Sanyo EP92H User Manual download pdf (Page 15)

This IC is based on a unique SANYO idea and is a high-efficiency charge pump IC that was newly-developed taking advantage

of CMOS technologies that fuse SANYO's circuit and process technologies. This IC is optimal for power supplies in portable

electronic equipment.

This IC introduces technologies that completely overturn the previous common knowledge that although charge pump circuits

were low noise, they suffered from poor efficiency.

2928

Support for High-Resolution CCDs

New Charge Pump ICs

CCD image sensors require a high drive voltage of 10 to 20 V. This 10 to 20 V level is created by stepping up the 3 V

power supply level.

Since conventional charge pump voltage step-up technologies suffer from increased power loss when used to step up

the original voltage by over three times, their use in cell phones was problematic.

SANYO has, however, discovered a way of fusing their high level analog circuit and device technologies to overcome

this problem.

This new charge pump technology can step up a regulated voltage by a factor of three or higher with an efficiency as

high as 70%. Furthermore it can provide an output current of several tens of mA.

SANYO was the first in the industry to develop a high-performance charge pump.

This new charge pump technology can provide both positive and negative stepped up levels, can be combined into

multiple stages, and can provide multiple output levels. Thus this circuit technology is optimal for use in future camera

cell phones that include a megapixel-class CCD image sensor.

● High efficiency

(Prior to the regulator: 90 to 95 %)

● Coilless, low noise

● Supports high output current designs

● The only external components are thin form

capacitors (no coils or diodes required)

● Can provide both positive and negative

stepped-up outputs

● Supports fine step-up step sizes

+0.5 × n × V

-0.5 × n × V

(n: integer)

● Optimal for use as the power supply in

portable equipment

Clock

Clock generator & driver

C1 C2 Cn Cn+1

Regulator

Charge pump

OUT

Dependency of efficiency on the supply voltage

Output current, I

OUT

(mA)

2.9 V

3.1 V

3.3 V

3.5 V

3.7 V

=3.3V

At I

OUT

=50 mA, efficiency=80.6%

At I

OUT

=100 mA, efficiency=72.0%

Maximum efficiency: 80.8%

Efficiency (%)

0102030405060708090100

Output current, I

OUT

(mA)

Positive step-up voltage vs. output current

Output current, I

OUT

(mA)

Negative step-up voltage vs. output current

■Plus step-up ■Minus step-up

IOUT=-50 mA

At V

DD=2.9 V, VPP=7.78 V

At V

DD=3.3 V, VPP=9.03 V

At V

DD=3.7 V, VPP=10.26 V

Output voltage, V

OUT

(V)

Output voltage, V

OUT

(V)

0102030405060708090100

IOUT=50 mA

At V

DD=2.9 V, Vbb=-7.44 V

At V

DD=3.3 V, Vbb=-8.71 V

At V

DD=3.7 V, Vbb=-9.96 V

-12

-10

-8

-6

-4

-2

-0

0102030405060708090100

2.9 V

3.3 V

3.7 V

Output voltages from positive and negative step-up operation

Sample characteristics of a high-current

charge pump (single supply voltage→±3×)

● Regulates a 3.3 to 4.5 V battery level

to 3.1 V and steps up that level 3×

and 6× using a charge pump, to

provide the two regulated power

supply levels required by the CCD

image sensor.

●

VH = +15.0 V

●

VL = -8 V

● Two independent charge pump

systems are provided for VH and VL

● Built-in regulators for the analog

system power supply, vertical driver

system, and DSP core

3 V

Charge pump

CCD

+15 V(10 mA)

-8 V(5 mA)

3 V

Charge pump LTPS

+7 V(500 µA)

-8 V(5 mA)

Charge pump White LED

+4.5 V(100 mA)

The ability to provide a stepped-up voltage with low noise makes this circuit optimal for

embedding in modules.

2528

3.3 to 4.5 V

1 µF

OUT2

VBAT2 VBAT1

VBAT3

VBAT4

OUT3

VSS2

OUT4

VDD3

VSS4

VSS5

C21A

C21B

C22A

C22B

C23B

VL_C24

(VDD✕3)

(VDD✕2)

(VDD✕3)

(VDD✕1)

VL_C25

STBY

SLEEP

EN VDD4 VSS7

VH_C17

VH_C16

VSS6

VSS3

C15B

C15A

C14B

C14A

C13B

C13A

C12B

C12A

C11B

C11A

VSS1

OUT1

VDD1,2,3,4

VDD1

VDD2

C23A

FVREF

1 µF

1µF

0.1 µF

0.47 µF

1 µF

3.1 V / 100 mA

LDO

1.8 V / 100 mA

LDO

Bandgap

voltage

reference

1.19 V

Timing

generator

Sequence

generator

-8-V Reg

15-V Reg

1/2 Divider

1.2-MHz

Oscillator

3.1 V / 1 mA

3.1 V / 100 mA

LDO

(VDD✕6)

(VDD✕5)

0.22 µF

1 µF

(VDD✕4)

0.22 µF

(VDD✕3)

0.22 µF

(VDD✕2)

0.22 µF

(VDD✕1)

0.22 µF

1 µF

-3 times

step up

circuit

6 times

step up

circuit

* Values in parentheses are actual

applied voltages to the capacitor.

Note: Short OUT1 to VDD1 through VDD4.

Features of New Charge Pump ICs Charge pump power supply application

CCD Power Supply IC for Camera Cell Phones

Under

development

LV5711FN

IPBlock diagram

Block diagram

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 21

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Sanyo EP92H User Manual Page 15

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