SRK2000ATR

SRK2000A Synchronous rectifier smart driver for LLC resonant converters Datasheet - production data Description SO-8 The SRK2000A smart driver implements a control scheme specific to secondary side synchronous rectification in LLC resonant converters that use a transformer with center tap secondary winding for full wave rectification.  Secondary side synchronous rectifier controller optimized for LLC resonant converters It provides two high current gate drive outputs, each capable of driving one or more N-channel Power MOSFETs. Each gate driver is controlled separately and an interlocking logic circuit prevents the two synchronous rectifier MOSFETs from conducting simultaneously. Features  Protection against current reversal  Safe management of load transient, light load and startup condition  Matched turn-off thresholds  Intelligent automatic sleep mode at light load  Dual gate driver for N-channel MOSFETs with 1 A source and 3.5 A sink drive current  Operating voltage range 4.5 to 32 V  Programmable UVLO with hysteresis  250 µA quiescent consumption  Operating frequency up to 500 kHz  Available in SO-8 package Applications  All-in-one PC The control scheme in this IC allows for each synchronous rectifier to be switched on as the corresponding half-winding starts conducting and switched off as its current goes to zero. The SRK2000A device implements matched turn-off MOSFET thresholds. A unique feature of this IC is its intelligent automatic sleep mode. It allows the detection of a low-power operating condition for the converter and puts the IC into a low consumption sleep mode where gate driving is stopped and quiescent consumption is reduced. In this way, converter efficiency improves at light load, where synchronous rectification is no longer beneficial. The IC automatically exits sleep mode and restarts switching as it recognizes that the load for the converter has increased. A noticeable feature is the very low external component count required.  High-power AC-DC adapters  80+/85+ compliant ATX SMPS  90+/92+ compliant server SMPS  Industrial SMPS May 2017 This is information on a product in full production. Table 1. Device summary Order code SRK2000A SRK2000ATR DocID025407 Rev 3 Package SO-8 Packing Tube Tape and reel 1/19 www.st.com Contents SRK2000A Contents 1 Internal block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4 Typical application schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 6 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6.1 7 2/19 6.1.1 Pull-up resistor configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6.1.2 Resistor divider configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.1.3 Remote on/off control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.2 Drain voltage sensing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6.3 Gate driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.4 Intelligent automatic sleep mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.5 Protection against current reversal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.6 Layout guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7.1 8 EN pin - pin function and usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 SO-8 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 DocID025407 Rev 3 SRK2000A 1 Internal block diagram Internal block diagram Figure 1. Internal block diagram 9&& 9 89/2 (1 9 9 89/2 9 9 U HJXODWRU   '5,9(5 '96 '96 &855(1792/7$*( &203$5$7256 *' &21752/ /2*,& 7,0(56 '5,9(5 *' 6*1' 3*1' $0 DocID025407 Rev 3 3/19 19 Pin description 2 SRK2000A Pin description Figure 2. Pin configuration 6*1'   9&& (1   *' '96   3*1' '96   *' $0 Table 2. Pin description No. Name 1 SGND Signal ground. Return of the bias current of the device and 0 V reference for drain-to-source voltage monitors of both sections. Route this pin directly to PGND. EN Drain voltage threshold setting for synchronous rectifier MOSFET turn-off. UVLO threshold programming. This pin is typically biased by either a pull-up resistor connected to VCC or by a resistor divider sensing VCC. Pulling the pin to ground disables the gate driver outputs GD1 and GD2 and can therefore be used also as Enable input. 