ViewSonic Corporation
Confidential - Do Not Copy
VX912-4
21
Pin number
Pin Name
Pin Number Usage
21
P1.3
Key / Power on ,off
13
P3.4
NV_RAM (U4) SDA
14
P3.5
NV_RAM (U4) SCL
25 P1.7
Key_down
9 P6.3
Key_right
24 P1.6
Key_up
16 P6.2
Key_left
37 P4.1
Key_mute
34 P5.6
VGA
connector
23 P1.5
Key_select
42 P5.3
LED_red
41 P5.4
LED_green
32
P6.6
LCD panel power1 on / off control
3
P5.0
LCD panel power2 on / off control
36
P4.0
Backlight on / off control
e).
Panel Power Sequencing ( VDDCTRL1, 2) ( Pin 32, 3) : The MTV312 has two dedicated outputs
VDDCTRL1 and 2 ( Pin32 and Pin3) to control LCD power sequencing once data and control signals
are stable.
f).
Panel interface (Pin 1~25, Pin75~128) : The MTV312 driver interface is highly programmable. It supports
dual bus / dual port for SXGA drivers.
6.1.2 Power Regulator MC34063A (U6),AIC1739 (Q4) : The MC34063A is a monolithic control IC containing the primary
functions required for DC to DC converters. The device consists of an internal temperature compensated reference, comparator,
controlled duty cycle.
Oscillator with an active current sense circuit. Desired output voltage are determined by the equation,
Volt = 1.25 ( 1 + R67 / R66), In this case, the output voltage are 3.3 Volts
The AIC1739 is a low dropout positive adjustable regulator with minimum of 300mA output current capability.
So it is well suited for 3.3 V and 2.5 V Regulator
.
6.1.3 Power Regulator MC34063A (U7) : The MC34063A is a monolithic control IC containing the primary functions required
for DC to DC converters. The device consists of an internal temperature compensated reference, comparator, controlled duty
cycle.
Oscillator with an active current sense circuit. Desired output voltage are determined by the equation,
Volt = 1.25 ( 1 + R85 / R86), In this case, the output voltage are 5.0 Volts for panel power.
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