PIC Microcontroller in Mobile Phone Remote Controller Low Power DesignAbstract: The combination of telephone remote controller for low-power design to explore the PIC single-chip low-power design methodology, and give the design of the circuit schematic. Keywords: PIC Single-chip low-power design telephone remote controller standby INTRODUCTION 20th century since the 90s, with the characteristic line width of integrated circuits continue to shrink and the chip density and a corresponding increase in operating frequency, lower power consumption has become a sub-micron and deep sub-micron VLSI design of a major consideration in factors. The increase in power will bring about a series of questions, such as the circuit parameters drift, reliability decreased chip package increase in production costs. Therefore, the system power consumption in the entire system design, especially in the use of battery-powered system, it is very important. Microchip Inc. PIC microcontroller series for the design of high-performance, low-power single-chip microcomputer system provided a good solution. The following from the low-power design methods and specific examples to introduce single-chip low-power applications PIC. One low-power design methodology To make the system work in the low-power state, must be properly set up single-chip configuration and work. The following combination of the most commonly used PIC12, PIC16, etc. Introduce Single-chip low-power system design. 1.1 The basic design method Have much technology can reduce system power consumption, the most commonly used are Sleep mode. Procedures for the enforcement of a SLEEP instruction, then entered a dormant (Sleep) mode. To Sleep mode, the crystal oscillation to stop, at which point single-chip microcomputer in the 3V power supply conditions, only 1A of current. System work, can be used single-chip watchdog or external events periodically wake-up single-chip, the electronic switch to provide power for the system to reduce system standby power consumption, extend battery life. Single-chip operating frequency and power consumption is also a great relationship, the higher the frequency, the greater the power consumption. Using 32kHz crystal oscillator, 3V voltage job, PIC12, PIC16 MCU and other typical operating current of only 15A; using 4MHz crystal, 5V operating voltage, the typical single-chip current job to meet a few mA. Low power consumption in many occasions, the use of low-speed low-power crystal oscillator implementation very effective. If using single-chip RC oscillation, but also through the I / O port operation to change the oscillation resistor, thus changing the single-chip operating frequency, to achieve the purpose of energy saving. As shown in Figure 1, an I / O pins can be in the wait state will be removed parallel resistor R1 to reduce the single-chip operating frequency. When Singlechip necessary work can be I / O pin is set to output and output high, thereby enhancing the oscillation frequency. 1.2 Oscillation Circuit Design In single-chip system design, the oscillator circuit is designed to be a very important aspect. PIC MCU typical oscillation circuit shown in Figure 2. Under normal circumstances, the design staff in accordance with the manufacturers give a choice of the parameter table. If the system can work properly, it will no longer be improved. In fact, this is not appropriate. Since Microchip microcontroller according to the model and version of the different job in the DC voltage range of 2.5 5.5V, the automotive-grade temperature can be in the range of -40 -125 , and the parameters of the table give only a limited number kinds of situations, the actual environmental parameters on the performance of oscillator circuit have a huge impact. Such as high temperature, low voltage can reduce the oscillation loop gain, while the oscillation frequency from the lower or more difficult to start; low temperature, high-voltage loop gain can become larger, so that crystal-off drive, resulting in the potential risk of damage or oscillation circuit The increased frequency of high harmonics, and increase system power consumption. Therefore, how to correct the oscillator circuit design system is necessary. For PIC MCU, the general design steps are as follows: Select crystal. According to the systems oscillation frequency required for crystal choices. In addition, the work of crystal temperature and frequency stability is also very important indicators. Select the type of oscillator. PIC MCU has RC, LP, XT, HS, such as oscillation modes. In addition to RC mode, the oscillation modes to choose is in fact the choice of loop gain. Low gain corresponds to a low oscillation frequency, high-gain corresponds to the high oscillation frequency. Generally required in accordance with the actual operating frequency can be selected reference manual. Select C1, C2. Ideally, the system