3 4 DVS1 DVS2 Drain voltage sensing for sections 1 and 2. These pins are to be connected to the respective drain terminals of the corresponding synchronous rectifier MOSFET via limiting resistors. When the voltage on either pin goes negative, the corresponding synchronous rectifier MOSFET is switched on; as its (negative) voltage exceeds a threshold defined by the EN pin, the MOSFET is switched off. An internal logic rejects switching noise, however, extreme care in the proper routing of the drain connection is recommended. 5 7 GD2 GD1 Gate driver output for sections 2 and 1. Each totem pole output stage is able to drive the Power MOSFETs with a peak current of 1 A source and 3.5 A sink. The high-level voltage of these pins is clamped at about 12 V to avoid excessive gate voltages in case the device is supplied with a high VCC. 6 PGND 2 8 4/19 Function VCC Power ground. Return for gate drive currents. Route this pin to the common point where the source terminals of both synchronous rectifier MOSFETs are connected. Supply voltage of the device. A small bypass capacitor (0.1 µF typ.) to SGND, located as close to the IC’s pins as possible, may be useful to obtain a clean supply voltage for the internal control circuitry. A similar bypass capacitor to PGND, again located as close to the IC’s pins as possible, may be an effective energy buffer for the pulsed gate drive currents. DocID025407 Rev 3 SRK2000A Pin description Figure 3. Typical system block diagram 3)&35(5(*8/$725237,21$/ //&5(621$17+$/)%5,'*(:,7+6 30 V IDVS1,2_b may be greater than 1 µA because of the possible current contribution of the internal clamp Zener (few tens of µA). 8/19 DocID025407 Rev 3 V V SRK2000A Application information 6 Application information 6.1 EN pin - pin function and usage This pin can perform three different functions: it sets the threshold VDVS1,2_Off for the drainto-source voltage of either synchronous rectifier (SR) Power MOSFET to determine their turn-off in each conduction cycle; it allows the user to program the UVLO thresholds of the gate drivers and can be used as Enable (remote on/off control). 6.1.1 Pull-up resistor configuration At startup, an internal 10 µA current sink (IEN) is active as long as the device supply voltage VCC is below the startup threshold VCCOn. The moment VCC equals VCCOn (4.5 V typ.), the voltage VEN on the EN pin determines the turn-off threshold VDVS1,2_Off for the drain voltage of both synchronous rectifiers during their cycle-by-cycle operation: if VEN < VEN_Th (= 0.36 V) the threshold is set at -25 mV, otherwise at -12 mV. Once the decision is made, the setting is frozen as long as VCC is greater than the turn-off level VCCOff (4.25 V typ.). A simple pull-up resistor R1 to VCC can be used to set VDVS1,2_Off turn-off threshold. The voltage on the EN pin as the device turns on is given by: Equation 1 VEN  VCCOn  IEN R1 Then, considering worst-case scenarios, we have: Equation 2 R1  633 k  VDVS1,2 _ Off  25 mV R1  296 k  VDVS1,2 _ Off  12 mV Some additional margin (equal to the resistor's tolerance) needs to be considered; assuming 5% tolerance, the use of the standard values R1 = 680 k in the first case and R1 = 270 k in the second case, is suggested. Figure 5. EN pin biased with a pull-up resistor (for logic level MOSFET driving) 9&& (1 65.$ 5 *1' $0 DocID025407 Rev 3 9/19 19 Application information SRK2000A As VCC exceeds VCCOn, the internal current sink IEN is switched off and the enable function is activated. The voltage on the pin is then compared to an internal reference VEN_On set at 1.8 V: if this threshold is exceeded the gate drivers GD1 and GD2 are enabled and the SR MOSFET is operated; otherwise, the device stays in an idle condition and the SR MOSFET in the off state. Using the pull-up resistor RP, the voltage on the EN pin rises as IEN is switched off and tends to VCC, therefore exceeding VEN_On and enabling the operation of both SR MOSFETs. Essentially, this results in enabling the gate-driving as VCC exceeds VCCOn and disabling it as VCC falls below VCCOn. This configuration is thereby recommended when SR MOSFETs are logic level types. 