Product
Light Blue 20x4 Character USB LCD
Part Number: CFA634-TFH-KU
This intelligent character display module allows the choice between the legacy serial communication for backward compatibility and Crystalfontz's error-reducing packet communication style. Both of these communication styles provide powerful command sets for controlling the display. Do you need to control fans too? Check out the CFAFBSCAB which is compatible with this module using packet communication.
The 20x4 character display in its attractive stainless steel bezel displays characters that are 7.3 mm (0.29") tall, making it easily readable. And the range of color options lets you choose the perfect module for your application.
Easily Choose Your Interface
With each module capable of communicating via 6 interfaces, and the interfaces configurable by the end user, this module offers tons of flexibility. While these modules can all be configured for any interface (see the datasheet for details), this module is configured for USB. (-KU)
Key Features:- Attractive stainless steel bezel.
- Optional PC CDROM mounting bracket with overlay to fit two 5.25" wide bays is available.
- The CFA634 can use any of SIX interfaces on any modules in the family by simply changing the interface selection using a command setting or tactile button and making the appropriate jumper configurations.
- Adjustable contrast. The module's default contrast value will be acceptable for many applications. If necessary, you can adjust the contrast by using the control function.
- Extended voltage (9-15 volts for interfaces using DB9 connector) and 5 volts power inputs standard for the controller.
- Backlight is 5 volts only.
- Use the nonvolatile memory capability (EEPROM) to customize the "power-on" display settings.
Not sure which intelligent LCD module to choose? Compare all of our intelligent display modules.
Currently Shipping: HW Version 4, Firmware Version: 4
Part Number:
CFA - Crystalfontz (no 4th letter indicates value added)
634 - Module Family Name
T - White LED backlight
F - FSTN, positive image, neutral glass
H - Transflective, 6:00 viewing direction
KU - USB Interface
Product Variations
Interfaces | Logic Level Serial InvertedSPILogic Level SerialI2CUSBRS232 |
|---|
Colors | Yellow-Green on Black Yellow-Green LED BacklightWhite on Blue White LED BacklightBlack on Yellow-Green Yellow-Green LED BacklightDark on Light-Gray White LED Backlight |
|---|
- square_foot Physical Characteristics
Physical Characteristics
Characters x Lines 20 x 4 Module Overall width height depth millimeters 130 63 19.9 inches 5.12 2.48 0.78 Diagonal Dimension 3.92" Viewing Area Width Height millimeters 102 41.5 inches 4.02 1.63 Active Area Width Height millimeters 93.54 34 inches 3.68 1.34 Character Size Width Height millimeters 3.84 7.3 inches 0.151 0.287 Character Pitch Width Height millimeters 4.68 8.9 inches 0.184 0.350 Dot Size Width Height millimeters 0.72 0.86 inches 0.028 0.034 Dot Pitch Width Height millimeters 0.78 0.92 inches 0.031 0.036 Weight 110g - visibility Optical Characteristics
Optical Characteristics
Glass Type/Glass Color STN/Neutral Polarizer Transflective View Direction 6 o'clock View Angle 60° Sunlight Readable Yes Backlight Color White Backlight Type LED Mode Positive Foreground Color Dark Background Color Light-Gray - electric_bolt Electrical Specification
Electrical Specifications
Supply Voltage for Logic Minimum 2.5V Supply Voltage for Logic Maximum 5.5V - electric_bolt Backlight Specification
Backlight Electrical Specifications
Forward Current Minimum 16mA Forward Current Maximum 130mA - nature Environmental
Environmental
Operating Temperatures min max Celsius -20° 70° Fahrenheit -4° 158° Storage Temperatures min max Celsius -30° 80° Fahrenheit -22° 176° Humidity min max Non-condensing 10% 90% - cable Electronics
Electronics
Interface USB -
picture_as_pdf DatasheetsPrevious Versions of DatasheetsCFA634 Series Data Sheet Release 2015-03-30.pdf(Datasheet V 2015-03-30, Hardware 3.2, Firmware 3.2)CFA634 Family Data Sheet Release 2013-09-10.pdf(Datasheet V 2013-09-10, Hardware 3.1, Firmware 3.1)CFA634 Family Preliminary Data Sheet Release 2013-08-21.pdf(Datasheet V 2013-08-21, Hardware 3.1, Firmware 3.1)
-
download Files and Downloads
-
assured_workload Compliance Documents
Other components worth considering
Part Change Notices
Subscribe to Part Change Notices by email 
or RSS 
- text_snippet
Product Update #11282: Updated CFA634-TFH-KU is now available
Product Affected: CFA634-TFH-KU Date Issued: July 25, 2024 Summary: Updated CFA634-TFH-KU is now available Description: CFA634-TFH-KU has been updated and released on our website (https://www.crystalfontz.com/product/cfa634tfhku-text-usb-20x4-display-module) and is now available for sale.
