An engineering guide for OEM designers integrating a full-color graphical display into industrial control panels, measurement equipment, and process instrumentation. Covers HMI color UI design, SSD2119 interface options, single-supply power architecture, wide operating temperature, integration path selection, and long-term part lifecycle management under IEC 61010 conditions.
Section 01 — Scope and Background
When a Graphic LCD Is No Longer Enough: The Case for Color TFT in Industrial Panels
Monochrome graphic LCD modules have served industrial control panels reliably for decades. For instruments that display a handful of numeric readings and a status indicator, they remain an excellent choice. But a growing class of industrial equipment demands more: multi-zone dashboards with alarm color coding, trend graphs, equipment state diagrams, and operator guidance that uses iconography rather than abbreviations. These requirements outpace what a 128×64 monochrome display can deliver, regardless of firmware cleverness.
The Crystalfontz CFAF320240F-035T is a 3.5-inch, 320×240 pixel, full-color TFT LCD module designed for exactly this transition point. It brings 65,536-color graphical capability, a flexible multi-interface controller, single-supply 3.3 V operation, and the same −20°C to +70°C industrial operating range that OEM engineers require for IEC 61010-class equipment. It is available as a bare module for direct PCB integration, pre-assembled on a carrier board for faster prototyping, or paired with an EVE accelerator for full GPU-offloaded UI development.
This application note is written for OEM hardware and firmware engineers evaluating the CFAF320240F-035T family for a new design or a display upgrade in an existing industrial product.
| Scope This note covers the CFAF320240F-035T bare module, the CFAF320240F-035T-CB carrier board kit, and the CFAF320240F-035T-A1-1 EVE accelerator board. It addresses IEC 61010-1 equipment environments and does not constitute a formal conformance assessment. Use alongside the relevant standard and your certification body. |
Section 02 — Color HMI in Industrial Equipment
What Color Adds to Industrial Control Panel Design
Color in an industrial HMI is not decoration. It is a functional communication channel that reduces operator response time, decreases misreads under stress, and allows a single display to carry information that would otherwise require multiple indicators, LEDs, or sub-displays.
Alarm State Visualization
ISO 11064 and IEC 60073 both address color coding conventions for industrial control systems. Green for normal, amber for caution, red for fault is a deeply established operator convention. A monochrome display can approximate this with text labels, but a color TFT implements it natively: a process value field turns red when it crosses a setpoint, without any additional indicator hardware. The CFAF320240F-035T’s 65K-color depth is well in excess of what alarm color coding requires, with headroom for UI polish that matters in competitive differentiation.
Trend and Waveform Display
Process controllers, data loggers, and analyzers often need to show trend data alongside current readings. At 320×240 pixels, the CFAF320240F-035T provides enough horizontal resolution for a meaningful time-window trend graph while leaving room for a sidebar of numeric values. A monochrome module at 128×64 renders the same content at the level of a postage stamp.
Multi-Zone Dashboards
A 3.5-inch color TFT supports layout patterns that are impossible on smaller monochrome displays: a header zone with equipment ID and timestamp, a primary measurement zone, a secondary readings zone, and a status/alarm zone, all simultaneously visible. The 6:00 o’clock viewing direction of the CFAF320240F-035T is matched to panel-mount instruments viewed from a standing position slightly above center, which is the dominant use case in process control and laboratory instrumentation.
Portrait and Landscape Flexibility
The CFAF320240F-035T can be used in either portrait (240×320) or landscape (320×240) orientation. Portrait orientation suits narrow rack-mount or DIN-rail instruments where vertical space is available. Landscape suits wide panel cutouts and handheld devices. The SSD2119 controller supports both orientations in hardware via address counter direction registers, requiring no rotation math in firmware.
