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Application Note: MICREL’s Power Solutions for Cellualar phone design Tel (+86)-10-6853 0126 mailto:[email protected] * RFT w ill be us e d w ith M SM 31000. And TX block w ill be s hrink e d into RFT. REG for TX 3.0V/125mA MIC5205, MIC5245, MIC5203, MIC5213, 1/2 MIC5210, 1/2 MIC5250 Op-Amp MICREL LMC7101 MMIC Up Converter REG for IFT(MSM3000) 3.0V/100mA MIC5205,MIC5245, MIC5203,MIC5213, 1/2 MIC5210, 1/2 MIC5250 REG for MSM core 2.7V/75mA + REG for MSM Digital 2.7V/150mA REG for Logic 2.7V 50mA MIC5219, MIC5203, MIC5213, MIC5205, MIC5210, MIC525 16MB/4MB *Combo Memory (Flash/SRAM) Power Amp B.P.F Driver Amp B.P.F B.P.F REG for SYNTHSIZER/VCO 3.0V/ 35mA MIC5205, MIC5245, 1/2 MIC5210, 1/2 MIC5250 Tx MSM3000 MSM3100 UART1 RS-232C Data Cable PLL UART2 REG for TCXO 3.0V/10mA MIC5205, MIC5245, 1/2 MIC5210, 1/2 MIC5250 Rx *Note: Intel Falsh Memory IFT Dual Local Oscillator 19.68Mhz Duplex er EEPROM (24C256/512) IRDA IFR USB Transceiver *MSM3100 only MIC2550 LNA B.P.F MMIC Down Converter REG for RX 3.0V/75mA MIC5205, MIC5245, MIC5203, MIC5213, 1/2 MIC5210, 1/2 MIC5250 B.P.F REG for IFR 3.0V/50mA MIC5205,MIC5245, MIC5203,MIC5213, 1/2 MIC5210, 1/2 MIC5250 * This simple building block will be updated for sales promotion use. * James Han, FAE, MICREL Korea office Tel; +82-2-3466-3000, [email protected] Cellular; +82-11-770-9672 Analog/ Audio Audio PA REG FOR MSM Analog 2.7V/50mA MIC5205, MIC5245, 1/2 MIC5210, 1/2 MIC5250 REG for Audio Power Amp 3.0V,3.3V 300mA MIC5219 1 Application Note: MICREL’s Power Solutions for Cellualar phone design Tel (+86)-10-6853 0126 mailto:[email protected] Introduction Micrel Semiconductor has had excellent reputation for it’s good performance of power management devices in CDMA cellular phone and PCS handset manufacturer in Korea and worldwide. Micrel has been selected by most of designers to meet their power requirements and to get more performance and high reliability in their cellular phone. MICREL has been supplying millions of devices to customers in Korea including LDOs, OP-Amps and DC/DC converters. In this application note we can review an example of cell phone design and its technical trends of designing CDMA and PCS phones in Korea. The block diagram is to make it easy for you to understand the cellular phone’s function inside and to find out more sockets for MICREL. And block diagrams are based on real design example with Qualcomm’s MSM3100/3000 chips. Overview on cellular phone design and power management As you can see in the simple cellular phone block diagram, it consists of battery, RF Rx and RF Tx blocks, baseband block including IFT/IFR, VCO and PLL/Synthesizer block, TCXO block, MSM processor and it’s subsystem including memories and audio, LCD/EL back-light, keypad. The function of RF Tx block is to generate the RF wave signal. And RF Rx block is to convert to the analog signal from RF wave. The digital and analog signals are processed between BaseBand chips and microprocessor. And finally it is converted to sound through Codec. In reviewing the power management in cellular phone we can put it in separated blocks to make it easy to understand the function of cellular phone and its devices for power management. Each block needs one or two LDOs for power management. But basically there is no rule how to configure the power management power in cell phone. Engineers are required to design it has more talk time and idle time without its performance sacrifice. In the design noise is very critical to get the required performance. Most cellular phone is employing 5 to 8 single LDOs to achieve its best performance. The battery Recently most of CDMA and PCS phone employing one cell Li-Ion battery pack and voltage output is 3.6Volt typical and 4.2V max at full charged. RF Tx and Rx Rx block including LNA, SAW filters, mixer, AGC amplifier consumes 75mA peak. Tx block including isolator, PAM, SAW filters, AGC amplifier, and mixer consumes 125mA peak except PAM. PAM will be connected from battery directly. MIC5205, MIC5210, MIC5245 and MIC5250 are suitable to use in Rx and Tx blocks