iW1690 Low-Power Off-line Digital PWM Controller 2.0 Description Primary-side feedback eliminates opto-isolators and simplifies design • Direct drive of BJT switching device • Multi-mode operation for highest overall efficiency • Built-in cable drop compensation • Very tight output voltage regulation • No external compensation components required • Complies with CEC/EPA no load power consumption and average efficiency regulations • Built-in output constant-current control with primary-side feedback • Low start-up current (10 µA typical) • Built-in soft start • Built-in short circuit protection and output overvoltage protection • Optional AC line under/overvoltage protection • Fixed switching frequency: 45 kHz, 65 kHz or 75 kHz • Dynamic base current control • PFM operation at light load • Built-in current sense resistor short protection D ew N Fo r The ultra-low start-up power and operating current at light load ensure that the iW1690 is ideal for applications targeting the newest regulatory standards for average efficiency and standby power. 3.0 Applications d de m en L N The iW1690 is a high performance AC/DC power supply controller which uses digital control technology to build peak current mode PWM flyback power supplies. The device directly drives a BJT switching device and provides high efficiency along with a number of key built-in protection features while minimizing the external component count, simplifying EMI design and lowering the total bill of material cost. The iW1690 removes the need for secondary feedback circuitry while achieving excellent line and load regulation. It also eliminates the need for loop compensation components while maintaining stability over all operating conditions. Pulse-by-pulse waveform analysis allows for a loop response that is much faster than traditional solutions, resulting in improved dynamic load response. The built-in power limit function enables optimized transformer design in universal off-line applications and allows for a wide input voltage range. es i • gn s 1.0 Features • Low power AC/DC adapter/chargers for cell phones, PDAs, digital still cameras • Low power AC/DC adapter/chargers to replace RCC implementations + VOUT GND N ot R ec om + 1 VSENSE VCC 8 2 VIN OUTPUT 7 3 RIN ISENSE 6 4 IBC GND 5 U1 iW1690 Figure 2.0.1 iW1690 Typical Application Circuit Rev. 1.8 iW1690 February 3, 2012 Page 1 iW1690 Low-Power Off-line Digital PWM Controller 4.0 Pinout Description VCC 8 2 VIN OUTPUT 7 3 RIN ISENSE 6 4 IBC GND 5 es i VSENSE Pin # Name Pin Description 1 VSENSE 2 VIN Analog Input Rectified AC line voltage sense. 3 RIN Analog Input Sense line input voltage. 4 IBC Analog Input Adjust maximum base current. 5 GND 6 ISENSE 7 OUTPUT Output 8 VCC Power Input N Type ew D 1 gn s iW1690 Ground Ground. d Fo r Analog Input Auxiliary voltage sense (used for primary regulation and ZVS). de Analog Input Primary current sense. Used for cycle-by-cycle peak current control and limit. m en Base drive for BJT. N ot R ec om Power supply for control logic and voltage sense for power-on reset circuitry. Rev. 1.8 iW1690 February 3, 2012 Page 2 iW1690 Low-Power Off-line Digital PWM Controller 5.0 Absolute Maximum Ratings Symbol Value DC supply voltage range (pin 8, ICC = 20mA max) VCC -0.3 to 18 Continuous DC supply current at VCC pin ICC 20 mA 120 mA Low voltage output (pin 7) VIN input (pin 2) V -0.6 to 4.0 V -0.3 to 18.0 V -0.3 to 4.0 V PD 526 mW TJ MAX 125 °C TSTG –65 to 150 °C TLEAD 260 °C θJA 160 °C/W 2,000 V ±100 mA N Low voltage analog input (pins 3, 4 and 6) Power dissipation at TA ≤ 25°C Storage temperature Thermal Resistance Junction-to-Ambient m en de ESD rating per JEDEC JESD22-A114 (HBM) d Lead temperature during IR reflow for ≤ 15 seconds Fo r Maximum junction temperature Latch-Up test per JEDEC 78 -0.3 to 4.0 ew VSENSE input (pin 1) V D ICCPK Peak DC supply current at VCC pin Units es i Parameter gn s Absolute maximum ratings are the parameteic values or ranges which can cause permanent damage if exceeded. For maximum safe operating conditions, refer to Electrical Characteristics in Section 6.0. 