AN2433 Freescale Semiconductor / Motorola, AN2433 Datasheet
AN2433
Related parts for AN2433
AN2433 Summary of contents
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... Freescale Semiconductor, Inc. Application Note AN2433/D Rev. 0, 12/2002 Design Considerations by Gianni Filippi Applications Engineering Motorola, East Kilbride Contents Introduction Low Voltage Microcontrollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Mixed Voltage Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Microcontroller Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Microcontroller Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Bi-directional Translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Interfacing to Motor Control Parts Power Supplies for Low Voltage Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Linear Voltage Regulators ...
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... Freescale Semiconductor, Inc. AN2433/D Introduction Hand-held and mobile communication products continue to require longer battery life and/or smaller product sizes. Both features are made possible by low voltage microcontrollers (MCUs) that help to reduce system power consumption, which then decreases system costs. While moving to more energy efficient products, designers may need to use a ...
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... For More Information On This Product, Figure 3 Volt Bus 3 Volt Bus 5 Volt Bus 5 Volt Bus (Ground) of the receiving device Design Considerations Go to: www.freescale.com AN2433/D Mixed Voltage Systems 1, where an MCU uses a 3V EEPROM EEPROM Motor Motor Drive Drive Motor Motor Speed Speed ...
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... Freescale Semiconductor, Inc. AN2433/D both be slightly on. Indeed, they will be in their respective saturation regions and their resistance to ground will be much lower than compared to their off states, see could be as high as 4 mA. Typically I This added current consumption will only occur when a logic high is applied to the pin and, normally, not all the inputs will be at ‘ ...
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... DD Figure Figure 3. Digital Input-Only Pin Design Considerations Go to: www.freescale.com AN2433/D Microcontroller Inputs , but some of the pins include SS . IRQ pins have clamped to V – 0.6V and not ...
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... Freescale Semiconductor, Inc. AN2433/D In some microcontroller families, instead of a thick-field protection device there is a normal n-channel transistor, but the following discussion is still valid, the only difference being the clamping voltage levels for V The thick-field protection device forms an inherent diode junction to V Therefore if the voltage applied becomes lower than V ...
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... DD will switch on and current will flow (GND) or beyond voltage the maximum input voltage should Design Considerations Go to: www.freescale.com AN2433/D Microcontroller Inputs DD , which is in parallel to SS and V , input signals are ...
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... Freescale Semiconductor, Inc. AN2433/D 5V TTL Output typical bipolar output has an active high output voltage level limitation of V MCU Inputs – 2*V BE the base-emitter and the diode voltage drops, which are both approximately 0.6V ...
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... =5.5V), or one from the LVX family, which has Imax Figure 7 shows such a solution with the MC74LCX244 buffer Design Considerations Go to: www.freescale.com AN2433/D Microcontroller Inputs (within tens of DD level and DD5max Figure 6 . 3 ...
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... Freescale Semiconductor, Inc. AN2433/D over-voltages because this kind of device has a larger latch-up current rating than most MCUs. Figure 7. 5V CMOS or TTL output to 3.3V MCU input using an LCX device Microcontroller Outputs Ports current drive The output structure of a digital circuit determines the output voltage swing and capabilities the current capability ...
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... OL = 2.7V, V > (V – 1.0V) at source current of 4mA < 1.0V at sink current of 6mA Design Considerations Go to: www.freescale.com AN2433/D Microcontroller Outputs and 85 C. This device was ) and ...
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... Freescale Semiconductor, Inc. AN2433/D And typically, for the high current I/O Ports, the sink current capability is as follows For the 3V only MC68HC9S08GB60 MCU the current sink and source specifications, at full drive, are as follows: Therefore, it can be concluded that moving from technology will not jeopardise the output high voltage and low voltage provided by the microcontrollers ...
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... Design Considerations Go to: www.freescale.com AN2433/D Microcontroller Outputs ...
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... Freescale Semiconductor, Inc. AN2433/D Similar TTL compatible product inputs offer additional protection when the V DD5 withstand input voltage regardless of the V feature simplifies power-up and power-down sequences of 5V and 3V parts of the system because 5V parts can be powered down while 3V parts are running without excessive currents on the 5V inputs ...
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... BEA BEA 13 13 BEB BEB QS3861 QS3861 GND GND Figure Design Considerations Go to: www.freescale.com AN2433/D Bi-directional Translation can be created CC resistor V V 3.3V 3. 3.3V System 3.3V System IN/OUT IN/OUT GND GND can be used. The MAX3370/MAX3371 15 ...
