Application Note, V1.0, Mar 2013 I CE 3B xx6 5 J ( G ) CoolSET® F3 Jitter Version Design Guide (DIP-8 & DSO-16/12) Power Management & Supply N e v e r s t o p t h i n k i n g . Published by Infineon Technologies AG 81726 Munich, Germany © 2013 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. ICE3Bxx65J(G) Revision History: Previous Version: Page 2013-03 V1.0 Subjects (major changes since last revision) CoolSET® F3 Jitter Version Design Guide (DIP-8 & DSO-16/12): License to Infineon Technologies Asia Pacific Pte Ltd Kyaw Zin Min Kok Siu Kam Eric We Listen to Your Comments Any information within this document that you feel is wrong, unclear or missing at all? Your feedback will help us to continuously improve the quality of this document. Please send your proposal (including a reference to this document) to: [email protected] AN-PS0076 ICE3Bxx65J(G) Table of Contents Page 1 Introduction .............................................................................................................................. 5 2 List of Features ........................................................................................................................ 5 3 Package .................................................................................................................................... 6 4 Block Diagram .......................................................................................................................... 7 5 Typical Application Circuit ...................................................................................................... 8 6 6.1 6.2 6.2.1 6.3 6.3.1 6.3.2 6.3.3 6.3.4 6.4 6.4.1 6.4.2 6.5 6.6 6.6.1 6.6.2 Functional description and component design ...................................................................... 9 Startup time ............................................................................................................................... 9 Soft Start .................................................................................................................................... 9 Vcc capacitor ........................................................................................................................... 10 Low standby power - Active Burst Mode ................................................................................... 10 Entering Active Burst Mode ...................................................................................................... 10 Working in Active Burst Mode................................................................................................... 11 Leaving Active Burst Mode ....................................................................................................... 12 Minimum VCC supply voltage during burst mode ....................................................................... 13 Low EMI noise ......................................................................................................................... 13 Frequency jittering.................................................................................................................... 13 Other suggestions to solve EMI issue ....................................................................................... 14 Tight control in maximum power (Propagation delay compensation) ......................................... 14 Protection Features .................................................................................................................. 15 Auto restart protection mode .................................................................................................... 15 Blanking Time for over load protection ...................................................................................... 15 7 Product portfolio of CoolSET ®-F3 Jitter Version (DIP-8 & DSO-16/12) ................................ 16 8 Useful formula for the SMPS design ..................................................................................... 