Product

20x4 Character Serial LCD Display

Part Number: CFA735-TFK-KR

Part of the CFA735 family of intelligent display modules, the CFA735-TFK-KR can make a powerful and customizable addition to your product. With an attractive stainless-steel bezel, six-button keypad, GPIOs, LEDs, and memory this module can leverage the command set supported by Crystalfontz to display system status information, receive user input via the keypad, monitor temperatures and control fans using the optional FBSCAB, replace a systems power-on and power-off buttons, and much more. Alternately, write custom firmware for the onboard STM32F401 microcontroller.

Crystalfontz offers a range of intelligent displays. Unsure which display to choose? Compare all of our intelligent display modules.

The CFA735 modules include an STM32F401 microcontroller and use a buck-boost switching supply to allow for a wide supply voltage range which makes these modules perfect for use in embedded systems. The CFA735-TFK-KR supports USB communication as well as Logic Level, inverted serial (0-5v). The two interfaces can be used simultaneously to communicate with two different host systems.

The display on this module is a 20x4 character display with a light background and dark font. For similar module with a graphic display, see the CFA835-TFK. The CFA735 family is designed to fit into a 1U rack mount case. Options for mounting brackets can be seen by clicking "Customize and add to Cart."

Key Features:
  • LED backlit 20x4 character LCD
    • FSTN Positive
    • Transflective
    • 12:00 viewing direction (best from above)
    • White Backlight
    • LCD characters are contiguous in both X and Y directions allowing "gapless" bar graphs
  • Integrated 6-button translucent silicon keypad
    • Screened legend on keys
    • LED backlit (blue)
    • Fully decoded keypad: any key combination is valid and unique
  • Four bicolor (red + green) LEDs
    • LED brightness is software controllable and allows mixing the LEDs to produce intermediary colors (yellow, amber, etc.)
  • USB and Logic Level, Inverted communications
  • Robust packet based communications protocol with 16-bit CRC.
  • Compact size: fits in a 1U rack mount case (37.5mm overall height)
  • Non-volatile memory capability ("EEPROM"):
    • Customize the "power-on" display and LED settings.
    • 16-byte "scratch" register for storing IP, netmask, system serial number
  • Run STM32 embedded applications on the CFA735 hardware using our open source firmware as a starting point
Options available after clicking "Customize and Add to Cart":
  • Cables for connecting to a variety of host systems
  • ATX power supply control functionality allows the buttons on the CFA735 to replace the "power" and "reset" buttons on host system, simplifying front panel design
  • System Cooling Accessory Board (FBSCAB) for controlling fans and reading temperature sensors
  • SLED or drive bay bracket for mounting into a system
Did you know?
Our CFA835-TFK is the exact same hardware, with graphic capabilities and direct access to the SD Card.

Currently Shipping: HW Version 2.0, FW Version 1.3




Add to cart without customizations
Need a written quote? Add to cart, then enter your email address in the "request a quote" box.
Price:
Prices without customizations:
Quantity Unit Price
1 $134.25
10 $129.75
20 $119.59
50 $113.25
100 $105.20
200 $99.10
500 $98.05
1000 $94.50
3462 Units In-Stock & Ready To Ship
Pricing is subject to change.
* Contact us about potential lead times.
Other components worth considering
4807 USB-C to MicroUSB
Need a USB-C to MicroUSB Cable? $5.25 ea.

Additional Resources

Part Change Notices

Subscribe to Part Change Notices by email Email subscription for changes to CFA735-TFK-KR or RSS RSS feed for changes to CFA735-TFK-KR
  • text_snippet
    Part Change Notice #11245: Keypad LED, H1 Header, and Polarizer Change
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT
    Date Issued: October 4, 2023
    Summary: Keypad LED, H1 Header, and Polarizer Change
    Description: The keypad LEDs are changing to an alternative LED, H1 has been changed by the manufacturer, and the FBSCAB header has been changed by the manufacturer. The polarizer is changing due to the manufacturer EOL'ing the existing material. There is no visual difference for the LEDs and polarizer and the headers still function the same.
    Reason: We are switching suppliers to improve the manufacturability of the LEDs. Hirose has changed the family of headers that are used on FBSCAB and H1 to address a packing change they made. The polarizer manufacturer has discontinued this polarizer.
    Availability: Contact Crystalfontz Support for up-to-date information by emailing support@crystalfontz.com.
  • text_snippet
    Product Update #11111: PCN 11097 is now in effect
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA835-TML, CFA835-TFK
    Date Issued: January 17, 2022
    Summary: PCN 11097 is now in effect
    Description: PCN 11097 has been completed and is now in effect. Please refer to PCN 11097 for more information. Please submit any questions to support@crystalfontz.com.
  • text_snippet
    Part Change Notice #11097: Display Controller Change
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA835-TML, CFA835-TFK
    Date Issued: August 4, 2021
    Summary: Display Controller Change
    Description: The display controller, UC1611, is no longer available in the form of bonding on the PCB which is how Crystalfontz has used it for this design. We are designing a drop-in replacement that uses the UC1611 heat seal package, which will continue to be supported, instead of the PCB bonding package.

