HT7A4016 Low Power, Wide Temperature Range General Purpose Current Mode PWM Controller Feature General Description • High Performance, Low Cost Current Mode PWM Controller especially designed for Energy Star 2.0 The HT7A4016 is a controller IC that includes the necessary features to implement off-line or DC-DC current mode control schemes with a minimal external parts count. Internal circuits include a specially designed Mixed-Mode/Analog Interface for multifunction and multi-topology control schemes (DC-DC Buck/Boost, Off-line AC-DC), a trimmed oscillator for precise duty-cycle control under voltage lockout with a start-up current of less than 0.5mA, a wide temperature range, precise voltage reference, internal Slope Compensation and Leading-Edge Blanking. The HT7A4016 features basic system protection functions such as Cycle-by-Cycle Current Limiting and Under Voltage Lock-Out (UVLO). • Very Low Startup Current (<20μA) and Operating Current • High-Voltage CMOS Process with Excellent ESD protection (>3KV) • ±5% Trimmed Oscillator for Precise Frequency Control • LEB (Leading-Edge Blanking) on CS Pin • Internal Slope Compensation • Programmable Switching Frequency • Internally Trimmed Reference with UVLO (Under Voltage Lockout) A Multi-Function Pin can be used as a dimming function for LED driving, and as a primary feedback control for Primary-Side Feedback AC-DC applications. • Cycle-by-Cycle Current Limiting Applications • Switching AC-DC Adaptors • DC-DC Switching Buck/Boost Converters • LED Backlights for LCD/LED TVs Application Circuits VIN=24V VCC Vref RT 0.1uF 2.2K GD 10 46uH 1N4148 20 10K COMP/FB 470K GND CS Rev. 1.00 470uF/50V 33pF Vo=55V/75W HFB20HJ20C IRF540 470uF /63V 820 0.22 0.22 220pF 0.1uF/100V 40K 1nF MF 2K 1 November 07, 2011 HT7A4016 Block Diagram Pin Assignment VREF VCC 7 UVLO 32V Trimmed OSC 4 MF 2 COMP/FB 1 CS 3 Driver Stage 6 GD S Q 5 R FB Compare Level = 2.5V 14V / 8V RT VCC Internal Bias & Vref GND Slope Compensation Mixed-Mode/Analog Interface OCP Output LEB 350ns OCP Level = 1V Pin Description Pin No. Pin Name Description 1 COMP/FB 2 MF Multi-Function Pin. By connecting this pin to different system sensing points, the device can be used for different circuit topologies such as Isolation Flyback or Non-Isolation DCDC Buck/Boost. 3 CS A voltage proportional to the inductor current is connected to this input. The PWM generator uses this voltage to terminate output switching. 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 Temperature-independent voltage reference output. Voltage Feedback Pin, Connected to a system voltage feedback point. Combined control circuitry and power ground. Power MOSFET gate driver output. Absolute Maximum Ratings Supply Voltage VCC�������������������������������������������������������������������������������������������������������������������������������� -0.3V~30.0V COMP/FB, RT, CS, MF Pins��������������������������������������������������������������������������������������������������������������������� -0.3V~5.0V 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 November 07, 2011 HT7A4016 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 Supply Voltage (VCC Pin) IST Startup Current VCC=7.7V — 12 30 mA ICC Operating Current VFB=VCS=0V — 2.0 3.0 mA VTL UVLO (Off) — 7.0 7.6 8.2 V VTH UVLO (On) — 7.8 8.4 9.0 V 4.85 5.00 5.15 V Reference Section VREF Output Voltage Tj = 25°C, IO = 1mA ∆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 — 0.9 1.0 1.1 V tLEB Leading Edge Blanking Time — — 350 — ns Delay to Output — — 100 — ns Oscillator (RT pin) fOSC ∆fOSC ∆TA ∆fOSC ∆VREF DMAX Oscillator Frequency Tj=25°C, RT=10kW 47 52 57 kHz Tempurature Stability -40°C ~105°C — 5 — % Voltage Stability VCC=10V~25V — 0.2 1.0 % — 97 — % Maximum Duty — 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 COMP pin open — 5 — V 2.42 2.50 2.58 V Voltage Feedback (COMP Pin) VCOMP Open Loop Voltage SCP (Short Circuit Protection) VREFA Reference Voltage VFB/PDM=2.5V ISINKA Output Sink Current