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CHAPTER 2 NOTES ON HANDLING DEVICES
2.1
Notes on Handling Devices
When handling devices, pay special attention to the following eight items or
procedures:
• Strict observation of maximum rated voltage (latch-up prevention)
• Stabilization of supply voltage
• Power-on
• Treatment of unused input pins
• Treatment of A/D converter power pin
• Notes on external clock
• Caution on operation during PLL clock mode
• Power supply pin
• Analog power-on sequence of A/D converter
■
Notes on Handling Devices
●
Strict observation of maximum rated voltage
A latch-up may occur on a CMOS IC if a voltage higher than Vcc or lower than Vss is applied to an input
or output pin other than medium-to-high voltage pins. A latch-up may also occur if a voltage higher than
the rating is applied between Vcc and Vss. A latch-up causes a rapid increase in the power supply current,
which can result in thermal damage to an element. Take utmost care that the maximum rated voltage is not
exceeded.
When turning the power on or off to analog circuits, be sure that the analog supply voltages (AVcc and
AVR) and analog input voltage do not exceed the digital supply voltage (Vcc).
●
Stabilize of supply voltages
Even within the operation guarantee range of the Vcc supply voltage, a malfunction can be caused if the
supply voltage undergoes a rapid change. For voltage stabilization guidelines, the Vcc ripple fluctuations
(P-P value) at commercial frequencies (50 to 60 Hz) should be suppressed to "10%" or less of the reference
Vcc value. During a momentary change such as when switching a supply voltage, voltage fluctuations
should also be suppressed so that the "transient fluctuation rate" is 0.1 V/ms or less.
●
Power-on
To prevent a malfunction in the built-in voltage drop circuit, secure "50
µ
s (between 0.2 V and 2.7 V)" or
more for the voltage rise time during power-on.
●
Treatment of unused input pins
An unused input pin may cause a malfunction if it is left open. Every unused input pin should be pulled up
or down.
●
Treatment of A/D converter power pin
When the A/D converter is not used, connect the pins as follows: AVcc = Vcc, AVss = AVR = Vss.
Содержание MB90460 Series
Страница 1: ...The following document contains information on Cypress products ...
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Страница 9: ...iv ...
Страница 41: ...22 CHAPTER 1 OVERVIEW ...
Страница 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Страница 83: ...64 CHAPTER 3 CPU ...
Страница 95: ...76 CHAPTER 4 RESET ...
Страница 107: ...88 CHAPTER 5 CLOCK ...
Страница 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Страница 175: ...156 CHAPTER 7 INTERRUPT ...
Страница 181: ...162 CHAPTER 8 MODE SETTING ...
Страница 223: ...204 CHAPTER 9 I O PORT ...
Страница 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Страница 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Страница 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Страница 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Страница 485: ...466 CHAPTER 16 PWC Timer ...
Страница 531: ...512 CHAPTER 17 UART ...
Страница 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Страница 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Страница 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Страница 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Страница 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
Страница 715: ...696 APPENDIX ...
Страница 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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