Section 03 — Module Specifications
CFAF320240F-035T: Key Specifications for Industrial Design
| ● CFAF320240F-035T — Physical and Optical Specifications | |
| Resolution | 320 × 240 pixels (QVGA) |
| Diagonal | 3.5" (3.45" diagonal module) |
| Active area (W × H) | 70.08 × 52.56 mm (2.76" × 2.07") |
| Module overall (W × H × D) | 77.6 × 64.4 × 3.1 mm |
| Colors | 65,536 (16-bit / RGB565) to 262,144 (18-bit / RGB666) |
| Dot pitch (W × H) | 0.22 × 0.22 mm |
| View direction | 6:00 o’clock — portrait and landscape both supported |
| Backlight | White LED, transmissive |
| Connector | 50-pin FFC/FPC, 0.5 mm pitch — mates with standard ZIF sockets |
| Weight | 113 g (with carrier board) |
| ● CFAF320240F-035T — Electrical and Environmental Specifications | |
| Supply voltage | 3.3 V single supply — powers both logic and panel |
| Panel voltage | Built-in DC-DC converter — no external boost required |
| Logic voltage | 3.3 V — direct connection to 3.3 V MCU GPIO |
| Controller | Solomon Systech SSD2119 or compatible |
| Operating temp. | −20°C to +70°C |
| Storage temp. | −30°C to +80°C |
| Humidity (operating) | 0–90% non-condensing |
Section 04 — Standards Environment
IEC 61010 Considerations for a Color TFT Module
Single 3.3 V Supply: Simplifying the Safety File
Many TFT modules require a separate higher-voltage supply for the LCD panel bias, creating a second power rail that must be assessed for clearance, creepage, and isolation in the IEC 61010-1 technical file. The CFAF320240F-035T eliminates this complexity. The SSD2119 includes an integrated DC-DC converter that generates the panel bias voltage internally from the 3.3 V rail. Your power design presents a single low-voltage supply to the display; there is no exposed high-voltage node on the module connector.
Thermal Derating in Sealed Enclosures
The CFAF320240F-035T is rated −20°C to +70°C. TFT backlights dissipate more power than monochrome LED backlights, and the SSD2119 frame buffer adds a small but non-zero thermal load. Apply the same thermal budget discipline described for any industrial display: ambient max plus expected internal enclosure rise plus PCB self-heating must remain below the module rating with a 10°C margin. Backlight PWM dimming is particularly effective on TFT modules for managing both power dissipation and extended backlight lifetime in always-on panel applications.
EMI Considerations for Parallel and RGB Interfaces
The SSD2119 supports parallel bus interfaces (8/9/16/18-bit) and a DOTCLK RGB interface. The parallel bus interface has a similar EMI profile to the CFAG12864B’s parallel bus: relatively benign, well-understood by EMC test labs, and easy to lay out with standard ground plane techniques. The DOTCLK/RGB interface runs at a higher clock rate and requires more layout discipline — shorter traces, controlled impedance on the clock line, and a solid ground plane under the FFC cable run. For the tightest IEC 61326 immunity margins, the parallel bus interface is the lower-risk choice. SPI is also available for microcontrollers with limited GPIO, at the cost of frame-rate throughput.
Section 05 — Interface Selection
Choosing the Right Interface for Your MCU or SoC
The SSD2119 controller on the CFAF320240F-035T supports more interface modes than almost any other display controller in this class. That flexibility is a genuine engineering advantage: you select the interface that fits your processor bus architecture rather than redesigning around the display’s constraints.
| Interface | GPIO Required | Throughput | Best Fit | EMI Risk |
|---|---|---|---|---|
| 16-bit parallel (8080) | ~22 pins | High | ARM MCU with FSMC/FMC bus, FPGA | Low |
| 8-bit parallel (8080) | ~14 pins | Moderate | 8-bit MCU, cost-optimized designs | Low |
| 18-bit parallel (8080) | ~26 pins | Highest | Full 262K color, fast redraw | Low |
| DOTCLK / RGB | ~12 pins + clock | High | Linux SoC, i.MX, AM335x with display controller | Moderate — clock trace discipline required |
| 4-wire SPI | 4–5 pins | Low | Low-update-rate status displays, pin-constrained MCU | Very low |
| 3-wire SPI | 3 pins | Low | Minimal pin-count applications | Very low |
Table 1 — SSD2119 interface options available on the CFAF320240F-035T.
Interface Recommendation by Platform
- →STM32 with FSMC/FMC: 16-bit parallel 8080. The FMC peripheral maps directly to the SSD2119 register and GRAM address space — pixel writes become memory writes with no bit-banging overhead.
- →ESP32 / RP2040: 16-bit parallel via GPIO, or SPI for lower-update-rate applications. The ESP32’s LCD_CAM peripheral supports parallel TFT directly in hardware.
- →Linux SoC (i.MX6, AM335x, RK3288): DOTCLK/RGB interface with a framebuffer driver. Most BSPs include SSD2119 panel timing parameters.
- →FPGA: 16-bit or 18-bit parallel. SSD2119 initialization over SPI, then pixel streaming over parallel bus is a common pattern for FPGA-based HMI designs.
- →8-bit AVR / PIC with limited GPIO: SPI interface. Full-screen redraws will be slow (several seconds at maximum SPI clock), but for instruments that update a few fields periodically, SPI is workable and pin-efficient.
Section 06 — Integration Paths
Three Ways to Integrate the CFAF320240F-035T into Your Design
Crystalfontz offers the CFAF320240F-035T in three configurations targeting different stages of development and different levels of design complexity. The right choice depends on your timeline, your firmware team’s experience with TFT integration, and your end-product PCB strategy.
