ETC AT1396DN

AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Features
• 95% Efficient possible DC/DC Converter
• Combine Step-Up and Step-Down for
90% Efficient Boost-Buck
• Bulit-in LED Driver and Open LED
Overvoltage Protection
• Transformerless Inverting Controller for CCD
Bias
• 2 Channel Built-in MOSFET Current- Mode
PWM and 4 Channel Extra PWM Controllers
(CH-3 Synchronous Output)
• Up to 1MHz Operating Frequency
• Shutdown Current <1uA
• Built-in Soft-Start Function
• Built-in Short-Circuit Protection Function
• QFN48 Package
General Description
The AT1396A/B/C/D provide a complete power
supply solution for digital cameras. They improve
performance, component count, and size compared
to other multi-channel controllers in 2-cell AA,
1-cell Li-Ion, and dual-battery designs. On-chip
MOSFETs provide up to 92~95% efficiency for
critical power supplies, while additional channels
operate with external FETs for optimum design
flexibility. All channels DC/DC operate at one
fixed frequency settable from 100KHz to 1MHz to
optimize size, cost, and efficiency.
Applications
• DSC Power Supply
Pin Assignment
Ordering Information
Part Number
AT1396AN
AT1396BN
AT1396CN
AT1396DN
Package
QFN48,Green
QFN48,Green
QFN48,Green
QFN48,Green
Marking
AT1396AN
AT1396BN
AT1396CN
AT1396DN
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Block Diagram
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Pin Description
Pin No. Pin name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
SS1
CTL5
CTL6
LXU
CTLU
PGND1
PGND2
CTLD
LXD
CTL3
CTL4
SS2
/SDOK
CSCP
PVCC2
COMP2
FBD
SS3
COMP3
FB3
SS4
COMP4
IN4
IP4
PVCC3
OUT3M
OUT3S
PGND3
OUT4
OUT5
OUT6
PVCC4
GND
FB5H
FB5
COMP5
VBG
SS5
FB6
COMP6
CT
VREG
FBU
COMP1
VCC
PVCC1
SS6
SEL4
I/O
I
I
I
O
I
P
P
I
O
I
I
I
O
I
P
O
I
I
O
I
I
O
I
I
P
O
O
P
O
O
O
P
P
I
I
O
O
I
I
O
O
P
I
O
P
P
I
I
Description
CH1 Soft-Start Input
CH5 Enable Input
CH6 Enable Input
Step-Up Converter Switching Node
CH1 Enable and Chip Enable Input
Power Ground
Power Ground
CH2 Enable Input
Step-Down Converter Switching Node
CH3 Enable Input
CH4 Enable Input
CH2 Soft-Start Input
Open-Drain, Active Low, Power Good for Step-Down
Short Circuit Protection Input
Step-Down Converter Input
Step-Down Converter Compensation Node
Step-Down Converter Feedback Input
CH3 Soft-Start Input
CH3 Compensation Node
CH3 Feedback Input
CH4 Soft-Start Input
CH4 Compensation Node
CH4 Negative Feedback Input
CH4 Positive Feedback Input
CH3 Power
CH3 Master Output Driver
CH3 Slave Output Driver
Power Ground
CH4 Output Driver
CH5 Output Driver
CH6 Output Driver
CH4 Power
Power Ground
CH5 Controller Voltage Feedback Input
CH5 Controller Voltage Feedback/Current Feedback
CH5 Compensation Node
Reference Bypass
CH5 Soft-Start Input
CH6 Feedback input
CH6 Compensation Node
Oscillator Control
Reference Output
Step-Up Converter Input
Step-Up Controller Compensation Node
IC power Input
Power Output of the Step-Up Converter
CH6 Soft-Start Input
Configures the CH4 as a Step-Up or Step-Down
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Absolute Maximum Ratings
Item
Symbol
Ratings
Units
Storage temperature
Operating temperature
TSTG
TOPR
-55~+150
-30~+85
-0.3~+5.5
℃
℃
V
VLX/OUT
-0.3V~+5.5
V
-0.3V~+5.5
3.6
2.25
200
1000
2
V
A
A
mA
mW
KV
PVCC1,PVCC2,PVCC3,PVCC
4 input voltage
LXU,LXD, OUT3M,OUT3S
input voltage
Other input Pin
LXU Current
LXD Current
OUT3M,OUT3S Current
Power consumption
ESD Classification
Pd
Electrical Characteristics
(PVCC1=PVCC2=PVCC3=PVCC4=VCC=3.6V, Ta=+250C)
Values
Parameter
Symbol
Condition
Unit
Min.
