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VIPER31 is the first ST high-voltage converter to provide up to 18 watts in a fly-back geography with a global input mains range (85– 265 VAC). Many thanks to its design, the VIPer31 is adaptable, durable, and also efficient. It was hence crucial to comprehend what the new high-voltage converter means to engineers.
Satisfy the New Family
The VIPER line covers a variety of applications, as we lately saw with the VIPER26K. The VIPERx1 family tailors to flyback topologies with both primary-side as well as secondary-side policy along with buck. In other words, we commonly locate this tool in switched-mode power supplies (SMPS) that do not have an optocoupler. The VIPER01 had a result power of 4 W, and the VIPER11 floated around 8 W. The 18 W of the VIPer31 is hence a considerable step forward. The new product also has a lower optimum RDS( on) of 3.5 Ω. Fairly, the VIPER01 has an RDS( on) of 30 Ω while the VIPER11 rests at 15 Ω.
There are presently 8 part numbers under the VIPer31 series, with more on the way. The VIPER317 has a drain existing limitation protection (IDLIM) of 710 mA. The VIPER318 has an IDLIM of 850 mA, and also the VIPER319 reaches 990 mA. There are also X, L, as well as H versions for these variations. The X kind has a jittered switching frequency (Fosc) of 30 kHz ± 7%. The L kind has a Fosc of 60 kHz ± 7%, and also the ones noted H are at 132 kHz ± 7%. Selecting the best oscillator frequency (Fosc) allows designers to pick more cost-efficient EMI filters and also decrease their costs of materials.
When engineers pick a component, they must frequently clarify their reasoning. And there’s no much easier method to outline a mind than to show it in action. Hence, we are generating several growth boards, including the STEVAL-VP319X1B. This system is extremely symbolic because it’s the very first time a VIPER product can resolve a dollar converter with a lots existing (IOUT) of 600 mA. Experts understand that it is unusual today to get to such a high load current with a high-voltage buck converter. Such growth boards therefore highlight the gadget’s attributes and also demonstrate how engineers can make the most of it.
Trans-Conductance Error Amplifier
The VIPER31 has a transconductance error amplifier with 1.2 V ± 2% referral voltage. As mentioned, the STEVAL-VP319X1B executes a dollar converter, whereas the STEVAL-VP318L1F is a fly-back converter with secondary-side guideline that would work wonderful in air conditioners. The STEVAL-VP318L2F is an 18 W separated flyback with primary-side regulation.Hence, its error amplifier enables the VIPER31 to resolve the most usual topologies, therefore enabling the qualification of one family members of gadgets for a broad range of items.
Wide Input Voltage Range
It is progressively common for ODMs to create a layout in one nation before exporting it to the remainder of the world. Engineers must, consequently, show that they took international standards right into account. Regrettably, a large bulk of the sector ships high-voltage converters with a slim variety of input voltages. Hence, designers can aid explain why they picked the VIPER31 by indicating its wide range of voltage input that prolongs from 85 V to 265 V.
Designers may likewise have problem with the fundamental complexities of certain applications. Smart meters, wise home systems, air conditioning units, or emergency illumination networks use an one-of-a-kind obstacle. They must deal with a loss of power at the grid that compels a global power supply to take control of. In this circumstances, the end product needs to still be useful even if the input voltage goes down at much reduced degrees than typical. Designers can hence find comfort in the truth that the VIPER31 has a drain-source start-up voltage of just 24 V. Moreover, we made certain that these functions are conveniently demonstrable. Experts can take the upcoming STEVAL-VP319X1B, modification capacitors C1 and C2, and also appreciate the lower nominal beginning input voltage.
VIPER31: Robustness and Efficiency
Undervoltage as well as Overvoltage Protection
Consumers pay enhancing interest to the safety and security and also effectiveness of their items. For this reason, groups usually ask how power tools can aid make their designs much more trusted. For example, engineers looking to develop ac unit are sensitive to these issues due to the fact that a breakdown can have a serious human expense. Developers additionally know that their firm will be more receptive to functions like the undervoltage (UVP) and also overvoltage security (OVP) of the VIPER31. Since each has a devoted pin, it’s possible to use the UVP pin to disable the IC or the whole SMPS, and also the inner threshold is typically 0.4 V. The OVP disables the pulse-width modulator also after the auto-restart and just resumes switching once the OVP condition ends. The VIPER31 likewise features overload defense as well as thermal closure. These features explain why we used an SO16N plan with even more pins than the SSOP10 of the VIPER01 and also VIPER11.
Much Better as well as Fewer External Components
Engineers also deal with cost problems because a part has several straight and indirect consequences. The cost of the part itself is an important aspect of the equation. Nevertheless, one high-voltage converter will dictate what energetic and easy parts will influence the general BOM. Hence, when developers try to discuss why they chose a VIPER31, really often, they point to its pulse skipping function, which permits them to select smaller inductors while shielding magnetic elements from existing peaks. Likewise, the versions with various oscillator frequency will certainly make certain styles have a more cost-efficient EMI filter. Ultimately, the current limitation is currently accurate enough in the VIPER31 that outside elements are no more needed.
Prepared for Low-Power MCUs as well as Energy Efficient Systems
The price considerations are also increasingly complicated as a result of customers’ awareness. Purchasers are more delicate than ever about a purchase’s impact on the setting as well as their utility expense. The very best means to address these demands is to select a component that matches low-power systems. As an example, the VIPER31 has an Error Amplifier recommendation voltage of 1.2 V to produce 3.3 V for MCUs easily. The ST converter also has a quiescent existing below 350 µA, hence accomplishing 10 mW of power intake in standby. Hence, designers can take satisfaction that even under one of the most difficult problems, their layouts supply substantial power savings.
Source: https://blog.st.com/viper31/