AIMTRON AT1453

AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Features
General Description
• 2.5 to 5.5V supply voltage operating range.
• Low current consumption: 1mA in operation,
• 50 kHz or 100kHz operation frequency .
• Built-in maximum duty control.
• Push-pull output.
• Built-in soft start circuit.
• Built-in auto-discharge function.
The AT1453 is a charger control IC for Photoflash
capacitor with soft start function, adjustable
maximum duty cycle and auto-discharge (soft start
capacitor) circuit. Adjustable soft start is
programmed with an external capacitor on SS pin.
The control technique allows for the use of
external resistor to change the switching duty and
use of transformer to control the input current. A
logic high on the CHARGE pin initiates charging,
while the READY pin signals that the capacitor is
fully charged. It is ideal for DSC flash unit.
Applications
•Digital Still Cameras flash unit
* Protected by U.S. Patent #6,724,989
Block Diagram
VCC
GND
Reference
Vref
1.1V
READY
Output
Control
Block
OUT
SS
DUTY
CHARGE
Enable
Block
FB
Aimtron reserves the right without notice to change this circuitry and specifications.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
1
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Pin Configuration
Ordering Information
Part number
AT1453AP
AT1453AP_GRE
AT1453BP
AT1453BP_GRE
Package
TSSOP8
TSSOP8,Green
TSSOP8
TSSOP8,Green
Marking
AT1453AP
AT1453AP, date code with one bottom line
AT1453BP
AT1453BP, date code with one bottom line
A:50kHz B:100kHz
Pin Description
Pin No.
Symbol
I/O
1
2
3
4
5
6
7
8
CHARGE
FB
DUTY
GND
OUT
VCC
READY
SS
I
I
I
O
O
I
Description
Charge enable input
Error amplifier input
Duty control input
Ground
Push-pull output
Power supply
Charge ready open drain output
Soft-start setting
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
2
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Absolute Maximum Ratings
Parameter
Power Supply Voltage
Source Average Current of OUT
Sink Average Current of OUT
Input Voltage to Error Amplifier
Continuous power dissipation
Operating temperature
Junction temperature
Storage temperature
Lead temperature
Condition
—
—
—
—
TSSOP8(Ta=+25℃)
SOP8(Ta=+25℃)
—
—
—
—
Rated Value
Min.
Max.
+6.5
-50
50
6.5
450
500
-30
+85
+125
-40
+150
+300
Unit
V
mA
mA
V
mW
mW
0
C
0
C
0
C
0
C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
Recommended Operating Conditions
(Ta=+250C)
Parameter
Power supply voltage
Operating temperature
Symbol
VCC
TOP
Values
Min.
2.5
-30
Typ.
-+25
Unit
Max.
5.5
+85
V
°C
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
3
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Electrical Characteristics
(VCC = 3.3V,Ta =+25℃, unless otherwise noted.)
Parameter
Symbol
Condition
Values
Unit
Min. Typ. Max.
Entire device
Oscillator
Soft-Start and Duty
Section
Output Section
Charge ON/OFF
Section
Input Supply Range
VCC
Feedback Voltage
VFB
Reference variation with
Temperature
Feedback Voltage
line-regulation
Ta = +25℃
Ta =-30℃ to +85℃
VFB-Line
Standby current
ICCS
Operating Current
ICC
Frequency
fosc
Threshold voltage of SS
VSS_0
Threshold voltage of SS
VSS
Charging current
2.5
100
ISS
Maximum duty cycle
TDUTY
Output source current
ISOURCE
Output sink current
ISINK
Output ON resistor
ROH
Output OFF resistor
ROL
Active mode Threshold
VONH
Disable mode Threshold
VONL
VCC=2.5V to 5.5V
CHRGE=GND
Duty=50%,
fOSC=50KHz
A
B
Duty Cycle=0%
Duty Cycle=100%
VSS=0V
Duty≧95%, OUT=0V
Duty≦5%, OUT=5V
OUT = -15mA
OUT = 15mA
--
5.5
V
1.080 1.100 1.120
V
-2
-
2
%
-5
1
5
mV
-
-
400
μA
-
1.0
-
mA
40
50
60
kHZ
90
100
110
kHZ
-
0.3
-
V
-
1.1
-
V
0.7
1.0
1.5
μA
80
83
90
%
-
-130
-80
mA
65
100
-
mA
-
18
30
Ω
-
16
25
Ω
2.0
V
0.8
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
4
V
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Timing Chart
AT1453 Charge Toggling Refresh Mode
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
5
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
DUTY Setting
The DUTY resistor selection depends on Duty Cycle , choose the component using the following
equation:
V DUTY (V ) = 0.3 +
RDUTY ( KΩ) =
DUTY
1.15
15
1.1
(
) − 1.073
VDUTY
Example:
Set duty cycle is 50%
V DUTY = 0.3 +
R DUTY =
0.5
= 0.734
1.15
15
1 .1
(
) − 1.073
0.734
≈ 35.2 KΩ
Output Voltage Setting
VOUT =
R1 + R 2
× V FB
R2
V FB = 1.1V
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
6
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Soft-Start Setting
The soft start operation is determined by the capacitor connected to the SS terminal. It can calculate the
soft start time Ts(s).