16 9 References ............................................................................................................................. 17 Application Note 4 2013-03-19 ICE3Bxx65J(G) 1 Introduction ® The CoolSET - F3(Jitter Version), ICE3Bxx65J(G) is the further development of the third generation CoolSET® -F3 with a frequency jitter feature for better EMI and BiCMOS technology to provide a wider Vcc operating range and a lower controller power consumption. The switching frequency is running at 67 kHz and it targets for DVD player, set-top box, portable game console, white goods, smart meter, auxiliary power supply for server/PC, etc. This application note provides detail functional description of the new features. The description of all other functions and calculations are shown in the datasheet as well as in the application note “AN-PS0076”. 2 List of Features 650V Avalanche Rugged CoolMOS® with built in Startup Cell Active Burst Mode for lowest Standby Power @ light load controlled by Feedback Signal Fast Load Jump Response in Active Burst Mode 67 kHz fixed Switching Frequency Auto Restart Mode for Over temperature Detection Auto Restart Mode for Over voltage Detection Auto Restart Mode for Over load and Open Loop Auto Restart Mode for VCC Under voltage User defined Soft Start Minimum of external Components required Max Duty Cycle 75% Overall Tolerance of Current Limiting < ±5% Internal Leading Edge Blanking BiCMOS technology provides wide VCC Range Frequency Jittering for Low EMI Application Note 5 2013-03-19 ICE3Bxx65J(G) 3 Package The package for F3(Jitter Version) ICE3Bxx65J product is DIP-8. Figure 1 Pin configuration - ICE3Bxx65J Pin Name 1 SoftS Soft-Start Description 2 FB Feedback 3 CS Current Sense/650V CoolMOS Source 4 Drain 650V CoolMOS Drain 5 Drain 650V CoolMOS Drain 6 N.C Not Connteced 7 VCC Controller Supply Voltage 8 GND Controller Ground ® 1 ® 1 ® The package for F3(Jitter Version) ICE3Bxx65JG product is DSO-16/12 N.C 12 Pin Name Description 1 N.C. Not Connected 2 SoftS Soft-Start 3 FB FeedBack 4 CS Current Sense/650V CoolMOS Source 5 Drain 650V CoolMOS Drain 6 Drain 650V CoolMOS Drain 7 Drain 650V CoolMOS Drain 8 Drain 650V CoolMOS Drain 9 N.C. Not Connected 10 N.C. Not Connected 11 VCC Controller Supply Voltage 12 GND Controller Ground GND SoftS 2 11 VCC FB 3 10 N.C CS 4 9 N.C. Drain 5 8 Drain Drain 6 7 Drain Figure 2 1 1 ® 1 ® 1 ® 1 ® 1 ® Pin configuration - ICE3Bxx65JG at Tj=110°C Application Note 6 2013-03-19 Application Note Figure 3 FB CSoftS SoftS 85 ... 270 VAC 7 2pF 25k RFB 3.0V 3.61V 1.35V 4.5V 4.0V 3.1V 20.5V VCC T1 T2 C6b C6a C5 C4 C3 C2 UVLO C13 3.25k FF2 R S G12 & Q T3 Spike Blanking 8.0us G5 & Tj >140°C & G6 & G11 Active Burst Mode Auto Restart Mode Power-Down Reset Thermal Shutdown G13 & 0.8V Internal Bias Power Management ICE3xxx65J / CoolSET™- F3 Jitter version Control Unit 5V S1 3V RSoftS 5V CBulk 5V x3.2 C8 PWM Comparator & G7 Soft-Start Comparator Current Mode PWM OP 0.6V C7 Soft Start 10.3V 18V Undervoltage Lockout Voltage Reference & G10 C12 C10 Vcsth 0.32V 1 G8 0.75 Propagation-Delay Compensation Freq Jitter Clock Duty Cycle max Oscillator VCC 1pF & G9 Gate Driver D1 10k Startup Cell Current Limiting Leading Edge Blanking 220ns FF1 S R Q Drain Depl. CoolMOS™ PWM Section CVCC Snubber CS RSense GND + 4 Converter DC Output VOUT - ICE3Bxx65J(G) Block Diagram Block Diagram of ICE3Bxx65J(G) 2013-03-19 Application Note Figure 4 N 0.5A F1 2 x 27mH, 0.5A EMI L1 2KBB40 BR1 8 1uF C7 1 FB 2 GND 8 C8 1nF 3 R4 1.5R Is en s e IC1 ICE3 B05 6 5 J D RA I N 5 D RA I N 7 510R R2 22u/25V V CC S of ts t ZD1 C5 D1 UF4005 R1 150k/2W + C6 0.1u 24V C2 47uF/400V + 4 R4A 15R D2 1N4148 C3 2n2F/400V 8 6 1 2 3 IC2 SFH617A-3 EF20 TR1 4 2 1 4 3 5 Rc6 470 R21 Rc5 2.2K D21 SB540 C23 * + Rc4 6.8k Rc3A * Cc1 1uF L21 1.5uH C21 1800uF/25V Cc2 1nF IC3 TL431 * Rc3 10k Rc2 0R Rc1 10k C22 220uF/25V + GND 5V/2.4A 5 85V - 265Vac L C1 0.1uF/275V C4 2.2nF/250V, Y1 ICE3Bxx65J(G) Typical Application Circuit Typical application circuit with ICE3B0565J 12W 5V 2013-03-19 ICE3Bxx65J(G) 6 Functional description and component design 