    This component package change requires us to alter the PCB by moving some components around so that the heat seal tool can be used without causing damage to any components.

    Availability of the current hardware version is very limited due to the ongoing worldwide chip shortage. Contact sales@crystalfontz.com for availability and to stay updated for a more accurate ship date.
    Reason: UC1611 is no longer supported in the PCB bondable package.
    Availability: Fourth-quarter of 2021. If you would like samples when it becomes available, please contact sales@crystalfontz.com.
  • text_snippet
    Part Change Notice #11083: Firmware Update
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA835-TML, CFA835-TFK
    Date Issued: April 27, 2021
    Summary: Firmware Update
    Description: Manufacturing changes for internal process improvements and updating the build instructions so that the serial number is properly returned when using command h01.

    Hardware Version Change: the hardware version is not changing
    Firmware Version Change: the firmware version is not changing
    Reason: The serial number was not being stored properly in the module's bootloader at the time of manufacturing.
    Availability: The update will go into effect in May of 2021.
  • text_snippet
    Part Change Notice #11070: Updating the firmware from v1.0 to v1.2.
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT
    Date Issued: October 29, 2020
    Summary: Updating the firmware from v1.0 to v1.2.
    Description: Both hardware versions v1.3 and v1.7 will be delivered with firmware version v1.2. This update is to resolve some bugs in the firmware. For more information, please contact support.
    Reason: Bug fixes.
    Impact: N/A
    Recommendation: This is a drop-in replacement. Contact sales if samples are needed.
    Availability: Available the first week of November 2020.
    Price Change: No pricing change at this time.
  • text_snippet
    Part Change Notice #11068: Updating the hardware and firmware to accommodate a new LCD controller.
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA835-TML, CFA835-TFK
    Date Issued: October 12, 2020
    Summary: Updating the hardware and firmware to accommodate a new LCD controller.
    Description: These changes are being made to the hardware for both the CFA735TFK and TML variants and 835 TFK and TML variants of displays:
    The hardware and firmware now support the new LCD controller
    The hardware has an improved ADC circuit for GPIO5 and GPIO6

    835 only:
    The firmware has been updated with new features including Live Display, analog to digital interpretation on GPIO5 and GPIO6, closed loop temperature control. The new datasheets will have more information on these changes.
    Reason: The LCD controller went end-of-life and a replacement is needed.
    Impact: This is intended as a drop-in replacement. If the new features listed for the 835 are not wanted, a field upgrade kit that supports the new controller without the new features is available.
    Recommendation: Request samples to validate the new version.
    Availability: Available now.
    Price Change: Price is subject to change.
  • text_snippet
    Part Change Notice #10959: As part of our continuous improvement program, the CFA735 and CFA835 series displays are being revised.
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT, CFA835-TML, CFA835-TFK, CFA835-YYK
    Date Issued: July 12, 2018
    Summary: As part of our continuous improvement program, the CFA735 and CFA835 series displays are being revised.
    Description: Components have been updated to ensure the long-term availability of the modules.

    The LCD glass used has been changed to improve contrast.
    Availability: Samples will be available in November 2018.
    Last time buys of the current design may be made until January 2019.
  • 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
    Product Update #10607: Price change for CFA735 based parts, effective 2014-09-01
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: July 25, 2014
    Summary: Price change for CFA735 based parts, effective 2014-09-01
    Description: All CFA735 based parts will have a price increase effective 2014-09-01.
    All standard parts, build options from website, and Defined Parts based on the CFA735 will have a price increase.
    Reason: Manufacturing and production cost increases.
    Impact: All CFA735 based parts are effected.
    Availability: No changes in availability.
    Price Change: Base part price changes are as follows; pricing for build options will be increase accordingly

    CFA735-TFK-KR
    1 US$89.98
    10 US$83.5
    20 US$78.62
    50 US$73.74
    100 US$68.86
    200 US$63.98
    500 US$51.91
    1000 US$54.22