6.0 Electrical Characteristics Parameter om VCC = 12 V, -40°C ≤ TA ≤ 85°C, unless otherwise specified (Note 1) Symbol Test Conditions Min Typ Max Unit VIN SECTION (Pin 2) VINST(LO) TA= 25°C, positive edge 332 370 407 mV Start-up voltage high threshold VINST(HI) TA= 25°C, positive edge 1.755 1.950 2.145 V 8 15 µA ec Start-up voltage low threshold IIN(ST) VCC = 10 V Shutdown low voltage threshold VUVDC TA= 25°C, negative edge 203 225 248 mV Shutdown high voltage threshold VOVDC TA= 25°C, positive edge 1.791 1.990 2.189 V IVSENSE VSENSE = 2 V 1 μA ot R Start-up current N VSENSE SECTION (Pin 1) Input leakage current Nominal voltage threshold VSENSE(NOM) TA=25°C, negative edge 1.522 1.538 1.553 V Output OVP threshold VSENSE(MAX) TA=25°C, negative edge 1.667 1.700 1.734 V Rev. 1.8 iW1690 February 3, 2012 Page 3 iW1690 Low-Power Off-line Digital PWM Controller VCC = 12 V, -40°C ≤ TA ≤ 85°C, unless otherwise specified (Note 1) Parameter Symbol Test Conditions Min Typ Max Unit 3 6.0 W OUTPUT SECTION (Pin 7) fS ISINK = 5 mA -02/-03/-08/-09 Suffixes PLOAD > 15% of maximum ew VOCP CC limit threshold VCC-TH Input leakage current IISENSE ISENSE = 1 V IRIN RIN = 1 V VIBC RBC = 100 kW kHz 1.2 V 1.1 V 2.5 µA 10 µA VCC SECTION (Pin 8) Undervoltage lockout threshold om 1 VCC(MAX) V 16 V VCC(ST) VCC rising 11 12 13.2 V VCC(UVL) VCC falling 5.0 5.5 6.1 V 2.5 6.0 mA m en Maximum operating voltage Fo r IBC pin voltage de IBC SECTION (Pin 4) Notes: kHz 65 1.6 d Input leakage current Quiescent current N Overcurrent limit threshold Start-up threshold 45 -00/-05 Suffixes PLOAD > 15% of maximum ISENSE SECTION (Pin 6) RIN SECTION (Pin 3) es i Output switching frequency RDS(ON)LO D Output low level ON-resistance gn s 6.0 Electrical Characteristics ICCQ RBC = 100 kW, no IBcurrent ec Note 1. Adjust VCC above the start-up threshold before setting at 12 V. N ot R Note 2. These parameters are not 100% tested, guaranteed by design and characterization. Rev. 1.8 iW1690 February 3, 2012 Page 4 iW1690 Low-Power Off-line Digital PWM Controller 7.0 Typical Performance Characteristics 44 43 VCC = 12 V -50 -25 0 25 50 Ambient Temperature (°C) 75 gn s 2.000 1.998 1.996 100 es i 45 2.002 D 46 -50 ew 47 42 -25 0 25 VCC = 12 V 50 Ambient Temperature (°C) 75 100 Figure 7.0.4 Internal Reference vs. Temperature 69 100 Fo r N Figure 7.0.1 Switching Frequency vs. Temperature -01/-02/-03/-08 Suffixes d 65 63 IOUT (mA) 80 67 de Switching Frequency (kHz) Internal Reference Voltage (V) 2.004 m en Switching Frequency (kHz) 48 60 40 20 VCC = 12 V 61 -50 -25 0 25 50 Ambient Temperature (°C) 75 100 om Figure 7.0.2 Switching Frequency vs. Temperature -00/-05 Suffixes 0 KBC = 10 40 60 RBC (kΩ) 80 100 Figure 7.0.5 IOUT vs. RBC ec VCC Start-up Threshold (V) 12.2 KBC = 31 R 12.1 ot 12.0 N 11.9 11.8 -50 -25 0 25 50 Ambient Temperature (°C) 75 100 Figure 7.0.3 Start-Up vs. Temperature Rev. 1.8 iW1690 February 3, 2012 Page 5 iW1690 Low-Power Off-line Digital PWM Controller 3 Start-up ENABLE ENABLE VIN_A 0.2 V ~ 2.0 V ADC 1V VCC 4 IBC D RIN 8 2 es i VIN gn s 8.0 Functional Block Diagram Signal Conditioning 1 Digital Logic Control VVMS N VFB ew VSENSE VOCP 5 r GND Fo DAC IPEAK 0.2 V ~ 1.1 V 1.2 V ISENSE 6 + – – d VIPK – + OUTPUT 7 m en 9.0 Theory of Operation de Figure 8.0.1 iW1690 Functional Block Diagram R ec om The iW1690 is a digital controller which uses a new, proprietary primary-side control technology to eliminate the opto-isolated feedback and secondary regulation circuits required in traditional designs. This results in a low-cost solution for low power AC/DC adapters. The core PWM processor uses fixed-frequency Discontinuous Conduction Mode (DCM) operation at higher power levels and switches to variable frequency operation at light loads to maximize efficiency. Furthermore, iWatt’s digital control technology enables fast dynamic response, tight output regulation, and full featured circuit protection with primary-side control. N ot Referring to the block diagram in Figure 8.0.1, the digital logic control block generates the switching on-time and off-time information based on the line voltage and the output voltage feedback signal and provides commands to dynamically control the BJT base current. The system loop is automatically compensated internally by a digital error amplifier. Adequate system phase margin and gain margin are guaranteed by design and no