ViewSonic VP2030b-1 Service Manual page 27

d) Panel interface (Pin B1,B2,C1,C2,D1,D2,A6,B6,A8,B8,A9,B9,A10,B10,) : The Gm1601 driver interface is
highly programmable.
6.1.2 Power Regulator AIC1577 (U23), AP1084 (U16,U20),LT1117(U18) : The AIC1577 is a current switching
regulator control IC containing the primary functions required for DC to DC converters and external
NMOS STEP-DOWN PWM controller ,operating input voltaqge from 4.5V to 24V The desired output
voltage is determined by the equation, Volt = 0.8[ ( R218+R219) / R218]. In this case, the output voltage is
5 Volts. The AIC1577 is a low dropout operation
6.1.3 Power Regulator AP1084 (U16,U20): The AP1084 is a low dropout positive adjustable or fixed mode
regulator with minimum of 5A output current capability. Specifically designed to provide supply for low
voltage IC and low current 3.3V logic supply. AP1084 is guaranteed to have lower than 1.4V dropout at
full load current ,provide well-regulated output of 1.25 to 3.3 with 4.7 to 12V input supply.
6.1.4 Power Regulator LT1117(U18): The LT1117 is a low drop voltage regulator ,provide up to 800 mA of
output current. Concerning fixed version, are offered the output voltage:1.2V, 1.8V, 2.5V, 2.85V, 3.0V,
3.3V, the regulator to reach a very tight output voltage tolerance, within ¡Ó 1% at 25?C. The adjustable
LD1117 is pin to pin compatible with the other LD1117.
6.3 Power (Inverter) Board
This is a specific power (inverter) board for VP2030B monitor with output of 56W /12V / 2.4A and 20V/1.8A. It
provides 20 VDC to drive the four cold cathode fluorescence tubes in the backlight.
6.3.1 The inverter's electrical specification is described below.
Input
Output
6.3.2 power
This is a general purpose AC / DC adapter which converts 90~240 Vac to a stabilized DC voltage: 12 Volts,
with a rated output current of 2.4A. The electrical specification is described below.
Viewsonic Corporation
AC2 LCD panel power1 on / off control
C25 Backlight on / off control
Rated Input Voltage
Input Voltage Range
Input Current
On / Off control Voltage
Rated Output Strike-on Voltage
Rated Output Voltage
Rate Output Frequency
Rated Output Current
Rated Input Voltage
Operation Input Voltage
20Vdc
19 ~ 21 Vdc
1.8A(MAX)
2.5~5.25 for on , 0~1 for off
1800Vrms
700~900Vrms
35~80KHz
5.5~8.0 mA
90~240 Vac , 50 / 60Hz
90~260 Vac , 47 ~ 63Hz
24 Confidential - Do Not Copy VP2030b-1