VFB=2.7V, VFB/PDM=1.1V 2 7 — mA ISOURCEA Output Source Current VFB=2.3V, VFB/PDM=4.8V -0.5 -1.0 — mA VOHA VFB/PDM High Voltage VFB=2.3V, RL=15kW to GND 4.8 5.0 — V VOLA VFB/PDM Low Voltage VFB=2.7V, RL=15kW to Vref — 0.8 1.1 V AVO DC Gain — 150 — dB — Note: These Parameters, although guaranteed, are not 100% tested in production. Rev. 1.00 3 November 07, 2011 HT7A4016 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 60 110 Temperature (degree C) 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 Frequency (KHz) Frequency (KHz) Temperature (degree C) -20 0 20 40 60 80 100 120 Temperature (degree C) 15 17 19 21 23 25 Vcc (V) Figure 4. Frequency vs. Vcc Figure 3. Frequency vs. Temperature Rev. 1.00 13 4 November 07, 2011 HT7A4016 Application Information Operation Overview The HT7A4016 is a low power, wide temperature range general purpose current mode PWM Controller. The device is designed to require a minimum of external components for different power circuit topologies such as Primary-Side Feedback Flyback and DC-DC Buck/Boost. The device can be used for LED driving applications such as LED backlights and LED lighting. To meet LED constant current requirements, the device can maintain a low current tolerance of ±1% for LED driving applications. Figure 6 LEB with R-C Filter Removed Under Voltage Lockout (UVLO) A UVLO comparator is provided to ensure that the device is fully functional before the output stage is enabled. As shown in Figure 5, hysteresis is provided to prevent the PWM Controller from shutting down during any voltage dips which might occur during the startup process. The turn-on and turn-off threshold levels are set at 16.0V and 10.0V, respectively. Internal Slope-Compensation An important issue with current mode control schemes is 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 controller applications, many external components are necessary to implement a Slope-Compensation function. However in the HT7A4016 the internal Slope-Compensation function eliminates the need for these external components resulting in a simplified application circuit design. Os Oscillator Frequency Tuning By choosing an appropriate value of external resistor between the RT Pin and GND, a suitable operating frequency can be generated. The relationship between the RT value and the operating frequency is provided in Figure 7. Figure 5 UVLO Scheme and Start-Up Current Current Sense and Leading-Edge Blanking (LEB) For Isolation Flyback applications, a LeadingEdge Blanking Scheme is necessary. A LeadingEdge Blanking Scheme is integrated in the device to prevent false triggering due to feedback current spikes which may appear on the CS pin. This eliminates the need for the usual R-C filter which is normally a requirement in typical current mode PWM Controller applications. Rev. 1.00 Figure 7 RT Resistor Value vs. Operating Frequency 5 November 07, 2011 HT7A4016 Multi-Function Pin Buck Constant Current LED Lighting Driver A specially designed Mixed-Signal/Analog Interface is provided in the HT7A4016. By connecting the Multi-Function (MF) pin to different system sensing points, the HT7A4016 can be used for different circuit topologies such as Isolation Flyback or Non-Isolation DC-DC Buck/Boost. The MF pin can also be used as an LED dimming pin for Buck LED driving. Some application circuit examples are introduced in the following pages. A low cost Buck Constant Current LED Lighting driver is introduced in Figure 10. Unlike the usual LED drives which have a fixed-voltage range and constant current control, this circuit can support very high output voltages, perhaps for high LED count serial configurations, with no maximum voltage limitations. Here the MF pin can be used as a PWM dimming pin. Constant Voltage Boost Application Constant Voltage Buck Application A Constant Voltage (CV) Boost application circuit is shown in Figure 8. This circuit can be used with DC inputs of 16~24V and provides a DC output of 55V ± 5% with an output power