external analog components are required for loop compensation. The iW1690 uses an advanced digital control algorithm to reduce system design time and improve reliability. Rev. 1.8 Furthermore, accurate secondary constant-current operation is achieved without the need for any secondary-side sense and control circuits. The iW1690 uses PWM mode control at higher output power levels and switches to PFM mode at light load to minimize power dissipation to meet the Blue Angel specification. Additional built-in protection features include overvoltage protection (OVP), output short circuit protection (SCP) and soft-start, AC low line brown out, overcurrent protection, single pin fault protection and Isense fault protection. iWatt’s digital control scheme is specifically designed to address the challenges and trade-offs of power conversion design. This innovative technology is ideal for balancing new regulatory requirements for green mode operation with more practical design considerations such as lowest possible cost, smallest size and high performance output control. iW1690 February 3, 2012 Page 6 iW1690 Low-Power Off-line Digital PWM Controller 9.2 Start-up Pin 1 – VSENSE Prior to start-up the VIN pin charges up the VCC capacitor through the diode between VIN and VCC. Pin 3 – RIN If at any time the VCC voltage drops below VCC(UVL) threshold then all the digital logic is fully reset. At this time ENABLE switches off so that the VCC capacitor can be charged up again towards the start-up threshold. N Sense line input voltage. Connect this pin to GND with the RIN resistor. es i Sense signal input representing the rectified line voltage. VIN is used for line regulation. The input line voltage is scaled using a resistor network. It also provides input undervoltage and overvoltage protection. This pin also provides the supply current to the IC during start-up. D Pin 2 – VIN When VCC is fully charged to a voltage higher than the startup threshold VCC(ST), the ENABLE signal becomes active to enable the control logic, the ENABLE switch turns on, and the analog-to-digital converter begins to sense the input voltage. Once the voltage on the VIN pin is above VINST(LO) but below VINST(HI), the iW1690 commences soft start function. An adaptive soft-start control algorithm is applied at startup state, during which the initial output pulses will be small and gradually get larger until the full pulse width is achieved. The peak current is limited cycle by cycle by Ipeak comparator. ew Sense signal input from auxiliary winding. This provides the secondary voltage feedback used for output regulation. gn s 9.1 Pin Detail Pin 4 – IBC Fo Pin 5 – GND r Adjusts the maximum base current for the BJT drive. Ground. Start-up Sequencing VIN d Pin 6 – ISENSE m en Pin 7 – OUTPUT de Primary current sense. Used for cycle-cycle peak current control limit. Base drive for the external power BJT switch. Pin 8 – VCC VCC ENABLE Figure 9.2.1 Start-up Sequencing Diagram 9.3 Understanding Primary Feedback Figure 9.3.1 illustrates a simplified flyback converter. When the switch Q1 conducts during tON(t), the current ig(t) is directly drawn from rectified sinusoid vg(t). The energy Eg(t) is stored in the magnetizing inductance LM. The rectifying diode D1 is reverse biased and the load current IO is supplied by the secondary capacitor CO. When Q1 turns off, D1 conducts and the stored energy Eg(t) is delivered to the output. N ot R ec om Power supply for the controller during normal operation. The controller will start up when VCC reaches 12 V (typical) and will shut-down when the VCC voltage is 5.5 V (typical). A decoupling capacitor should be connected between the VCC pin and GND. VCC(ST) Rev. 1.8 iW1690 February 3, 2012 Page 7 iW1690 Low-Power Off-line Digital PWM Controller + ig(t) id(t) N:1 D1 vg(t) vin(t) VO + CO VAUX = VO x IO VAUX VAUX 0V Figure 9.3.1 Simplified Flyback Converter dt = vg (t ) (9.1) LM vg (t ) × tON (9.2) LM LM E = × ig _ peak (t ) 2 g 2 m en This current represents a stored energy of: de ig _ peak (t ) = (9.3) ec om When Q1 turns off at tO, ig(t) in LM forces a reversal of polarities on all windings. Ignoring the communication-time caused by the leakage inductance LK at the instant of turn-off