Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

ADM8830 Datasheet(PDF) 7 Page - Analog Devices

Part # ADM8830
Description  Charge Pump Regulator for Color TFT Panel
Download  8 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  AD [Analog Devices]
Direct Link  http://www.analog.com
Logo AD - Analog Devices

ADM8830 Datasheet(HTML) 7 Page - Analog Devices

  ADM8830_15 Datasheet HTML 1Page - Analog Devices ADM8830_15 Datasheet HTML 2Page - Analog Devices ADM8830_15 Datasheet HTML 3Page - Analog Devices ADM8830_15 Datasheet HTML 4Page - Analog Devices ADM8830_15 Datasheet HTML 5Page - Analog Devices ADM8830_15 Datasheet HTML 6Page - Analog Devices ADM8830_15 Datasheet HTML 7Page - Analog Devices ADM8830_15 Datasheet HTML 8Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 7 / 8 page
background image
–6–
ADM8830
ADM8830
–7–
SCANNING AND BLANKING
A TFT LCD panel is essentially made up of a bank of capacitors,
each representing a pixel in the display.These capacitors store
different levels of charge, depending on the amount of lumines-
cence required for a given pixel.When a picture is being displayed
on the panel, a scan of all the pixel capacitors is performed, placing
different levels of charge on each in order to create the image.The
process of updating the display like this is called “scanning.” Once
scanned, an image will be held by pixel capacitance and the con-
troller and source line drivers can be put into a low power mode.
This low power mode is referred to as the blanking mode on the
ADM8830. Over a finite period of time, this pixel charge will leak
and the capacitors will have to be refreshed in order to maintain
the image.
The ADM8830 caters to the two modes of operation described
above as follows.When the TFT LCD panel is in scanning mode,
a logic high on the SCAN/BLANK input places the device in high
current power mode, providing extra power (extra current) to the
LCD controller and the source line drivers. If the panel continues
to be updated (as when a moving picture is being displayed), then
the ADM8830 can be continually operated in scanning mode. If
the same image is kept on the panel, a logic low is applied to the
SCAN/BLANK input and the ADM8830 enters blanking (low
current) mode. Depending on how often the image is being updated,
the ADM8830 can be operated with a variable SCAN/BLANK
duty cycle.This helps to maximize power efficiency and therefore
extends the battery life.
90%
10%
tR
tF
tH
tT
tR: RISETIME
tF: FALLTIME
tH
tT
@ 100% = DUTY CYCLE
Figure 1. Duty Cycle of External Clock
POWER SEQUENCING
The gate drive supplies must be sequenced such that the –10 V
supply is up before the +15 V supply for the TFT panel to power
up correctly.The ADM8830 controls this sequence.When the
device is turned on (a logic high on SHDN), the ADM8830 allows
the –10 V output to ramp immediately but holds off the +15 V
output. It continues to do this until the negative output has reached
–3 V. At this point, the positive output is enabled and allowed to
ramp up to +15 V.This sequence is highlighted in Figure 2.
VCC
LOAD
SCAN/BLANK
EXTERNAL CLOCK
SHDN
+5V
+15V
–10V
tF5V
tF15V
tR10V
tR15V
tR5V
tDELAY
tF10V
–3V
90%
10%
10%
90%
Figure 2. Power Sequence
TRANSIENT RESPONSE
The ADM8830 features extremely fast transient response, making
it very suitable for fast image updates on TFT LCD panels.This
means that even under changing load conditions there is still very
effective regulation of the 5 V output.TPCs 10 and 11 show how
the 5.1 V output responds when a maximum load is dynamically
connected and disconnected. Note that the output settles within
5 µs to less than 1% of the output level.
EXTERNAL CLOCK
The ADM8830 has an internal 100 kHz oscillator, but an external
clock source can also be used to clock the part.This clock source
must be applied to the CLKIN pin. Power is saved during blank-
ing periods by disabling the internal oscillator and switching to
the lower frequency external clock source.To achieve optimum
performance of the charge pump circuitry, it is important that the
duty cycle of the external clock source be 50% and that the rise
and fall times be less than 20 ns.
SOLDER MASK
BOARD METALLIZATION
DIMENSIONS IN
MILLIMETERS
0.2
0.25
0.5
0.75
0.28
0.4
0.25
0.9
3.10
1.95 2.10
Figure 3. Suggested LFCSP 4 mm  4 mm 20-Lead
Land Pattern
REV. B
REV. B


Similar Part No. - ADM8830_15

ManufacturerPart #DatasheetDescription
logo
Analog Devices
ADM8830ACP AD-ADM8830ACP Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
ADM8830ACP-REEL7 AD-ADM8830ACP-REEL7 Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
ADM8830ARU AD-ADM8830ARU Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
ADM8830ARU-REEL AD-ADM8830ARU-REEL Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
ADM8830ARU-REEL7 AD-ADM8830ARU-REEL7 Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
More results

Similar Description - ADM8830_15

ManufacturerPart #DatasheetDescription
logo
Analog Devices
ADM8830 AD-ADM8830 Datasheet
1Mb / 8P
   Charge Pump Regulator for Color TFT Panel
REV. B
ADM8832 AD-ADM8832_15 Datasheet
212Kb / 12P
   Charge Pump Regulator for Color TFT Panel
REV. A
ADM8832 AD-ADM8832 Datasheet
202Kb / 12P
   Charge Pump Regulator for Color TFT Panel
REV. A
ADM8840 AD-ADM8840 Datasheet
166Kb / 10P
   Charge Pump Regulator & COM Driver for Color TFT Panel
REV. PrG 2/03
ADM8839 AD-ADM8839_15 Datasheet
372Kb / 12P
   Charge Pump Regulator for Color TFT Panels
REV. C
ADM8839 AD-ADM8839 Datasheet
233Kb / 8P
   Charge Pump Regulator for Color TFT Panels
REV. A
logo
Lowpower Semiconductor ...
LP3100 POWER-LP3100 Datasheet
918Kb / 8P
   Dual Channel Charge Pump Power Solution For TFT LCD Panel
logo
E-CMOS Corporation
ELP3100 E-CMOS-ELP3100 Datasheet
581Kb / 8P
   Dual Channel Charge Pump Power Solution For TFT LCD Panel
logo
Lowpower Semiconductor ...
LP3101A POWER-LP3101A Datasheet
895Kb / 8P
   Dual Channel Charge Pump Power Solution For TFT LCD Panel
LP3102 POWER-LP3102 Datasheet
743Kb / 7P
   Dual Channel Charge Pump Power Solution For TFT LCD Panel
More results


Html Pages

1 2 3 4 5 6 7 8


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.NET
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com