AT1397AN - Aimtron Technology

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

1

Features

• 95% Efficient possible DC/DC Converter

• 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

Applications

• DSC Power Supply

General Description

The AT1397A/B provide a complete power

supply solution for digital cameras. They improve

performance, component count, and size compared

to other multi-channel controllers in 1-cell Li-Ion

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.

Pin Assignment

AT1397

1110987654321

343536

37

38

39

40

41

42

43

44

21

20

19

18

17

16

15

14

13

12

22

23

24

252627282930313233

45

46

47

48

CH1

Synchronous Rectified

Current Mode Step-Down

On-Chip MOSFET

CH1

Synchronous Rectified

Current Mode Step-Down

On-Chip MOSFET

CH2

Synchronous Rectified

Current Mode Step-Down

On-Chip MOSFET

CH2

Synchronous Rectified

Current Mode Step-Down

On-Chip MOSFET

CH3

Synchronous Rectified

Voltage Mode Step-Down

CH3

Synchronous Rectified

Voltage Mode Step-Down

CH4

Seletable Voltage Mode

Step-Up/Down/Inverting

CH4

Seletable Voltage Mode

Step-Up/Down/Inverting

CH5

Voltage Mode PWM

LED Driver

CH5

Voltage Mode PWM

Step-Up

CH6

Voltage Mode Step-Up

CH6

Voltage Mode Step-Up

AT1397AN AT1397BN

Ordering Information

Part Number Package Marking

AT1397N QFN48,Green 

： A:1397AN B:1397BN

： Date Code

*For more marking information, contact our sales representative directly.

Aimtron reserves the right without notice to change this circuitry and specifications.

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

2

Block Diagram

Ramp1

0.8V

FB1

CTL3

-

+

-

+

COMP1

SS1

CTL1

PVCC1

LX1

PGND1

Ramp2

0.8V

FB2 Step-

Down

Pre-

Driver

Current

Sense

-

+

-

+

COMP2

SS2

PVCC2

LX2

PGND2

Power

Good

/SDOK

OSC1

0.8V

FB3 Step-

Down

Pre-

Driver

-

+

-

COMP3

SS3

PVCC3

OUT3S

OUT3M

PGND3

OSC2

IN4 Step-

Up/

Down

Pre-

Driver

-

+

-

SS4

PVCC4

OUT4

SEL4

COMP4

IP4

CTL4 *Selectable P-ch or N-ch

driver for step-down/up/

inverting converter

OSC1

FB5 Step-

Up

Pre-

Driver

-

+

-

SS5

OUT5

CTL5

COMP5

VREF

FB5H +

-

1V

OVP

OSC2

FB6 Step-

Up

Pre-

Driver

-

+

-

SS6

OUT6

0.8V

COMP6

CTL6

Short-Circuit

Protection CSCP

SCP3 SCP4 SCP5 SCP6 OVP

VRGENVBGEN LDO

2.3V

OSC

CTLU

Ramp

Gen

CT

VBG

2V 1.22V

VREG

VCC

GND

CTL2

*Metal Option

LED Driver (VREF=0.2V)

or Step-Up(VREF=0.8V)