Orders can be placed directly from our website or by submitting a purchase order to sales@crystalfontz.com.
Contact support@crystalfontz.com for any technical questions.
- text_snippet
Part Change Notice #11226: Change to ENIG from Gold Plating
- text_snippet
Part Change Notice #11204: CFA634 Update to PCN11149
Products Affected: CFA634-TFH-KS, CFA634-TMI-KS, CFA634-YFH-KS, CFA634-YDI-KS, CFA634-TFH-KU, CFA634-TMI-KU, CFA634-YFH-KU, CFA634-YDI-KU, CFA634-YDI-KC, CFA634-TMI-KC, CFA634-YFH-KC, CFA634-TFH-KC, CFA634-YFH-KL, CFA634-TFH-KL, CFA634-TMI-KL, CFA634-YDI-KL, CFA634-TFH-KP, CFA634-YFH-KP, CFA634-TMI-KP, CFA634-YDI-KP, CFA634-TFH-KN, CFA634-YFH-KN, CFA634-TMI-KN, CFA634-YDI-KN Date Issued: June 19, 2023 Summary: CFA634 Update to PCN11149 Description: Update to PCN11149:
Electrical characteristics will be different including logic voltage. The inputs will be 5V tolerant but outputs from the CFA634 display modules will be 3.3V. For detailed changes, we will be releasing the updated datasheets on the relevant product pages. Contact support@crystalfontz.com if you would like to be notified when the updated datasheet is released.
Original notice:
The CFA634 family is having a hardware revision that utilizes a new processor and has other improvements that include: an independent voltage source so that the contrast is not affected by the input voltage, an interface select button, and will now support packet-based communication. The firmware has also been updated with additional features.
JPBL will be closed by default which will enable the backlight to be powered from USB.
Please refer to the datasheet for more information about the new hardware and firmware functions.Reason: Continuous improvement for this family of products. Availability: Contact Crystalfontz Support for up-to-date information by emailing support@crystalfontz.com.
Contact Crystalfontz Sales to order samples of the new revision by emailing sales@crystalfontz.com. - text_snippet
Part Change Notice #11149: New Hardware Revision
- text_snippet
Part Change Notice #10658: Deprecation of "Drive Bay Kit Configurator" / New part numbers for drive bay kits.
Products Affected: CFA631-RMF-KU1, CFA631-RMF-KU2, CFA631-RMF-KU, CFA633-YYB-KS, CFA633-TMC-KS, CFA633-RMC-KS, CFA633-YYB-KU, CFA633-TMC-KU, CFA633-RMC-KU, CFA635-YYE-KS, CFA635-TMF-KS, CFA635-TFE-KS, CFA635-TMF-KL, CFA635-TFE-KL, CFA631-TMF-KU, CFA635-TFE-KU, CFA635-YYE-KL, CFA635-TMF-KU, CFA635-YYE-KU, DS635-AL, DS635-BG, DS635-BK, DS635-AK, CFA533-YYH-KS, CFA533-YYH-KU, CFA533-TMI-KS, CFA533-TMI-KU, CFA533-YYH-KL, CFA533-TMI-KL, CFA533-YYH-KC, CFA533-TMI-KC, CFA533-YYH-KI, CFA633-YYH-KS, CFA633-TMI-KS, CFA633-YYH-KU, CFA633-TMI-KU, CFA632-YFH-KS, CFA632-YDI-KS, CFA632-YFH-KU, CFA632-YDI-KU, CFA634-TFH-KS, CFA634-TMI-KS, CFA634-YFH-KS, CFA634-YDI-KS, CFA634-TFH-KU, CFA634-TMI-KU, CFA634-YFH-KU, CFA634-YDI-KU, CFA633-RDI-KU, CFA633-RDI-KS, CFA533-TFH-KU, CFA533-TFH-KS, CFA633-TFH-KU, CFA633-TFH-KS, CFA533-TFH-KL, CFA533-TFH-KC, CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT, CFA631-RMF-KU32, CFA631-RMF-KU128, CFA631-RMF-KU160, CFA631-RMF-KU33, CFA631-RMF-KU129, CFA631-RMF-KU161, CFA631-RMF-KU-162, CFA632-YDI-KL, CFA632-YDI-KN, CFA632-YDI-KC, CFA632-YDI-KP, CFA632-YFH-KL, CFA632-YFH-KN, CFA632-YFH-KC, CFA632-YFH-KP, CFA634-YDI-KC, CFA634-TMI-KC, CFA634-YFH-KC, CFA634-TFH-KC, CFA634-YFH-KL, CFA634-TFH-KL, CFA634-TMI-KL, CFA634-YDI-KL, CFA634-TFH-KP, CFA634-YFH-KP, CFA634-TMI-KP, CFA634-YDI-KP, CFA634-TFH-KN, CFA634-YFH-KN, CFA634-TMI-KN, CFA634-YDI-KN, CFA631P-TMF-KU Date Issued: July 1, 2015 Summary: Deprecation of "Drive Bay Kit Configurator" / New part numbers for drive bay kits. Description: Starting August 1, 2015 the "Drive Bay Kit Configurator" located at https://www.crystalfontz.com/products/select_kit.html will no longer be functional for ordering one of our Serial or USB displays (CFA533, CFA631, CFA632, CFA633, CFA634, CFA635, and CFA735) in a bracket or SLED. This functionality is being moved to the Customize and Add to Cart process when checking out. This will allow for further customization by our customers to better fit their needs.