    CFA735-TML-KR
    1 US$88.88
    10 US$79.58
    20 US$74.92
    50 US$70.28
    100 US$65.62
    200 US$60.98
    500 US$56.32
    1000 US$51.68

    CFA735-YYK-KR
    1 US$89.14
    10 US$79.8
    20 US$75.14
    50 US$70.48
    100 US$65.8
    200 US$61.16
    500 US$56.48
    1000 US$51.82

    CFA735-TFK-KT
    1 US$99.98
    10 US$93.5
    20 US$88.62
    50 US$82.74
    100 US$76.86
    200 US$71.98
    500 US$59.91
    1000 US$62.22

    CFA735-TML-KT
    1 US$98.88
    10 US$89.58
    20 US$84.92
    50 US$79.28
    100 US$73.62
    200 US$68.98
    500 US$64.32
    1000 US$59.68

    Orders placed before price change effective will reflect existing pricing.
    Orders placed after price change effective will reflect new pricing.
  • text_snippet
    Product Update #10429: Hardware version update from 0vA to 1v0.
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: August 23, 2012
    Summary: Hardware version update from 0vA to 1v0.
    Last revision: 0vA
    Description: Manufacturer was changed for the micro-USB connector and microSD card socket.
    Reason: As generally occurs in the process between Pilot and Production Release, product/process improvements were identified and implemented. These improvements in manufacturability are reflected in the product between hardware versions 0vA and 1v0. They do not represent a form, fit or function change.
    Impact: String returned by command 1 (get HW and FW version) will reflect the new hardware version 1v0: "CFA735:h1v0,f0vB" will now be the response when queried using command 1.
    Recommendation: If the end-user application relies on the firmware string response being the same as previous versions, it will need to be changed to accept the new response to command 1.
    Availability: As product becomes available, estimated completion by Q2 2013.
    Price Change: N/A
  • text_snippet
    Part Change Notice #10404: WHQL Drivers for CFA735 family
    Products Affected: CFA735-TFK-KR, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: March 13, 2012
    Summary: WHQL Drivers for CFA735 family
    Last revision: 1.0.0.0
    Description: USB drivers for the CFA735 are now WHQL certified
    Availability: Immediate
    Price Change: N / A
  • text_snippet
    Part Change Notice #10401: CFA735 family firmware 0vB
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: February 3, 2012
    Summary: CFA735 family firmware 0vB
    Last revision: 0vA
    Description: As part of our continuous improvement process, a new version of the CFA735 firmware is being released to address possible functional and performance issues.
    Reason: Corrects the RAM Layout for the STM32F103RC microcontroller.
    Impact: Low.
    Recommendation: We are recommending that all CFA735 modules be updated to 0vB firmware as soon as possible.

    NOTE: 0vB firmware requires 0vA hardware. See PCN 10400.
    Availability: CFA735 modules shipped from Crystalfontz America Inc, on or after 2012-02-06
    Price Change: This firmware update does not effect the pricing of the CFA735 family.
  • text_snippet
    Part Change Notice #10400: CFA735 family hardware 0vA
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: January 31, 2012
    Summary: CFA735 family hardware 0vA
    Last revision: 0v9
    Description: As part of our continuous improvement process, a new version of the CFA735 hardware is being released to address functional and performance issues.

    There is a supporting firmware revision for this hardware release. See PCN 10399.
    Reason: A 1MΩ 0603 resistor has been added at RC2 in support of fixing and extraneous byte received by the host when using the serial interface after a module reset. There is additional support for this fix in firmware 0vA.
    Impact: All CFA735 family modules are affected with this hardware update.
    Recommendation: All CFA735 modules that use the serial interface or GPIO lines should update to the new 0vA hardware and supporting firmware.

    If you require assistance loading the 0603 1MΩ resistor in RC2, please contact support@crystalfontz.com.
    Availability: Hardware 0vA and supporting firmware is shipping as standard release as of 2012/01/30.
    Price Change: No price change.
  • text_snippet
    Part Change Notice #10399: CFA735 family firmware 0vA
    Products Affected: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: January 31, 2012
    Summary: CFA735 family firmware 0vA
    Last revision: 0v9
    Description: As part of our continuous improvement process, a new version of the CFA735 firmware is being released to address functional and performance issues.

    There is a supporting hardware revision for this firmware release. See PCN 10400.
    Reason:

    1. Correct Command 0x9 Data[0] to only accept 0-7 as the index for the custom characters. In 0v9 0-15 were valid but 8-15 were references to 0-7 respectively.

