digital batteries

USB Power Manager – LTC4085

LTC4085 is a portable USB power manager self monolithic ideal diode controller and standalone linear battery charger. LTC4085 PowerPath control with, or the USB VBUS power adapter AC to power the system load, and single-cell lithium ion / polymer battery charger. To comply with USB specifications to the limit, LTC4085 automatically when the system load current increases, thus reducing the battery charge current. To ensure that the battery is fully charged when the bus connection is not used as such, the IC by the USB bus to power the load Shusong, but have no power to the battery practice. Once the power is off, the current through a 200mΩ ideal diode low loss rate of the battery to the load, thus reducing the voltage drop and power dissipation. Provided advice to drive an optional external PFET GATE circuit for connecting peripherals to the case in the application necessary for the overall ideal diode impedance below 30mΩ the following. LTN141W3 LTN141X7 LTN141X8

LTC4085 unique feature is the AC adapter can detect the access and use it as a kind of power system load while charging the battery backup power. LTC4085 also provides access to an AC adapter in the case of higher values to USB specifications allow (100/500mA) rating (up to 1.5 A) to charge the battery option, so they can dramatically increased rates of charges the battery. The total cost of time late charge by an external resistor to set. When the load current decreases, the load timer period will be automatically extended to ensure that the battery is always fully charged state. Additional features include automatic recharge, NTC thermistor input, input adapter is automatically removed the battery, limiting the inrush current, reverse current blocking, lock-out under-voltage and thermal setting.

LTC4085 float voltage is preset at 4.2V from 0 to 85 ℃ temperature to ensure the accuracy of 0.8%. Charging current can be easily adjusted using a resistor. The optimum temperature for charging the battery of pre-treatment and certification will automatically be set to 10% of the total flow of the trickle charge current battery until the battery voltage exceeds 2.8V up at. LTN141XA LTN141XB LTN141XC

For, like GPS navigation devices, PDAs, digital cameras, digital photo player, MP3/MP4 players and other handheld devices, offering the USB port and the input voltage, high load capacity and battery has many advantages such as energy USB if you have not driven on the road to bring the convenience of the charger, a laptop from a PC or other device with USB port to power your device. Such as FireWire, 12 ~ 24V AC adapter or car adapter, car power can input-output high voltage to provide a higher speed of USB charging, and allow more places (like cars), taxation , which is to improve facilities One of the keys to portability.

Convenience features and high power

LTC408 And LTC408 -5 Is a portable USB power manager self, ideal diode controller and standalone high-voltage battery charger for high efficiency. To achieve efficient load their switching topology can be adapted to a variety of appetizers, including up to 36V (40V max) of high voltage (like 12V AC adapter, car adapter and a FireWire port). In addition, they also accepted such as adapters and USB 5V supply low voltage. LTC408? -5 With PowerPath control feature, available on the USB or power adapter to the equipment and materials of the lithium-ion battery charging, but also the introduction of a severe shortage of battery power is exhausted or the situation to achieve “instant-on” operation. LTN154X1 LTN154X2 LTN154X3

To comply with USB specifications to the limit, LTC408? -5 Load current increases in the system automatically reduces battery charge current when. To ensure that a fully charged battery is connected to a full charge state when the bus termination, the IC by the USB bus to transport power to the load, but did not take lessons from battery approach. Once all food was removed, then the current through a 200mΩ ideal diode low loss rate of the battery to the load, thus reducing the voltage drop and power dissipation. Provided to drive an optional external PFET circuit board to the case in the application necessary for the overall ideal diode impedance below 30mΩ the following, which will enhance the work efficiency.

