AN8083S [PANASONIC]
Low Voltage Operation IC for DC-DC Converter; 低工作电压IC的DC-DC转换器
| 型号： | AN8083S |
| 厂家： | 
PANASONIC |
| 描述： | Low Voltage Operation IC for DC-DC Converter |
| 文件： | 总5页 (文件大小：65K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
ICs for CD/CD-ROM Player
AN8083S
Low Voltage Operation IC for DC-DC Converter
■ Overview
Unit : mm
The AN8083S is an IC for controlling a DC-DC convert-
er suitable for the switching power supply of various
portable equipments. It can operate with input voltage
1.1V or more.
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
■ Features
•
•
•
•
•
•
•
Operatable with low voltage input (PVCC>1.1V)
Decreased voltage detection circuit built-in
Short-circuit protection feature built-in
Provided with reset output
Synchronizable with outside clock
Low consumption current in stand-by mode
Output voltage in secondary side; 4.8V+0.3V (Variable
by using external resistance)
0.3
4.2±0.3
6.5±0.3
16-lead SOP package (SOP016-P-0225A)
■ Block Diagram
EMP
13
START CT
RESET VCC
VSEN
14
VREF
12
15
16
10
7
2.15V
VREF
0.85V
0.25V
+
–
+
–
Triangular
Wave
Starter
9
8
CLK
PVCC
1.25V
3.0 → 2.5V
Starter SW
4.8V
Early Value Set.
2.0V
–
+
Power
OFF
+
–
POWER
GND
11
–25µA
–
+
+
+
–
Switching
Circuit
30kΩ
0.725V
6
63kΩ
1
2
3
4
5
IN
FB
SPRO
DED
OUT
ICs for CD/CD-ROM Player
AN8083S
■ Absolute Maximum Ratings (Ta=25˚C)
Parameter
Symbol
Rating
Unit
V
VCC
PVCC
PD
14.4
14.4
Supply Voltage
Power Dissipation
380
mW
˚C
Operating Ambient Temperature
Storage Temperature
Topr
Tstg
–20 ~ +75
–55 ~ +125
˚C
■ Recommended Operating Range (Ta=25˚C)
Paramenter
Symbol
VCC
Range
1.8V ~ 12V
1.1V ~ 12V
Operating Supply Voltage Range
PVCC
■ Electrical Characteristics (Ta=25˚C)
Parameter
Symbol
IPVCC
IPVCC
Condition
VCC=0V, PVCC=3V
VCC=3.1V, PVCC=3V
min.
typ.
max.
Unit
µA
Power VCC Stand-by Mode Supply Current
Power VCC Operating Mode Supply Current
Output Voltage
2
1.2
3
mA
V
VO
4.8
4.2
Reset Output Threshold Voltage
Decreased Voltage Detection Threshold Voltage
Short-Circuit Protection Operating Voltage
Short-Circuit Protection Operating Voltage
Oscillation Frequency in Normal Operation
PVCC=3V
VTH (RESET)
VTH (VSEN)
VO (SPRO)
VO (SPRO)
fOSC1
4
2.05
1.35
1.7
4.4
2.25
2.1
V
PVCC=3V
2.15
V
VIN=0V, VPOWER=2V
VIN=1V, VPOWER=0V
RREF=33kΩ, CT=330pF
V
3.2
V
60
70
80
kHz
R
REF=33kΩ, CT=330pF
Oscillation Frequency at Start
fOSC2
80
kHz
100
120
VCC=1.9V, PVCC=3V
IO= –20mA, VCT=0V
IO=20mA, VCT=1V
Output Voltage (Normal)
Output Voltage (Normal)
VOH (OUT)
VOL (OUT)
1.2
1.6
0.4
V
V
Note) Unless otherwise specified, VCC=4.8V, PVCC=3V
■ Application Circuit
4.8V±0.3V
+
330pF
VREF
33kΩ
VCC
EMP
16 13
RESET
CT
START
VSENSE
15
14
10
7
12
2.15V
VREF
0.85V
0.25V
CLK
+
–
+
–
Triangular
Wave
Starter
9
1.25V
3.0V→ 2.5V
PVCC
Starter SW
Initial set
4.8V
8
POWER
2.0V
–
Power
OFF
+
–
+
11
–25µA
–
+
+
+
–
SW
circuit
30kΩ
0.725V
GND
0.01µF
6
63kΩ
1
2
3
4
5
100Ω
SPRO
DED
OUT
IN
FB
+
47µF
0.01µF
33kΩ
0.01µF
Connect Pin11 to the secondary side and Pin10 to GND at oscillation start. (Pin10 is always open.)
ICs for CD/CD-ROM Player
AN8083S
■ Pin Description
Pin No.
Symbol
Pin Description
• Input pin for error amplifier
Threshold voltage ; 0.7V
1
2
IN
•
FB
• Output pin for error amplifier
• Short-circuit protection input pin.
If output of error amplifier does not become “L” when t=CVth/ISPRO output of IC is not
3
4
SPRO
DED
switched.