Typ.
Max.
1.2
-
5.5
V
-
1
1.1
mA
-
1.2
1.3
mA
-
1
10
μA
2.275
2.30
2.325
V
-
5
10
mV
-
-
5
mV
CT=82pF
-
500
-
KHz
∆fOSC1 Ta=-20°C ~+85°C
-
1
10
%
GENERAL
Input Voltage Range
VCC Channel 1 DC/DC
CH1,CH2
Switch- Off Input Current
IVCC
CH1,CH2, CH3(or 4,5,6)
Switch- Off Input Current
IVCC
Shutdown Current
IVCC
No Switching,
FBU=FBD=0.9V
CTLU=CTLD=3.6V,other
disable
No Switching,
FBU=FBD=FB3=0.9V
CTLU=CTLD=CTL3=3.6V
other disable
All CTL disable
REFERENCE
Reference Output Voltage
Reference Load
Regulation
VREG IREG =1mA
∆VREG1 1mA< IREG <10mA
Reference Line Regulation ∆VREG2 2.5<VCC<5.5V
OSC
Frequency
Frequency variation with
Temperature
fOSC
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Frequency variation with
Input Voltage
∆fOSC2 VCC =2.5V~5.5V
-
1
5
%
-
2.45
-
V
∆VCC1
-
100
-
mV
VCC
-
2.45
-
V
1.2
-
6.0
V
0.8
1
1.5
µA
0.784
0.8
0.816
V
-
-
100
nA
CHANNEL 1(STEP-UP)
Pre-OSC to OSC Trip
Level
Pre-OSC to OSC
Hysteresis
Under Voltage Lockout
Input Voltage Range
VCC1 VCC rising edge
PVCC1 Channel 1 DC/DC
Normal Operating
Soft-Start Charge Current
ISS1
FBU Regulation Voltage
VFBU Ta=-20°C ~+85°C
FBU input Current
IFBU
Current-Sense Amplifier
Transresistance
RCS
-
0.285
-
V/A
Transconductance
GMEA
-
140
-
µs
Maximum Duty Cycle
DMAX FBU=0.7V
85
90
95
%
VCC =2.5V~5.5V
FBU=0.8V
PVCC1 Leakage Current
IL1
VLXU=0V,PVCC1=5.5V
-
5
12
µA
LX Leakage Current
ILX1
VLXU=5.5V
-
1
5
µA
RN
N-Channel
-
95
150
mΩ
RP
P-Channel
-
150
250
mΩ
Switch On-Resistance
N-Channel Current Limit
ILimit1
1.8
2.1
2.4
A
P-Channel Turn-off
Current
IREV1
-
20
-
mA
Startup Current Limit
ILimit-s PVCC1=1.5V
-
450
-
mA
Startup Frequency
fSTART PVCC1=1.5V
-
200
-
KHz
1.2
-
6.0
V
0.8
1
1.5
µA
0.784
0.8
0.816
V
-
-
100
nA
CHANNEL 2(STEP-DOWN)
Input Voltage Range
PVCC2 Channel 2 DC/DC
Normal Operating
Soft-Start Charge Current
ISS2
FBD Regulation Voltage
VFBD Ta=-20°C ~+85°C
FBD input Current
IFBD
Current-Sense Amplifier
Transresistance
RCS
-
0.6
-
V/A
Transconductance
GMEA
-
140
-
µs
Maximum Duty Cycle
DMAX FBD=0.7V
-
100
-
%
VCC =2.5V~5.5V
FBD=0.8V
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
LX Leakage Current
ILX2
VLX=0~3.6V,PVCC2=3.6V
-
1
5
µA
RN
N-Channel
-
95
150
mΩ
RP
P-Channel
-
150
250
mΩ
ILimit2
1.0
1.2
1.4
A
Switch On-Resistance
P-Channel Current Limit
N-Channel Turn-off
Current
/SDOK Output Low
Voltage
IREV2
-
20
-
mA
VSDOK 0.1mA into /SDOK
-
0.01
0.1
V
/SDOK Leakage current
IL_SDOK CTLD=0V,/SDOK=5.5V
-
0.1
1
µA
1.2
-
6.0
V
0.8
1
1.5
µA
-
-
100
nA
0.784
0.8
0.816
V
80
-
-
dB
-
5
-
MHz
VOH
-
1.0
-
V
VOL
-
10
-
mV
Isource COMP=0.8V
-
-0.5
-
mA
-
60
-
µA
-
-130
-80
mA
65
100
-
mA
CHANNEL 3
Input Voltage Range
PVCC3 Channel 3 DC/DC
Normal Operating
Soft-Start Charge Current
ISS3
VCC =2.5V~5.5V
FB3 input Current
IFB3
FB3=0.8V
FB3 Regulation Voltage
VFB3
Ta=-20°C ~+85°C,
FB3=COMP3
AV
DC
BW
AV=0dB
Error Amplifier Voltage
Gain
Error Amplifier Frequency
Bandwidth
Error Amplifier Output
Voltage
Error Amplifier Output
Source Current
Output Source Current
Output Sink Current
Isink
COMP=0.8V
Isource DUTY=90%,OUT=1/2VCC
Isink
DUTY=0%,OUT=1/2VCC
ROH
OUT=-15mA
-
18
30
Ω
ROL
OUT=15mA
-
16
25
Ω
85
90
95
%
-
