HM17CM256 HYNIX [Hynix Semiconductor], HM17CM256 Datasheet - Page 39

• Manufacturer Part Number: HM17CM256
• Description: 128XRGBX82 OUTPUT LCD DRIVER IC with built-in RAM
• Manufacturer: HYNIX [Hynix Semiconductor]

(24) ELECTRIC VOLUME
(25) VOLTAGE REGULATOR CIRCUIT
(26) REFERENCE VOLTAGE GENERATION CIRCUIT
(27) LCD DRIVING VOLTAGE GENERATION CIRCUIT
by adjusting V
controlled levels by setting 7 bit electric volume register.
using V
regulator is output at V
voltage is stable because boosting voltage level is higher than the amplified regulator voltage V
And so, stable voltage level can be generated even if there is load variation.
V
output voltage level from V
terminal V
voltages V
each of LCD power terminals.
display the LCD.
supply the V
C
C
circuit is not activated, you should supply reference voltage through V
voltage converting circuit at V
REG
4
1
The electric volume is within voltage converting circuit and the brightness of LCD can be controlled
The LCD driving voltage V
The voltage regulator circuit is within voltage converting circuit and generates regulated voltage
The reference voltage generation circuit is within voltage converting circuit.
This circuit generates reference voltage V
The LCD driving voltages can be made by applying reference voltage to reference voltage input
The generation circuit of LCD driving voltage is within voltage converting circuit and generates
The bias ratio of LCD driving voltages can be one of 1/5, 1/6, 1/7, 1/8, 1/9, 1/10.
When using built-in power supply circuit, you should connect voltage stabilization capacitor CA
When using external voltage supply, disable the built-in power supply circuit(AMPON, DCON=‘00’),
When using external voltage source and parts of built-in voltage converting circuit, the terminals of
Connecting stabilization capacitor CA
+ , C
+ , C
is used as input voltage of electric volume circuit to generate LCD driving voltage.
4
1
REF
- , C
- , C
REF
LCD
input with magnification by adjusting internal resistor. The generated voltage by voltage
5
OUT
2
+ , C
.
, V
+ , C
LCD
V
, V
BA
1
, V
level with command.
5
LCD
= V
- , C
2
- , C
2
, V
, V
EE
6
3
REG
1
+ , C
, V
3
x 0.9
, V
+ , C
BA
4
2
terminal.
by resistively dividing V
, V
6
LCD
terminal is as following description.
- , V
OUT
3
- , C
3
, V
.
EE
is generated by selecting 1 level within 128 step electric volume
There is need for selecting the coefficient of capacitor CA
4
4
voltages externally and open the C
, V
+ , C
REF
3
Even though boosted voltage variation, generated regulator
4
at V
, V
- , C
REG
BA
REG
5
+ , C
terminal for using at regulator circuit through. The
terminals.
terminal is recommended.
LCD
5
- , C
into 4 levels.
6
+ , C
6
- should be open because boosting
REF
1
+ , C
terminal and the voltage for
1
- , C
HM17CM256
2
+ , C
2
- , C
3
+ , C
2
- 39 -
after
REG
2
3
- ,
at
.