I
SPRO=25µA
Vth=0.9V
• Dead time control input.
Maximum duty ratio set to 85%.
Maximum duty ratio can be changed by installing
external resistance between Pins 12 and 4.
• Switching output pin
Output current ; IO=20mA (max.)
5
6
OUT
GND
• GND pin
• Triangular oscillating capacitor pin
CV
CV
I (Charged)
T1 =
f =
T2 =
I Discharged=52µA
I Charged=30µA
V=0.58V
I (Discharged)
7
CT
V
1
T1+T2
In normal mode
T1
T2
• DC voltage input pin
Operates with 1.2V or more.
8
9
PVCC
CLK
• Clock input
· It is used to synchronize triangular oscillation with clock input and operates at rise edge of
clock.
· The threshold level is TTL level.
· It is open when not used.
• Start pin
10
11
START
· Starts switching of starter
· Threshold voltage, PVCC – 0.9V
• Power ON/OFF pin
Output ON/OFF switching pin (Output is off at “L.”)
POWER
• Reference voltage pin
· 1.25V output
· Charged and discharged current of triangular oscillation is determined by external R.
12
VREF
VREF – 0.7
I (Charged) =
RREF+1kΩ
I (Discharged) =1.40 × I (Charged)
• Decreased voltage detection output pin
13
14
EMP
VSEN
“H” when detected by open collector output form
• Decreased voltage detection input pin
· Threshold voltage ; 2.15V
• Reset output pin
15
16
Reset
VCC
· “H” when VCC becomes 4.2V or more
· Open collector output form
• DC voltage input pin
Operates with 1.8V or more.
ICs for CD/CD-ROM Player
AN8083S
■ System Block Diagram
16
+
VCC
OUT
5
P–VCC
8
AN8083S
1.5V
1.5V
Power SW
11
CPU
Power OFF at “L”
Start
SW
10
CLK
9
EMP
13
RESET
15
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
1) When Pin10 becomes “L” by operation of CPU or
push switch, oscillation starts and boosted voltage is
outputted to the secondary side.
4) When “L” pulse is sent from CPU to Pin11, oscillation
is stopped and it enters the stand-by mode. In this
status consumption current is 2µA max.
2) When the secondary side voltage exceeds 3.6V, starter
circuit is stopped and PWM operation is started by using
the voltage in the secondary side as power supply.
3) When the secondary side voltage becomes 4.2V,
Pin15 becomes “H” and CPU operation is started.
5) For re-start, when Pin10 becomes “L” by operation of
CPU or push switch, oscillation starts.
■ Supplementary Explanation
• Operational Description
When power VCC pin (Pin8) is connected to the supply output and start pin (Pin10) is set to “Low,” the triangular oscillation is
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
inputted to VCC pin (Pin16) of the AN8083S. When the voltage of VCC pin becomes 3V or more, start oscillation is stopped and
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
For normal mode oscillation, when output/FB pin (Pin2) of error amplifier is in “High” condition, oscillation is stopped, since the
power supply system is judged to be in an abnormal condition. With the time constant of discharged current ISPRO of SPRO pin
(Pin3) and capacitor CSPRO, pin voltage is increased, and oscillation is stopped when it becomes 1.25V or more. During this time,
when the error amplifier becomes “Low,” charged current no longer exits and SPRO is maintained to 0.9V.
2. Decreased voltage detection circuit
When VSEN pin (Pin14) gets 2.15V or less, EMS pin (Pin13) gets “High.”
3. Reset output
When VCC pin voltage is 4.2V or more, RST pin (Pin15) gets “High.”
ICs for CD/CD-ROM Player
AN8083S
• Miscellaneous
1. Method for making output voltage variable
VCC = 0.7V × (R1 + R2)/R2
R1 = RX // R3
V
CC (16)
RX
RY
R3 =20.5kΩ
R4 =3.5kΩ
R2 = RY // R4
ex) Where VCC = 5V,
RX = 51kΩ
IN (1)
RY = 7.5kΩ
2. Method for making decreased voltage detection variable
R1 + R2
VSEN
=
× 1.25
R2
R3
VSEN (14)
ex) VSEN = 3V
R1 =7kΩ
R1 + R2 + R3
R2
VSEN
=
× 1.25
R2 =10kΩ
R3 = 7kΩ
However, take care that an external resistance causes different temperature characteristics.
3. Reset output
When the output voltage is made variable, detection voltage changes.
15
16
VCC = 4.8V→ 4.2V (No changes)
51kΩ
1.25V
VCC = 5V→ 4.27V
3.64kΩ
1
3.5kΩ
7.5kΩ
• Chopper type application
16
AN8083S
8
4.8V±0.3V
51kΩ
1
2
5
0.01µF
0.01µF
33kΩ
7.5kΩ
2SD1328
2SD1328
100Ω
0.01µF
100Ω
相关型号：
©2020 ICPDF网 联系我们和版权申明