100
-
%
Output On-Resistor
DMAX Step-Up Mode
Maximum Duty Cycle
DMAX Step-Down Mode
CHANNEL 4,5,6
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Input Voltage Range
PVCC4 Channel 4,5,6 DC/DC
1.2
-
6.0
V
0.8
1
1.5
µA
0.784
0.8
0.816
V
0.19
0.20
0.21
V
0.98
1.00
1.02
V
80
-
-
dB
-
5
-
MHz
VOH
-
1.0
-
V
VOL
-
10
-
mV
Isource COMP=0.8V
-
-0.5
-
mA
-
60
-
µA
DMAX FB_=0.7V
85
90
95
%
DMAX FB5=0.1V
85
90
95
%
-
-130
-80
mA
65
100
-
mA
Normal Operating
Soft-Start Charge Current
FB4/5/6 Regulation
Voltage
FB5 Regulation Voltage
for LED Driver
VFB4/5/6
FB5H OVP Trip Level
VFB5H Ta=-20°C ~+85°C,
Error Amplifier Voltage
Gain
Error Amplifier Frequency
Bandwidth
Error Amplifier Output
Voltage
Error Amplifier Output
Source Current
ISS4/5/6 VCC =2.5V~5.5V
VFB5
Ta=-20°C ~+85°C,
FB_=COMP_
Ta=-20°C ~+85°C,
FB5=COMP5
AV
DC
BW
AV=0dB
Isink
COMP=0.8V
Maximum Duty Cycle
Output Source Current
Output Sink Current
Isource DUTY=90%,OUT=1/2VCC
Isink
DUTY=0%,OUT=1/2VCC
ROH
OUT=-15mA
-
18
30
Ω
ROL
OUT=15mA
-
16
25
Ω
-
0.9
-
V
0.8
1.0
1.5
µA
Output On-Resistor
SHORT CIRCUIT PROTECTION
Threshold Voltage
VTH
CSCP Charge Current
ICSCP
CH3,CH4,CH5,CH6
CONTROL BLOCK
VIH
PVCC1=VCC=1.5 ~5.5V
1.1
-
VCC
V
VIL
PVCC1=VCC=1.5 ~5.5V
0
-
0.5
V
VIH
PVCC1 , 2=VCC=1.5 ~5.5V
CTLD=VIH
PVCC1 , 2=VCC=1.5 ~5.5V
CTLD=VIH
1.1
-
VCC
V
0
-
0.5
V
CTLU input Voltage
CTLD input Voltage
VIL
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
VIH
CTL3 input Voltage
VIL
VIH
CTL4 , 5 , 6 input Voltage
VIL
VIH
SEL4 input Voltage
VIL
PVCC1 , 3=VCC=1.5 ~5.5V
CTLU=VIH
PVCC1 , 3=VCC=1.5 ~5.5V
CTLU=VIH
PVCC1 , 4=VCC=1.5 ~5.5V
CTLU=VIH
PVCC1 , 4=VCC=1.5 ~5.5V
CTLU=VIH
PVCC1 , 4=VCC=1.5 ~5.5V
CTLU=CTL4=VIH
PVCC1 , 4=VCC=1.5 ~5.5V
CTLU=CTL4=VIH
1.4
-
VCC
V
0
-
0.5
V
1.4
-
VCC
V
0
-
0.5
V
1.4
-
VCC
V
0
-
0.5
V
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Typical Characteristics
CH1 Efficiency VS. Load Current
CH3 Efficiency VS. Load Current
CH1 + CH2 Efficiency VS. Load Current
CH2 Efficiency VS. Load Current
CH1 + CH2 Efficiency VS. Load Current
CH4 , 5 , 6 Efficiency VS. Load 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]
9
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
CH4 , 5 , 6 Efficiency VS. Load Current
CH4 , 5 , 6 Efficiency VS. Load 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]
10
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter 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]
11
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
CH3 Start-Up Waveform
VBAT = 2.0V
Time : 20mS/Div
CTL3 , 2V/Div , DC
VM=3.3V , 2V/Div , DC
IoutM ,100mA/Div , DC
IBAT , 1A/Div , DC
CH3 Start-Up Waveform
VBAT = 3.0V
Time : 20mS/Div
CTL3 , 2V/Div , DC
VM=5.0V , 2V/Div , DC
IoutM , 100mA/Div , DC
IBAT , 1A/Div , DC
CH1,CH2,CH3 Start-Up Waveform
VBAT = 3.0V
Time : 50mS/Div
CTLU , 2V/Div , DC
VDSP_IO=3.3V , 2V/Div , DC
VDSP_Core=1.8V , 1V/Div , DC
VM=5V , 5V/Div , DC
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
CH1 Load Transient Response
VBAT = 3.0V
Time : 1mS/Div
VM , 100mV/Div , AC
Iout1 , 200mA/Div , DC
CH2 Load Transient Response
VBAT = 2.0V
Time : 1mS/Div
VDSP_Core , 100mV , AC
