• 29Aug

    Cell phone chargers to the market

    1. At present, mobile phone chargers can be divided into single slot shape and Dual Chamber of chargers, chargers are being single-channel two-channel attacks. Two-channel charger in addition to slow charge, fast charge, discharge and nickel-cadmium, nickel-hydrogen laptop battery and charge a standard feature, there are some products with automatic temperature control and voltage control, to prevent the filling of new features, thus consumption Who should be inclined to choose Dual Chamber of chargers.

         2. With the increasing variety of mobile phones, various models for different chargers, power is not the size of the same port, which can not be used interchangeably, has brought inconvenience to consumers. Standard charger is that you can connect all the phone at the bottom outlet (port) of the charger pavilion battery. Moreover, the production of mobile power for the port will apply to the unified standard charger specifications. In this way, consumers will not have to phone each other at the same time to buy a new charger. Thus, from the sit-in charger to the portable, such as the development of Dual Chamber at the same time, also began to standardize the general direction of development.

         3. Standby power consumption of mobile phone chargers to reduce gradually become the Chargers in the design process an important part. Compared to the previous chargers, the future production of the products will improve the function at the same time further reducing its own standby power consumption F2024A . In order to achieve this objective, can design a judgement whether the AC adapter connected load (phone) IC, when not connected load, the AC adapter DC output side (two circuits) switch to high-impedance circuits. This measure can be adopted to substantially reduce standby consumption of two circuit current (can reach tens of μ A). In addition, the exchange can also enter the 100 V (a circuit) circuit in the switch settings. Not connected load, through the switch circuit to reduce supply to the DC output side (two circuits), thereby reducing power consumption.

         4. Now on the market most of the charger, only lithium batteries or nickel-hydrogen batteries, but with the development of the market, automatic identification of two F2024B  charging and the corresponding process of the charger is gradually occupy the mainstream. Can automatically distinguish between lithium batteries or nickel-hydrogen battery Zuochong can “to prevent the discharge of lithium wrong moves” if the rechargeable lithium battery when not carefully Zuochong according to the “release button,” can identify good Zuochong is out Lithium batteries, it will not do discharge movements of the poor while不管三七二十一Zuochong conduct discharge, which will result in the impairment of lithium F2299A life.

  • 29Aug

    Monitoring way

    In many automotive systems, the monitor is an important function of monitoring the battery voltage to the laptop battery voltage circuit to maintain the system within the acceptable scope of work. Monitor can monitor the input from two sides: the internal or external adjustment settings. Built-in threshold will allow users to directly control input pins with the monitoring of the power link, without any external components. However, the monitoring threshold must choose built-in form. These choices are often based on the almost standard logic supply (5 V below) and therefore are often not suitable for battery monitoring. In addition, if the control input pin directly connected to the battery, it must withstand 60 V peak voltage.

    For these reasons, adjustable external input is usually a better choice. Enter the adjustment of fixed threshold is relatively low, at around 0.5 V, but it is high impedance input, it can be monitored with the power to connect a resistor divider pavilion battery. The divider of these resistors can be set in any high voltage monitoring threshold. External divider also provides a flexible, and that is devoted to the study of the system (for example: regardless of the minimum working voltage to 9.5 V or only up to 10 V) to match the power to choose an acceptable range. Divider in the more protected the resistance will monitor the importation of its load dump or other abnormal conditions of the incident from the impact of current damage.

    Batteries may need to monitor the importation of over-voltage F2024B  detection or under-voltage conditions. In both cases very easily, and will weaken the function of the system. The basic monitor is often only available under-voltage monitoring. If the pressure monitoring threshold set up independent of the under-voltage threshold, the two independent adjustable resistor divider external input is usually to be used to detect under-voltage or over-voltage. Even in normal operation, the vehicle power supply may also have a large number of high-frequency components, such as when they come from at-fault for the wiper motor and load, such as car headlights, alternator output generated by the ripple and various forms of EMI. Monitor treatment in the form of high-frequency content can seriously affect the effectiveness of the monitor. For example, the scope of work close to the edge of the AC generator power supply ripple is undesirable, because it could lead to thousands of microprocessor reset pin-hyuk of frequency hopping. To some extent, the use of monitoring the retardation threshold can solve this problem. This is often not an ideal solution, because retardation threshold accuracy equivalent to the decline, which will shorten the start-up time or to relax the components of the scope of power.

    Bellows also available through reduction of overtime to ease the way, this is often the monitor. When a F2299A  power supply from outside the scope of work to convert the scope of the work at the power good instructions before the Monitor will wait for a period of the scheduled time. If the power in the overtime period of any de facto again from the scope of work, overtime will be reset, and the next voltage to re-enter the work began. Timer can be avoided from the output of high-frequency than any of the overtime. On the other hand, the timer can also cycle through overtime and delayed the start-up and recovery system, in order to achieve a balance must be on the power play and the characteristics of the microprocessor. Some monitors can be provided to adjust the overtime period, in order to achieve a given system optimization of the compromise, while others were from the factory-programmed and fixed overtime (normally 200 ms), which can save users external components of the set-up time.

    Finally, the majority of modules will continue through short-term transient voltage in more than their normal scope of work under the conditions of work, which mainly depend on local supply bypass capacitor. In addition, the acceptability of this transient period with the amplitude often change. For example, a Pavilion DV1000 battery system may have to 2 V interference in the operation under the conditions of 50 s, or 1 V interference in the running 100 s. For this reason, many monitors can provide some input interference filters, in response to interference in the energy supply, not just its amplitude.

  • 29Aug

    Samples of the use of MAXIM create ultra-low-power battery boost circuit

        The last two months suddenly ultra-low power circuit from the interest, just two days before the company has a small project, the need to design a 1.5 v battery boost circuit. Output to 3.3 v 100MA. Of course, boost the election integrated circuit DC / DC Rafah, the external components  more less more best . Mind immediately thought of MAXIM, MAXIM fact, there are several things kind of performance in the industry is really good. Samples of applications is also extremely convenient. I chose a MAX1674, the importation of 1.1 to 5.5 v, output 3.3 v, no-load current is about 16 uA, performance or very good manner. Samples of hand immediately thermal transfer. After the actual measurement, 1.55 v input voltage unladen 60 uA, SHDN model 10 uA, 10uA appears to be tantalum capacitor leakage, it is the no-load current 50 uA, or very large (I think, in fact DC / DC chips now This is the manufacturing level). Circuit decided to increase it to be transformed. To make no-load current of less than 3 uA

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