C×
− 0 .3
V
∆V
= I → C × DUTY
= 1µA
∆t
∆t
Ts( s ) = (V DUTY − 0.3) × C ( µF )
Example: (Fig C)
R5=47K
Æ VDUTY=0.790V
Æ
Ts(s)=(0.790-0.3)*1=0.49(sec)
CH1:VOUT CH2:SS CH3:DUTY CH4:IBAT
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
7
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Reduce the Output Voltage Decay
The output voltage is sensed by a voltage divider connecting to the anode of the
rectifying diode. The voltage sensing path is cut off when charging complete to
minimize the output voltage decay.
CH1:READY CH2:FB CH3:VOUT CH4:IBAT
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
8
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Typical Curve
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
9
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
10
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Typical Application Schematic
(A) IGBT Trigger
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
11
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
(B) SCR Trigger
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
12
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
(C) Li-Ion Application
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
13
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
CH1:CHARGE CH2:READY CH3:VOUT(300V) CH4:IBAT
Fig 3. VBAT=4.2V
Fig 1. VBAT=3.0V
VBAT
3.0V
3.6V
4.2V
* RDUTY
Charge
Time
6.79s
4.62s
3.36s
Charge Input
Current
500mA
600mA
800mA
can be change the Input Current.
Fig 2. VBAT=3.6V
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
14
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
(D) 2-Cell Battery Application
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
15
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
CH1:READY CH2:SS CH3:VOUT(300V) CH4:IBAT
VBAT
3.0V
2.0V
* RDUTY
Charge
Time
4.79s
13.6s
Charge Input
Current
800mA
500mA
can be change the Input Current.
Fig 4. VBAT=2.0V
Fig 5. VBAT=3.0V
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
16
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Application Information
Photoflash Capacitor Charger Charge Time:
The energy stored in the output capacitor is:
C ×V 2
E=
2
The output power required by the flyback converter to charge the capacitor in a period
of time is:
E C ×V 2
=
= V IN × I AVG × D × η
t
2×t
The approximate charge time for the converter circuit is:
PCAP =
2
C OUT × VOUT
t=
2 × V IN × I AVG × D × η
Where:
fs= Switching frequency
D= Maximum Duty Cycle
LPRI= Primary Inductance
η= Efficiency
I AVG = I BAT =
I PK =
I PK × D
2
V IN × D
LPRI × f s
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
17
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Avoid the Feedback Resistor Leakage Current:
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
18
AT1453
Preliminary Product Information
Photoflash Capacitor Charger for DSC
Small Outline
SYMBOL
A
B
C
D
E
F
H
K
M
α
8-pin TSSOP
INCHES
MIN
MAX
0.114
0.122
0.169
0.177
0.244
0.260
0.026
BSC
0.010
0.012
0.002
0.006
0.041
0.047
0.005
BSC
0.020
0.028
80
00
MILLIMETERS
MIN
MAX
2.90
3.10
4.30
4.50
6.20
6.60
0.65 BSC
0.25
0.30
0.05
0.15
1.05
1.20
0.127 BSC
0.50
0.70
00
80
NOTES
-
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
WWW: http://www.aimtron.com.tw
Fax: 886-3-563-0879
Email: [email protected]
19