Iout2 , 100mA/Div , DC
CH3 Load Transient Response
VBAT = 3.0V
Time : 1mS/Div
VDSP_IO , 100mV/Div , AC
Iout3 , 100mA/Div , DC
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Typical Application Circuit
Multi-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]
14
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
2-AA 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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
1-Li 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]
16
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Application Information
The AT1396A/B/C/D include 6 channels DC/DC to generate a multiple-output digital
camera power-supply system. It include:
z Step-Up DC/DC converter with on-chip synchronous MOSFETs.(CH1)
z Step-Down DC/DC converter with on-chip synchronous MOSFETs.(CH2)
z Main synchronous DC/DC controller can be configured as either a Step-Up or
Step-Down converter.(CH3)
z Selectable DC/DC controller for boost/flyback/buck/inverting converters.(CH4)
z White LED driver with open LED protection or boost controller.(CH5)
z Boost/flyback controller.(CH6)
Step-Up DC/DC Converter (CH1)
The step-up DC/DC converter typically is used to generate a 5V or the highest of the
DSC power system requirement from a 1.5V to 4.2V battery input and self-power the
AT1396. The efficiency is up to 95% with an internal MOSFET and external
synchronous rectifier.
Step-Down DC/DC Converter (CH2)
The step-down DC/DC is optimized for generating DSP core voltage (down to 0.8V)
at high efficiency. It runs from the voltage at PVCC2. This pin can be connected
directly to the battery if sufficient headroom exists to avoid dropout. It can be
powered from the output of another converter (CH1 or CH3) for boost-buck
operation.
The CH2 also features an open-drain /SDOK output that goes low when the CH2 is in
regulation. /SDOK may be used to drive an external P-MOSFET that gates 3.3V
power to the DSP after the core voltage is in regulation (Figure 1). The R1,R2 and C1
is for MOSFET soft-start function to avoid the more inrush current .
Step-Up or Step-Down DC/DC Converter (CH3)
The CH3 can be as a step-up (AT1396B/D) or step-down (AT1396A/C) voltage mode
PWM converter. An external MOSFET and synchronous rectifier allow conversion
efficiencies as high as 93%. Step-down operation can be direct from Li-Ion cell if the
minimum input voltage exceeds the desired output by approximately 200mV. When
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
generating 3.3V from Li-Ion, boost-buck operation may be needed so a regulated
output can be maintained for input voltages above and below 3.3V. The efficiency is
best than SEPIC or ZETA structure. In this case, it may be configure the CH3 as a
step-down and connect its input PVCC3 to the CH1 output, set to a voltage at or
above 4.2V. The output efficiency with this topology is typically up to 90%. Note that
the step-up output (CH1) supplies both the step-up(CH1) load and the step-down
(CH2) input current when the CH3 is powered from the CH1. The CH3 input current
reduces the available step-up output (CH1) current for other loads.
