Other Power Saving Methods - Epson S1C17W22 Technical Manual

APPENDIX B POWER SAVING
OSC3 (crystal/ceramic) oscillator circuit configurations
The OSC3 (crystal/ceramic) oscillator circuit provides some configuration items to support various crystal and
ceramic resonators. These configurations trade off current consumption for performance as shown below.
• The lower oscillation inverter gain setting (CLGOSC3.OSC3INV[1:0] bits) decreases current consumption.
• Using lower OSC3 external gate and drain capacitances decreases current consumption.
• Using a resonator with lower C
However, these configurations may reduce the oscillation margin and increase the frequency error, therefore, be
sure to perform matching evaluation using the actual printed circuit board.
B.2 Other Power Saving Methods
Supply voltage detector configuration
Continuous operation mode (SVDCTL.SVDMD[1:0] bits = 0x0) always detects the power supply voltage,
therefore, it increases current consumption. Set the supply voltage detector to intermittent operation mode or
turn it on only when required.
LCD driver configurations
• Setting the LCD voltage regulator to operate with the V
increases current consumption. Select the V
power supply voltage V
• The lower booster clock frequency setting (LCD24TIM2.BSTC[1:0] bits) for the LCD voltage booster de-
creases current consumption. Note, however, that the load characteristic becomes worse.
• Setting the LCD voltage regulator into heavy load protection mode (LCD24PWR.HVLD bit = 1) increases
current consumption. Heavy load protection mode should be set only when the display becomes unstable.
AP-B-2
value decreases current consumption.
L
reference voltage (LCD24PWR.VCSEL bit = 1) when the
C2
is 2.2 V or higher.
DD
Seiko Epson Corporation
reference voltage (LCD24PWR.VCSEL bit = 0)
C1
S1C17W22/W23 TECHNICAL MANUAL
(Rev. 1.3)