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... Freescale Semiconductor, Inc. AN2433 3.3V 3. 3.3V system 3.3V system I/O I/O GND GND Figure 13. 3.3V MCU to 5V system bi-directional interface The NCN6010/1 level translators (respectively with and without charge pump) allow the interfacing of more than one signal. Those devices are originally targeted for interfacing 5V SIM cards to 3.3V microprocessors or GSM controllers, see 2 unidirectional lines ...
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... Moving to a lower MCU operating voltage will not have any impact on 3.3 V MCU applications Sensed Sensed Voltage Voltage MOTOROLA For More Information On This Product Vss Vss Figure 15. Voltage Sensor Design Considerations Go to: www.freescale.com AN2433/D Interfacing to Motor Control Parts Figure 15 ). MCU MCU A/D A/D Input Input 17 ...
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... Freescale Semiconductor, Inc. AN2433/D Current sensing is used for motor over-current protection as well as determination of accurate back emf voltage. A current sensing resistor is often used in low-cost applications ( return path of the DC-Bus lines for DC-Bus current measurement the individual legs of the inverter bridge for phase current measurements. The voltage drop created on the current sense resistor is amplified using an operational amplifier ...
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... For More Information On This Product, < DD3min = 2.7V level shifter needs to be used in order to prevent the current . (3.0V). Among suitable MOSFET types are the On DD3min DS(ON Design Considerations Go to: www.freescale.com AN2433/D Interfacing to Motor Control Parts IH (3.0V), such as the IR2181 from 3V =0.135ohm at V =2.7V and others ...
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... Freescale Semiconductor, Inc. AN2433/D Driving TRIACs Driving of TRIACs does not bring any issues for transition, except that the value order to have enough TRIAC gate current. The number of MCU pins should be chosen according to the driving capability of the MCU outputs to comply with the TRIAC minimum gate current requirement, which is 15mA for MAC4DC type for example ...
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... V pre-regulation device. A number of semiconductor suppliers manufacture both adjustable and fixed linear voltage regulators. The following table is a partial list of 3.3 V linear regulators: MOTOROLA For More Information On This Product Design Considerations Go to: www.freescale.com AN2433/D Power Supplies for Low Voltage Systems 21 ...
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... Freescale Semiconductor, Inc. AN2433/D Manufacturer ON Semiconductor ON Semiconductor ON Semiconductor ON Semiconductor ON Semiconductor ON Semiconductor Semiconductor Semiconductor Linear Technology Linear Technology Linear Technology Linear Technology Typically linear voltage regulator design, the input bypass (bulk) capacitor is placed close to the input terminal of the regulator. The input bypass capacitor provides a low impedance source into the voltage regulator ...
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... Part Number LM2575D2T-3.3 LM2576D2T-3.3 MC33163P LM2574-3.3 LM1575-3.3 LM2655-3.3 LM2576-3.3 LTC1701 LTC1878 LTC1772 shows a basic schematic for a switching voltage regulator containing Design Considerations Go to: www.freescale.com AN2433/D Power Supplies for Low Voltage Systems Output Ext. MOSFET Rqd. Current 3.6A No 500mA ...
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... Freescale Semiconductor, Inc. AN2433/D Self Contained Switcher 1 Input Power VIN + Input Bypass 5uF to 100uF Figure 19. Typical Step-down Switching Voltage Regulator Schematic With Internal MOSFET Figure 20 external MOSFET power device. 1 Input Power VIN + Input Bypass 5uF to 100uF Figure 20. Typical Step-down Switching Voltage Regulator Schematic With External MOSFET In summary, designing a power supply for 3 ...
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... MOTOROLA For More Information On This Product, Ability to reduce power consumption Smaller on board power sources Increase in operational lives of battery powered applications Decrease in battery weight of portable applications Lower costs for the overall system Design Considerations Go to: www.freescale.com AN2433/D Conclusions 25 ...
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... Freescale Semiconductor, Inc. AN2433/D Bibliography • • • • • • • • • • • • • 26 For More Information On This Product, "M68HC11 Reference Manual", Motorola. "Analog-to-digital converter Reference Manual", Motorola. "Interfacing 3V and 5V applications", Application Note AN240, Philips Semiconductors. ...
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... Freescale Semiconductor, Inc. Acknowledgements I am very grateful to the following colleagues for their invaluable contributions: Jaromir Chocholac, Bill Lucas and Pavel Pekarek. MOTOROLA For More Information On This Product Design Considerations Go to: www.freescale.com AN2433/D Acknowledgements 27 ...
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... Motorola and the Stylized M Logo are registered in the U.S. Patent and Trademark Office. digital dna is a trademark of Motorola, Inc. All other product or service names are the property of their respective owners. Motorola, Inc Equal Opportunity/Affirmative Action Employer. © Motorola, Inc. 2002 AN2433/D Go to: www.freescale.com ...