EL5226 INTERSIL [Intersil Corporation], EL5226 Datasheet - Page 10

• Manufacturer Part Number: EL5226
• Description: 10- and 12-Channel TFT-LCD Reference Voltage Generators
• Manufacturer: INTERSIL [Intersil Corporation]

Block Diagram
CHANNEL OUTPUTS
Each of the channel outputs has a rail-to-rail buffer. This
enables all channels to have the capability to drive to within
50mV of the power rails, (see Electrical Characteristics for
details).
When driving large capacitive loads, a series resistor should
be placed in series with the output. (Usually between 5Ω and
50Ω).
Each of the channels is updated on a continuous cycle, the
time for the new data to appear at a specific output will
depend on the exact timing relationship of the incoming data
to this cycle.
The best-case scenario is when the data has just been
captured and then passed on to the output stage
immediately; this can be as short as 48µs. In the worst-case
scenario this will be 480µs for EL5226 and 576µs for
EL5236, when the data has just missed the cycle.
When a large change in output voltage is required, the
change will occur in 2V steps, thus the requisite number of
timing cycles will be added to the overall update time. This
means that a large change of 16V can take between 4.8ms
I
2
I
C CLOCK IN
2
C DATA IN
10
FILTER
CHANNEL
MEMORY
EIGHT
STD/REG
EL5226, EL5326
CONTROL IF
A0
SOURCES
VOLTAGE
OSCILLATOR
and 5.3ms for EL5226 and between 6.9ms to 7.48ms for
EL5236 depending on the absolute timing relative to the
update cycle.
POWER DISSIPATION
With the 30mA maximum continues output drive capability
for each channel, it is possible to exceed the 125°C absolute
maximum junction temperature. Therefore, it is important to
calculate the maximum junction temperature for the
application to determine if load conditions need to be
modified for the part to remain in the safe operation.
The maximum power dissipation allowed in a package is
determined according to:
where:
• T
• T
• θ
• P
SELECT
P
DMAX
JA
AMAX
JMAX
DMAX
= Thermal resistance of the package
=
= Maximum junction temperature
= Maximum ambient temperature
= Maximum power dissipation in the package
INPUT/OUTPUT
T
-------------------------------------------- -
OSCILLATOR
JMAX
Θ
- T
JA
AMAX
REFERENCE HIGH
OUTA
OUTB
OUTJ
OUTK
OUTL
REFERENCE LOW
REFERENCE DECOUPLE