tO, the primary current transfers to the secondary at a peak amplitude of: NP × ig _ peak (t ) NS R id = (t ) (9.4) N ot Assuming the secondary winding is master, the auxiliary winding is slave. Rev. 1.8 NP ew Figure 9.3.2 Auxiliary Voltage Waveforms The auxiliary voltage is given by: N AUX (VO + ∆V ) NS N = VAUX (9.5) and reflects the output voltage as shown in Figure 9.3.2. The voltage at the load differs from the secondary voltage by a diode drop and IR losses. The diode drop is a function of current, as are IR losses. Thus, if the secondary voltage is always read at a constant secondary current, the difference between the output voltage and the secondary voltage will be a fixed ΔV. Furthermore, if the voltage can be read when the secondary current is small, ΔV will also be small. With the iW1690, ΔV can be ignored. d At the end of on-time, the current has ramped up to: NAUX Fo dig (t ) VAUX = -VIN x r In order to tightly regulate the output voltage, the information about the output voltage and load current needs to be accurately sensed. In the DCM flyback converter, this information can be read via the auxiliary winding or the primary magnetizing inductance (LM). During the Q1 on-time, the load current is supplied from the output filter capacitor CO. The voltage across LM is vg(t), assuming the voltage dropped across Q1 is zero. The current in Q1 ramps up linearly at a rate of: D Q1 NS es i – TS(t) NAUX gn s iin(t) The real-time waveform analyzer in the iW1690 reads this information cycle by cycle. The part then generates a feedback voltage VFB. The VFB signal precisely represents the output voltage under most conditions and is used to regulate the output voltage. 9.4 Constant Voltage Operation After soft-start has been completed, the digital control block measures the output conditions. It determines output power levels and adjusts the control system to a light load or a heavy load. If this is in the normal range, the device operates in the Constant Voltage(CV) mode, and changes the pulse width (Ton), and off time (Toff) in order to meet the output voltage regulation requirements. During this mode the PWM switching frequency is either 45 kHz or 65kHz, depending on which product option is being used. If no voltage is detected on VSENSE it is assumed that the auxiliary winding of the transformer is either open or shorted and the iW1690 shuts down. iW1690 February 3, 2012 Page 8 iW1690 Low-Power Off-line Digital PWM Controller 9.8 Internal Loop Compensation The constant current mode (CC mode) is useful in battery charging applications. During this mode of operation the iW1690 will regulate the output current at a constant maximum level regardless of the output voltage drop, while avoiding continuous conduction mode. The iW1690 incorporates an internal Digital Error Amplifier with no requirement for external loop compensation. For a typical power supply design, the loop stability is guaranteed to provide at least 45 degrees of phase margin and –20dB of gain margin. To achieve this regulation the iW1690 senses the load current indirectly through the primary current. The primary current is detected by the ISENSE pin through a resistor from the BJT emitter to ground. 9.9 Voltage Protection Functions es i D ew r N CC mode Output Voltage The iW1690 includes functions that protect against input line undervoltage and overvoltage (UV/OV) and the output overvoltage (OVP). The input voltage is monitored by the VIN pin and the output voltage is monitored by the VSENSE pin. If the voltage at these pins exceed their undervoltage or overvoltage thresholds the iW1690 shuts down immediately. However, the IC remains biased which discharges the VCC supply. Once VCC drops below the UVLO threshold, the controller resets itself and then initiates a new soft-start cycle. The controller continues attempting start-up until the fault condition is removed. CV mode VNOM gn s 9.5 Constant Current Operation Figure 9.6.1 Power Envelope ec om The iW1690 normally operates in a fixed frequency PWM mode when IOUT is greater than approximately 10% of the specified maximum load current. As the output load IOUT is reduced, the on-time tON is decreased. At the moment that the load current drops below 10% of nominal, the controller transitions to Pulse Frequency Modulation (PFM) mode. Thereafter, the on-time will be modulated by the line voltage and the off-time is modulated by the load current. The device automatically returns to PWM mode when the load current increases. 