Ramp2Ramp1OSC2OSC1

-

+

Step-

Down

Pre-

Driver

Current

Sense

SS1OK

UVLO

0.8V

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

3

Pin Description

Symbol Pin No. Descript

SS1 1 CH1 Soft-Start Input

CTL5 2 CH5 Enable Input

CTL6 3 CH6 Enable Input

LX1 4 CH1 Converter Switching Node

CTL1 5 CH1 Enable and Chip Enable Input

PGND1 6 Power Ground

PGND2 7 Power Ground

CTL2 8 CH2 Enable Input

LX2 9 CH2 Converter Switching Node

CTL3 10 CH3 Enable Input

CTL4 11 CH4 Enable Input

SS2 12 CH2 Soft-Start Input

/SDOK 13 Open-Drain, Active Low, Power Good for CH2

CSCP 14 Short Circuit Protection Input

PVCC2 15 CH2 Converter Input

COMP2 16 CH2 Controller Compensation Node

FB2 17 CH2 Converter Feedback Input

SS3 18 CH3 Soft-Start Input

COMP3 19 CH3 Compensation Node

FB3 20 CH3 Feedback Input

SS4 21 CH4 Soft-Start Input

COMP4 22 CH4 Compensation Node

IN4 23 CH4 Negative Feedback Input

IP4 24 CH4 Positive Feedback Input

PVCC3 25 CH3 Power Input

OUT3M 26 CH3 Master Output Driver

OUT3S 27 CH3 Slave Output Driver

PGND3 28 Power Ground

OUT4 29 CH4 Output Driver

OUT5 30 CH5 Output Driver

OUT6 31 CH6 Output Driver

PVCC4 32 CH4, CH5 and CH6 Power Input

GND 33 Power Ground

FB5H 34 CH5 Controller Over Voltage Protection Input

FB5 35 CH5 Controller Voltage Feedback/Current Feedback

COMP5 36 CH5 Compensation Node

VBG 37 Reference Bypass

SS5 38 CH5 Soft-Start Input

FB6 39 CH6 Feedback Input

COMP6 40 CH6 Compensation Node

CT 41 Oscillator Control

VREG 42 Reference Output

FB1 43 CH1 Converter Feedback Input

COMP1 44 CH1 Controller Compensation Node

VCC 45 IC Power Input

PVCC1 46 CH1 Converter Input

SS6 47 CH6 Soft-Start Input

SEL4 48 Configures the CH4 as a Step-Up or Step-Down

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

4

Absolute Maximum Ratings*1

Rated Value

Parameter Symbol

Min. Max.

Units

Storage Temperature TSTG -55 150 ℃

Operating Temperature TA TOPR -35 85 ℃

PVCC1,PVCC2,PVCC3,PVCC4 Input Voltage - -0.3 6.0 V

LX1,LX2, OUT3M,OUT3S Input Voltage VLX/OUT -0.3 6.0 V

Other Input Pin - -0.3 6.0 V

LX1, LX2 Current - - 2.25 A

OUT3M,OUT3S Current - - 200 mA

HBM - 2 KV

ESD Susceptibility*2 MM - 200 V

Power Consumption Pd - 1000 mW

1. 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.

2. Device are ESD sensitive. Handling precaution recommended. The Human Body model is a 100pF

capacitor discharged through a 1.5KΩ resistor into each pin.

Recommended Operating Conditions

(Ta=+250C)

Value

Parameter Symbol

Min Typ Max Unit

Startup power supply voltage Vcc 2.5 -- 5.5 V

Power supply voltage PVCC 2.5 -- 5.5 V

Feedback input voltage VIN 0 -- Vcc-2 V

Control input voltage VCTL 0 -- Vcc V

Soft start capacitor CSS -- 0.1 1.0 µF

Short Circuit Protection Capacitor CSCP -- 0.1 1.0 µF

VREG pin capacitor CVREG 0.082 0.1 -- µF

Operating ambient temperature* TA -20 25 85 ℃

*Using X5R or X7R input capacitors.

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

5

Electrical Characteristics

(PVCC1=PVCC2=PVCC3=PVCC4=VCC=3.6V, Ta=+250C)

Values

Parameter Symbol Condition

Min. Typ. Max.

Unit

GENERAL

Input Voltage Range VCC IC Power Input 2.5 - 5.5 V

VCC Under Voltage Lockout VUV - 2.35 2.4 2.45 V

UVLO Hysteresis VHY - - 100 - mV

CH1,CH2 Switch- Off Input

Current IIN1

No Switching,

FB1=FB2=0.9V

CTL1=CTL2=3.6V, other

disable

- 1.1 1.2 mA

CH1,CH2, CH3(or 4,5,6)