When LTC408? -5 Power from USB port to provide power management system allows the maximum available power, which increased by 2.5 W (500 mA x 5V) from the USB power solution available. In addition, it would, the system automatically adjust the load current lithium-ion / polymer battery charge current to maintain the total input current limit consistent with the USB. LTN154X7 LTN154XA LTN156AT01

LTC408 Switching regulator with output track the BAT-based adaptive control, which greatly improved its offer 1.2A charge current from the battery charger efficiency, because the output voltage of the switching regulator automatically tracks the voltage of the battery. LTC408 -5 from the input voltage high is a fixed 5V output, used in single-cell lithium-ion / polymer battery charger. The float voltage battery charger is preset to 4.2V, at intervals of 0 ~ 85 ℃ temperature to ensure the accuracy of 1.0%. Charging current can be easily adjusted through a resistor. The total cost of time late charge set by an external capacitor, and provides an output charge detection C/10 current. Additional features include automatic adjustment for temperature qualified charging heat to the NTC thermistor input, the battery will automatically recharge, reverse blocking and lock-out being energized. LTC408 -5 With flat (height of only 0.75 mm) 6mm 22-pin 3mm × tiny DFN package, and the guarantee of -40 ~ 85 ℃ operating temperature. dell gw240 dell rn873 dell y6142

BAT-track control output adjustment

LTC408 AT-Track function adaptive output control is a form. This is a battery charger and switching regulator integrated, so that the switching regulator does not produce enough to sustain the required voltage of the battery charger, but does not produce additional tension. Linearly supply for the product, the input voltage and voltage difference of the battery in the charging process is lost as waste heat.

Where implementation of a switching regulator, the switch to both ends of the pressure drop as large as possible is beneficial because it can effectively accomplish the (absorbed by the input current is less than the current supplied to the charger). dell gk479 dell nf343 dell pc764

BAT-Track function is responsible for detecting the voltage of BAT, and switching regulator output VOUT to adjust to the battery voltage VBAT exceeds 300mV, minimizing power loss caused by heat, can charge the battery properly and maximize reduce total electricity consumption. This greatly improves the efficiency of the battery charger. For example: When the load current IBAT = 600mA, VBAT = 3.7 V input voltage VIN = 5V charger, the charger efficiency (with the substitution method element) is as follows: 100 × POUT / (POUT + PDIS) = 100 × (× VBAT IBAT) / (× VBAT IBAT PDIS +) = 100 × (× VBAT IBAT) / (VIN x IIN) = (3.7 × 600mA) / (5V × 600mA) = 74%.

Conversely, if the charger voltage VBAT input exceeds 300mV the charger efficiency: 100 × (× VBAT IBAT) / (VIN x IIN) = (3.7 × 600mA) / ((3.7 V 0.3 V) × 600 mA) = 92.5%.

This difference in efficiency will significantly reduce energy consumption. In addition, if the battery against discharge and voltage VBAT to low, the minimum should be 3.6V VOUT, to ensure that the system load for a sufficient supply voltage. dell hd438 dell y9943 dell fk890

Devices, small portable consumer batteries, cheaper, and accepting a variety of input power to achieve the usability requirements engineers to design the system to bring many challenges. Using PowerPath series battery management can effectively address these challenges, is an independent operating characteristics can be independently a wide range of supply (cigarette lighter adapter Ru FireWire input, AC USB, and the battery itself) between Qiehuan transparent implementation of effective management. LP154WE2 LP154WX2 LP154WX3

Handheld battery today engineers design equipment, they are the major challenges facing Suo Yi Xie minimize energy consumption and minimize Tigaoxiaoshuai, simplify design and reduce Chengben.

Many battery-powered portable electronics available today from the AC adapter, car adapter, USB port, or lithium ion / polymer. However, these sequences between different power supply control of self-management has great technical challenge. Throughout, the designers are trying to adopt a “discreet” way to accomplish this function, which uses a large number of MOSFETs, op amps and other discrete components, but during the meeting are likely to cause major system problems, and the influx of hot-plug and other current issues. Recently, even discrete IC solution also needs to use multiple chips to achieve a practical and integrated power management ICs can easily solve these problems. In addition, CI own independent operation also removes an additional termination for the realization of the need for an external microprocessor, thus further simplifying the design. LP154WX4 LP171W01 LP171WP3

When used, such as FireWire, is not regulated high voltage (> 5.5) AC adapter and cigarette lighter adapter, the adapter voltage source and portable devices, the voltage difference between batteries large. Therefore, the linear charger may not be able to solve the problem of high energy consumption, while the use of topology switching IC is able to improve efficiency and reduce thermal management problems. Note that when using USB, Lithium ion polymer battery or adapter input less than 5.5V to power the linear charger device power management is a more appropriate choice.