6.1.2 Resistor divider configuration To enable gate-driving with a VCC voltage higher than a predefined value VCC_G, to properly drive a standard SR MOSFET, the EN pin is biased by a resistor divider (R1 upper resistor, R2 lower resistor) whose value is chosen so as to exceed VEN_On when VCC = VCC_G and also to set the desired VDVS1,2_Off level. Note that, with a falling VCC, gate-driving is disabled at a VCC level about 2.5% lower than VCC_G, because of the 45 mV hysteresis of the comparator. The equations that describe the circuit in the two crucial conditions VCC = VCCOn (when the decision of the VDVS1,2_Off level is made) and VCC = VCC_G (when gate-driving is to be enabled) are respectively: Figure 6. EN pin biased with a resistor divider to program the gate drive UVLO threshold VCC_G 9&& (1 65.$ 5 5 *1' $0 Equation 3 V  VCCOn  VEN  IEN  EN  R 1 R2  R 2 VCC _ G  VEN _ On R1  R2  10/19 DocID025407 Rev 3 SRK2000A Application information Solving these equations for R1 and R2 we get: Equation 4 V  VCCOn  VEN CC _ G  VEN _ On R1  IEN   VEN _ On R2  R1 VCC _ G  VEN _ On  If VCC_G is not too low (< 8 ÷ 9 V), its tolerance is not critical because it is related only to that of VEN_On (± 5.6%) and of the external resistors R1, R2 (± 1% each is recommended). Then, some care needs to be taken only as far as the selection of the -12/-25 mV threshold is concerned: in fact, the large spread of IEN considerably affects the voltage on the EN pin as the device turns on, a value that can be found by solving the first of (1) for VEN: Equation 5 VEN  VCCOn  IEN R1 R1 1 R2 A couple of examples clarify the suggested calculation methodology. Example 1 VCC_G = 10 V, VDVS1,2_Off = - 25 mV. In this case, VEN must definitely be lower than the minimum value of VEN_Th (= 0.32 V). From the second of (2), the nominal ratio of R1 to R2 is (10 – 1.8) / 1.8 = 4.555. Substituting the appropriate extreme values in (3) it must be (4.75 - 7·10-6·R1) / (1 + 4.555) < 0.32; solving for R1 yields R1 > 425 k; let us consider an additional 4% margin to take both the tolerance and the granularity of the R1 and R2 values into account, so that: R1 > 425·1.04 = 442 k. Choose R1 = 442 k (E48 standard value) and, from the second of (2), R2 = 442/4.555 = 97 k; use 97.6 k (E48 standard value). Example 2 VCC_G = 10 V, VDVS1,2_Off = - 12 mV. In this case, VEN must definitely be higher than the maximum value of VEN_Th (= 0.40 V). From the second of (2), the nominal ratio of R1 to R2 is (10 – 1.8) / 1.8 = 4.555. Substituting the appropriate extreme values in (3) it must be (4.25 - 13·10-6·R1) / (1 + 4.555) > 0.4; solving for R1 yields R1 < 156 k; with 4% additional margin R1 < 156/1.04 = 150 k. Choose R1 = 147 k (E48 standard value) and, from the second of (2), R2 = 147/4.555 = 32.3 k; use 32.4 k (E48 standard value). Note: In both examples the gate drivers are disabled as VCC falls below 9.75 V (nominal value), as the voltage on the EN pin falls 45 mV below VEN_On. 6.1.3 Remote on/off control Whichever configuration is used, since a voltage on the EN pin 45 mV below VEN_On disables the gate drivers, any small-signal transistor can be used to pull down the EN pin and force the gate drivers into an off state. Finally, it should be noted that during power-up, power-down, and under overload or shortcircuit conditions, the gate drivers are shut down if the VCC voltage is insufficient: < VCCOff in DocID025407 Rev 3 11/19 19 Application information SRK2000A case of pull-up resistor configuration, < 0.975 · VCC_G in case of resistor divider configuration (the coefficient 0.975 depends on the hysteresis on the Enable pin threshold). 