6.1 Startup time Startup time is counted from applying input voltage to IC turn on. ICE3Bxx65J(G) has a startup cell which is connected to input bulk capacitor. When there is input voltage, the startup cell will act as a constant current source to charge up the Vcc capacitor and supply energy to the IC. When the Vcc capacitor reaches the Vcc_on threshold 18V, the IC turns on. Then the startup cell is turned off and the Vcc is supplied by the auxiliary winding. Start up time is independent from the AC line input voltage and it can be calculated by the equation (1). Figure 4 shows the start up time of 85Vac line input. where, IVCCcharge : 0.965mA (average current of IVCCcharge2 and IVCCcharge3) VVCCon : IC turns on threshold ( 18V ) CVCC : Vcc capacitor Please refer to the datasheet for the symbol used in the equation. 490ms Channel Channel Channel Channel 1; C1 : Drain voltage (VD) 2; C2 : Supply voltage (VCC) 3; C3 : Feedback voltage (VFB) 4; C4 : Soft Start voltage ( VSoftS ) Measured startup time = 490ms Start-up @ 85Vac & max. load Figure 5 The start-up time at AC line input voltage of 85Vac Pre-caution : For a typical application, start up should be VCC ramps up first, other pin (such as FB pin) voltage will follow VCC voltage to ramp up. It is recommended not to have any voltage on other pins (such as FB; SoftS and CS) before VCC ramps up. 6.2 Soft Start When the IC is turned on after the start-up time, the soft start capacitor at pin1, CSoftS is immediately charged up to approximately 0.8V and from this point IC starts switching. The soft start voltage VSoftS is generated by CSoftS and the internal pull up resistor RSoftS. The duty cycle of the gate drive is determined by the VSoftS during the soft start phase, which is terminated when VSoftS reaches 3.1V. Afterward, IC goes into normal mode and the duty cycle is dependent on the FB signal. The duration of the soft start can be estimated by the equation (2). Figure 6 shows the soft start behaviour at 85VAC input and full load. It can be seen that the primary peak current follows VSST voltage and slowly increase to the maximum. The soft start time is approximately 35.6ms. where, Rsofts Csofts Application Note : internal soft start resistor (45kΩ) : Soft start capacitor 9 2013-03-19 ICE3Bxx65J(G) 35.6ms Channel Channel Channel Channel 1; C1 : Current sense voltage (VCS) 2; C2 : Supply voltage (VCC) 3; C3 : Feedback voltage (VFB) 4; C4 : Soft Start voltage ( VSoftS ) Soft Start time = 35.6ms Soft start @ Vin=85Vac & max. load Figure 6 Soft start at AC line input voltage of 85 Vac & full load 6.2.1 Vcc capacitor The minimum value of the Vcc capacitor is determined by voltage drop during the soft start time. The formula is expressed in equation (3). where, IVCCsup_g_max tss VCChys : supply current with active gate ( 3.6mA) : soft start time ( 35.6ms ) : Vcc turn-on/off hysteresis voltage ( 7.7V ) Therefore, the minimum Vcc capacitance can be 11.09μF. In order to give more margins, 22uF is taken for the design. The startup time tStartUp is then 0.41s. The measured start up time is 0.49s (Figure 5). A 0.1uF filtering capacitor is always needed to add as near as possible to the Vcc pin to filter the high frequency noise. 6.3 Low standby power - Active Burst Mode The IC will enter Active Burst Mode function at light load condition which enables the system to achieve the lowest standby power requirement of less than 100mW. Active Burst Mode means the IC is always in the active state and can therefore immediately response to any changes on the FB signal, VFB. 6.3.1 Entering Active Burst Mode Because of the current mode control scheme, the feedback voltage VFB actually controls the power delivery to output. When the output load is getting lower, the feedback voltage VFB drops. If it stays below 1.35V for a timeframe set by the blanking time, the IC enters into the burst mode operation. The threshold power to enter burst mode is: where, Lp : transformer primary inductance VFBC5 : feedback level to enter burst mode (1.35V) VMax-Ramp fs AV : voltage ramp offset (0.6V) : switching frequency : PWM OP gain (3.2) Rcs : current sense resistor Application Note 10 2013-03-19 ICE3Bxx65J(G) Figure 7 shows the waveform with the load drops from nominal load to light load. After the 21ms blanking time IC goes into burst mode. The blanking time to enter burst mode is: where, Rsofts Csofts : internal soft start resistor (45kΩ) : Soft start capacitor Channel Channel Channel Channel 21ms 1; C1 : Drain voltage (VD) 2; C2 : Feedback voltage (VFB) 3; C3 : Soft Start voltage ( VSoftS ) 4; C4 : Output voltage ( Vo ) Entering Active Burst mode with blanking time when load changes from full to light @ Vin=85Vac Figure 7 Entering active burst mode 6.3.2 Working in Active Burst Mode In the active burst mode, the IC is constantly monitoring the output voltage by feedback pin, V FB, which controls burst duty cycle and burst frequency. The burst “ON” starts when VFB reaches 3.61V and it stops when VFB is dropped to 3V. During burst “ON”, the primary current limit is reduced to Vcs2 ( 32% of maximum peak current ) to reduce the conduction losses and to avoid audible noise. The FB voltage is swinging like a saw tooth between 3V and 3.61V. The corresponding secondary output ripple (peak to peak) is controlled to be small. It can be calculated by equation (6). where, Ropto Rfb Gopto GTL431 :series resistor with opto-coupler at secondary side (e.g. Rc6 in Figure 4) :IC internal pull up resistor connected to FB pin (Rfb=14KΩ) :current transfer gain of opto-coupler :voltage transfer gain of the loop compensation network (e.g. Rc1, Rc2, Rc3, Rc4, Rc5, Rc6, Cc1, Cc2 in Figure 4) Vfb : feedback voltage change (0.61V) Figure 8 is the output ripple waveform of the 12W 5V demo board. The burst ripple voltage is about 19mV. Channel 1; C1 : Drain voltage (VD) Channel 2; C2 : Feedback voltage (VFB) Channel 4; C4 : Output ripple voltage (Vripple_pk_pk ) Vripple_pk_pk=60mV Probe terminal end with decoupling capacitor of 0.1uF(ceramic) & 1uF(electrolytic), 20MHz filter Output ripple voltage @ 85Vac and 0.5W load Figure 8 Application Note Output ripple during Active Burst Mode at light load 11 2013-03-19 ICE3Bxx65J(G) 6.3.3 Leaving Active Burst Mode When the output load increases to be higher than the maximum exit level of burst mode, Vout will drop a little and VFB will rise up fast to exceed 4.5V. The system leaves burst mode immediately when VFB reaches 4.5V. Once system leaves burst mode, the current sense voltage limit is set to Vcsth =1.06V & the feedback voltage VFB swings back to the normal control level. The leaving burst power threshold (i.e. maximum power to be handled during burst operation) is expressed in equation (7). However, the actual power can be higher as it would include propagation delay time. where, Vcs 2 : peak current in the burst mode (0.32V) Vcsth : maximum current limit threshold at CS pin Pin_max : maximum input power RCS : current sense resistor Lp : primary inductance of transformer The leave burst mode timing diagram is shown in Figure 9. 4.5V 3.61V V FB 3V Vout Vout_AV Vout_drop_max Vcsth V CS2 Figure 9 Vout_drop during leaving burst mode The maximum output drop during the transition can be estimated in equation (8). where, Ropto Rfb Gopto GTL431 :series resistor with opto-coupler at secondary side (e.g. Rc6 in Figure 4) :IC internal pull up resistor connected to FB pin (Rfb=14KΩ) :current transfer gain of opto-coupler :voltage transfer gain of the loop compensation network (e.g. Rc1, Rc2, Rc3, Rc4, Rc5, Rc6, Cc1, Cc2 in Figure 4) Figure 10 is the captured waveform when there is a load jump from light load to full load. The output ripple drop during the transition is about 123mV. Application Note 12 2013-03-19 ICE3Bxx65J(G) Channel 1; C1 : Current sense voltage (VCS) Channel 3; C3 : FB voltage (VFBB) Channel 4; C4 : Output ripple voltage (Vo) 123mV Leaving Active Burst mode when load change from light to full @ Vin=85Vac Figure 10 Leaving burst mode waveform 6.3.4 Minimum VCC supply voltage during burst mode It is particularly important that the Vcc voltage must stay above VVCCoff (i.e. 10.3V). Otherwise, the expected low standby power cannot be achieved. The IC will go into auto-restart mode instead. A reference Vcc circuit is presented in Figure 4. This is for a low cost transformer design where the transformer coupling is not too good. Thus the circuit ZD1 is added to clamp the Vcc voltage exceeding 25.5V in extreme case such as high load and the Vcc OVP protection is triggered. If the transformer coupling is good, this circuit is not needed. 