PowerPath control

With control device from PowerPath USB VBUS power adapter for his own power, and its lithium-ion rechargeable single cell. To ensure that the battery is fully charged when the connection is not used in the state of the bus, the IC directly through the USB bus power the load, rather than receiving power from the battery. Once removed from office, the current through an internal low loss ideal diode current from the battery to the load, thus reducing the voltage drop and power dissipation. LP171WP5 LP171WP6 LP171WX2

Features PowerPath control:

1. Food USB access adapter or battery;

2. In the OUT pin is connected to a circuit application and a battery connected to the power transmission BAT pin (assuming that access to external power, battery);

3. Does the battery charge current is regulated to ensure that the load current and load current and no more to define the boundary USB input current;

4. AC adapter current through an external device (such as power Schottky diodes or FET) connected to the output (load side);

5. With a unique feature, you can use the AC adapter to power the output power to the load while charging the battery;

6. Output pin of the load may be a priority in the current USB input. LT141X7 LT150X3 LTN141W1

Ideal diode

When the output / load current exceeds the input current or voltage input is removed, the ideal diode low loss battery to provide power. The ideal diode (not to load directly connected to the battery) to give the load a fully charged battery can power an external power to maintain full charge before the state abolished. Once the external power source is removed, the output voltage drops until the ideal diode forward bias is applied so far. Canada has the ideal diode voltage before the battery then provides an output to the load. Ideal diode voltage drop much lower than conventional diodes, and reverse leakage current of less. Small forward voltage drop to reduce energy consumption and self-heating, which prolongs the life of the battery.

Ideal diode has the following characteristics:

1. When the output / load current exceeds the input current, or when the input voltage is removed, the ideal diode components for supplying power from the battery; Dell Vostro A860 battery Dell Vostro A860n battery

2. The ideal diode (not to load directly connected to the battery) to give a full load power supply can recharge the battery in the external power source is removed to maintain full charge state Zhi Qian, and makes the unit even in a fully depleted by the battery cases to function properly;

3. Once the external power source is removed, the output voltage drops until the ideal diode forward bias is applied so far. It also has an ideal diode voltage before the battery then provides an output to the load;

4. If the battery is the only power source available or load current exceeds the input current has been set, then the battery will be filed by a bat and pins on the ideal diode circuit between the power transmission automatic load; Dell Vostro 1720 battery Dell Vostro A840 battery

5. Ideal diode (as well as recommended capacitors on pin OUT) allows IC to the body without using large capacitors in the treatment of high dynamic loads and the AC adapter or USB VBUS connection disconnection model /;

6. Ideal diode low loss path to power by reducing the IR drop extended run time battery.

Linear Technology Power Management IC Series for solving design problems above. In the field realize the function of two important new products LTC4085 USB power manager and high-voltage battery charger LTC408 Source Manager. Dell Vostro 1510 battery Dell Vostro 1710 battery

Current measurement of the degree of compensation

To accurately measure the magnitude of tension mV in itself quite a challenge, stand on chips for accurate measurement of temperature Bianhua O’clock Geng Xian Shi is difficult, because Zhu Yao Ji Shi is a work laptop in the room diannao, Huan Shi Jing Li temperature changes will be. For example, in the battery during the rest of the leadership, BMU in a FET maximum power from the battery, resulting in significant increase in chip temperature. And offset parameters are related to many changes in temperature, if not eliminate these effects will affect measurement accuracy. Atmel offset calibration method has been proved that taking into account the thermal effect is also very effective. Figure shows the effect of temperature has been completely eliminated, ensuring that migration is no longer an impact on the measurement accuracy. Dell XPS M1330 Screen Dell XPS M140 Screen

Bandgap reference voltage characteristics and the impact on the voltage measurement

Bandgap reference voltage is a key factor in access to high-precision results. The expected value of the gap voltage reference firmware will result in an actual gain error of measurement results, and in most cases it is the measurement of battery voltage and current measurement the main source of large error.