Switch- Off Input Current IIN2

No Switching,

FB1=FB2=FB3=0.9V

CTL1=CTL2=CTL3=3.6V,

other disable

- 1.3 1.4 mA

Shutdown Current ICC All CTL disable,

VCC=3.6V - 1 10 µA

REFERENCE

Reference Output Voltage VREG I

REG =1mA 2.25 2.30 2.35 V

Reference Load Regulation ∆VREG1 1mA< IREG <5mA - 5 10 mV

Reference Line Regulation ∆VREG2 2.5<VCC<5.5V - - 5 mV

OSC

Frequency fOSC CT=82pF - 500 - KHz

Frequency variation with

Temperature ∆fOSC1 Ta=-20°C ~+85°C - 1 10 %

Frequency variation with

Input Voltage ∆fOSC2 VCC =2.5V~5.5V - 1 5 %

CHANNEL 1, 2

Input Voltage Range PVCC1/2 - 2.5 - 5.5 V

Normal Operating Soft-Start

Charge Current ISS1/2 V

CC =2.5V~5.5V 0.7 1 1.3 µA

FB Regulation Voltage VFB1/2 Ta=-20°C ~+85°C 0.784 0.8 0.816 V

FB input Current IFB1/2 FB1/2=0.8V - - 100 nA

Current-Sense Amplifier

Transresistance RCS - - 0.6 - V/A

Transconductance GMEA - - 120 - µs

Maximum Duty Cycle DMAX FB1/2=0.7V - 100 - %

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

6

LX Leakage Current ILX1/2 VLX1/2=0~3.6V - 1 5 µA

RN N-Channel - 200 250 mΩ

Switch On-Resistance

RP P-Channel - 250 300 mΩ

P-Channel Current Limit ILimit2 - 1.0 1.2 1.4 A

N-Channel Turn-off Current IREV2 - - 20 - mA

/SDOK Output Low Voltage VSDOK 0.1mA into /SDOK - 0.01 0.1 V

/SDOK Leakage current IL_SDOK CTL2=0V, /SDOK=5.5V - 0.1 1 µA

CHANNEL 3

Input Voltage Range PVCC3 - 2.5 - 5.5 V

Normal Operating Soft-Start

Charge Current ISS3 V

CC =2.5V~5.5V 0.7 1 1.3 µA

FB3 input Current IFB3 FB3=0.8V - - 100 nA

FB3 Regulation Voltage VFB3 Ta=-20°C ~+85°C,

FB3=COMP3 0.784 0.8 0.816 V

Error Amplifier Voltage Gain AV DC 80 - - dB

Error Amplifier Frequency

Bandwidth BW AV=0dB - 5 - MHz

VOH - - 1.0 - V

Error Amplifier Output

Voltage VOL - - 10 - mV

Isource COMP=0.8V - 1 - mA

Error Amplifier Output

Source/Sink Current Isink COMP=0.8V - 60 - µA

Maximum Duty Cycle DMAX FB3=0.7V - 100 - %

Isource DUTY=90%,OUT=1/2VC

C - -130 -80 mA

Output Source/Sink Current

Isink DUTY=0%,OUT=1/2VCC 65 100 - mA

ROH OUT=-15mA - 18 30

Ω

Output On-Resistor

ROL OUT=15mA - 16 25

Ω

CHANNEL 4, 5, 6

Input Voltage Range PVCC4 CH4, 5, 6 2.5 - 5.5 V

Normal Operating Soft-Start

Charge Current ISS4/5/6 VCC =2.5V~5.5V 0.7 1 1.3 µA

FB4/5/6 Regulation Voltage VFB4/5/6

Ta=-20°C ~+85°C,

FB_=COMP_ 0.784 0.8 0.816 V

FB5 Regulation Voltage for

LED Driver VFB5 Ta=-20°C ~+85°C,

FB5=COMP5 0.19 0.20 0.21 V

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

7

FB5H OVP Trip Level VFB5H Ta=-20°C ~+85°C, 0.98 1.00 1.02 V

Error Amplifier Voltage Gain AV DC 80 - - dB

Error Amplifier Frequency

Bandwidth BW AV=0dB - 5 - MHz

VOH - - 1.0 - V

Error Amplifier Output

Voltage VOL - - 10 - mV

Isource COMP=0.8V - 1 - mA

Error Amplifier Output

Source/Sink Current Isink COMP=0.8V - 60 - µA

DMAX FB_=0.7V 85 90 95 %

Maximum Duty Cycle

DMAX FB5=0.1V 85 90 95 %

Isource DUTY=90%,OUT=1/2VC