level of 60~70W. The output power level can be changed by choosing a suitable inductor value and power MOSFET, while the output voltage can be changed by choosing a suitable feedback resistor ratio. A Constant Voltage (CV) Buck (High-Side Buck) application circuit is shown in Figure 11. This circuit can be used with DC inputs of 24V or higher voltage and provides a Constant DC voltage output. The output power level can be changed by choosing a suitable inductor value, Transformer’s turn ratio and power MOSFET, while the output voltage can be changed by choosing a suitable feedback resistor ratio. Boost Constant Current (CC) LED Driver for Back-light Primary Side Feedback, Isolation Flyback AC-DC Converter A Boost CC LED Driver shown in Figure 9 is designed for LED backlight applications. The topology is similar to Boost topologies, but the feedback point is changed from the Voltage Output terminal to the Current Sense Resistor. This circuit can be used with a DC input of 16~24V, for a DC output of 55V and output power level of 60~70W at an output current level of 380mA ± 1% (16S10P). This circuit’s constant current capability is more than that required by backlights and also good enough for LED lighting applications. The device can also can be used for isolation ACDC applications. A typical primary side feedback, isolation Flyback AC-DC converter is shown in Figure 12. VIN=24V VCC Vref RT 0.1uF 2.2K GD 470uF/50V 10 46uH 1N4148 20 10K COMP/FB 470K GND CS 33pF Vo=55V/75W HFB20HJ20C IRF540 470uF /63V 820 0.22 0.22 220pF 0.1uF/100V 40K 1nF MF 2K Figure 8 Constant Voltage Boost Application (DC-DC Boost) Rev. 1.00 6 November 07, 2011 HT7A4016 VIN=24V VCC 470uF/50V Vref RT 0.1uF 2.2K 10 GD 46uH 1N4148 20 10K COMP/FB CS 33pF 470uF /63V 820 0.22 0.22 0.1uF/100V 220pF 470K GND Vo=55V/75W HFB20HJ20C IRF540 Output Channels 1nF MF Rs Figure 9 DC-DC Boost Constant Current (CC) LED Driver for Back-light VIN 470uF/50V D1 L1 VCC Q1 GD RT Dimming MF RT GND CS RS Vref C1 COMP/FB Figure 10 Buck Constant Current LED Lighting Driver Rev. 1.00 7 November 07, 2011 HT7A4016 2SK941 10k 100uF 1N4148 Vout/5Vdc 47uH 1 : 30 VIN=24Vdc 1nF 15 5.1k 1N4148 1 : 0.8 200 220uF MBR160 10k 1k 5.1k 5.1k 56pF 1uF 1N4148 10 CS GD VCC MF 1M Vref 0.1uF COMP/FB 0.1uF GND 10nF 2.2k RT Figure 11 Constant Voltage Buck Regulator (High-Side Buck) L F1 Vac=90V~265V L2:A L1:A T1 R1 C1 BD1 1 R2 C2 N R7 D1 Vout 7 R3 R5 C14 C3 C4 R4 8 R8 D4 3 D3 4 U1 R21 VCC R22 MF 5 C12 COMP/FB R23 C13 Q1 GD R19 C15 Vref CS RT R11 C11 GND Figure 12 Primary Side Feedback, Isolation Flyback AC-DC Converter Rev. 1.00 8 November 07, 2011 HT7A4016 Package Information Note that the package information provided here is for consultation purposes only. As this information may be updated at regular intervals users are reminded to consult the Holtek website (http://www.holtek.com.tw/english/ literature/package.pdf) for the latest version of the package information. 8-pin SOP (150mil) Outline Dimensions MS-012 Symbol Nom. Max. A 0.228 ― 0.244 B 0.150 ― 0.157 C 0.012 ― 0.020 C' 0.188 ― 0.197 0.069 D ― ― 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 Min. 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° 9 November 07, 2011 HT7A4016 Reel Dimensions SOP 8N (150mil) Symbol Description Dimensions in mm A Reel Outer Diameter 330.0±1.0 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 2.0±0.5 12.8 +0.3/-0.2 18.2±0.2 10 November 07, 2011 HT7A4016 Carrier Tape Dimensions SOP 8N (150mil) Symbol Description W Carrier Tape Width P Cavity Pitch E Perforation Position F Cavity to Perforation (Width Direction) Dimensions in mm 12.0+0.3/-0.1 8.0±0.1 1.75±0.10 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 2.1±0.1 t Carrier Tape Thickness C Cover Tape Width Rev. 1.00 0.30±0.05 9.3±0.1 11 November 07, 2011 HT7A4016 Holtek Semiconductor Inc. (Headquarters) No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan Tel: 886-3-563-1999 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 12 November 07, 2011