48 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
			
		
		
	
	
			48 lines
		
	
	
	
		
			2 KiB
		
	
	
	
		
			Text
		
	
	
	
	
	
| HHKB Power consumption
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| ----------------------
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| 
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| **Power consumption
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|     board   clock/prescaler     keyswitch   power ctrl      current
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|     --------------------------------------------------------------------------
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|     tmk     16MHz               no          no              26.4mA
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|     tmk     16MHz               pro1        no              45.1mA
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|     tmk     16MHz/2             no          no              18.1mA
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|     tmk     16MHz/2             pro1        no              37.3mA
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|     tmk     8MHz                no          no              18.9mA
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|     tmk     8MHz                pro2        no(w/o FET)     32.1mA
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|     tmk     8MHz                pro2        no(w FET)       32.1mA withou POWER_ON/FF
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|     tmk     8MHz                pro2        no(w FET)       32.6mA with POWR_ON/OFF
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|     tmk     8MHz                pro2        15ms(w FET)     21.3mA with POWR_ON/OFF, enumerated but error -32
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|     tmk     8MHz                pro2        60ms(w FET)     13.3mA with POWR_ON/OFF, not enumerated
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| 
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|     gh60    16MHz                                           25.8mA
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|     gh60    16MHz               USB suspend w LED breathing 17.6-29.1mA
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|     gh60    16MHz               USB suspend w/o LED         0.2mA(0.231-0.276mA)
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|     Poker                                                    5.6mA
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|     Poker                       USB suspend                  0.3mA(0.301mA)
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|     gh60    16MHz               stock firmware by komar     26.8mA
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| 
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| 
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|     HHKB pro2 Over All                                     139.4mA
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|     HHKB pro2 Controller                                   115.1mA
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|     HHKB pro1 Controller                                    25.9mA
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| 
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| 
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| keyswitch power consumption:
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| pro1: 45.1-26.4=18.7mA
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|       37.3-18.1=19.2mA
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| pro2: 32.1-18.9=13.2mA
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| 
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| 
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| 
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| 
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| 
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| **Low Freq Crystal or Prescaler?
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| No advantage of Low Freq Crystal against Prescaled.
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| 
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| Clock routing
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| X'tal --+---->Prescaler-------> System Clock
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|         |
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|         +---------------------> USB PLL
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| 
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| Design Decision: Install 16MHz crystal on board with using clock rescaler.
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