Figure 1. Using /SDOK to drive external MOSFET that gates 3.3V power to DSP after 1.8V core voltage is in regulation
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Auxiliary Controller (CH4,CH5,CH6)
The three auxiliary controllers operate as fixed-frequency voltage-mode PWM
controllers. They use the external MOSFETs, so output power is determined by
external components. All of auxiliary controllers have a guaranteed duty cycle of
minimum duty cycle of 85%(boost-type) or 100%(buck/inverting type). In boost
designs that employ continuous current (CCM), the maximum duty cycle limits the
boost ratio so:
1−
V IN
≤ 85%
VOUT
With discontinuous inductor current(DCM), no such limit exists for the input/output
ratio since the inductor has time to fully discharge before the next cycle begins. The
discontinuous conduction mode boost voltage conversion relationship is given by:
1+ 1+
VO = Vi ×
4 × D2
K
2
D = K × M × ( M − 1)
Where K is defined as:
2×L
K=
R × TS
M =
VO
Vi
The CH4 is selectable DC/DC controller for drive N-channel MOSFETs (SEL=high)
or P-channel MOSFETs (SEL=low). It can be configure as the inverting circuit
(Figure 2), typically for CCD and LCD bias. This is useful in height-Limited designs
where transformers may not be desired. The efficiency is more than the charge-pump
inversion for some load conditions.
The CH5 can be configure as a switching-mode boost current source for white LEDs,
FB5(0.2V) provides current-sensing feedback, while FB5H(1.0V) provides (optional)
open-LED over-voltage protection(Figure 3). If used as a boost converter, FB5H is
grounded and FB5(0.8V) is used as the feedback input. In this case, CH5 behaves
exactly like CH4 and CH6.
The CH6 can be used for conventional DC/DC boost and flyback designs.(Figure
4 ,Figure 5 and Figure 6)
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
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Figure 2. Regulated –7.5V negative CCD Bias.
Figure 3. LED Drive with open LED over-voltage protection
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]
20
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Figure 4. +15V and –7.5V CCD Bias with transformer
Figure 5. +15V and –7.5V CCD Bias with Charge-Pump Inversion
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]
21
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Figure 6. +15V and –7.5V CCD Bias with Charge-Pump (using AT1202 to regulated the negative output)
Soft-Start Setting (CH1~CH6)
The AT1396 all channels feature a soft-start function that limits inrush current and
prevents excessive battery loading at start-up by ramping the output voltage of each
channel up to the regulation voltage. Consider the input voltage and load current to
design the capacitor connected to the SS pin. It can calculate the CH1~6 soft start
time Ts(s)(valid threshold 0.3~0.8V interval).
C×
∆V
=I
∆t
Ts( s ) = 0.5 × C ( µF )
Note : It could be disabled soft start function by floating SS pin.
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]
22
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
SCP Protection Setting (CH3~CH6)
The CSCP comparator detects CH3,CH4,CH5 and CH6 output voltage while the
power converter work at normal condition. At the same time, the voltage level of
CSCP pin is held at low level. If the output load of these converters rapidly
malfunction or short, causing the output voltage to drop, the CSCP comparator detects
that to enable short circuit protection. The time period when short circuit protection
show as follow equation.
Short detection time (TPE(s))
TPE(s) = 0.9 * CCSCP (μF)
Note : It could be disabled short circuit protection function by connecting CSCP pin
into the ground.
Determine the triangular Oscillator Frequency
The triangular oscillator frequency is determined by the timing capacitor (CT). It is
difficult to incorporate these non-linear characteristics into the equation. This
difference is caused by characteristics, such as changes in the maximum voltage
amplitude of the sawtooth waveform with the CT value and the circuit delay causing
the maximum amplitude to become large in the case of a high oscillating frequency
even for the same capacitor. In practical use, therefore, the user should read the CT
values from the characteristic curve or should determine an approximate target value
by using the equation.
f OSC ( KHz ) =
41000
CT ( pF )
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: servic[email protected]
23
REVD: 05/05/23
AT1396A/B/C/D
Preliminary Product Information
6-Channel DC-DC Converter for DSC
Package Outline: QFN48
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]
24
REVD: 05/05/23