STE2004S STMicroelectronics, STE2004S Datasheet - Page 6

• Manufacturer Part Number: STE2004S
• Description: 102 x 65 Single Chip Lcd Controller / Driver
• Manufacturer: STMicroelectronics

STE2004S
3
3.1 Supplies Voltages and Grounds
V
not used, this should be connected to V
could be different form V
3.2 Internal Supply Voltage Generator
The IC has a fully integrated (no external capacitors required) charge pump for the Liquid Crystal Display
supply voltage generation. The multiplying factor can be programmed to be: Auto, X5, X4, X3, X2, using
the ’set CP Multiplication’ Command. If Auto is set, the multiplying factor is automatically selected to have
the lowest current consumption in every condition. This make possible to have an input voltage that chang-
es over time and a constant V
CDSENSE
temperature) can be programmed using TC1 & TC0 or T2, T1 and T0 bits. This will ensure no contrast
degradation over the LCD operating range.
An external supply could be connected to V
such event the internal voltage generator must be programmed to zero (PRS = [0;0], Vop = 0 - Reset con-
dition) and the Charge pump (CP[0;0]) set to 5x or Auto Mode.
3.3 Oscillator
A fully integrated oscillator (requires no external components) is present to provide the clock for the Dis-
play System. When used the OSC pad must be connected to V
used and fed into the OSC pin.If an external oscillator is used, it must be always present when STE2004S
is not in power down mode. An oscillator out is provided on the OSCOUT Pad to cascade two or more
drivers.
3.4 Master/Slave Mode
STE2004S support the Master Slave working Mode for Both Control Logic and Charge Pump. This func-
tion allows to drive matrix such as 204x65 or 102x130 using two synchronized STE2004S and the internal
Charge Pump of both device.
If M/S is connected to VDD1, the driver is configured to work in Master Mode. When STE2004S is in Mas-
ter Mode the Vsense_Slave Pin is disabled and is possible to control the VLCD value using Vop Bits. The
Master Time Generator outputs on FR_OUT and on OSC_OUT the relevant timing references.
If M/S is connected to GND, the driver is configured to work in Slave Mode. When STE2004S is in Slave
Mode, the VLCD configuration set by Vop registers and the thermal compensation slope set by TC register
are neglected. The VLCD Value generated is equal to the Voltage value present on Vsense_Slave Pin so
the slave configuration can follow the master configuration. The only recognized configuration is Vop=0
that forces the Charge Pump to be in off state whatever is the value of Vsense_aux.
To Synchronize the Master & Slave timing circuits, the slave driver FR_IN pad must be connected to Mas-
ter Driver FR_OUT pad and Slave Driver OSC_IN pad must be connected to the master driver OSC_OUT
Pad (Fig. 4). This connection ensure a synchronization at both Frame level (R0 on the master is driven
together with the Slave R0 driver) and at Oscillator Level (same Frame frequency on the master and on
the slave). If the Synchronization at Frame level is not required, FR_IN pin must be connected toVDD1 or
to VDD1_aux (Fig. 5).
During Power Up Procesure, Master device must be forced to exit from power down before the slave de-
vice. To enter in PowerDown Mode, Slave Device must be forced in Power Down state before Master De-
vice.
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DD2
CIRCUIT DESCRIPTION
is supply voltages to the internal voltage generator (see below). If the internal voltage generator is
pad. For this voltage, eight different temperature coefficients (TC, rate of change with
DD2
.
LCD
voltage. The output voltage (V
V
DD2
DD1
LCD
≥
pad. V
2 VLCD
------------------------ -
to supply the LCD without using the internal generator. In
(
⋅
n
+
DD1
4
)
supplies the rest of the IC. V
+
200mV
DD1
LCD
) is tightly controlled through the V
pad. An external oscillator could be
DD1
supply voltage
L-