Xilinx ML561 manual Controller Power Supply Circuits, Figure C-5Power Supply Circuits

Models: ML561

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Appendix C: LCD Interface

R

Controller – Power Supply Circuits

Figure C-5shows the power supply circuits. The power supply is used in the five times boost mode, where VDD is 3.3V and VOUT is 16.5V. VOUT is the operating voltage of the operational amplifier delivering the operating voltage, V0, for the LCD panel.

2 VDD

1

VSS

DUTY1

DUTY2

BSTS

VOUT

VR

5 x VDD

MS INTRS

17 VDD

18 VOUT

25

26

27

28

 

VDD

 

 

 

 

 

29

 

 

 

 

 

30 VSS1

 

 

 

VSS

 

 

 

16 VSS DCDC5B

UG199_C_05_050106

Figure C-5:Power Supply Circuits

The LCD operating voltage, V0, is set with two resistors RA and RB. INTRS is driven Low when the resistors are external. INTRS is driven High when the resistors are internal. For the Virtex-5 FPGA ML561 Development Board, internal resistors are selected.

The LCD operating voltage (V0) and the Electronic Volume Voltage (VEV) can be calculated in units of V using Equation C-1and Equation C-2:

 

V0

=

RB

V

 

 

Equation C-1

 

1 + ------

 

 

 

 

 

 

R

 

 

EV

 

 

 

 

 

 

A

 

 

 

 

 

V

 

=

1

63 α⎞

V

 

Equation C-2

EV

--------------

REF

 

 

 

300

 

 

 

In Equation C-2, VREF is equal to 2.0V at 25 ° C.

The values of the reference voltage parameter, α, and the ratio RA/RB are determined with bit settings in the LCD controller’s instruction registers. Thus, it is possible to change physical operating parameters of the LCD through register bit settings, controlling the operating voltage, and the electronic volume level.

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Virtex-5 FPGA ML561 User Guide

 

 

UG199 (v1.2) April 19, 2008

Page 126
Image 126
Xilinx ML561 manual Controller Power Supply Circuits, Figure C-5Power Supply Circuits