AN8083 Panasonic Semiconductor, AN8083 Datasheet - Page 4

• Manufacturer Part Number: AN8083
• Description: Low Voltage Operation IC for DC-DC Converter
• Manufacturer: Panasonic Semiconductor

AN8083S
inputted to V
when the error amplifier becomes “Low,” charged current no longer exits and SPRO is maintained to 0.9V.
2. Decreased voltage detection circuit
• Operational Description
outputted to CT pin (Pin7) and the rectangular wave to OUT pin (Pin5). In this condition, called start condition, PWM control is not
obtained and only oscillation is repeated. By this oscillation at start, supply output is increased. This supply output voltage is
oscillation in normal operation is outputted. PWM control is started only after entering normal mode. The voltage switching
between start and normal operation has 0.5V hysteresis. When power pin (Pin11) is set to “High” in normal operation, normal mode
oscillation is started. In this status, output of the supply is 4.8V fixed.
• Other features
1. Short-circuit protection feature
power supply system is judged to be in an abnormal condition. With the time constant of discharged current I
(Pin3) and capacitor C
3. Reset output
1) When Pin10 becomes “L” by operation of CPU or
2) When the secondary side voltage exceeds 3.6V, starter
3) When the secondary side voltage becomes 4.2V,
When power V
For normal mode oscillation, when output/FB pin (Pin2) of error amplifier is in “High” condition, oscillation is stopped, since the
When V
When V
System Block Diagram
Supplementary Explanation
push switch, oscillation starts and boosted voltage is
outputted to the secondary side.
circuit is stopped and PWM operation is started by using
the voltage in the secondary side as power supply.
Pin15 becomes “H” and CPU operation is started.
1.5V
1.5V
SEN
CC
pin voltage is 4.2V or more, RST pin (Pin15) gets “High.”
CC
pin (Pin14) gets 2.15V or less, EMS pin (Pin13) gets “High.”
pin (Pin16) of the AN8083S. When the voltage of V
CC
pin (Pin8) is connected to the supply output and start pin (Pin10) is set to “Low,” the triangular oscillation is
SPRO
8
9
, pin voltage is increased, and oscillation is stopped when it becomes 1.25V or more. During this time,
P–V
CLK
RESET
15
AN8083S
CC
Power SW
V
16
CC
EMP
OUT
Start
13
10
11
SW
5
Oscillation starts at “L.”
“L” when the battery voltage is 2.15V or less.
“H” when the secondary voltage is 4.2V or more.
Oscillation synchronization signal
4) When “L” pulse is sent from CPU to Pin11, oscillation
5) For re-start, when Pin10 becomes “L” by operation of
is stopped and it enters the stand-by mode. In this
status consumption current is 2 A max.
CPU or push switch, oscillation starts.
CC
pin becomes 3V or more, start oscillation is stopped and
Power OFF at “L”
+
ICs for CD/CD-ROM Player
CPU
SPRO
of SPRO pin