6.2 Drain voltage sensing In the following explanations it is assumed that the reader is familiar with the LLC resonant half bridge topology and its waveforms, especially those on the secondary side with a center tap transformer winding for full wave rectification. To understand the polarity and the level of the current flowing in the SR MOSFETs (or their body diodes, or diodes in parallel to the MOSFETs) the IC is provided with two pins, DVS1-2, able to sense the voltage level of the MOSFET drains. Figure 7. Typical waveform seen on the drain voltage sensing pins 'UDLQVRXUFH YROWDJH 9 9 97+2)) 97+21 *DWHGULYH $0 The logic that controls the driving of the two SR MOSFETs is based on two gate-driver state machines working in parallel in an interlocked way to avoid both gate drivers being switched on at the same time. There are four significant drain voltage thresholds: the first one, VDVS1,2_A (= 1.4 V), sensitive to positive-going edges, arms the opposite gate driver (interlock function); the second, VDVS1,2_PT (= 0.7 V), sensitive to negative-going edges, provides a pre-trigger of the gate driver; the third is the (negative) threshold VTH-ON that triggers the gate driver as the body diode of the SR MOSFET starts conducting; the fourth is the internal (negative) threshold VDVS1,2_Off where the SR MOSFET is switched off (selectable between -12 mV or -25 mV by properly biasing the EN pin). The VDVS1_Off and VDVS2_Off thresholds are matched in order to have the same current turnoff level in both SR MOSFETs. The value of the ON threshold VTH-ON is affected by the external resistor in series to each DVS1-2 pin needed essentially to limit the current that might be injected into the pins when one SR MOSFET is off and the other SR MOSFET is conducting. In fact, on the one hand, when one MOSFET is off (and the other one is conducting), its drain-to-source voltage is slightly higher than twice the output voltage; if this exceeds the voltage rating of the internal clamp (VCCZ = 36 V typ.), a series resistor RD must limit the injected current below an appropriate value, lower than the maximum rating (25 mA) and taking the related power 12/19 DocID025407 Rev 3 SRK2000A Application information dissipation into account. On the other hand, when current starts flowing into the body diode of one MOSFET (or in the diode in parallel with the MOSFET), the drain-to-source voltage is negative ( -0.7 V); when the voltage on pins DVS1,2 reaches the threshold VDVS1,2_TH (-0.2 V typ.), an internal current source IDVS1,2_On is activated; as this current exceeds 50 µA, the gate of the MOSFET is turned on. Therefore, the actual triggering threshold can be determined by Equation 6. Equation 6 VTHON  RD  IDVS1,2 On  VDVS1,2 _ TH For instance, with RD = 2 k, the triggering threshold is located at - (2 k  50 µA) - 0.2 V = -0.3 V. To avoid false triggering of the gate driver, a debounce delay TPD_On (= 250 ns) is used after sourcing IDS1,2_On (i.e. the current sourced by the pin must exceed 50 µA for more than 250 ns before the gate driver is turned on). This delay is not critical for the converter’s efficiency because the initial current is close to zero or anyway much lower than the peak value. Once the SR MOSFET has been switched on, its drain-to-source voltage drops to a value given by the flowing current times the MOSFET RDS(on). Again, since the initial current is low, the voltage drop across the RDS(on) may exceed the turn-off threshold VDVS1,2_Off, and determine an improper turn-off. To prevent this, the state machine enables the turn-off comparator referenced to VDVS1,2_Off only in the second half of the conduction cycle, based on the information of the duration of the previous cycle. In the first half of the conduction cycle only an additional comparator, referenced to zero, is active to prevent the current of the SR MOSFET from reversing, which would impair the operation of the LLC converter. Once the threshold VDVS1,2_Off is crossed (in the second half of the conduction cycle) and the GATE is turned off, the current again flows through the body diode causing the drain-tosource voltage to have a negative jump, going again below VTH-ON. The interlock logic, however, prevents a false turn-on. It is worth pointing out that, due to the fact that each MOSFET is turned on after its body diode starts conducting, the ON transition happens with the drain-source voltage equal to the body diode forward drop; therefore there is neither a Miller effect nor switching losses at MOSFET turn-on. Also at