Fuel-Gauge ICs Target Mobile and Portable Devices

Maxim Integrated Products has announced the MAX17262 single-cell and MAX17263 single-/multi-cell fuel-gauge ICs. The MAX17262 features just 5.2 µA quiescent current, along with integrated current sensing. The MAX17263 features just 8.2 µA quiescent current and drives 3 to 12 LEDs to indicate battery or system status. Such LEDs are useful in rugged applications that do not feature a display.

According to the company, electronic products powered by small Li-ion batteries struggle to extend device run-times to meet user expectations. Factors such as cycling, aging and temperature can degrade Li-ion battery performance over time. Inaccurate state of charge (SOC) data from an unreliable fuel gauge forces the designer to increase the battery size or compromise the run-time by prematurely shutting the system down, even if there is usable energy available.
Such inaccuracies can contribute to a poor user experience due to abrupt shutdown or an increase in device charging frequency. Designers also strive to get their products to market quickly due to competitive demands. Maxim’s two new fuel-gauge ICs help designers meet end-user performance expectations and time-to-market challenges.

The MAX17262 and MAX17263 combine traditional coulomb counting with the novel ModelGauge m5 EZ algorithm for high battery SOC accuracy without requiring battery characterization. With their low quiescent current, both fuel-gauge ICs prevent current loss during long periods of device standby time, extending battery life in the process.

Both also have a dynamic power feature that enables the highest possible system performance without crashing the battery. In the MAX17262, an integrated Rsense current resistor eliminates the need to use a larger discrete part, simplifying and reducing the board design. In the MAX17263, the integrated, push-button LED controller minimizes battery drain and alleviates the microcontroller from having to manage this function.

The ICs provide accurate time-to-empty (1%) and time-to-full SOC data across a wide range of load conditions and temperatures, using the proven ModelGauge m5 algorithm. The ModelGauge m5 EZ algorithm eliminates the time-consuming battery-characterization and calibration process. A quiescent current of just 5.2 µA for the MAX17262 and 15/8.2 µA for MAX17263 extends run-time, Rsense current resistor (voltage and coulomb counting hybrid) reduces overall footprint and BOM cost, eases board layout

At 1.5 mm × 1.5 mm IC size, the MAX17262 implementation is 30% smaller in size compared to using a discrete sense resistor with an alternate fuel gauge; at 3 mm × 3 mm, MAX17263 is the smallest in its class for lithium-ion-powered devices. The single-/multi-cell MAX17263 also drives LEDs to indicate battery status on a pushbutton press or system status on system microcontroller commands

The MAX17262 is available at Maxim’s website for $0.95 (1000 pieces, FOB USA); the MAX17263 is also on the site for $1.49 (1,000 pieces). Both parts are also available via select authorized distributors. The MAX17262XEVKIT# evaluation kit is available for $60; the MAX17263GEVKIT# is available for $60.

Maxim Integrated | www.maximintegrated.com

Fuel-Gauge ICs Maximize Battery Runtimes for Devices

Maxim Integrated offers the MAX17260 and MAX17261 ModelGauge m5 EZ fuel gauges IC that are well suited for a broad range of Li-ion battery powered applications.  These battery characterization-free solutions provide high levels of accuracy while also offering small size and ease of design.

The MAX17260 and MAX17261, which feature the ModelGauge m5 EZ algorithm, provide a high level of accuracy in fuel gauging compared to competing solutions. This allows designers to maximize their devices’ runtime by preventing premature or sudden device shutdowns, while maintaining a smaller battery size. The fuel gauges, which are housed in an ultra-small 1.5 mm x 1.5 mm package, feature a very low quiescent current of 5.1 µA to minimize draining the battery during long periods of standby time. The products allow designs to be quickly done without battery characterization or calibration.
As devices have become more sophisticated with their feature offerings and increasing power density, designers are now challenged with achieving an enhanced user experience without compromising battery runtimes. There is also a huge market need for highly accurate fuel gauges, as less accuracy may introduce uncertainty that must be compensated with higher battery capacity and larger physical dimensions.

Accurate battery state of charge (SOC) prevents sudden crash and premature device shutdown; Provides easy to understand battery information for end users such as time to empty, time to full under current, as well as hypothetical load conditions; Dynamic power technology enables high system performance without crashing the battery and results in smaller battery size.

The very low quiescent current of 5.1µA of these chips prevent excessive energy loss during long periods of standby time. This battery characterization-free solution offers no battery size limit; MAX17260 offers a high-side Rsense option to simplify ground-plane design; MAX17261 offers a flexible switched resistor divider option to support any number of series cells (multi-cell batteries). The devices support small electronics with 1.5 mm x 1.5 mm wafer-level packaging (WLP) as well as 3 mm x 3 mm TDFN.

The MAX17260 is available for $0.93 (1000-up); MAX17261 is available for $1.22 (1000-up). MAX17260GEVKIT and MAX17261GEVKIT evaluation kits are available for $60.

Maxim Integrated | www.maximintegrated.com

Step-Down Converters Target Always-On Car Systems

Maxim Integrated Products has announced the ultra-compact, pin-compatible MAX20075 and MAX20076 step-down converters that enable system designers looking to create small and highly efficient 40-V load dump-tolerant applications. The MAX20075 and MAX20076 step-down converters offer low quiescent current (IQ) and feature integrated compensation. This enables minimal external components that can lead up to 50% savings in board space making them well-suited for always-on automotive applications.

According to Maxim Integrated, car customers expect always-on applications to bring them experiences richer and more compelling than ever before. However, car system designers are challenged with having to balance delivering advanced features with meeting size constraints, power-saving features and high efficiency.

The MAX20075 and MAX20076 in peak current mode draw just 3.5 µA in the low power operating mode, which is key to meeting the stringent OEM IQ consumption requirements of 100 µA per module. The converters enable low noise operation via pin-controlled spread spectrum and fixed 2.1 MHz operation to meet CISPR 25 Class 5 EMI compliance. Furthermore, added advantage of the 2.1 MHz operation and internal compensation is that it lowers the solution size and the bill of materials (BOM) compared to a non-synchronous device that operates in the AM band.

The MAX20075 and MAX20076 are available with a low minimum on-time mode operation, which allows the converters to support large input-to-output conversion ratios. For example, Vbatt input to Vout of less than 3 V at 2.1 MHz; this translates to not having to use a secondary supply, which reduces overall BOM cost by $0.30 to incorporate new functions into the design for greater flexibility. The MAX20075 and MAX20076 meet AEC-Q100, are available in a 3 mm x 3 mm TDFN package, and operate over the -40°C to +125°C temperature range.

Maxim Integrated | www.maximintegrated.com

Nanopower Comparator

TLV3691The TLV3691 comparator offers a wide supply range, low quiescent current, and rail-to-rail inputs. These features come in industry-standard and extremely small packages, making this device ideal for low-voltage and low-power applications.

Available as a single channel, the comparator’s low power, wide supply, and temperature range make the device flexible enough to handle applications from consumer to industrial. The TLV3691 is available in SC70-5 and 1-mm × 1-mm DFN-6 packages. This device is specified for operation across the –40°C-to-125°C expanded industrial temperature range.

The TLV3691’s features include a 24-µs response time, push-pull output, and a range that extends 100 mV beyond both rails. Texas Instruments offers a variety of tools and resources to speed development with the TLV3691, including a SPICE Model, TINA-TI SPICE Model, and the DIP adapter evaluation module.

Contact Texas Instruments for pricing.

Texas Instruments, Inc.
www.ti.com