Panasonic KX-TVM200BX / KX-TVM204X / KX-TVM296X Service Manual ▷ View online
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 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
DC40v 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.
DC40v 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-TVM200BX
About jumper J108 for the lithium battery
J108 is a jumper switch to supply the lithium battery voltage to the main board. Please note that the power supply of the real-
time clock is stopped and the time setting of the system is reset to its initial state when this jumper switch is turned off. In this
case, a red alarm LED in the front panel lights up by the battery back alarm, displaying the state.
time clock is stopped and the time setting of the system is reset to its initial state when this jumper switch is turned off. In this
case, a red alarm LED in the front panel lights up by the battery back alarm, displaying the state.
Caution:
When the jumper J108 is turned on in the power off mode, immediately turn on the power to the main board to supply 3.3V to
the CPU. Once the power of the main board has been turned on, the main power supply might be off.
As stated above, turning on J108 in the power off leads to a more rapid drain of the lithium battery.
the CPU. Once the power of the main board has been turned on, the main power supply might be off.
As stated above, turning on J108 in the power off leads to a more rapid drain of the lithium battery.
6.1.13. AC ADAPTOR SPECIFICATION
AC adaptor: PSLP1244**
Rated input voltage
AC 100v - 240v
Input voltage range
AC 90v - 276v
Input Frequency range
47Hz - 63Hz
Rated input current
Max 1.5A
Power Supply efficiency
Min 80%
Rated output voltage
38.9v - 40.0v
Output load current
+40v 1.38A
Output ripple/noise
600mVp - p
Direct current output terminal connection
DC output plug Center
+40v DC
DC output plug Circumference
GND
Circuit Protection
Over input-current Protection
This AC adaptor shall have a safety recognized fuse for over-current protection in primary live line.
Short-circuit Protection
The product shall have no permanent damage in case of the output short circuit conditions.
The Power Supply shall return to normal operating conditions after output condition recovers.
Short circuit condition shall not exceed 10 hours.
The Power Supply shall return to normal operating conditions after output condition recovers.
Short circuit condition shall not exceed 10 hours.
Over voltage Protection
During over voltage condition output not rise to dangerous voltage.
Over voltage protection range 44.0v - 57.3v.
Over voltage protection range 44.0v - 57.3v.
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KX-TVM200BX
6.2. VOICE DATA PATH SWITCHING BASED ON DIFFERENCE IN
INTERFACE
6.2.1. During DPT interface
When DPT interface is selected, each DPT and each DSP are connected as pairs. Each McBSP0 highway between each pair
is a path independent from the highways of other channels. The clock master is the ECO ASIC making up the DPT interface.
The Dch highway on which control data is sent and received by DPT link is usually a path formed between the ECO chip of the
channel earliest in order and the HDLC controller embedded in the ASIC. By controlling the Dch highway gate, this path can be
formed between any ECO chip, and support is possible even in cases where the ECO of the channel earliest in order breaks
down.
is a path independent from the highways of other channels. The clock master is the ECO ASIC making up the DPT interface.
The Dch highway on which control data is sent and received by DPT link is usually a path formed between the ECO chip of the
channel earliest in order and the HDLC controller embedded in the ASIC. By controlling the Dch highway gate, this path can be
formed between any ECO chip, and support is possible even in cases where the ECO of the channel earliest in order breaks
down.
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KX-TVM200BX
6.2.2. During VM-Link interface
When a connection is made with the VM-Link interface, the VM-Link interface signal is first received by the ASIC (iVDC) and
separated into voice data and Dch control data. The voice data is transmitted to the voice highway McBSP0 common to all
channels, and the Dch control data is transmitted to the HDLC controller in the ASIC.
separated into voice data and Dch control data. The voice data is transmitted to the voice highway McBSP0 common to all
channels, and the Dch control data is transmitted to the HDLC controller in the ASIC.
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KX-TVM200BX
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