- 您現在的位置：買賣IC網 > PDF目錄385657 > OM4068H (NXP Semiconductors N.V.) LCD driver for low multiplex rates PDF資料下載
參數資料
| 型號： | OM4068H |
| 廠商： | NXP Semiconductors N.V. |
| 元件分類： | LCD驅動器 |
| 英文描述： | LCD driver for low multiplex rates |
| 封裝： | OM4068H/2<SOT307-2 (QFP44)|<<http://www.nxp.com/packages/SOT307-2.html<1<Always Pb-free,; |
| 文件頁數： | 9/28頁 |
| 文件大?。?/td> | 125K |
| 代理商： | OM4068H |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁當前第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
1998 Jun 18
9
Philips Semiconductors
Product specification
LCD driver for low multiplex rates
OM4068
Power-on reset
The on-chip power-on reset block initializes the chip after
power-on or power failures. The OM4068 resets to a
starting condition as follows:
All backplane and segment outputs are set to V
SS
(display off)
All shift registers and latches are set in 3-state
SDOUT (allowing serial cascading) is set to logic 0 (with
SCE LOW)
Power-down mode.
Data transfers on the serial bus should be avoided for
0.5 ms following power-on to allow completion of the reset
action.
Power-down
After power-on the chip is in power-down mode as long as
the serial clock is not active. During power-down all static
currents are switched off (no internal oscillator, no timing
and no bias level generation) and all LCD-outputs are
3-stated. The power-on reset functions remain enabled.
The power-down mode is disabled at the first rising edge
of the serial clock SCLK.
LCD bias voltage generator
The intermediate bias voltages for the LCD display are
generated on-chip. This removes the need for an external
resistive bias chain and significantly reduces the system
power consumption. The full-scale LCD voltage V
OP
equals V
LCD
V
SS
. The optimum value of V
OP
depends on
the LCD threshold voltage (V
th
) and the number of bias
levels.
Fractional LCD biasing voltages are obtained from an
internal voltage divider of three series resistors (
1
3
bias)
connected between V
LCD
and V
SS
. The centre resistor can
be switched out of the circuit to provide a
1
2
bias voltage
level for the 1 : 2 multiplex configuration.
The bias levels depend on the multiplex rate and are
selected automatically when the display configuration is
selected using M1 and M0.
LCD voltage selector
The LCD voltage selector (control logic) coordinates the
multiplexing of the LCD in accordance with the selected
drive or display configuration. The operation of the voltage
selector is controlled by the input pins M0 and M1
(see Table 2).
Table 2
Drive mode selection
For multiplex rates of 1 : 2 three bias levels are used
including V
LCD
and V
SS
. Four bias level are used for the
1 : 3 multiplex rate. The various biasing configurations
together with the biasing characteristics as functions of
V
OP
= V
LCD
V
SS
and the resulting discrimination ratios
(D), are given in Table 3.
A practical value for V
OP
is determinated by equating
V
off(rms)
with a defined LCD threshold voltage (V
th
),
typically when the LCD exhibits approximately 10%
contrast. In static mode a suitable choice is V
OP
> 3V
th
.
M1
M0
DRIVE MODE
0
0
1
1
0
1
0
1
test mode (not user accessible)
static drive (1 : 1)
duplex drive (1 : 2)
triplex drive (1 : 3)
相關PDF資料 |
PDF描述 |
|---|---|
| OM4068H | LCD driver for low multiplex rates |
| OM5597 | POS Reference Design |
| OPB703W | REFLECTIVE OBJECT SINSORS |
| OPB704W | REFLECTIVE OBJECT SINSORS |
| OPB705W | REFLECTIVE OBJECT SINSORS |
相關代理商/技術參數 |
參數描述 |
|---|---|
| OM4068H/2,518 | 功能描述:LCD 驅動器 CHIPS DIGITAL MOS IC RoHS:否 制造商:Maxim Integrated 數位數量:4.5 片段數量:30 最大時鐘頻率:19 KHz 工作電源電壓:3 V to 3.6 V 最大工作溫度:+ 85 C 最小工作溫度:- 20 C 封裝 / 箱體:PDIP-40 封裝:Tube |
| OM4068P | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:LCD driver for low multiplex rates |
| OM4068U | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:LCD driver for low multiplex rates |
| OM4068U/5 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:LCD driver for low multiplex rates |
| OM4085 | 制造商:PHILIPS 制造商全稱:NXP Semiconductors 功能描述:Universal LCD driver for low multiplex rates |
發(fā)布緊急采購，3分鐘左右您將得到回復。