9.7 Variable Frequency Operation R Peak-current limit (PCL), over-current protection (OCP) and sense-resistor short protection (SRSP) are features built-in to the iW1690. With the ISENSE pin the iW1690 is able to monitor the primary peak current. This allows for cycle by cycle peak current control and limit. When the primary peak current multiplied by the ISENSE sense resistor is greater than 1.2 V an over current (OCP) is detected and the IC will immediately turn off the base drive until the next cycle. The OCP is not a latched shutdown. The base drive will send out switching pulse in the next cycle, and the switching pulse will continue if the OCP threshold is not reached; or, the switching pulse will shut down again if the OCP threshold is still reached. d m en 9.6 PFM Mode at Light Load de Output Current IOUT(CC) Fo 9.10 PCL, OC and SRS Protection N ot At each of the switching cycles, the falling edge of VSENSE will be checked. If the falling edge of VSENSE is not detected, the off-time will be extended until the falling edge of VSENSE is detected. The maximum switching period is seen at 75 µs. When the switching period reaches 75 µs, the iW1690 immediately shuts off. This avoids operating at continuous conduction mode. If the ISENSE sense resistor is shorted there is a potential danger of the over current condition not being detected. Thus the IC is designed to detect this sense-resistor-short fault after the start up, and shutdown immediately. Similar to the OVP shutdown, the VCC will be discharged since the IC remains biased. Once VCC drops below the UVLO threshold, the controller resets itself and then initiates a new soft-start cycle. The controller continues attempting start-up, but does not fully start-up until the fault condition is removed. Rev. 1.8 iW1690 February 3, 2012 Page 9 iW1690 Low-Power Off-line Digital PWM Controller 9.12 Dynamic Base Current Control 1V RBC gn s es i D (9.6) m en de d I BC _ REF = Where KBC is dynamically changed by the digital control block: the heavier the load is, the higher KBC becomes. The minimum KBC is limited to 10, and the maximum KBC is limited to 31. Therefore, the maximum IB_OUT is set by (1V/ RBC)*100*31. The range of RBC is 40 kΩ to 100 kΩ. Choosing different RBC can adjust the maximum IB_OUT for different BJT’s and/or different power levels. The minimum and maximum IB_OUT are given by table 9.12.1. Fo One important feature of the iW1690 is that it directly drives a BJT switching device with dynamic base current control to optimize performance. The reference BJT base current is adjusted by connecting an external RBC resistor from IBC to GND, which generates a constant current source with a value of: (9.7) ew To calculate the amount of cable compensation needed, take the resistance of the cable and connector and multiplyby the maximum output current. I B _ OUT = I BC _ REF ×100 × K BC N The iW1690 incorporates an innovative method to compensate for any IR drop in the secondary circuitry including cable and cable connector. A 5 W AC adapter with 5 V DC output has 6% deviation at 1 A load current due to the drop across the DC cable without cable compensation. The iW1690 cancels this error by providing a voltage offset to the feedback signal based on the amount of load current detected. IBC_REF is multiplied by 100 times inside the IC and is then used to control the base current for the BJT drive, IB_OUT, which is the output IB current at the OUTPUT pin. The IB_OUT is dynamically controlled according to the power supply load change, as: r 9.11 Cable Drop Compensation IBC_REF IB_OUT IBC_REF IB_OUT 0.025 25 0.01 10 mA 31 0.025 77.5 0.01 31 mA KBC RBC = 100 kW Units Table 9.12.1 N ot R ec Maximum 10 om Minimum RBC = 40 kW Rev. 1.8 iW1690 February 3, 2012 Page 10 iW1690 Low-Power Off-line Digital PWM Controller 8-Lead Small Outline (SOIC) Package H e h x 45° A1 A2 B 1.75 A1 0.0040 0.010 0.10 0.25 A2 0.049 0.059 1.25 1.50 B 0.014 0.019 0.35 0.49 C 