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Battery sensor integrates MCU, CAN and analogue front-end Freescale has an AEC-Q100 (automotive) qualified intelligent battery sensor that combines three measurement channels, a 16/32-bit MCU, and a CAN protocol module in a single package. Designed to support both conventional and emerging battery chemistries for automotive and industrial applications, the MM9Z1J638 battery sensor measures key battery parameters for monitoring state of health (SOH), state of charge (SOC) and state of function (SOF) for early failure prediction. A flexible four-cell front end architecture supports conventional 12V lead acid batteries as well as emerging battery applications, such as 14V stacked cell Li-Ion, high voltage junction boxes, and 24V truck batteries. Integrating a 16/32 bit S12Z microcontroller with 128K Flash, 8K RAM and 4K EEPROM together with a CAN protocol module, LIN interface and a three-channel analogue measurement front end, the MM9Z1J638 battery sensor combines analogue, processor and communication functions in a single package to help lower total bill of materials and accommodate advanced battery monitoring algorithms. The analogue front end includes a two-channel, 16-bit sigma delta (ΣΔ) analogue-to-digital converter (ADC) for simultaneous measurement of battery voltage and current, as well as a third 16-bit ΣΔ ADC for temperature monitoring using the integrated sensor and redundant measurement plausibility checks to support functional safety. Freescale www.freescale.com Synchronous forward MOSFET driver needs no signal transformer LT8311 is a high efficiency secondary-side MOSFET driver that operates without the need for primary control in an isolated synchronous forward converter. The LT8311’s preactive mode eliminates the need for a signal transformer for primary to secondary-side communication by sensing signals on the secondary side to control synchronous rectification. This mode reduces component count and solution size. The device operates over a 3.7V to 30V input voltage range and is used with a primary-side IC, such as the LT3752/-1. The complete forward converter can operate with input voltages ranging from 6.5V up to 400V+ making it ideal for a wide range of applications including hybrid/ electric vehicle automotive requirements. It combines a 10 mA opto-driver and a feedback loop error amplifier to enable output voltage feedback from the secondary to the primary side. The entire system provides fixed frequency peak current mode control that has excellent line/load regulation and fast transient response. Additional features include a 1.5% reference voltage, a power-good monitor and programmable soft-start of the output voltage. The IC comes in a TSSOP-20 package with several pins removed for high peak-voltage spacing, in E- and I-grade (-40°C to 125°C junction temperature), H grade (-40°C to 150°C) and MP grade (-55°C to 150°C). Linear Technology www.linear.com DC-DC regulators offer 15 A output with 0.1% line regulation Exar has extended its PowerBlox switching regulators with the XR76108, XR76112 and XR76115, synchronous step down regulators delivering point-of-load (POL) supplies of 8A, 12A and 15A, respectively. The XR761xx family is designed to achieve excellent transient response and output accuracy, of 0.25% load and 0.1% line regulation, using Exar’s proprietary emulated current mode Constant On-Time (COT) control loop. These devices deliver core voltage rails for ASICs, FPGAs, DSPs and Network Processors in communications, networking and industrial markets. Input voltage range is 4.5V to 22V for an adjustable output voltage from 0.6V to 18V. With its 0.1% line regulation across the entire input voltage range and 1% output accuracy over full temperature range, XRP761xx provides increased headroom. The emulated current mode COT control scheme has the fast transient response of conventional COT control loops without any of the compromises. Exar’s COT control loop enables operation with ceramic output capacitors, eliminating loop compensation, which simplifies system design and reduces overall component count. The XR761xx offers a suite of supervisory and protection features for proper sequencing, safe operation under abnormal operating conditions and light load operation. The control loop also maintains constant operating frequency. A selectable power saving mode allows the user to operate in discontinuous mode (DCM) at light current loads, significantly increasing the converter efficiency. The XR76108 and XR76112 come in 30-pin 5x5mm QFN packages. The XR76115 is in a 30-pin 6x6mm QFN. Exar www.exar.com DC-DC converter boasts internal compensation Maxim Integrated has posted information on a device that it believes to be the only available 60V, 1.7A, internal FET, synchronous buck converter in its class. MAX17505 is a high-efficiency, high-voltage, synchronously rectified stepdown converter with dual integrated MOSFETs that operates over a 4.5V to 60V input. It delivers up to 1.7A and 0.9V to 90% VIN output voltage. Built-in compensation across the output voltage range eliminates the need for external components. The feedback (FB) regulation accuracy over -40°C to +125°C is ±1.1%. The device is available in a compact (4 x 4mm) TQFN lead(Pb)-free package with an exposed pad. Simulation models are available. The device features a peakcurrent mode control architecture with a MODE feature that can be used to operate the device in pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuousconduction mode (DCM) control schemes. PWM operation provides constant frequency operation at all loads, and is useful in applications sensitive to switching frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high efficiency. DCM features constant frequency operation down to lighter loads than PFM mode, by not skipping pulses but only disabling negative inductor current at light loads. DCM operation offers efficiency performance that lies between PWM and PFM modes. The low-resistance, on-chip MOSFETs ensure high efficiency at full load and simplify the layout. Maxim Integrated www.maximintegrated.com www.electronics-eetimes.com Electronic Engineering Times Europe May 2014 31


EETE MAY 2014
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