since LDO’s very low noise features are most important factor when engineer select LDO. The required voltages are mainly 3.0V. MICREL’s LDO has super low noise performance than any other LDOs in the market. Engineers prefer to use MICREL device since it’s very low noise performance. MICREL strongly recommends you to evaluate MIC5205 and MIC5245 to get low output noise performance. Both MIC5210 and MIC5250 are dual LDOs of MIC5205 and MIC5245 in single small package. Also MIC5245 and MIC5250 are designed to operate either small ceramic capacitor or tantalum output capacitor. So customers are having more choices when they have troubles of tantalum capacitor shortages. The PAM is connected to battery directly since lower voltage operating PAM is available in the market and it requires huge current at its 29-dBm power output. Along with the operating voltage going down MICREL’s LMC7101 has strong benefit when it is used to control the PAM power output since MICREL’s LMC7101 has more rail-to-rail output performance. It swings 100mV close to supply voltage rail and also 100mV to ground rail. IFT/IFR IFT and IFR chips require 100mA and 50mA of current. Most of cell phone will be optimized its operation at 3.0V nowadays. We recommend you to evaluate MIC5205 and MIC5245 for IF blocks. And any of MIC5205, MIC5245, MIC5203 and MIC5213 can be placed in for these areas. As for Cellular phone, everybody is trying to reduce weight and space to get more market share. Therefore MIC5213 in SC70 package is going to be more popular to the manufacturer. Also dual LDOs are getting more popular. VCO and PLL, TCXO VCO and Synthesizer require 35mA. TCXO requires 10mA. Those blocks using mainly 3.0V for the best operation. We recommend you to evaluate MIC5205 and MIC5245 for this noise critical function. MSM and its Subsystems The required total power for MSM chip and its memory subsystem are pretty much depends on the Qualcomm’s MSM chip version. In MSM3100 chip, 2.7V with 75mA of power is required on MSM core and 2.7V with 150mA for MSM digital function. It also could be adjusted by design engineer. Also 2.5V to 2.7V with 50mA of power is required for MSM3100 analog function. We recommend you to evaluate MIC5219, MIC5205, MIC5245, MIC5210, MIC5250, MIC5203 and MIC5213 for using in these areas. As you understand CMOS devices in electronic devices are 2 Application Note: MICREL’s Power Solutions for Cellualar phone design Tel (+86)-10-6853 0126 mailto:[email protected] rapidly changing in its process technology so it allows lower power operation. The next generation of Qualcomm’s MSM3100 chip will be requiring much lower power. The total memory subsystem and remains are requiring 100mA of current at mainly 2.7V and could be adjusted its operating voltage at 2.5V to 3.0V. Design engineers can build up with variety of configuration of power management. When the phone is having speaker phone function it requires amp and MIC5219 is recommended. A few of audio amp is requiring hundreds of current and MIC5219 is very suitable on this application. For higher power application like this Micrel offers MIC5219, which can supply 500mA in sot-23-5 package and also 8 pin MSOP. MIC5219 is the only LDO in the market, which can supply 500mA current in sot-23-5 package. It can supply 500mA maximum and it’s dependent on circumstance condition including input and output voltage. Please refer to the attached LDO selection table regarding power dissipation. For lower power application we are offering fixed output 2.X volts LDOs as well. For many of the designers are studying the USB implementation in their next generation cellular phone. When designing USB function in cellular phone it requires USB transceiver chip. MICREL’s MIC2550 USB transceiver is designed for this and it allows you to save a lot of battery power. Attached -LDO selection table -LDO power dissipation table -CDMA/PCS design example ---------------------------------------------------If you require more support from MICREL or any question on this application note please call us or email me. Galaxy Far East Corp. 010-68530126 021-64956484 3