    2. Fix H1 Pins not functioning when used as GPIOs

    3. Fix extraneous byte received by the host when using the serial interface after a module reset. For this fix to be fully effective the module requires a 1 MΩ 0603 resistor at RC2 (which is standard in the 0vA hardware).

    Impact: All CFA735 family modules are affected with this firmware update.


    Firmware version 0vA requires supporting hardware version 0vA.
    Recommendation: All CFA735 modules that use the serial interface or GPIO lines should update to the new 0vA firmware and supporting hardware.

    If you require assistance loading the 0603 1MΩ resistor in RC2, please contact support@crystalfontz.com.
    Availability: Firmware 0vA and supporting hardware is shipping as standard release as of 2012/01/30.
    Price Change: No price change.
  • text_snippet
    Product Update #10378: (New Product) CFA735-TFK-KR
    New Product: CFA735-TFK-KR
    Date Issued: January 5, 2012
    Summary: (New Product) CFA735-TFK-KR
    Description: Under Intelligent USB LCD Modules: 20x4 with Keypad, White Edge LED Backlight, FSTN Positive, Transflective, -20°C to +70°C, 12:00.
  • text_snippet
    Product Update #10377: CFA635 to CFA735 Migration
    Products Affected: CFA635-YYE-KS, CFA635-TMF-KS, CFA635-TFE-KS, CFA635-TMF-KL, CFA635-TFE-KL, CFA635-TFE-KU, CFA635-YYE-KL, CFA635-TMF-KU, CFA635-YYE-KU, CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: January 3, 2012
    Summary: CFA635 to CFA735 Migration
    Description: Detailed in formation on migrating from the CFA635 family to the CFA735 family of intelligent modules. The document covers the similarities and differences between the two family of modules.
    Reason: Support for the CFA735 product announcement.
    Recommendation: All CFA635 users should download and read the document.
    Availability: Q1 2012 – Initial run of CFA735 family available. Limited Quantities.

    Q2 2012 – Production level shipments of CFA735 family.

    Q3 2012 - CFA735 fully replaces CFA635.
    Attachment: CFA735_Migration_doc.pdf (734KB)
  • text_snippet
    Product Update #10376: Announcing CFA735 family of intelligent LCD modules with CFA635 emulation.
    New Products: CFA735-TFK-KR, CFA735-TFK-KT, CFA735-TML-KR, CFA735-TML-KT, CFA735-YYK-KR, CFA735-YYK-KT
    Date Issued: January 3, 2012
    Summary: Announcing CFA735 family of intelligent LCD modules with CFA635 emulation.
    Description: Crystalfontz America Inc. is proud to announce the release of the CFA735 family of intelligent modules. The CFA735 family represents the first of a new generation of our serial and USB interface modules as part of our continuous improvement process. Designed as an easy replacement for the CFA635 family of modules, the CFA735 family is a significant improvement in capability, capacity, flexibility and usability.

    The CFA735 family in CFA635 Emulation Mode has native support for simultaneous USB and Serial operation. There is an option to order the CFA735 with the CFA-RS-232-01 level inverter for full-swing RS-232 interfaces.

    The CFA735 family is available as a bare module, with your choice of internal / external USB cable, or with a serial cable kit (power, internal, and external connectivity).

    Reason: The CFA735 in CFA635 emulation mode is being released as a replacement for the CFA635 family of modules. The CFA635 family of modules has reached it's EOL.
    Impact: Customers migrating from the CFA635 family should place orders for engineering samples, and qualify as required by established procedures.
    Availability: The first run of the CFA735 family is available for immediate shipment in limited quantities.

    The initial release of the CFA735 family is CFA635 Emulation Mode. Our goal was to allow our customers that have integrated the CFA635 into their systems the ability to migrate to the CFA735 in CFA635 Emulation Mode with the least amount of interruption.

    Q1 2012 – Initial run of CFA735 family available. Limited Quantities.

    Q2 2012 – Production level shipments of CFA735 family.

    Q3 2012 - CFA735 fully replaces CFA635.
    Price Change: Please see the individual product pages for current pricing.
    Attachment: CFA735_Product_Announcement.pdf (2MB)
Part Change Notices

Subscribe to Part Change Notices by
email Email subscription for changes to CFA735-TFK-KR or RSS RSS feed for changes to CFA735-TFK-KR for CFA735-TFK-KR

Help Us Improve Our Product Offerings?