turn-off the switching losses are not present, in fact, the current is always flowing from source to drain and, when the MOSFET is switched off, it goes on flowing through the body diode (or the external diode in parallel to the MOSFET). Unlike at turn-on, the turn-off speed is critical to avoid current reversal on the secondary side, especially when the converter operates above the resonance frequency, where the current flowing through the MOSFET exhibits a very steep edge while decreasing down to zero: the turn-off propagation TPD_Off delay has a maximum value of 60 ns. The interlock logic, in addition to checking for consistent secondary voltage waveforms (one MOSFET can be turned on only if the other one has a positive drain-to-source voltage > VDVS1,2_A) to prevent simultaneous conduction, allows only one switching per cycle: after one gate driver has been turned off, it cannot be turned on again before the other gate drive has had its own on/off cycle. The IC logic also prevents unbalanced current in the two SR MOSFETs: if one SR MOSFET fails to turn on in one cycle, the other SR MOSFET is also not turned on in the next cycle. DocID025407 Rev 3 13/19 19 Application information SRK2000A Figure 8. Typical connection of the SRK2000A to the SR MOSFET 7R;IRUPHU ,65 65.$ 5' '96 65 5* *' $0 6.3 Gate driving The IC is provided with two high current gate drive outputs (1 A source and 3.5 A sink), each capable of driving one or more N-channel Power MOSFETs. Thanks to the programmable gate drive UVLO, it is possible to drive both - the standard MOSFETs and logic level MOSFETs. The high-level voltage provided by the driver is clamped at VGDclamp (= 12 V) to avoid excessive voltage levels on the gate in case the device is supplied with a high VCC. The two gate drivers have a pull-down capability that ensures the SR MOSFETs cannot be spuriously turned on even at low VCC: in fact, the drivers have a 1 V (typ.) UVLO saturation level at VCC below the turn-on threshold. 6.4 Intelligent automatic sleep mode A unique feature of this IC is its intelligent automatic sleep mode. The logic circuitry is able to detect a light load condition for the converter and stop gate driving, also reducing the IC’s quiescent consumption. This improves converter efficiency at light load, where the power losses on the rectification body diodes (or external diodes in parallel to the MOSFETs) go lower than the power losses in the MOSFETs and those related to their driving. The IC is also able to detect an increase of the converter’s load and automatically restart gate driving. The algorithm used by the intelligent automatic sleep mode is based on a dual time measurement system. The duration of a switching cycle of an SR MOSFET (that is one half of the resonant converter switching period) is measured using a combination of the negative-going edge of the drain-to-source voltage falling below VDVS1,2_PT and the positive-going edge exceeding VDVS1,2_A; the duration of the SR MOSFET conduction is measured from the moment its body diode starts conducting (drain-to-source voltage falling below VTH-ON) to the moment the gate drive is turned off (in case the device is operating) or the moment the body diode ceases to conduct (drain-to-source voltage going over VTH-ON). While at full load the SR MOSFET conduction time occupies almost 100% of the switching cycle, as the load is reduced, the conduction time is reduced and as it falls below 40% (DOFF) of the SR MOSFET switching cycle the device enters sleep mode. To prevent 14/19 DocID025407 Rev 3 SRK2000A Application information erroneous decisions, the sleep mode condition must be confirmed on at least one of the two sections for 16 consecutive switching cycles of the resonant converter. Once in sleep mode, SR MOSFET gate driving is re-enabled when the conduction time of the body diode (or the external diodes in parallel to the MOSFET) exceeds 60% (DON) of the switching cycles. Also in this case the decision is made considering the measurement on 8 consecutive switching cycles (i.e. 8 consecutive cycles for each SR MOSFET of the center tap). Furthermore, after each sleep mode entering/exiting transition, the timing is ignored for a certain number of cycles, to let the resulting transient in the output current fade out. The number of ignored resonant converter switching cycles is 128 after entering the sleep mode and 256 after exiting the sleep mode. If by the end of the ignored cycles the condition to enter or exit the sleep mode is already met for the required number of cycles, the state will be changed immediately; otherwise the controller (after the ignored cycles) will wait until that condition is satisfied. 