This change will eliminate the current "kits", but will add options not previously available such as pre-configured ATX functionality, and ALL the currently available interfaces will be orderable in a drive bay bracket or SLED.
The new part numbers will have the bracket / SLED and overlay type as a PREFIX to the configured part number. The choice for bracket / SLED to a display order will be via the cart options. Our CFA835 displays were introduced with these configuration options.
To see how the new options will look, and what the new part numbers will look like, please see one of our CFA835 parts:
https://www.crystalfontz.com/cart/addtocart.php?product_id=2277&qty=1
NOTE: The SLED is only available for the CFA635, CFA735, and CFA835 products.
Reason: As part of our continuous improvement process, we are integrating the ordering of displays in drive bay and SLED kits as part of the display ordering process. Impact: Drive bay kits in their current configuration will no longer be available. Recommendation: Place orders prior to 2015-08-01 for upcoming production needs via our website or by contacting our logistics department via email: sales@crystalfontz.com, or by calling 1-888-206-9720 (International call +1-509-892-1200).
After the 2015-08-01, please contact our engineering department via support@crystalfontz.com to assist you with ordering your bracket / SLED kits.
Availability: Starting 2015-08-01, the bracket and SLED options for our serial and USB display will be part of the ordering process for the displays Price Change: Pricing bracket / SLED configurations will reflect manufacturing costs. - text_snippet
Part Change Notice #10650: CFA634 Firmware update
- text_snippet
Part Change Notice #10580: Reverted the SPI functionality to Crystalfontz CFA634 legacy implementation
- text_snippet
Product Update #10494: New pricing for CFA634 family effective 2013-07-01
Products Affected: CFA634-TFH-KS, CFA634-TMI-KS, CFA634-YFH-KS, CFA634-YDI-KS, CFA634-TFH-KU, CFA634-TMI-KU, CFA634-YFH-KU, CFA634-YDI-KU Date Issued: May 17, 2013 Summary: New pricing for CFA634 family effective 2013-07-01 Description: PCN #10454 announced the new v3.1 hardware version for CFA634 family of modules:
https://www.crystalfontz.com/products/pcn.phtml?id=10454
Pricing at the time of the PCN was issued was published as TBD. This update notices publishes pricing for the CFA634 family of modules effective 2013-07-01
2013-07-01 Edit: Corrected TMI variant 200 piece pricing.Impact: All CFA634 based parts. Availability: New pricing is effective orders placed on 2013-07-01 or later. Price Change: - - Effective 2013-07-01 - -
CFA634-TFH-KS and CFA634-TFH-KU
1 + : US$55.00
10 + : US$49.40
20 + : US$46.60
50 + : US$43.90
100 + : US$41.20
200 + : US$38.40
500 + : US$35.70
1000 + : US$32.90
CFA634-TMI-KS and CFA634-TMI-KU
1 + : US$54.00
10 + : US$48.40
20 + : US$45.70
50 + : US$43.00
100 + : US$40.30
200 + : US$38.00
500 + : US$35.00
1000 + : US$32.30
CFA634-YDI-KS and CFA634-YDI-KU
1 + : US$56.00
10 + : US$49.80
20 + : US$47.00
50 + : US$44.30
100 + : US$41.50
200 + : US$38.70
500 + : US$36.00
1000 + : US$33.20
CFA634-YFH-KS and CFA634-YFH-KU
1 + : US$54.00
10 + : US$47.90
20 + : US$45.20
50 + : US$42.60
100 + : US$39.90
200 + : US$37.20
500 + : US$34.60
1000 + : US$31.90 - text_snippet
Part Change Notice #10455: New v3.1 firmware to support CFA634 hardware v3.1 family of module
- text_snippet
Part Change Notice #10454: New v3.1 hardware version for CFA634 family of modules.
