PCF8820U Philips Semiconductors, PCF8820U Datasheet - Page 48

• Manufacturer Part Number: PCF8820U
• Description: 67 x 101 Grey-scale/ECB colour dot matrix LCD driver
• Manufacturer: Philips Semiconductors

Philips Semiconductors
13.5
The PCF8820 is a low power LCD driver designed to
interface with microcontrollers and a wide variety of LCDs.
The host microcontroller and the PCF8820 are both
connected to the I
connected to the positive power supply via pull-up
resistors.
The internal oscillator requires no external components.
The appropriate intermediate biasing voltage for the
multiplexed LCD waveforms are generated on-chip.
The only other connections required to complete the
system are the power supplies (V
ground supplies (V
system reset (RES), including suitable capacitors for
decoupling.
2000 Dec 07
handbook, full pagewidth
67 101 Grey-scale/ECB colour dot matrix
LCD driver
Typical system configuration
RES
SDA
V P1
SCL
V P2
5.5 V
2
C-bus. The SDA and SCL lines must be
SS1
R pu
and V
R pu
SS2
MICROCONTROLLER
), LCD supply (V
DD1
, V
HOST
DD2
Fig.31 Typical system configuration.
and V
LCDIN
DD3
) and
) and
PCF8820
48
13.6
If an external LCD supply voltage is used, it must be
connected to pad V
V
pad V
status of bits shown in Table 8. To obtain the highest
resistance and the lowest current into pad V
recommended to set the V
HIGH (bit PRS = 1) and the V
127 (maximum value) with bits V
It should be noted that V
than V
An external V
it must be turned off before (or when) V
(see Fig.25). It is recommended that the external V
applied after leaving the reset state. The external V
stay turned on in Power-down mode.
LCDIN
LCDOUT
DD1
External supply of V
are connected together, the impedance of
V LCD
.
LCD
should be set high-impedance by setting the
101 column drivers
must be applied after applying V
67 row drivers
LCDIN
I
2
. If pads V
MGT138
LCDIN
C-bus
LCD
LCDIN
LCD
is not allowed to be lower
programming range to
OP6
control register value to
LCDOUT
LCD PANEL
Product specification
to V
DD1
PCF8820
OP0
, V
is turned off
LCDSENSE
LCDSENSE
.
DD1
LCD
LCD
, and
, it is
and
can
is