Linear Technology Corporation introduces the LTC4420, a dual input monolithic power prioritizer for 1.8V to 18V systems. To enable portability, preserve memory during brownouts, and ensure a graceful shutdown on power loss, electronic systems employ batteries and capacitors for backup power. The LTC4420 normally powers the load from the higher priority main supply such as a wall adapter or battery, switching to the backup supply—typically a battery or large-value capacitor—during primary brownout or power loss conditions. With up to 18V operating capability, the LTC4420 accommodates a wide range of power sources such as wall adapters, USB ports, supercapacitors, and stacked batteries with Li-Ion, alkaline or NiMH cells. By reducing device operating current to 3.6µA and the backup supply’s standby current drain to a low 0.32µA, the LTC4420 extends run time in portable battery-operated systems.
Unlike other solutions, the LTC4420 does not require the backup supply voltage to be lower than the main supply voltage. When the backup supply voltage is higher than the main supply voltage, a prioritizer is a better solution than a simple diode-OR as the prioritizer does not necessarily draw current from the highest voltage supply. Internal 500mA (min) current-limited switches multiplex from the primary to the backup supply when the primary voltage falls below the adjustable switchover threshold. Carefully designed break-before-make fast switch control blocks reverse and cross conduction currents while minimizing output voltage droop. To reduce quiescent current, the backup supply’s resistive divider is connected to a strobed ground with a duty cycle that is adjustable down to a low 0.0015%, and an optional undervoltage disconnect prevents deeply discharged batteries. A freshness seal mode further lowers standby current to 0.12µA, minimizing battery discharge during product storage and shipment. Reversed-battery voltages up to -15V are blocked from propagating to the load.
Specified over the 0°C to 70°C commercial and -40°C to 85°C industrial temperature ranges, the LTC4420 is offered in thermally enhanced 12-pin MSOP and 3mm x 3mm DFN packages. 1,000-piece pricing starts at $2.95 each. Device samples and evaluation circuit boards are available online or from your local Linear Technology sales office.
Vishay Intertechnology, Inc. announced that it is upgrading several Vishay Siliconix analog switch products to boost device performance and longevity. Replacing aging silicon technology with an advanced process that improves a range of device parameters, the move signals Vishay's continuing support for its analog switch and multiplexer product lines, which the company pioneered in the 1960s.
The new enhanced family of analog switches and multiplexers introduced by Vishay Siliconix is designed on a high-density 18 V process. The process not only offers an upgrade path for customers using Vishay's current 12 V series products, but also enables Vishay to develop new precision analog products with higher complexity for sensitive analog designs.
Key improvements to device specifications include an increase of the operating voltage from 12 V to 16 V; lower leakage, reduced parasitic capacitance, and faster switching speeds; and enhanced ruggedness, with higher latch-up current and ESD protection ratings. For example, the new DG9408E and DG9409E - drop-in upgrades for the popular DG9408 and DG9409 - feature 20 % lower switch on-resistance, 10 % faster switching speeds, 35 % lower parasitic capacitance, enhanced latch-up capability to 400 mA, and guaranteed ESD protection to 2.5 kV (human body model).
Vishay is building the new devices on a mature process platform in an established facility with an eye towards shortening lead times and fully supporting the long life cycles of these analog switch products, which are widely used in such market applications as industrial control and automation systems, audio and video signal routing, instrumentation and test equipment, data acquisition, communication systems, and medical and healthcare systems. The 12 V device families being upgraded to enhanced versions are summarized in the table below.
Samples and production quantities of the enhanced analog switch products are available now, with lead times of 10 weeks. Pricing varies depending on family and package type.
Vincotech announced the launch of a new fastPACK 0 HC improving UPS, SMPS, solar and welding applications in speed, efficiency and full-current capability for bidirectional usage. The new H-bridge module is available in the low-inductive flow 0 housing.
The new fastPACK 0 HC module featuring high frequency 650 V IGBT H5 technology in combination with a fast diode enables outstanding efficiency, reliability and perfectly balances cost and performance. This utmost efficient H-bridge module delivers 30+ kHz fsw and is suitable for soft switching to reduce switching losses.
The fastPACK 0 HC enables bidirectional operation for charger and SMPS applications with full current FWD. It is also equipped with integrated capacitors reducing electromagnetic interference.
Packaged in the low-inductive flow 0 12 mm housing the module can also be provided with phase-change material on special request.
Microsemi Corporation announced the availability of its PDS-EM-8100 Power-over-Ethernet (PoE) 2.5 Gbps Multiplexer. As the first device of its kind, the unique offering enables installations of new 802.11ac access points with 2.5 Gbps rates without the need to replace the Ethernet switch with a 2.5G NBASE-T interface.