- text_snippet
Part Change Notice #10316: Minor PCB revision to accommodate longer life MLCC capacitors. Hardware and firmware updating to v2.4.
Products Affected: CFA634-NFG-KS, CFA634-TFH-KS, CFA634-TMI-KS, CFA634-YFH-KS, CFA634-YDI-KS, CFA634-NFG-KU, CFA634-TFH-KU, CFA634-TMI-KU, CFA634-YFH-KU, CFA634-YDI-KU Date Issued: February 1, 2011 Summary: Minor PCB revision to accommodate longer life MLCC capacitors. Hardware and firmware updating to v2.4. Last revision: Hardware v2.3, Firmware v2.3 Description: In a continuation of product improvement the CFA634 series has the following improvements:
- PCB changes to accommodate MLCC capacitors. This hardware revision to v2.4 impacts C7, C3, and C4.
- The firmware will be updated to v2.4 to reflect the new hardware version. No other changes to the firmware are being made.
Minor PCB revision to v2.4 to accommodate longer life MLCC capacitors. Firmware will be updated to v2.4 reflect hardware version.Reason: Manufacturing improvements allow for building the CFA634 series with MLCC capacitors. The MLCC have a longer life than the electrolytic capacitors currently being used. Impact: The new version is designed to be Fit, Form, and Function compatible with previous versions of the CFA634 series.
Please see the v2.3 PCN for physical differences from older versions:
https://www.crystalfontz.com/products/pcn.phtml?id=10308Recommendation: Engineering samples should be available by the end of Quarter 1, 2011. Please send an email to support@crystalfontz.com to work with our engineering and support team to assist you with the migration. Availability: Volume availability Second Quarter 2011. Price Change: No price change at this time - text_snippet
Part Change Notice #10308: Update CFA634 series to firmware v2.3 and wide temperature LCD.
Products Affected: CFA634-YMC-KS, CFA634-NFA-KS, CFA634-TFB-KS, CFA634-TMC-KS, CFA634-YFB-KU, CFA634-YMC-KU, CFA634-NFA-KU, CFA634-TFB-KU, CFA634-TMC-KU, CFA634-NFG-KS, CFA634-TFH-KS, CFA634-TMI-KS, CFA634-YFH-KS, CFA634-YDI-KS, CFA634-NFG-KU, CFA634-TFH-KU, CFA634-TMI-KU, CFA634-YFH-KU, CFA634-YDI-KU Date Issued: January 10, 2011 Summary: Update CFA634 series to firmware v2.3 and wide temperature LCD. Last revision: Hardware v2.3, Firmware v2.0 Description: In a continuation of product improvement the CFA634 series has the following improvements:
- Wide temperature support with -20°C to +70°C operation / -30°C to +80°C storage
- The bezel changed from black painted metal to stainless steel. Stainless steel has lower environmental impact and improves ESD protection. If your design has the bezel exposed, it will show the silver color of the stainless steel rather than the previous painted black bezel.
- The previous CFA634-YMC-KS and CFA634-YMC-KU (new CFA634-YDI-KS and CFA634-YDI-KU) changed from STN to double negative (FFSTN) LCD for improved appearance.
- Firmware revision to match hardware revision and is now displayed on the boot screen
Reason: Improvements in design allow for better manufacturing, ESD protection, and appearance. Impact: The new version is designed to be Fit, Form, and Function compatible with previous versions of the CFA634 series. Semi-Custom and Defined Parts will have updated part numbers. Recommendation: Engineering samples should be available by the end of Quarter 1, 2011. Please send an email to support@crystalfontz.com to work with our engineering and support team to assist you with the migration. Availability: Volume availability Second Quarter 2011. Price Change: No price change at this time Attachment: 634_Wide_Temp_PCN.pdf (285KB)
