datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

CXD1178Q View Datasheet(PDF) - Sony Semiconductor

Part Name
Description
View to exact match
CXD1178Q
Sony
Sony Semiconductor Sony
CXD1178Q Datasheet PDF : 15 Pages
First Prev 11 12 13 14 15
CXD1178Q
Notes on Operation
How to select the output resistance
The CXD1178Q is a D/A converter of the current output type. To obtain the output voltage connect the
resistance to current output pins (RO, GO and BO). For specifications we have;
Output full scale voltage VFS=1.8 to 2.2 [V]
Output full scale current IFS=less than 15 [mA]
Calculate the output resistance value from the relation of VFS=IFS × ROUT. Also, 16 times resistance of the
output resistance is connected to reference current pin IREF. In some cases, however, this turns out to be a
value that does not actually exist. In such a case a value close to it can be used as a substitute.
Here please note that VFS becomes
VFS=VREF × 16ROUT/RIR.
VREF is the voltage set at the VREF pin and ROUT is the resistance connected to current output pins (RO, GO
and BO) while RIR is connected to IREF.
Increasing the resistance value can curb power consumption. On the other hand glitch energy and data
settling time will inversely increase. Set the most suitable value according to the desired application.
Phase relation between data and clock
To obtain the expected performance as a D/A converter, it is necessary to set properly the phase relation
between data and clock applied from the exterior. Be sure to satisfy the provisions of the setup time (tS) and
hold time (tH) as stipulated in the Electrical Characteristics.
Power supply and ground
To reduce noise effects separate analog and digital systems in the device periphery. For power supply pins,
both digital and analog, bypass respective grounds by using a ceramic capacitor of about 0.1 µF, as close as
possible to the pin.
Latch up
Analog and digital power supply have to be common at the PCB power supply source. This is to prevent
latch up due to voltage difference between AVDD and DVDD pins when power supply is turned ON.
On inverted current output pins
The RO, GO and BO are the inverted current output terminal as described in the Pin Description.
The sums shown below become the constant value for any input data.
a) The sum of the currents output from the RO and RO pins.
b) The sum of the currents output from the GO and GO pins.
c) The sum of the currents output from the BO and BO pins.
However, the output current from the RO, GO and BO pins is not guaranteed of its performances such as
linearity errors, etc.
On output full-scale voltage
When the output full-scale voltage is used without adjustment in the application that uses the RGB signal, the
color balance may be broke.
—11—
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]