Toshiba TLCS-870/C Series Manual page 173

15. LCD Driver
15.2 Control
Note 1: When the TMP86PM29BUG uses the booster circuit to drive the LCD, the power supply and capacitor for the booster cir-
cuit should be connected as shown above.
Note 2: When the reference voltage is connected to a pin other than V1, add a capacitor between V1 and GND.
Note 3: The connection examples shown above are different from those shown in the datasheets of the previous version. Since
the above connection method enhances the boosting characteristics, it is recommended that new boards be designed
using the above connection method. (Using the existing connection method does not affect LCD display.)
Figure 15-3 Connection Examples When Using the Booster Circuit (LCDCR<BRES> = "1")
Table 15-3 V3 Pin Current Capacity and Boosting Frequency (typ.)
Note 1: The current capacity is the amount of voltage that falls per 1µA.
Note 2: The boosting frequency should be selected depending on your LCD panel.
Note 3: For the reference pin V1 or V2, a current capacity ten times larger than the above is recommended to ensure stable oper-
ation.
For example, when the boosting frequency is fc/2
capacity of the reference pin V1.
15.2.3.2 When using an external resistor divider (LCDCR<BRES>="0")
on V1, V2, and V3 to generate the output voltages for segment/common signals.
Keep the following
condition.
V 3
= 0.1 to 0.47 µF
C
Keep the following
condition.
V 3 =
= 0.1 to 0.47 µF
C
VFSEL Boosting frequency
13 5
00
fc/2 or fs/2
11 3
01
fc/2 or fs/2
10 2
10
fc/2 or fs/2
9
11
fc/2
When an external resistor divider is used, the voltage of an external power supply is divided and input
VDD
V3
V2
V1
C1
C0
VSS
c) Reference pin = V3
VDD
V3
V2
V1
C1
C0
VSS
d) Reference pin = V3
fc = 16 MHz fc = 8 MHz
−37 mV/ µA −80 mV/ µA
−19 mV/ µA −24 mV/ µA
−17 mV/ µA −19 mV/ µA
−16 mV/ µA −17 mV/ µA
9 (at fc = 8 MHz), −1.7 mV/ µA or more is recommended for the current
Page 158
C
C
Reference voltage
C
C
C
C
C
C
fc = 4 MHz fc = 32.768 MHz
−138 mV/ µA −76 mV/ µA
−37 mV/ µA −23 mV/ µA
−24 mV/ µA −18 mV/ µA
−19 mV/ µA
–
TMP86PM29BUG