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Home » Products » USB LCD Displays » Character

20x4 Character RS232 LCD Module

Part Number: CFA735-YYK-KT

USB + Full Swing RS-232 20x4 character LCD module with Keypad, Yellow-Green Edge LED Backlight, STN Positive, Yellow-Green, Transflective, -20°C to +70°C, 12:00. Includes CFARS-232 daughter board for Full-Swing serial communications.

LED backlit 20x4 LCD.
Integrated LED backlit 6-button translucent silicon keypad with screened legend.
Four bicolor (red + green) LEDs. The LEDs’ brightness can controlled by the host software, which allows mixing the LEDs to produce other colors (yellow and orange.)
Fully decoded keypad: any key combination is valid and unique.
LCD characters are contiguous in both X and Y directions to allow the host software to display "gapless" bar graphs in horizontal or vertical directions.
Robust packet based communications protocol with 16-bit CRC.
Compact size: fits in a 1U rack mount case (37.5mm overall height.)
ATX power supply control functionality allows the buttons on the CFA735 to replace the "power" and "reset" buttons on your system, simplifying your front panel design (requires additional cables or hardware).
Built-in microcontroller with field-upgradeable firmware.
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.
Open source firmware for CFA735 displays allows you to customize and write/run your own user code.

Did you know?
Our CFA835-YYK is the exact same hardware, with graphic capabilities and direct access to the SD Card at the same low price.

Not sure which character USB display to choose? Compare all of our intelligent display modules.

Currently Shipping: HW Version 1v0, FW Version 0vB

Order soon! We've only got 513 left!

Product Variants

Logic Level Serial/USB

20x4 Character Serial LCD Display

20x4 Character USB Display Module

20x4 Character USB Display

RS232/USB

20x4 Character RS232 Display Module

20x4 Character RS232 Display

20x4 Character RS232 LCD Module

Prices without customizations:
Quantity	Price
1	$80.98

Components worth considering

USB-C to MicroUSB
Need a USB-C to MicroUSB Cable? $5.25 ea.

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Datasheet

CFA735-YYK-KT Datasheet
(Hardware 1v0, Firmware 0vB)

Previous Versions of Datasheets

CFA735-xxx-KT Data Sheet Release Date 2012-02-03.pdf
(Datasheet V 2012-02-03)

CFA735-xxx-KT Data Sheet Release Date 2012-10-12.pdf
(Datasheet V 2012-10-12, Hardware 1v0, Firmware 0vB)

CFA735-xxx-KT Data Sheet 0v9 Preliminary.pdf
(Datasheet V 0v9 Preliminary, Hardware 0v9, Firmware 0v9)

CFA735-xxx-KT Data Sheet Release Date 2012-02-13.pdf

Files

Software Source - Linux - List USB Device Path Script

Software Binary - WHQL CFA735/835 USB Driver

Hardware Design - 3D Model - CFA735/835

1 to 1 Template - CFA735 Family 1:1 Outline Drawing

Other Document - BRKT635 5.25" Half-Height LCD Drive Bay Mounting Bracket

Other Document - Copyrights Acknowledgment for CFA635 Emulation Code

Other Document - Intelligent LCD Comparison

Part Change Notices

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Compliance Documents

TECHNICAL SPECS

Physical Characteristics

Characters x Lines

20 x 4

Module Overall	width	height	depth
millimeters	142	38	34.6
inches	5.591	1.496	1.362
*depth doesn't include Keypad

Diagonal Dimension

3.19"

Viewing Area	width	height
millimeters	83.1	27.54
inches	3.272	1.084

Active Area	width	height
millimeters	77.97	22.38
inches	3.070	0.881

Character Size	width	height
millimeters	3.23	4.88
inches	0.127	0.192

Character Pitch	width	height
millimeters	3.9	5.6
inches	0.154	0.220

Dot Size	width	height
millimeters	0.3	0.33
inches	0.012	0.013

Dot Pitch	width	height
millimeters	0.33	0.35
inches	0.013	0.014

Weight

57g

Keystroke Travel	2.4mm
Keypad Depth	12:00mm

Optical Characteristics

Glass Type/Glass Color	STN/Yellow-Green
Polarizer	Transflective
View Direction	12 o'clock
Sunlight Readable	Yes

Backlight Color	Yellow-Green
Backlight Type	LED
Mode	Positive
Foreground Color	Dark
Background Color	Yellow-Green

Electrical Specifications

Supply Voltage for Logic Maximum

5.5V

Module Connector Pitch

2.54mm

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	0%	90%

Electronics

Interface

RS232, USB

Compatible Products
Dimensions
Product Notices

Part Change Notice

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End-Of-Life #11224: EOL Notification

Products Affected:	CFA735-YYK-KR, CFA735-YYK-KT, CFA835-YYK
Date Issued:	August 30, 2023
Summary:	EOL Notification
Description:	These products are going EOL and will no longer be available once stock runs out.
Reason:	These products are outdated and are being phased out.
Availability:	Contact Crystalfontz Support for up-to-date information by emailing support@crystalfontz.com.
Price Change:	These will be sold at a reduced price until the stock is depleted.

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.

Part Change Notice #10658: Deprecation of "Drive Bay Kit Configurator" / New part numbers for drive bay kits.

Products Affected:	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, 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.

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.

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

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

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.

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.

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:	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. Fix H1 Pins not functioning when used as GPIOs 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.

Product Update #10390: (New Product) CFA735-YYK-KT

New Product:	CFA735-YYK-KT
Date Issued:	January 5, 2012
Summary:	(New Product) CFA735-YYK-KT
Description:	Under Intelligent USB LCD Modules: 20x4 with Keypad, Yellow-Green Edge LED Backlight, STN Positive, Yellow-Green, Transflective, -20°C to +70°C, 12:00

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)

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)