AN1058 Freescale Semiconductor / Motorola, AN1058 Datasheet
AN1058
Related parts for AN1058
AN1058 Summary of contents
Page 1
... MCU offers the flexibility afforded to all software-based systems. MCUs have liberated many board-level designers from selecting, designing, and debugging microprocessor peripherals in multichip assemblies. This type of highly integrated solution is becoming more © Motorola, Inc., 1990, 2001 For More Information On This Product, Go to: www.freescale.com Order this document by AN1058/D AN1058 ...
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... MCU/ADC combination. The type of design precautions and applications details needed to avoid problems varies as a function of the type of ADC used. Understanding the mechanics of the given ADC is crucial to improving performance. 2 For More Information On This Product, Go to: www.freescale.com AN1058 MOTOROLA ...
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... Nothing about the servo converter would prevent its inclusion onto an MCU die; once BiCMOS processes improve, this converter type will probably become a popular feature of future MCUs (particularly the sigma-delta variation, most of which is linear circuitry). AN1058 MOTOROLA For More Information On This Product, Integrating ...
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... (c) FLASH ADC SAR DATA OUT CLOCK OUT V RH DAC V In (d) Successive Approximation ADC Figure 1. ADC Types For More Information On This Product, Go to: www.freescale.com START n CLOCK COUNTER OUT STOP n CLOCK UP/DOWN COUNTER OUT UP/DOWN COMBINATIONAL LOGIC n OUT n – + AN1058 MOTOROLA ...
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... The fifth ADC category is the hybrid converter. In this case, the term hybrid is not used to reference a specific implementation approach, but rather implies combining one or more ADC types to form an ADC with different performance characteristics. AN1058 MOTOROLA For More Information On This Product, 1(c)), albeit at lower resolutions (four to six bits are common). As 1(d)) ...
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... If the comparator fails to respond to the voltage ramp in a timely fashion, the digital counter will register an incorrect count when compared to the results obtained Bandwidth Power supply connections For More Information On This Product, Go to: www.freescale.com AN1058 MOTOROLA ...
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... MCU. With an analog-based subsystem, such as the M68HC11 ADC, normally accepted digital design practices may not be sufficient to ensure satisfactory performance of the converter. AN1058 MOTOROLA For More Information On This Product, Figure Go to: www.freescale.com ...
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... MCU indicate not, strictly speaking, a parts-related anomaly, but rather a significant interaction of the part’s characteristics with the electrical environment. 8 broadband noise riding on top of the positive voltage PP OH For More Information On This Product, Go to: www.freescale.com for HCMOS. Thus, the 100-mV AN1058 MOTOROLA ...
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... PPBULK XTAL OSCILLATOR EXTAL E POWER MODA MODE (LIR) SELECT MODB (V ) STBY Figure 2. MC68HC11E9 Block Diagram AN1058 MOTOROLA For More Information On This Product, PULSE ACCUMULATOR TIMER OC5/IC4 PERIODIC INTERRUPT COP WATCHDOG SCK SPI MOSI MISO SCI RxD M68HC11 CPU ADDRESS/DATA BUS HANDSHAKE I/O ...
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... V bypass capacitors should be attached as close as possible to the IC power pins they are intended to bypass. In addition, PCB trace 10 shows an example of such a PCB layout which, although perform the decoupling function properly, DD For More Information On This Product, Go to: www.freescale.com AN1058 MOTOROLA ...
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... ADC performance. Specific PCB designs involving MCU/ADCs should be carefully engineered. A better PCB layout is depicted in which connects the defects shown GND AN1058 MOTOROLA For More Information On This Product, illustrates a few of the PCB-related errors that can degrade Figure 3. Poor Layout Design SENSOR ...
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... In the hold mode (see 12 Figure 5). A conversion is accomplished by a sequence (0 volts), and the bottom plates are connected to the L , resulting in a stored charge on the top plate that is X For More Information On This Product, Go to: www.freescale.com Figure 5(a)), the top plate Figure 5(b)), the AN1058 MOTOROLA ...
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... V before the next capacitor is switched. Conversion proceeds in this manner until all bits have been determined and the result is stored in the successive-approximation register (SAR). AN1058 MOTOROLA For More Information On This Product, Figure 5(c)) begins by testing the value of the ...
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... The problem is caused by n-channel device junction leakages ANALOG INPUT + ~20 V PIN – ~0.7 V < Figure 6. Electrical Model of an M68HC11 ADC Input Pin For More Information On This Product, Go to: www.freescale.com DIFFUSION AND POLY COUPLER SEE NOTE 4 k ~20 pF DAC CAPACITANCE 400 nA JUNCTION LEAKAGE V RL AN1058 MOTOROLA ...
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... Because the M68HC11 ADC uses a very wide bandwidth comparator capable of responding to noise components in excess of 20 MHz, it must be guarded against unwanted noise at its input terminals and V pins AN1058 MOTOROLA For More Information On This Product, and V , the power pins that supply the rest of the M68HC11 ...
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... These sources and an estimate of the impact on a given M68HC11 system are presented in detail in the M68HC11 Reference Manual, Motorola document order number M68HC11RM/AD. 16 Signals). Efforts should be made to ensure that noise cannot For More Information On This Product, Go to: www.freescale.com Wide Bandwidth AN1058 MOTOROLA ...
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... ADC measurements. The M68HC11 was selected for this application because of its high level of integration as well as the 1 least significant bit (LSB) 8-bit ADC performance. AN1058 MOTOROLA For More Information On This Product, Go to: www.freescale.com Application Note ...
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... Figure 8). These two histograms display ranges of A/D For More Information On This Product, Go to: www.freescale.com AN1058 MOTOROLA ...
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... R EADING (HEX) 0–90 91–98 99–A0 A1–A8 A9–B0 B1–B8 B9–C0 C1–FF Note: Readings are rounded to nearest 1% value. Columns with 0% and a grey bar imply >0% and <0.5%. AN1058 MOTOROLA For More Information On This Product ITION BYPASSING TAL SAM PLES = 8192 ...
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... The noise was reduced by isolating the leading to the M68HC11. Discrete wires were then run RH Figure For More Information On This Product, Go to: www.freescale.com noise (spaced the graph shows, an Figure 9 and V pins. The DD SS Figure 10, are an apparent MOTOROLA , AN1058 ...
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... ADC input multiplexer. Although not usually considered a wideband opamp, it proved too wideband for this system. Most data coming from the devices AN1058 MOTOROLA For More Information On This Product, CO NDITIO NS: SEPARATE M CU POW ER SUPPLY FREQ ...
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... EXPANDED SCALE Figure 11. Capacitor on ADC Pin noise had not been completely eradicated. Rather than inserting a For More Information On This Product, Go to: www.freescale.com Figure M 68HC 11 IND USTRIAL CO NTRO LLER PERCENT OCCURRENCE forming a peak detector DD AN1058 MOTOROLA 11, 100 DD ...
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... A1–A8 A9–B0 B1–B8 B9–C0 C1–FF Note: Readings are rounded to nearest 1% value. AN1058 MOTOROLA For More Information On This Product, 12(a)). To check the thoroughness of this last circuit fix, the , inclusively, the 1 LSB spec could be observed directly. The ITIO NS ...
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... ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; Silicon Harbour Centre, 2 Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong. 852-26668334 Technical Information Center: 1-800-521-6274 HOME PAGE: http://www.motorola.com/semiconductors/ are registered trademarks of Motorola, Inc. Motorola, Inc Equal Opportunity/Affirmative Action Employer. For More Information On This Product, Go to: www.freescale.com © Motorola, Inc., 1990, 2001 AN1058/D ...