6.4 Low EMI noise 6.4.1 Frequency jittering The IC is running at a fixed frequency of 67kHz with jittering frequency of ±4% (±2.7kHz) and adjustable jittering period in a switching modulation period by changing the value of the capacitor, CSoftS. This kind of frequency modulation can effectively help to obtain a low EMI noise level particularly for conducted EMI. The jittering frequency measured for ICE3B0565J is 63 KHz ~ 68 KHz with a jittering period of 3.2ms which is controlled by CSoftS (refer to Figure 11). where, Channel 1; C1 : Drain voltage (VD) Channel 4; C4 : Soft Start voltage ( VSoftS ) Channel F1; F1 : Frequency track of Drain Frequency jittering from 63 kHz ~ 68 kHz with a jittering period of 3.2ms Frequency jittering @ 85Vac and max. load Figure 11 Application Note Switching frequency jittering 13 2013-03-19 ICE3Bxx65J(G) 6.4.2 Other suggestions to solve EMI issue Some more suggestions to improve the EMI performance are listed below. 1. Add RCD clamper circuit to the primary winding of the transformer: RCD clamper circuit (D1, R1 & C3) can absorb the current due to leakage inductance of transformer during switch off time of the MOSFET, so voltage spike of the drain can clamp to desired voltage level and suppress the EMI noise (refer to Figure 4). 2. Add capacitor (CDS) at the drain source pin: CDS can slow down the turn off speed of the MOSFET and the high ΔV/Δt noise will be reduced and so is the EMI noise. The drawback is more energy will be dissipated due to slower turn off speed of MOSFET. 3. Add snubber circuit to the output rectifier: Most of the radiated EMI noise comes out from the output of the system especially for a system with output cable. Adding snubber circuit (R21 and C23) to the output rectifier is a more direct way to suppress those EMI noise (refer to Figure 4). 4. Reduce the reflection voltage: if the secondary to primary reflection voltage is reduced, the switching voltage at drain can also be reduced. Hence the voltage switching noise is reduced and so is the EMI noise. The drawback is the reverse voltage of the secondary rectifier will increase. 6.5 Tight control in maximum power (Propagation delay compensation) The maximum power of the system is changed with the input voltage; higher voltage got higher maximum power. This is due to the propagation delay of the IC and the different rise time of the primary current under different input voltage. The propagation delay time is around 200ns. But if the primary current rise time is faster, the maximum power will increase. The power difference can be as high as >14% between high line and low line. In order to make the maximum power control become tight, a propagation delay compensation network is implemented so that the power difference is greatly reduced to best around 2%. Figure 14 shows the compensation scheme of the IC. The equation (10) explains the rate of change of the current sense voltage is directly proportional to the input voltage and current sense resistor. For a DCM operation, the operating range for the dVsense/dt is from 0.1 to 0.7. It can show in Figure 12 that higher dVsense/dt will give more compensation; i.e. lower value of Vsense. dI p dt dI p Vin V dV V Rsense Rsense in sense Rsense in Lp dt Lp dt Lp (10) where, Ip : primary peak current, Vin : input voltage, Lp : primary inductance of the transformer, Vsense : current sense voltage, Rsense : current sense resistor This function is limited to discontinuous conduction mode flyback converter only. without compensation with