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Circuit Description
Samsung Electronics
4-13
4-6-2 Schematic Description
DC-DC CONTROLLER
KA7500B(U1) is DC-DC Controller. It reads the
voltage difference between E1I+ Port and E1I- Port
and controls time to turn on Q1. E2I+ and E2I-
turn on Q1 in the same way. U1 also su5V
of Reference Voltage(Vref).
STATIC CURRENT
E1I- Port of U1 detects about 1.25V untill Full-
Charge and controls the TURN ON time of Q1 in
order to detect 1.25V at E1I+ Port. To make the
E1I+ Port detect 1.25V continuously, 0.19V of
voltage reduction will be generated on R4. At the
equation of V=I*R, the current of R4 is around
390mA and it will be the charge current.
BATTERY CHARGE CURRENT CUTTING BY
RELATIVE TEMPERATURE
Although every battery sample applied to the
SCH-1000 has almost the same battery
temperature at Full-Charge, it varies according to
the relative temperature.
So the battery temperature at Full-Charge may be
different according to the temperature around the
cellular phone.
If Full-Charge occures at 25
°…
, the voltage of U3C
to which the battery thermistor is connected is
around 2.11V and the voltage of the parallel
resistance of Th1 and R18 is about 2.11V. PIN 8 of
U3C will be HIGH and turn on Q3 if the
temperature is up. This generates the voltage
detected at E1I- of U1 around 0.1V and the charge
current reduces to 40mA. If Full-Charge occurs at
high temperature and low temperature, the battery
temperature varies and the voltage decline of Th1
and R18 relatively varies. So the battery Full-
Charge condition will be fulfilled.
PREVENT CHARGE CIRCUIT IN THE CASE
OF MOBILE PHONE CARRIER-ON
In the case of Mobile Phone carrier-on, the voltage
loaded on PIN-13 of U3D is lower than that of
PIN-12. So PIN-14 ouputs HIGH and Q3 is TURN
ON again. It results to the Prevent Charge.
LED-DRIVING CIRCUIT
When battery is inserted to CLC, the voltage
loaded to PIN-2 of U3A is lower than that of PIN-3
and PIN-1 outputs HIGH. This TURN ON Q7 and
drives LED.
Summary of Contents for SCH-1000
Page 2: ...Samsung Electronics Co Ltd GH68 60563A Printed in Korea ...
Page 31: ...Samsung Electronics 6 1 6 Troubleshooting 6 1 Logic Section 6 1 1 No Power ...
Page 33: ...Samsung Electronics 6 3 Troubleshooting 6 1 3 Abnormal Backlight Operation ...
Page 34: ...Troubleshooting 6 4 Samsung Electronics 6 1 4 Abnormal Key Data Input ...
Page 35: ...Samsung Electronics 6 5 Troubleshooting 6 1 5 Abnormal Keytone ...
Page 36: ...Troubleshooting 6 6 Samsung Electronics 6 1 6 Abnormal Alert Tone ...
Page 37: ...Samsung Electronics 6 7 Troubleshooting 6 2 Transmitter Section ...
Page 38: ...Troubleshooting 6 8 Samsung Electronics ...
Page 39: ...Troubleshooting 6 9 Samsung Electronics 6 3 Receiver Section ...
Page 40: ...Troubleshooting 6 10 Samsung Electronics ...
Page 41: ...Samsung Electronics 6 11 Troubleshooting ...
Page 43: ...Troubleshooting 6 13 Samsung Electronics 6 4 2 No Power HHP PWR 5 8V 13 5V Supply ...
Page 44: ...Samsung Electronics 6 14 Troubleshooting 6 4 3 Hands Free RX Path ...
Page 45: ...Troubleshooting 6 15 Samsung Electronics 6 4 4 Hands Free TX Path ...
Page 46: ...Samsung Electronics 6 16 Troubleshooting 6 5 Desk Top Rapid Charger ...
Page 47: ...Troubleshooting 6 17 Samsung Electronics 6 6 Cigarette Lighter Adapter 6 6 1 Power Fault ...
Page 48: ...Troubleshooting 6 18 Samsung Electronics 6 6 2 LED On Fault ...
Page 49: ...Troubleshooting 6 19 Samsung Electronics 6 6 3 Charge Fault ...
Page 50: ...Troubleshooting 6 20 Samsung Electronics 6 7 Travel Charger ...
Page 52: ...Exploded View and its Parts List 7 2 Samsung Electronics 7 1 Main Set Exploded View ...
Page 54: ...Exploded View and its Parts List 7 4 Samsung Electronics 7 3 Hands Free Kit Exploded View ...
Page 62: ...Exploded View and its Parts List 7 12 Samsung Electronics 7 11 Main Set Packing Layout ...
Page 64: ...7 14 Samsung Electronics Exploded View and its Parts List 7 13 Hands Free Kit Packing Layout ...
Page 66: ...7 16 Samsung Electronics Exploded View and its Parts List ...
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Page 102: ...Electrical Parts List 9 30 Samsung Electronics ...
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