DEMO9S08LIN Freescale, DEMO9S08LIN Datasheet - Page 151

• Manufacturer Part Number: DEMO9S08LIN
• Manufacturer: Freescale

Specifications of DEMO9S08LIN

• Lead Free Status / RoHS Status: Compliant

Figure 9-17
VIn = VOut, and, because the input impedance of the op amp is very high, VIn is isolated from VOut This
isolation can protect VIn from things like current draw from VOut; however, if the buffer is disabled
((~BBYPASS & powersw3) = 0), the output and input will be configured in a tri-state condition; that is,
floating.
Freescale Semiconductor
VSUPPLY[1:0] powersw1 powersw2 powersw3
also illustrates a buffer, a voltage follower with an ideal op amp. The buffer, if enabled, gives
00
01
10
11
The charge pump is optimized for 1/3 bias mode operation only.
During the first 16 timebase clock cycles after the LCDCPEN bit is set, all
the LCD frontplane and backplane outputs are disabled regardless of state
of the LCDEN bit.
The charge pump requires external capacitance for is operation. To provide
this external capacitance, the V
is recommended that a low equivalent series resistance (ESR) capacitor be
used. Proper orientation is imperative when using a polarized capacitor. The
recommended value for the external capacitor is 0.1 μF.
Figure 9-17. LCD Charge Pump and V
V
LCD
1
0
0
0
MC9S08LC60 Series Data Sheet: Technical Data, Rev. 4
0
1
0
0
R1
R1
R1
(~(LCDCPMS) & powersw3)
0
0
1
0
~(LCDCPMS)
LCDCPMS
cap1
NOTE:
and V
LCD
cap2
Voltage Divider Block Diagram
external pins are provided. It
VOLTAGE DIVIDER
BLOCK
CHARGE PUMP
(~(BBYPASS) & powersw3)
(BBYPASS & powersw3)
Chapter 9 Liquid Crystal Display Driver (S08LCDV1)
+
–
powersw1
V
LL1
V
DD
V
V
V
powersw2
LL1
LL2
LL3
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