0.007 0.010 0.19 0.25 D 0.189 0.197 4.80 5.00 E 0.150 0.157 3.80 4.00 e A SEATING PLANE L α C 0.050 BSC MAX 1.27 BSC H 0.228 0.244 5.80 6.20 h 0.10 0.020 0.25 0.50 L 0.016 0.049 0.4 1.25 α 0° 8° r COPLANARITY 0.10 (0.004) 1.35 es i 4 MIN 0.069 D 1 MAX 0.053 Millimeters ew 5 MIN A N E 8 Inches Symbol D gn s 10.0 Physical Dimensions Fo Figure 10.0.1. Physical dimensions, 8-lead SOIC package Compliant to JEDEC Standard MS12F d Controlling dimensions are in inches; millimeter dimensions are for reference only de This product is RoHS compliant and Halide free. m en Soldering Temperature Resistance: [a] Package is IPC/JEDEC Std 020D Moisture Sensitivity Level 1 [b] Package exceeds JEDEC Std No. 22-A111 for Solder Immersion Resistance; package can withstand 10 s immersion < 270˚C Dimension D does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15 mm per end. Dimension E1 does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25 mm per side. N ot R ec om The package top may be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plastic bocy exclusive of mold flash, tie bar burrs, gate burrs and interlead flash, but including any mismatch between the top and bottom of the plastic body. Rev. 1.8 iW1690 February 3, 2012 Page 11 iW1690 Low-Power Off-line Digital PWM Controller gn s 11.0 Ordering Information Part Number Options Package Description iW1690-00 fSW = 65 kHz, Cable Comp = 0 mV SOIC-8 Tape & Reel2 iW1690-02 fSW = 45 kHz, Cable Comp = 150 mV, No OVDC1 SOIC-8 iW1690-03 fSW = 45 kHz, Cable Comp = 412 mV, No OVDC1 iW1690-05 fSW = 65 kHz, Cable Comp = 337 mV iW1690-07 fSW = 75 kHz, Cable Comp = 0 mV iW1690-08 fSW = 45 kHz, Cable Comp = 337 mV iW1690-09 fSW = 45 kHz, Cable Comp = 0 mV, No OVDC1 es i Tape & Reel2 SOIC-8 Tape & Reel2 SOIC-8 Tape & Reel2 SOIC-8 Tape & Reel2 SOIC-8 Tape & Reel2 ew D SOIC-8 N Note 1: No input over-voltage shutdown. Tape & Reel2 N ot R ec om m en de d Fo r Note 2: Product is provided on 13” reels, 2,500 per reel. Minimum ordering quantity is 2,500. This product is RoHS compliant and Halide free. Rev. 1.8 iW1690 February 3, 2012 Page 12 iW1690 Low-Power Off-line Digital PWM Controller About iWatt gn s iWatt Inc. is a fabless semiconductor company that develops intelligent power management ICs for computer, communication, and consumer markets. The company’s patented pulseTrain™ technology, the industry’s first truly digital approach to power system regulation, is revolutionizing power supply design. es i Trademark Information © 2012 iWatt, Inc. All rights reserved. iWatt, EZ-EMI, and pulseTrain are trademarks of iWatt, Inc. All other trademarks and registered trademarks are the property of their respective companies. D Contact Information ew Web: https://www.iwatt.com E-mail: [email protected] r Fo Disclaimer N Phone: 408-374-4200 Fax: 408-341-0455 iWatt Inc. 675 Campbell Technology Parkway, Suite 150 Campbell, CA 95008 de d iWatt reserves the right to make changes to its products and to discontinue products without notice. The applications information, schematic diagrams, and other reference information included herein is provided as a design aid only and are therefore provided as-is. iWatt makes no warranties with respect to this information and disclaims any implied warranties of merchantability or non-infringement of third-party intellectual property rights. m en iWatt cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an iWatt product. No circuit patent licenses are implied. Certain applications using semiconductor products may involve potential risks of death, personal injury, or severe property or environmental damage (“Critical Applications”). om IWATT SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE‑SUPPORT APPLICATIONS, DEVICES OR SYSTEMS, OR OTHER CRITICAL APPLICATIONS. ec Inclusion of iWatt products in critical applications is understood to be fully at the risk of the customer. Questions concerning potential risk applications should be directed to iWatt, Inc. N ot R iWatt semiconductors are typically used in power supplies in which high voltages are present during operation. High-voltage safety precautions should be observed in design and operation to minimize the chance of injury. Rev. 1.8 iW1690 February 3, 2012 Page 13