6.1.12. DC-DC Converter Circuit
This system has external AC adaptor, and DC40V is supplied by an external AC adaptor to the system.
AC Adaptor specification
AC input (Primary)
100 V AC to 240 V AC, 1.5A, 50 Hz/60 Hz
DC output (Secondary)
DC40 V, 1.38 A (55.2 W)
In the power supply circuit, the DC-DC converter generates 12V, 5v for the HDD, 3.3v for logic, and 1.9v for the CPU from the
DC40 input from the AC adapter. An alarm circuit is provided in the 40V route by which a DC power stop generates a DC down
alarm signal when LOW is asserted. The overvoltage detection circuit monitors 12v, 5v, and 3.3v described below and shuts
off the supply of 40v when each voltage reaches the predetermined value or higher.
The DC-DC converter generates 12v and 5v necessary for the HDD power supply. 5v is generated branching off from 12v. 12v
supplies the backup circuit with a large-capacitance capacitor for backup in the event of a momentary power failure. The inrush
current prevention circuit is provided to ease the inrush current that is generated by the capacitor on startup.
The DC-DC converter also supplies 3.3v to logic components of the main board from the 40v. 3.3v is set to start after 40V and
5V are raised to 10v and 4.3v respectively. 3.3v mounts the backup circuit with a large-capacitance capacitor for backup in the
event of a momentary power failure. The inrush current prevention circuit is provided to ease the inrush current that is generated
by the capacitor on startup.
In addition, this 3.3v generates 1.9v that is supplied as the core power supply to the CPU, and 1.9v is generated for the CPU´s
RTC circuit that has the backup circuit by the lithium battery. Particularly because the load changes of 1.9v for the CPU are
large, a converter with high transient characteristics is used. The lithium battery circuit is provided with a battery alarm, and an
nBAT_ALM signal is asserted LOW when the amount of the lithium battery remaining is exhausted.
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KX-TVM200E / KX-TVM200NE
Summary of Contents for KX-TVM200E
Page 6: ...VM LINK KX TVM200E KX TVM200NE DSP KX TVM204X 6 KX TVM200E KX TVM200NE ...
Page 7: ...DPT KX TVM204X 7 KX TVM200E KX TVM200NE ...
Page 15: ...4 5 SYSTEM CONNECTION DIAGRAM 15 KX TVM200E KX TVM200NE ...
Page 16: ...4 6 NAMES AND LOCATIONS 4 6 1 Outside Inside View 16 KX TVM200E KX TVM200NE ...
Page 22: ...4 11 EXPLANATION CONCERNIG MODE SWITCH 22 KX TVM200E KX TVM200NE ...
Page 23: ...4 12 EXPLANTATION CONCERNING LED 23 KX TVM200E KX TVM200NE ...
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Page 70: ...8 6 MODEM CARD IS OUT OF ORDER 8 7 MAIN CARD IS OUT OF ORDER 70 KX TVM200E KX TVM200NE ...
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Page 72: ...9 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 72 KX TVM200E KX TVM200NE ...
Page 74: ...11 FIXTURES AND TOOLS 74 KX TVM200E KX TVM200NE ...
Page 75: ...12 CABINET AND ELECTRICAL PARTS LOCATION 75 KX TVM200E KX TVM200NE ...
Page 76: ...13 ACCESSORIES AND PACKING MATERIAL 76 KX TVM200E KX TVM200NE ...
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Page 115: ...18 KX TVM204X 4 PORT DIGITAL EXPANSION CARD 115 KX TVM200E KX TVM200NE ...
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Page 126: ...Reference 1 126 KX TVM200E KX TVM200NE ...
Page 127: ...Reference 2 127 KX TVM200E KX TVM200NE ...
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Page 132: ...18 4 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 132 KX TVM200E KX TVM200NE ...
Page 133: ...18 5 CABINET AND ELECTRICAL PARTS 133 KX TVM200E KX TVM200NE ...
Page 134: ...18 6 ACCESSORIES AND PACKING MATERIALS 134 KX TVM200E KX TVM200NE ...
Page 140: ...18 8 MEMO 140 KX TVM200E KX TVM200NE ...
Page 154: ...19 KX TVM296NE MODEM CARD 154 KX TVM200E KX TVM200NE ...
Page 157: ...19 3 TERMINAL GUIDE OF ICS TRANSISTORS AND DIODES 157 KX TVM200E KX TVM200NE ...
Page 158: ...19 4 CABINET AND ELECTRICAL PARTS 158 KX TVM200E KX TVM200NE ...
Page 159: ...19 5 ACCESSORIES AND PACKING MATERIALS 159 KX TVM200E KX TVM200NE ...