C - -130 -80 mA

Output Source/Sink Current

Isink DUTY=0%,OUT=1/2VCC 65 100 - mA

ROH OUT=-15mA - 18 30

Ω

Output On-Resistor

ROL OUT=15mA - 16 25

Ω

SHORT CIRCUIT PROTECTION

Threshold Voltage VTH CH3,CH4,CH5,CH6 - 0.9 - V

VCSCP Detect Voltage VTH CH3,CH4,CH5,CH6 - 0.7 - V

CSCP Charge Current ICSCP CH3,CH4,CH5,CH6 0.7 1 1.3 µA

CONTROL BLOCK

VIH Active Mode 1.5 - VCC V

CTL Input Voltage

VIL Standby Mode 0 - 0.5 V

CTL Hysteresis △VH - - 100 - mV

VIH Step-Up Type 1.5 - VCC V

SEL4 Input Voltage

VIL Step-Down Type 0 - 0.5 V

SEL4 Hysteresis △VH - - 100 - mV

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

8

Typical Characteristics

CH1,2 Efficiency VS. Load Current

50

60

70

80

90

100

10 100 1000

Load Current(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

VBAT=3.3V

VBAT=3.0V

VBAT=2.5V

CH1,2 Efficiency VS. Load Current

50

60

70

80

90

100

10 100 1000

Load Current(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

CH3 Efficiency VS. Load Current

50

60

70

80

90

100

10 100 1000

Load Current(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

VBAT=3.3V

CH4,5,6 Efficiency VS. Load Current

50

60

70

80

90

100

10 100 1000

Load Curre nt(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

VBAT=3.3V

VBAT=3.0V

VBAT=2.5V

CH4,5,6 Efficiency VS. Load Current

0

10

20

30

40

50

60

70

80

90

100

110100

Load Current(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

VBAT=3.3V

VBAT=3.0V

VBAT=2.5V

CH4 Efficiency VS. Load Current

0

10

20

30

40

50

60

70

80

90

100

110100

Load Current(mA)

Efficiency(%)

VBAT=4.2V

VBAT=3.8V

VBAT=3.6V

VBAT=3.3V

VBAT=3.0V

VBAT=2.5V

Vout =1.8V Vo u t =3 . 3 V

Vout =3.0V Vo u t =5 . 0 V

Vout=15V Vout =-7.5V

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

9

Typical Characteristics (Continued )

Efficiency VS. Input Voltage

80

85

90

95

100

2.53.03.54.04.5

Input Voltage -VIN (V)

Efficiency(%)

No-Load Input Current VS. Input Voltage

0.6

0.8

1.0

1.2

1.4

1.6

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Input Voltage-VIN (V)

Input Current(mA)

CH1

CH1+CH2

Reference Voltage VS. Temperature

2.275

2.280

2.285

2.290

2.295

2.300

2.305

-20 0 20 40 60 80 100

Temperature

Reference Voltage(V)

Switching Frequency VS. Temperature

460

470

480

490

500

510

520

-20 0 20 40 60 80 100

Temperature

Switching Frequency(KHz)

Maximum Duty VS. Temperature

87

88

89

90

91

92

93

94

95

96

-20 0 20 40 60 80 100

Te mpe rature

Maximum Duty(%

)

P-MOS

N-MOS

FB Regulation Voltage VS. Temperature

0.785

0.790

0.795

0.800

0.805

-20 0 20 40 60 80 100

Te mpe rat ure

FB Regulation Voltage(V

)

Vout1,2=1.8V

Iout1,2=300mA

Vout4=5.0V

Iout4=50mA

Vout1,2=3.3V

Iout1,2=300mA

Vout3=3.0V

Iout3=300mA

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

10

Typical Characteristics (Continued )

