������������200V Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum Ratings” may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Rev. 1.00 2 May 27, 2011 HT7A6003 Electrical Characteristics Unless otherwise stated, this specifications apply for 0°C ≤ Ta ≤ 70°C, VCC=15V, RT=10kW Symbol Parameter Test Condition Min. Typ. Max. Unit VCC=12.9V — 12 30 mA VCOMP=0V — 2.0 3.0 mA Supply Voltage (VCC Pin) IST Startup Current ICC Operating Current — 2.5 — mA VTL UVLO (Off) — 7 8 9 V VTH UVLO (On) — 13 14 15 V VCC OVP Trip Level 26.5 28.0 29.5 V VCC OVP Strobe Time — 80 — ms VCOMP=3V VCC(Over Voltage Protection) — Reference Section VREF Output Voltage Tj = 25°C, IO = 1mA — 5.5 — V ∆VREF Line Regulation 12V ≤ VCC ≤ 25V — 3 20 mV ∆VREF Load Regulation 1mA ≤ IO ≤ 10mA — 4 25 mV Current Sensing (CS Pin) VCS(OFF) Maximum Input Voltage, Vcs(off) — 0.9 1.0 1.1 V tLEB Leading Edge Blanking Time — — 350 — ns tD-OVP Delay to Output — — 100 — ns Oscillator (RT pin) fOSC ∆fOSC ∆TA ∆fOSC ∆VREF DMAX Oscillator Frequency Tj=25°C, RT=10kW 49 52 55 kHz Temperature Stability -40°C ~105°C — 5 — % Voltage Stability VCC=10V~25V — 0.2 1.0 %/V Maximum Duty — — 75 — % Frequency Jitter — — ±4 — % Gate Drive Output (GD Pin) VOL Output Low Level VCC=15V, Isink=20mA — — 1 V VOH Output High Level VCC=15V, Isource=20mA 9 — — V tr Rising Time Tj=25°C, Load Capacitance=1nF — 50 150 ns tf Falling Time Tj=25°C, Load Capacitance=1nF — 50 150 ns Voltage Feedback (COMP Pin) ISINK Short Circuit Current VCOMP=0V — 1.5 2.2 mA VCOMP Open Loop Voltage COMP pin open — 5.5 — V SCP Trip Level VCOMP (SCP) — 4.7 — V SCP Delay Time (See Note) fS=52kHz — 40 — ms Soft-Start Time RT=10kW — 8.5 — ms SCP (Short Circuit Protection) VCOMP Soft-Start tSTART Note: These Parameters, although guaranteed, are not 100% tested in production. Rev. 1.00 3 May 27, 2011 HT7A6003 Typical Performance Characteristics 15.5 10 9.5 UVLO (off)(V) UVLO (on)(V) 15 14.5 14 13.5 13 12.5 8 7.5 7 12 11.5 9 8.5 6.5 -40 -20 0 20 40 60 80 100 6 120 -40 10 60 Figure 1. UVLO (on) (V) vs. Temperature Figure 2. UVLO (off)(V) vs. Temperature 57 56 55 54 53 52 51 50 49 48 47 -40 57 56 55 54 53 52 51 50 49 48 47 11 -20 0 20 40 60 80 100 120 13 15 17 Temperature (degree C) -20 0 20 40 60 80 100 23 25 31 29 27 25 23 21 19 17 15 11 120 Temperature (degree C) 13 15 17 19 21 23 25 Vcc (V) Figure 6. Green Mode Frequency vs. Vcc Figure 5. Vcomp for SCP vs. Temperature Rev. 1.00 21 Figure 4. Frequency vs. Vcc Green Mode Frequency (KHz) 4.9 4.85 4.8 4.75 4.7 4.65 4.6 4.55 4.5 4.45 4.4 -40 19 Vcc (V) Figure 3. Frequency vs. Temperature Vcomp (V) 110 Temperature (degree C) Frequency (KHz) Frequency (KHz) Temperature (degree C) 4 May 27, 2011 HT7A6003 Application Information Base on device field test demo board results, for the Full-Range (115V, 230V Vac) input, the Stand-by Power will remain less than 0.3W@Pno=60W(as shown in Table 2).This is within the Energy Star 2.0 criteria. Operation Overview The HT7A6003 is a highly function-integrated off-line PWM Controller which is optimized for applications that needs strong EMI-Restraining and various abnormal conditions protecting capability. This device has a wide operating temperature range (-40°C to 85 °C), and provides many protection functions such as Cycle-by-Cycle Current Limiting, SCP/ OLP, OVP, and Soft-Start function,, that ensure the system implemented by HT7A6003 can operate very stably at extreme environment like outdoor with ultra low temperature (-40°C, the polar region), or high EMI environment (factory or the region with highly electromagnetic wave). The device is optimized for the Energy-Star 2.0 specification, this ensures that any EPS (External Power Supply) implemented using the HT7A6003 can fully satisfy the Energy Star 1.1/2.0 Stand-by (No-Load) criteria. Demo Board Input Condition (Pno=60 watts) 0 to < 50 watts ≥ 50 to ≤ 250 watts Stand-by Power 115V VAC < 0.3W 230V VAC < 0.3W Table 2. Demo Board Stand-by Power Results Advanced Precise-Oscillator for Green-Mode Switching and Non-Acoustic Noise Requirement A Trimmed Precise Green Mode Oscillator is implemented in the device to enhance the conversion efficiency under conditions of light loads. As the data shown in Fig. 8, the efficiency difference of the traditional current mode PWM Controller between light loads and heavy loads is more than 8%, while the average efficiency is only 82%, the efficiency difference of the HT7A6003 is only 1%, while average efficiency is up to 87.5%. Energy Consumption Criteria for No-Load Nameplate Output Power (Pno) Input Range Maximum Power in No-Load AC-AC EPS AC-DC EPS ≤ 0.5 watts ≤ 0.3 watts ≤ 0.5 watts ≤ 0.3 watts Table 1: Energy Star 2.0 No-Load Criteria Ultra Low Stand-by Power for Energy Star 2.0 and Later Energy Star Requirement The device contains many advanced control schemes for Low Stand-by Power like tiny Operating/Standby Current, Green Mode for Light-Load, etc. By choosing an appropriate Stand-by resistor (as shown in Fig. 7), EPS implemented by the device can fully satisfy the Energy Star 2.0 No-Load criteria. Figure 8. Efficiency Comparison between HT7A6003 & Traditional Current Mode PWM Figure 7. Stand-by Resistor Controller (Measured at HT7A3942 Demo Board) Rev. 1.00 5 May 27, 2011 HT7A6003 The Green Mode Oscillator types supplied by other PWM Controller providers are plagued by the problems of Acoustic-Noise. This is because, under the conditions of light loads, the frequency will keep decreasing through Human Acoustic Range (from 20Hz to 20KHz), these audio frequencies may create audible noise in the transformer. Holtek’s HT7A6003 patented Green Mode Oscillator designed using an advanced Non-Acoustic Noise Scheme to prevent the generation of frequencies in the audio frequency band, thus eliminating any transformer noise. Figure 10. UVLO Scheme and Start-Up Current Current Sense and Leading-Edge Blanking (LEB) A Leading-Edge Blanking Scheme is integrated in the device to prevent false triggering due to feedback current spikes which may appear on the CS pin, further eliminate the need for R-C filter which is always a requirement in the traditional current mode PWM Controller applications. Figure 9. Oscillator Behavior Compared with HT7A6003 and other Green Mode PWM Controller Under Voltage Lockout (UVLO) An UVLO comparator is implemented in to ensure that the device is fully functional before the output stage is enabled. As shown in Fig. 10, a hysteresis is provided to prevent the PWM Controller from shutting down during any voltage dips which might occur during startup process. The turn-on and turnoff threshold levels are set at 16.0V and 10.0V, respectively. Rev. 1.00 Figure 11. LEB with R-C Filter Removed 6 May 27, 2011 HT7A6003 Internal Slope-Compensation Over-Voltage Protection (OVP) on VCC Pin An important issue with the current mode control schemes is the instability due to Sub-Harmonic Oscillation when the Duty-Cycle > 50%. To prevent this problem from occurring, a Slope-Compensation function is always necessary. In traditional current mode PWM Controller application, many external components are necessary for Slope-Compensation function, but in HT7A3942 the internal SlopeCompensation eliminates the need for these external components resulting in simplified the application circuit design. VCC Over-Voltage Protection is integrated in this device to prevent components damage due to over voltage condition on VCC pin. The OVP is triggered when VCC reaches 28V and lasts for 80ms, and the PWM pulses are disabled when OVP is enabled. Frequency