compensation V 1,3 1,25 VSense 1,2 1,15 1,1 1,05 1 0,95 0,9 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 2 dVSense dt Figure 12 Application Note V s Propagation delay compensation curve 14 2013-03-19 ICE3Bxx65J(G) 6.6 Protection Features Protection is one of the major factors to determine whether the system is safe and robust. Therefore sufficient protection is necessary. A list of protections and the failure conditions are shown in the following table. Protection function Failure condition Protection Mode Vcc over-voltage Vcc > 20.5V & VSoftS < 4V & VFB > 4.5V & last for 8μs Auto Restart Mode Over-temperature (controller junction) TJ > 140°C & last for 8μs Auto Restart Mode Over-load / Open loop VFB > 4.5V & VSOFTS > 4V (blanking time counted from charging C SST from (3.2V~3.6V to 4V ) Auto Restart Mode Vcc under-voltage / short opto-coupler Vcc < 10.3V Auto Restart Mode 6.6.1 Auto restart protection mode When the failure condition meets the auto restart protection mode, the IC will go into auto restart. The switching pulse will stop. Then the Vcc voltage will drop. When the Vcc voltage drops to 10.3V, the startup cell will turn on again. The Vcc voltage is then charged up. When it hits 18V, the IC will turn on and the startup cell will turn off. It would then start the startup phase with soft start. After the startup phase the failure condition is checked to determine whether the fault persists. If the fault is removed, it will go to normal operation. Otherwise, the IC will repeat the auto restart protection and the switching pulse stop again. 6.6.2 Blanking Time for over load protection The IC controller provides a blanking window before entering into the auto restart mode due to output overload/short circuit. The purpose is to ensure that the system will not enter protection mode unintentionally. The blanking time calculation for overload protection is same as active burst mode blanking window (equation 5). Channel Channel Channel Channel 1; C1 : Drain voltage (VD) 2; C2 : Supply voltage (VCC) 3; C3 : Feedback voltage (VFB) 4; C4 : Soft Start voltage ( VSoftS ) Blanking time =21ms Over load protection with blanking time @ 85Vac Figure 13 Application Note blanking window for over load protection 15 2013-03-19 ICE3Bxx65J(G) Product portfolio of CoolSET®-F3 Jitter Version (DIP-8 & DSO16/12) 7 1 2 Device Package VDS Frequency / kHz Rdson /Ω 230Vac±15% ICE3B0365J PG-DIP-8 650V 67 6.45 22W 10W ICE3B0565J PG-DIP-8 650V 67 4.70 25W 12W ICE3B1565J PG-DIP-8 650V 67 1.70 42W 20W ICE3B2065J PG-DIP-8 650V 67 0.92 57W 28W ICE3B0365JG PG-DSO-16/12 650V 67 6.45 22W 10W ICE3B0565JG PG-DSO-16/12 650V 67 4.70 25W 12W 8 85-265Vac 2 Useful formula for the SMPS design Transformer ( DCM flyback) , , Input data Drain to source voltage composition Turn ratio Duty maximum Primary Inductance Primary peak current Primary rms current Primary turns 1 Typ @ 25°C 2 Calculated maximum input power rating at T a=75°C, Tj=125°C and without copper area as heat sink. Application Note 16 2013-03-19 ICE3Bxx65J(G) Secondary turns Auxiliary turns ICE3Bxx65J(G) other components Current sense resistor Soft start time Vcc capacitor Startup time Enter burst mode power Output ripple during burst mode Leave burst mode power Blanking time for over load protection/ active burst mode 9 References ® [1] Infineon Technologies, Datasheet “CoolSET -F3(Jitter Version) ICE3Bxx65J Off-Line SMPS Current Mode Controller with Integrated 650V CoolMOS® and Startup Cell in DIP-8” [2] Infineon Technologies, Datasheet “CoolSET -F3(Jitter Version) ICE3Bxx65JG Off-Line SMPS Current Mode Controller with Integrated 650V CoolMOS® and Startup Cell in DSO-16/12” [3] Kok Siu Kam Eric, Jeoh Meng Kiat, Infineon Technologies, Application Note “AN-EVALSF3ICE3B0565J, 12W 5V SMPS Evaluation Board with CoolSET®-F3 ICE3B0565J” [4] Kyaw Zin Min, Kok Siu Kam Eric, He Yi, Jeoh Meng Kiat, Infineon Technologies, Application Note “ANEVALSF3-ICE3B0365J, 5W 2 outputs (5V & 18V) DC/DC SMPS Demo Board with CoolSET®-F3 ICE3B0365J” ® Application Note 17 2013-03-19