Microsemi's new PDS-EM-8100 PoE 2.5 Gbps Multiplexer converts two ports of 1G into a single port with a 2.5G NBASE-T NBASE-T interface and 30 watts (W) IEEE802.3at PoE. The device enables faster adoption of 802.11ac 2.5G by offering a compact, cost-effective and pre-configured solution for 2.5 Gbps product installations such as WLAN access points, small cells and other Internet Protocol (IP) terminal installations.
According to market research firm Dell'Oro Group's April 2016 report titled, "Ethernet Alliance Analyst Hour," there will be approximately 20 million 802.11ac Wave 2 access points in 2018, which will require 2.5G and 5G Ethernet technology. Microsemi's PDS-EM-8100 PoE 2.5 Gbps Multiplexer caters to this growing demand for 802.11ac Wave 2 and 2.5G, offering a simple, fast installation that can deliver up to 30 W of PoE.
As an ideal alternative to using high-end expensive PoE switches, Microsemi's new device caters to the specific needs of the communications market and more specifically, for Wi-Fi 802.11ac technology. It is suitable for fast-growing applications such as enterprise IT, with plug and play/zero configuration needed, and the ability to perform remote software upgrades.
Microsemi's PDS-EM-8100 PoE 2.5 Gbps Multiplexer is available now for $399.
Silicon Labs has expanded its ISOdriver portfolio with a family of isolated gate drivers designed to protect sensitive insulated-gate bipolar transistor (IGBT) switches in power inverter and motor drive applications. The new Si828x ISOdriver family provides industrial-grade isolation (5 kVrms withstand), including an optional dc-dc converter, the industry's fastest desaturation detection, superior timing characteristics, and exceptional noise and transient immunity.
The Si828x family combines robust isolation, advanced gate driver technology and fast over-current monitoring in a single, cost-effective device designed to protect costly IGBT switches. High-power inverter and power converter systems typically use IGBTs for the switching element, and over-current conditions can destroy IGBTs, compromise system-critical functions, jeopardize product safety and diminish reliability. Efficient switching of IGBTs requires the use of isolated gate drivers like the Si828x devices with specialized monitoring and control features.
The defining Si828x feature is a 4 amp gate driver coupled with desaturation detection to monitor the IGBT for over-current. In that event, the Si828x driver initiates a controlled shutdown of the switch while updating the controller with the fault status, protecting the IGBT and the system. Additional integrated features include split outputs, a Miller clamp to prevent parasitic gate turn-on, and driver power state and fault feedback to the controller.
Diodes Incorporated has introduced a family of primary side power switchers that enables power supply designers to handily achieve the high conversion efficiency needed to meet Energy Star Level 6 and EU CoC Tier 2 requirements. Operating up to 80kHz, the AP3983 series employs piecewise Pulse Frequency Modulation (p PFM) in discontinuous conduction mode to regulate the primary-side voltage and current to better than ±5% and provide an audible noise-free solution for chargers, ADSL adapters and home appliance power supplies.
As a primary side device with an integrated 650V or 700V BVDSS MOSFET, the AP3983 family eliminates opto-couplers and secondary-side CV/CC control circuitry to minimize external component count. Other features include built-in fixed cable voltage-drop compensation, adjustable line-voltage compensation and a range of safety functions, such as, over-voltage and over-temperature protection, and a hiccup function to improve response to short circuits.
A low start-up current (0.6µA, max) combined with a no-load power consumption (75mW, max) and excellent load transient stability all contribute to the high performance offered by the AP3983 switcher, which provides a highly integrated and cost-effective solution for consumer power supplies.
Devices in the AP3983 family support ranges of adapter power ratings (6W to 20W), package types (SO-7 or PDIP-7), and MOSFET voltage ratings (650V or 700V).
Infineon Technologies AG introduces the 800 V CoolMOS P7 series. Based on the superjunction technology, this 800 V MOSFET combines best-in-class performance with exceptional ease-of-use. This new product family is a perfect fit for low power SMPS applications, fully addressing market needs in performance, ease of design, and price/performance ratio. It mainly focuses on flyback topologies which are typically found in applications like adapter, LED lighting, audio, industrial and auxiliary power. The 800 V CoolMOS P7 series offers up to 0.6 percent efficiency gain. This translates into 2 to 8 °C lower MOSFET temperature compared to the CoolMOS C3 or to competitor parts tested in typical flyback applications. This new benchmark results from a combination of optimized device parameters: including the reduction of more than 50 percent in Eoss and QG, as well as a reduced CISS and COSS. The further improved performance enables higher power density designs through lower switching losses and better DPAK RDS(ON) products. Overall, this helps customers to save BOM costs and reduce assembly efforts.