VBAT=3.8V

CH1：CTL1， CH2：VOUT1

CH3：IOUT1， CH4：Iin

VBAT=4.2V

CH1：CTL， CH2：VOUT1

CH3：VOUT2， CH4：VOUT3

VBAT=3.8V

CH2：VOUT2， CH3：IOUT2

VBAT=3.8V

CH1：CTL2， CH2：VOUT2

CH3：IOUT2， CH4：Iin

VBAT=3.8V

CH2：VOUT1， CH3：IOUT1

VBAT=3.8V

CH2：VOUT3， CH3：IOUT3

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

11

Typical Application Circuits

OUT5

SS6

FB6

OUT6

PGND3

PVCC4

VBAT

1-Cell Li-Ion

3.4V~4.2V

FB5H

FB5

SS5

LED+

2~4Cell

20mA

VBAT

OUT4

IP4

SS4

VREG

PVCC3

VBAT

FB3

SS3

SEL4

PGND1

LX1

PVCC1

FB1

SS1

PVCC4

PGND2

LX2

PVCC2

FB2

SS2

VDSP_Core

+1V8/200mA

VBG

VCC

GND

COMP1

COMP2

CT

CTL1

CTL3

CTL4

CTL5

CTL6

/SDOK

OUT3M

OUT3S

CH6

Voltage-Mode

Step-Up PWM

CH4

Voltage-Mode

Inverting PWM

IN4

CH5

Voltage-Mode

PWM LED

Driver

CH3

Voltage-Mode

Synchronous

Step-Down

PVCC4

CH1

Current-Mode

Synchronous

Step-Down

PWM

CH2

Current-Mode

Synchronous

Step-Down

PWM

CSCP

COMP6

COMP5

COMP4

COMP3

VBAT

VDSP_IO

+3V3/200mA

CCD Bias

-6V3/50mA

Short-Circuit

Protection

Power ON

LENS ON

CCD ON

LED ON

AT1397A

6.8uH

VBAT

1uF

0.1uF

22uF

10uF

125K

100K

1uF

0.1uF

6.8uH

100K

312.5K

22uF

0.1uF

MBR140WS

10uH

0.1uF

10K

100K

275K

10uF

1uF

UPM2032BN

UPM2031AN

22uF

0.1uF

10K 0.1uF 10K

140K

10uF

MBR140WS

UPM2031AN

10uF

10uH

UPM2031AN

MBR140WS

1K

0.1uF

10R

1uF

10K

150K

0.22uF

1uF

0.22uF

10K

0.1uF

10uF

/6V3

MBR140WS

10uH

UPM2032BN

10uF

LED-

10K

64.9K

1500pF 51K

51K

1500pF

82pF

CTL2

0.47uF

10K

VBAT

10uF

MBR140WS

VLENS

+3V/300mA

10uH

10uF CCD Bias

+12V/50mA

33pF

PVCC3

1-Li Battery Application 1

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

12

Typical Application Circuits ( Continued )

OUT5

SS6

FB6

OUT6

PGND3

PVCC4

VBAT

1-Cell Li-Ion

3.4V~4.2V

FB5H

FB5

SS5

LCD

+12V/50mA

VBAT

OUT4

IP4

SS4

VREG

PVCC3

VBAT

FB3

SS3

SEL4

PGND1

LX1

PVCC1

FB1

SS1

PVCC4

PGND2

LX2

PVCC2

FB2

SS2

VDSP_Core

+1V8/200mA

VBG

VCC

GND

COMP1

COMP2

CT

CTL1

CTL3

CTL4

CTL5

CTL6

/SDOK

OUT3M

OUT3S

CH6

Voltage-Mode

Step-Up PWM

CH4

Voltage-Mode

Inverting PWM

IN4

CH5

Voltage-Mode

Step-Up PWM

CH3

Voltage-Mode

Synchronous

Step-Down

PVCC4

CH1

Current-Mode

Synchronous

Step-Down

PWM

CH2

Current-Mode

Synchronous

Step-Down

PWM

CSCP

COMP6

COMP5

COMP4

COMP3

VBAT

VDSP_IO

+3V3/200mA

CCD Bias

-6V3/50mA

Short-Circuit

Protection

Power ON

LENS ON

CCD ON

LED ON

AT1397B

6.8uH

VBAT

1uF

0.1uF

22uF

10uF

125K

100K

1uF

0.1uF

6.8uH

100K

312.5K

22uF

0.1uF

MBR140WS

10uH

0.1uF

10K

100K

275K

10uF

1uF

UPM2032BN

UPM2031AN

22uF

0.1uF

10K 0.1uF 10K

140K

10uF

MBR140WS

UPM2031AN

10uF

10uH

UPM2031AN

MBR140WS

1K

0.1uF

10uF

10K

140K

0.1uF

1uF

0.22uF

10K

0.1uF

10uF

/6V3

MBR140WS

10uH

UPM2032BN

10uF

10K

64.9K

1500pF 51K

51K

1500pF

82pF

CTL2

0.47uF

VBAT

10uF

MBR140WS

VLENS

+3V/300mA

10uH

10uF CCD Bias

+12V/50mA

33pF

PVCC3

1- Li Battery Application 2

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

13

Application Information

The AT1397A/B includ 6 channels DC/DC to generate a multiple-output digital

camera power-supply system. It include :

z Step-Down DC/DC converter with on-chip synchronous MOSFETs.(CH1, CH2)

z Main synchronous DC/DC controller for 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-Down DC/DC Converter (CH1, CH2)

The step-down DC/DC is optimized for generating DSP voltage (down to 0.8V) at

high efficiency. It runs from the voltage at PVCC1/PVCC2. This pin can be connected

directly to the battery if sufficient headroom exists to avoid dropout.

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 3V power

to the LENs after the DSP_IO voltage is in regulation (Figure 1). The R1,R2 and C1

is for MOSFET soft-start function to avoid the more inrush current .

Step-Down DC/DC Converter (CH3)

The CH3 is step-down 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.