6.5 Protection against current reversal The IC provides protection against SR MOSFET current reversal. If a current reversal condition is detected for two consecutive switching cycles, the IC goes into sleep mode, avoiding the turn-on of the SR MOSFETs until a safe condition is restored. 6.6 Layout guidelines The IC is designed with two grounds, SGND and PGND. SGND is used as the ground reference for all the internal high-precision analog blocks, while PGND is the ground reference for all the noisy digital blocks, as well as the current return for the gate drivers. In addition, it is also the ground for the ESD protection circuits. SGND is protected by ESD events versus PGND through two anti-parallel diodes. When laying out the PCB, make sure to keep the source terminals of both SR MOSFETs as close as possible to one another and to route the trace that goes to PGND separately from the load current return path. This trace should be as short as possible and be as close to the physical source terminals as possible. A layout that is as geometrically symmetrical as possible helps the circuit to operate in the most electrically symmetrical way as possible. SGND should be directly connected to PGND using a path as short as possible (under the device body). Also drain voltage sensing should be performed as physically close to the drain terminals as possible: any stray inductance crossed by the load current that is in the drain-to-source voltage sensing circuit may significantly alter the current reading, leading to a premature turn-off of the SR MOSFET. It is worth mentioning that, especially in higher power applications or at higher operating frequencies, even the stray inductance of the internal wire bonding can be detrimental. In this case, a cautious selection of the SR MOSFET package is required. The use of bypass capacitors between VCC and both SGND and PGND is recommended. They should be low-ESR, low-ESL types and located as close to the IC pins as possible. Sometimes a series resistor (in the tens) between the converter's output voltage and the VCC pin, forming an RC filter along with the bypass capacitor, is useful in order to get a cleaner VCC voltage. DocID025407 Rev 3 15/19 19 Package information 7 SRK2000A Package information In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark. 16/19 DocID025407 Rev 3 SRK2000A 7.1 Package information SO-8 package information Figure 9. SO-8 package outline Table 6. SO-8 package mechanical data Symbol Dimensions (mm) Dimensions (inch) Min. Typ. Max. Min. Typ. Max. A 1.35 - 1.75 0.053 - 0.069 A1 0.10 - 0.25 0.004 - 0.010 A2 1.10 - 1.65 0.043 - 0.065 B 0.33 - 0.51 0.013 - 0.020 C 0.19 - 0.25 0.007 - 0.010 4.80 - 5.00 0.189 - 0.197 E 3.80 - 4.00 0.15 - 0.157 e - 1.27 - - 0.050 - H 5.80 - 6.20 0.228 - 0.244 h 0.25 - 0.50 0.010 - 0.020 L 0.40 - 1.27 0.016 - 0.050 - 0.004 D (1) k ddd 0° (min.), 8° (max.) - - 0.10 - 1. D dimensions do not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs should not exceed 0.15 mm (0.006 inch) in total (both sides). DocID025407 Rev 3 17/19 19 Revision history 8 SRK2000A Revision history Table 7. Document revision history 18/19 Date Revision Changes 18-Oct-2013 1 Initial release. 13-Dec-2013 2 Updated Table 1 on page 1 (removed “D” from order codes). Minor modifications throughout document. 04-May-2017 3 Updated text in Section 6.4 on page 14. Minor modifications throughout document. DocID025407 Rev 3 SRK2000A IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. © 2017 STMicroelectronics – All rights reserved DocID025407 Rev 3 19/19 19