Ease-of-use of is an intrinsic feature designed into this product family. The integrated Zener Diode significantly improves ESD ruggedness, thus reducing ESD related production yield losses. The MOSFET is easy to drive and to design-in due to its industry leading V(GS)th of 3 V and the smallest VGS(th) variation of only ±0.5 V. This combination allows for lower driving voltage and lower switching losses. Additionally, it helps to avoid unintentional operation in the linear region.
The family of 800 V CoolMOS P7 MOSFETs will be available in twelve RDS(ON) classes and in six packages to fully address the needs of target applications. Products with RDS(ON) of 280 mW, 450 mW, 1400 mW and 4500 mW can be ordered now.
Allegro MicroSystems, LLC announces a new 40 V motor driver IC capable of driving one stepper motor and one DC motor. The stepper driver outputs are rated up to 1.6 A and the DC driver at 3.2 A. Allegro's A5989 includes fixed off-time pulse width modulation (PWM) current regulators, along with 2- bit nonlinear DACs (digital-to-analog converters) that allow stepper motors to be controlled in full, half, and quarter step. This new device is targeted at the consumer, industrial and office automation markets with end applications that include, point of sale, lottery, ticketing, laser, inkjet and label printers, copiers, vending, and ATM machines.
The A5989 stepper driver PWM current regulator uses the Allegro® patented mixed-decay mode for reduced audible motor noise, increased step accuracy, and reduced power dissipation. The DC driver can operate in forward, reverse, coast and brake modes with either fast or slow PWM decay control.
Protection features include thermal shutdown with hysteresis, under voltage lockout (UVLO), crossover current, and over current protection. Low current sleep mode is included to improve efficiency.
The A5989 is supplied in a leadless 6 mm - 6 mm- 0.9 mm, 36-pin QFN package with exposed power tab for enhanced thermal performance. The package is lead (Pb) free, with 100% matte-tin leadframe plating. It is priced at $2.07 in quantities of 1,000.
Exar Corporation announced a family of high-speed RS-485/RS-422 receivers that accommodate the complex demands of next generation high-speed serial communications designs. The XR33180, XR33181, XR33183, and XR33184 occupy a 3mm x 3mm footprint and feature 52Mbps data rates, fast 15ns propagation delay and 2ns maximum receiver skew. This family is best suited for high performance industrial applications such as multi-drop clock distribution, telecom networking, robotic control, process automation and local area network applications.
The XR33180/81/83/84 (XR3318x) operate from either a 3.3V or 5V supply and are available in tiny 5-pin and 6-pin TSOT23 packages, ideal for high-speed point-to-point RS-485 applications where space is a concern. The XR33184 includes a low voltage logic pin that eliminates the need for a level shifter when interfacing to MCUs or FPGAs that run off of lower supply voltages.
All devices feature ±15kV ESD protection on the receiver inputs and exceed the highest ESD rating of IEC 61000-4-2 and operate over an extended temperature range of -40°C to +125°C.
The XR33180, XR33181, XR33183, and XR33184 are available now in a RoHS compliant and green, TSOT23-5 and TSOT23-6 packages. Pricing starts at $0.55 in quantities of 1,000.
STMicroelectronics has introduced the industry's first 800V surface-mount Silicon Controlled Rectifiers (SCR, or thyristor) specified for operation at temperatures up to 150°C without derating, giving freedom to miniaturize power modules for applications that demand high reliability in harsh conditions.
With its 80A current rating, the new TM8050H-8 SCR, housed in the High-Voltage D3PAK (TO-268-HV), enables mid-power applications in the 1-10kW range to leverage surface-mount assembly efficiencies and reduce PCB and heatsink sizes, lowering system cost. The package has very low junction-to-case thermal resistance of 0.25°C/W, ensuring efficient heat dissipation, and a large pin-to-tab creepage distance of 5.6mm that gives a large safety margin in the presence of high applied voltages. A TO-247 package option is also available.
The TM8050H-8 is the latest addition to ST's family of SCRs that all bring state-of-the-art device and package technologies to automotive and industrial power control. Spanning current ratings from 12A to 80A, the devices enable designers to create extremely compact and reliable car or motorcycle voltage regulators, induction motor starters, soft starters, industrial heater or cooker controls, Solid-State Relays (SSRs), uninterruptible power supplies (UPS), and AC-line conditioners.
With low dynamic resistance (RD) and on-state voltage (VTO) of 5.5 mW (TJ = 150°C) and 0.85V respectively, and leakage current of 20µA max (at 800V, Tj = 25°C), the TM8050H-8 ensures extremely high energy efficiency under all operating conditions.
The TM8050H-8 is in production now, priced from $2.20 in TO-247 or $2.50 in High-Voltage D3PAK.
Whether you are looking for miniature connectors or resistors, Power Electronics has you covered. Here are some of the latest products to optimize your systems and devices.
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