Jitter for EMI Restraining EMI restraining is accomplished by Frequency Jitter function, which spreads the energy over a wider frequency range than the bandwidth measured by the EMI test equipment. An internal Frequency Jitter circuit changes the switching frequency between +4% and -4% of central frequency with a period of 4ms. Short-Circuit Protection (SCP) and Over-Load Protection (OLP) To protect all the devices of a system from being damaged under over load or short circuit conditions, a smart SCP function is implemented in the device. Here the feedback system will force the voltage loop to move toward a saturation value and then pull up the voltage on the COMP pin. Whenever the VCOMP increases to the SCP threshold of 4.7V and remains there for longer than 40mS, the protection scheme will activate and then turn off the gate output to stop the switching of power circuit. By using such a protection mechanism, the average input power can be reduced to a very low level so that the component temperature and stress can be controlled within safe operating levels. Oscillator Frequency Tuning By choosing an appropriate value of an external resistor between the RT Pin and GND, a suitable operating frequency can be generated. The relationship between the value of RT and the operating frequency is provided in the Figure 13. Figure 12. SCP Function Behavior Figure 13. RT Resistor value vs. Operating Frequency Rev. 1.00 7 May 27, 2011 HT7A6003 Package Information 8-pin SOP (150mil) Outline Dimensions MS-012 Symbol Min. Nom. Max. A 0.228 ― 0.244 B 0.150 ― 0.157 C 0.012 ― 0.020 C' 0.188 ― 0.197 D ― ― 0.069 E ― 0.050 ― F 0.004 ― 0.010 G 0.016 ― 0.050 H 0.007 ― 0.010 α 0° ― 8° Symbol Rev. 1.00 Dimensions in inch Dimensions in mm Min. Nom. Max. A 5.79 ― 6.20 B 3.81 ― 3.99 C 0.30 ― 0.51 C' 4.78 ― 5.00 D ― ― 1.75 E ― 1.27 ― F 0.10 ― 0.25 G 0.41 ― 1.27 H 0.18 ― 0.25 α 0° ― 8° 8 May 27, 2011 HT7A6003 Reel Dimensions SOP 8N (150mil) Symbol Description Dimensions in mm A Reel Outer Diameter B Reel Inner Diameter 100.0±1.5 C Spindle Hole Diameter 13.0 +0.5/-0.2 D Key Slit Width T1 Space Between Flange T2 Reel Thickness Rev. 1.00 330.0±1.0 2.0±0.5 12.8 +0.3/-0.2 18.2±0.2 9 May 27, 2011 HT7A6003 Carrier Tape Dimensions SOP 8N (150mil) Symbol Description W Carrier Tape Width P Cavity Pitch E Perforation Position Dimensions in mm 12.0+0.3/-0.1 8.0±0.1 1.75±0.10 F Cavity to Perforation (Width Direction) 5.5±0.1 D Perforation Diameter 1.55±0.1 D1 Cavity Hole Diameter 1.50 +0.25/-0.00 P0 Perforation Pitch 4.0±0.1 P1 Cavity to Perforation (Length Direction) 2.0±0.1 A0 Cavity Length 6.4±0.1 B0 Cavity Width 5.2±0.1 K0 Cavity Depth t Carrier Tape Thickness C Cover Tape Width Rev. 1.00 2.1±0.1 0.30±0.05 9.3±0.1 10 May 27, 2011 HT7A6003 Holtek Semiconductor Inc. (Headquarters) No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan Tel: 886-3-5631999 Fax: 886-3-563-1189 http://www.holtek.com.tw Holtek Semiconductor Inc. (Taipei Sales Office) 4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan Tel: 886-2-2655-7070 Fax: 886-2-2655-7373 Fax: 886-2-2655-7383 (International sales hotline) Holtek Semiconductor Inc. (Shenzhen Sales Office) 5F, Unit A, Productivity Building, No.5 Gaoxin M 2nd Road, Nanshan District, Shenzhen, China 518057 Tel: 86-755-8616-9908, 86-755-8616-9308 Fax: 86-755-8616-9722 Holtek Semiconductor (USA), Inc. (North America Sales Office) 46729 Fremont Blvd., Fremont, CA 94538, USA Tel: 1-510-252-9880 Fax: 1-510-252-9885 http://www.holtek.com Copyright © 2011 by HOLTEK SEMICONDUCTOR INC. The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. Holtek's products are not authorized for use as critical components in life support devices or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw. Rev. 1.00 11 May 27, 2011