Read Sony NW-HD3 (serv.man2) Service Manual online
Copying is strictly prohibited
7
3. Charging Circuit
3-1. Outline
Fig.3-1 shows the charging circuit. In this model, the charge control IC9501 controls all charge operation. This unit, NW-HD3 has the USB charging function.
= When the voltage is supplied to the unit from the AC power adapter =
At the time the unit is connected to the USB Adaptor and 6[V] is supplied to pin-1[IN] and pin-2[VCC] of the charge control IC9501, IC9501 starts the charging operation.
= When the VBUS voltage is supplied to the unit from PC =
At the time the unit is connected to the USB Adaptor and VBUS voltage is supplied to the unit, it is supplied to pin-2[IN] and pin-3[IN] of the USB CHARGE CONTROL IC9505.
Next, if 6[V] from AC power adapter is not supplied to the unit, MULTI INTERFACE IC7001 outputs “L” signal from pin-162[XCHG_USB]. By this “L” signal, IC9505 starts up,
and outputs VBUS voltage from pin-5, pin-6 and pin-7[OUT]. Then, VBUS voltage is supplied to the charge control IC9501 via D9506 and IC9501 starts the charging
operation.
Point:
USB CHARGE CONTROL IC9505 has the function to control the current output from pin-5 through pin-7[OUT]. Therefore the current output from IC9505 becomes
always 500[mA].
always 500[mA].
MAIN SYSTEM CONTROLLER IC1003 can judge whether the unit is in the AC power adapter driving or not by monitoring the input signal of pin-150[PQ4].
(See Table.1-2 on page 3)
(See Table.1-2 on page 3)
USB Charging function does not work when the unit is in the AC power adapter driving. (“H” signal is output from pin-162[XCHG_USB] of MULTI INTERFACE IC7001.)
= Charging Operation =
As the rechargeable Lithium-ion Battery is built in, the charging method is the constant current and constant voltage method. CHARGE CONTROL IC9501 performs the
constant current charging by monitoring the voltage into pin-6[ISET] after converting current into voltage by the resistors. The charging current is controlled according to the
operation mode of the unit. In the Wake-up mode, Q9501(1/2) turns “ON” and Q9501(2/2) turns “OFF” by “H” signal (CHG_LIM) supplied from pin-163[CHG_LIM] of MULTI
INTERFACE IC7001. That controls the monitoring voltage input into pin-6[ISET] of IC9501. CHARGE CONTROL IC9501 performs the constant current charging shown in
Table.3-1. When the constant current charging terminates, CHARGE CONTROL IC9501 changes the charging mode from the constant current charging method to the
constant voltage charging method.
Table.3-1 Constant Current Charging Control
Operational Mode
Charging current
Remark
Wake-up Mode
160 to 185 [mA]
Q9501(1/2) turns “ON” and Q9501(2/2) turns “OFF” by “H” signal (CHG_LIM)
Sleep Mode
525 to 580 [mA]
Q9501(1/2) turns “OFF” and Q9501(2/2) turns “ON” by “L” signal (CHG_LIM)
Click on the first or last page to see other NW-HD3 (serv.man2) service manuals if exist.