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

14

PGND3

PVCC3

PGND1

LX1

PVCC1

FB1

SS1

PGND2

LX2

PVCC2

FB2

SS2

VDSP_IO

+3V3

VBG

VCC

GND

/SDOK

OUT3M

OUT3S

CH3

Voltage-Mode

Synchronous

Step-Down

CH1

Current-Mode

Synchronous

Step-Down

PWM

CH2

Current-Mode

Synchronous

Step-Down

PWM

VLENS

+3V

VBAT

SS3

R1

C1

R2

COMP3

FB3

VBAT

VDSP_Core

+1V8

VBAT

COMP1

COMP2

Figure 1. Using /SDOK to drive external P-MOSFET that gates 3V power to LENs after 3.3V I/O voltage is in regulation

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW: http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

15

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

maximum 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:

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:

Where K is defined as:

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)

%851 ≤−

OUT

IN

V

S

TR

L

K×

×

=2

i

O

V

M=

2

4

11

2

K

D

VV iO

×

++

×= )1( −××= MMKD

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

16

VBAT

OUT4

IP4

SS4

VREG

SEL4

CH4

Voltage-Mode

Inverting PWM

IN4

PVCC4

COMP4

-7.5V

CCD Bias

Figure 2. Regulated –7.5V negative CCD Bias.

OUT5

PVCC4

FB5H

FB5

SS5

LED+

2~4Cell

20mA

CH5

Voltage-Mode

PWM LED Driver

COMP5

VBAT

LED-

Figure 3. LED Drive with open LED over-voltage protection

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

17

SS6

FB6

OUT6

PVCC4

VBAT

CH6

Voltage-Mode

Step-Up PWM

COMP6

-7.5V

15V

Figure 4. +15V and –7.5V CCD Bias with transformer

SS6

FB6

OUT6

PVCC4

VBAT

CH6

Voltage-Mode

Step-Up PWM

COMP6

15V

-7.5V

Figure 5. +15V and –7.5V CCD Bias with Charge-Pump Inversion

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

18

SS6

FB6

OUT6

PVCC4

VBAT

CH6

Voltage-Mode

Step-Up PWM

COMP6

15V

-

+

GND/SHDN

OUT

FB

1.24V

IN

AT1202

Figure 6. +15V and –7.5V CCD Bias with Charge-Pump (using AT1202 to regulated the negative output)

Soft-Start Setting (CH1~CH6)

The AT1397A/B 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. However that CH2 to CH6 start until the CH1

reaches regulation. 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).

Note : It could be disabled soft start function by floating SS pin.

I

t

V

C=

∆

×

)(5.0)( FCsTs

µ

×

=

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

19

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))

T

PE(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.

)(

41000

)( pFC

KHzf

T

OSC =

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

20

Package Outline: QFN48

AT1397A/B

Preliminary Product Information

6-Channel DC-DC Converter for DSC

7F, No.9, Park Avenue II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.

Tel: 886-3-563-0878 Fax: 886-3-563-0879 WWW:

http://www.aimtron.com.tw

1/10/2006 REV:1.0 Email: service@aimtron.com.tw

21

Reflow Profiles

Sn-Pb Eutectic Assembly Pb-Free Assembly

Profile Feature

Large Body

Pkg. thickness

≥2.5mm or Pkg.

volume ≥350mm3

Small Body

Pkg. thickness

<2.5mm or Pkg.

volume <350mm3

Large Body

Pkg. thickness

≥2.5mm or Pkg.

volume ≥350mm3

Small Body

Pkg. thickness

≥2.5mm or Pkg.

volume ≥350mm3

Average ramp-up rate

(TL to TP) 3°C/second max. 3°C/second max.

Preheat

-Temperature Min(Tsmin)

-Temperature Max (Tsmax)

-Time (min to max)(ts)

100°C

150°C

60-120 seconds

150°C

200°C

60-180 seconds

Tsmax to TL

-Ramp-up Rate - 3°C/second max.

Time maintained above:

-Temperature (TL)

-Time (tL)

183°C

60-150 seconds

217°C

60-150 seconds

Peak Temperature(TP) 225+0/-5°C 240+0/-5°C 245+0/-5°C 250+0/-5°C

Time within 5°C of actual

Peak Temperature (tP) 10-30 seconds 10-30 seconds 10-30 seconds 20-40 seconds

Ramp-down Rate 6°C/second max. 3°C/second max.

Time 25°C to Peak

Temperature 6 minutes max. 8 minutes max.

*All temperatures refer to topside of the package, measured on the package body surface.