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HE84770D

HE80000 SERIES

August 7, 2006

Page 13 of 29

V1.2

This specification is subject to change without notice. Please contact sales person for the latest version before use.

pump the 2.25 volts to 9 volts requires 4 times multiplier; to pump the 3 volts to 9 volts requires only 3

time multiplier which consumes less power. So it is advisable not to adjust the LVREG to an unnecessary

low level.

Voltage multiplication: The LVREG is then multiplied by 3, 4, or 5 times, depending on external

capacitors configurations as shown below, to generate LVP. Please note that LVP must be lower than 9

volts to prevent chip from breaking down.

LVL1

LVL1

LVL1

LVL2

LVL2

LVL2

LVL3

LVL3

LVL3

LVL4

LVL4

LVL4

LVL5

LVL5

LVL5

LGS2

LGS2

LGS2

LVP

LVP

LVP

LCAP4A

LCAP4A

LCAP4A

LCAP2B

LCAP2B

LCAP2B

LCAP2A

LCAP2A

LCAP2A

LCAP1A

LCAP1A

LCAP1A

LCAP1B

LCAP1B

LCAP1B

LCAP3A

LCAP3A

LCAP3A

LVREG

LVREG

LVREG

LGS1

LGS1

LGS1

LVAG

LVAG

LVAG

0.1uF

0.1uF

0.1uF

0.1uF

0.1uF

R

R

0.1uF

0.1uF

0.1uF

0.1uF

R

R

4.7uF

0.1uF

0.1uF

0.1uF

0.1uF

0.1uF

0.1uF

R

R

0.1uF

0.1uF

4.7uF

4.7uF

0.1uF

0.1uF

4.7uF

4.7uF

10uF

4.7uF

0.1uF

0.1uF

4.7uF

4.7uF

4.7uF

10uF

10uF

x4 multiplier

x5 multiplier

x3 multiplier

The LVP is then regulated to generated LVL1 ~ LVL5. LVL5 can be adjusted by the resistor between

LGS2 and LV5. Be sure to leave at least 0.3 volt between LVP and LV5 for the regulator circuit to

function properly. The formula is:

LVL5 = (1 + R2/80K) x 0.9V

Different duties require different bias settings. There is some theoretical correspondence between the

Duty and Bias Setting. However, it is better to use it as starting point and adjust it with real LCD panel

connected to it to determine the final setting. The theoretic relationship between the duty and bias setting

as following:

Duty Cycle Normal Bias Alternative Bias

32 duty

1/7

1/7.5

48 duty

1/8

1/7.5, 1/8.5

64 duty

1/9

1/8.5, 1/9.5

80 duty

1/10

1/9.5, 1/10.5

The bias setting is made by mask option MO_LBSR[2..0].

MO_LBSR[2..0] Bias Setting