Standard voltage bandgap reference is proportional to absolute temperature by a (PTAT) current and a complementary relationship with the absolute temperature (CTAT) in the current composition of the two added together, can provide the change in stream temperature and relatively stable. This current flows through resistance, not the temperature change and the formation of relatively constant voltage. However, the shape of a curve of CTAT, PTAT and is linear, so be tension – temperature relationship graph is curved. Dell XPS M1530 Screen Dell XPS M170 Screen

BGR in the current level of production of certain differences (changes in output), making reference numeral 25 ℃, the curve of curvature of the flattest part of the shape and location changes occur, to Hence the need for factory calibrated to try to reduce the impact of this change, as shown in Figure 3 as a benchmark does not calibrate the changes made by the bodies of the source. At -20 ~ +85 ℃ temperature range, the maximum difference of -0.9 ~ 0.20%. Figure 3 shows the curves of two extreme values of the curve with most other devices there is a big difference.

BM devices commonly used in reference bandgap standard was calibrated against the change in rating, at 25 ℃ high precision. However, changes in curvature of the shape and location of compensation is also fairly common, and this generation and significantly related to changes in temperature, which makes high and low temperatures in the measurement of battery voltage n is not specific enough. In addition, it can not detect and display the shape of the curve was significantly different outliers. Dell XPS M1710 Screen Dell XPS M1730 Screen

Novel voltage reference calibration method

Under different temperature changes to achieve better performance, Atmel adds an additional mechanism for voltage reference calibration to adjust the temperature coefficient bandgap reference. The calibration step to adjust the curvature of the shape and position, and significantly improve the stability with temperature changes, as shown in Figure 4, the range of -20 ~ 85 ℃ temperature of 0.5 %, the biggest change. Note that the second calibration step can detect and display a very different form of the curve of outliers.

On the basis of factors of production cost criterion, in general, BM components are the implementation of the second calibration step. Because industry standards are packaged in a test device temperature, while the second school in two temperature standards required under the semiconductor device testing accurate simulation, which has the added requirements of high accuracy of the simulation are generally the second test will be a big step increase in costs. HP G50 Screen HP G60 Screen

Atmel is developing a new approach, minimizes the additional cost to conduct a second test step. Traditionally, the test of the second step requires a measuring equipment of high precision and complex arithmetic operations. In addition, each device under test, the first step of test data must be stored, and then recover in the second stage of testing. These requirements will increase the cost of the test. Atmel’s proprietary technology to take full advantage of the characteristics of the WB unit itself, the test equipment is required as a minimum: a precise external reference voltage through the use of onboard ADC to implement the measure; CPU utilization to perform computing tasks required, and the first step in using flash memory to store measurement data. Therefore, as long as the use of very low cost high precision test equipment will get the result. In this way, Atmel is able to test at a very low additional cost to provide peak performance. pb992a pb994a pb995a

Offset voltage with a precision of temperature measurement

When the battery is fully charged or fully discharged state, the voltage measurement will determine when to terminate the application or stop recharging the battery. Because the maximum and minimum battery voltage safety issues are not compromised, and therefore should be built with a guard (guard band) to ensure that all safety cases. More accurate measurement of voltage, protection zone will be less necessary, use the battery, the actual capacity will be higher. A voltage and temperature data, voltage measurements can be calibrated, and the conditions of measurement error voltage will be minimal. When taking into account the change in temperature, the measurement error is the main source of reference voltage drift. Figure 5 shows the use of the compensation standard reference compared to the curvature reference voltage caused by uncertainty. As indicated, the compensation curve can significantly improve the accuracy. f4812a hstnn-lb31 pb991a

Conclusion

To maximize the use of the battery after each charge of energy and prolong battery life without sacrificing battery safety, high accuracy is essential. To avoid increasing the cost of calibration, the inherent accuracy BMU for the highest possible. In addition, the council may make full use of resources and flexible MCU new calibration technique, we can achieve a good benchmark for the minimum cost, elimination of the temperature.

Figure 32 hours, a discharge cycle of the battery 10Ah, respectively 3h/1.5A, and 7h/0.6A 22h/60mA. temperature variation of ± 10 ℃, using resistance 5mΩ sense. Using the standard calibration method with a common BMU charge accumulation of errors is greater than 400mAh, in this case, the equivalent of 10Ah batteries for more than 4%. Atmel’s integrated solution using a proprietary analog design flexible calibration method can greatly improve accuracy. With these improvements, the following error may be reduced to 20mAh, equivalent to 0.2%.f2024b f4486b f4809a