Path 1: Bare Module (CFAF320240F-035T)
The bare module is the appropriate choice for production designs where you are integrating the display directly onto your host PCB. The 50-pin 0.5 mm FFC connector mates with widely available ZIF sockets (Digi-Key HFJ150CT-ND and HFK150CT-ND are direct-fit options). You route the interface bus, provide 3.3 V power and backlight drive, and implement the SSD2119 initialization sequence in your firmware. Sample initialization code in C is available for download from the product page.
| ZIF Connector Note The 50-pin 0.5 mm ZIF socket is a commodity component in production quantities. Verify the ZIF socket’s contact force specification against your FFC assembly process — some low-cost sockets have high insertion force that can stress the FFC tail on the module during automated assembly. Crystalfontz also stocks a 50-pin ZIF breakout board (CFABB-CS050Z50G-B0) for bench validation before committing to a ZIF socket on your production PCB. |
Best for: Production PCB integration, cost-optimized builds, existing host board with available interface bus.
Order: CFAF320240F-035T →
Path 2: Carrier Board Kit (CFAF320240F-035T-CB)
The carrier board kit ships with the CFAF320240F-035T pre-mounted on the CFA-10074 carrier board. The carrier board breaks out the FFC connector to 0.1" headers, includes an LED backlight current driver, and is sized for direct integration into an end product as well as bench prototyping. For teams that want to validate firmware and UI layout before committing to a custom PCB, the carrier board eliminates the FFC routing and backlight driver design from the critical path.
The 0.1" header pitch is compatible with standard jumper wire, breadboard jumpers, and ribbon cable assemblies for connection to virtually any development board. The carrier board can also be incorporated into the final product PCB stack if your mechanical envelope accommodates it, eliminating a custom board spin entirely for low-to-medium volume programs.
Best for: Rapid prototyping, firmware development before custom PCB, medium-volume products where carrier board simplifies assembly.
Order: CFAF320240F-035T-CB →
Path 3: EVE Accelerator Board (CFAF320240F-035T-A1-1)
The EVE accelerator board pairs the CFAF320240F-035T with a Bridgetek EVE (Embedded Video Engine) GPU. Rather than driving pixels directly from your MCU, the EVE board accepts high-level display list commands over SPI — “draw a button at coordinates X, Y with this label and color” — and handles all pixel rendering internally. This approach dramatically reduces MCU load and firmware complexity for rich graphical interfaces, and provides built-in support for smooth animation, gradient fills, anti-aliased fonts, and touch processing.
The EVE path is particularly well-suited to industrial HMI designs with complex, frequently updated UIs — process dashboards, equipment control panels, instrumentation frontends — where the MCU has significant other work to do and cannot dedicate cycles to pixel-level rendering. The SPI interface also simplifies EMC layout compared to a wide parallel bus.
| EVE vs. Direct Drive The EVE accelerator board uses the same CFAF320240F-035T panel but routes it through the Bridgetek BT817 EVE4 GPU. The programming model is completely different from direct SSD2119 access — display lists replace register-and-GRAM writes. If your team has existing SSD2119 firmware, the bare module or carrier board is the faster path to production. If you are starting fresh with a complex UI requirement, EVE’s abstraction layer repays the learning investment quickly. |
Best for: Complex animated UIs, teams new to TFT integration, designs where MCU resources are constrained, rapid UI prototyping with Bridgetek’s EVE Screen Editor tool.
Order: CFAF320240F-035T-A1-1 →
| Attribute | Bare Module | Carrier Board | EVE Board |
|---|---|---|---|
| Integration effort | High | Moderate | Low (SPI + display list) |
| Prototype speed | Slower | Fast | Fast (EVE Screen Editor) |
| Production unit cost | Lowest | Moderate | Higher |
| MCU GPIO required | 14–26 pins (parallel) | 14–26 pins (parallel) | 4 pins (SPI) |
| MCU rendering load | High (pixel-level) | High (pixel-level) | Minimal (display list) |
| Firmware complexity | High | High | Low |
| EMI profile | Moderate (parallel bus) | Moderate (parallel bus) | Low (SPI only) |
Table 2 — Integration path comparison for the CFAF320240F-035T family.
Section 07 — Thermal Performance
Operating Temperature and Thermal Budget
The CFAF320240F-035T shares the −20°C to +70°C industrial operating range with the CFAG12864 monochrome family. The same thermal budget rules apply, with one additional consideration: TFT backlights consume more power than monochrome edge-lit LEDs, and the SSD2119 frame buffer ASIC adds thermal dissipation that a passive monochrome module does not.
| ● CFAF320240F-035T — Temperature Ratings | |
| Operating min | −20°C (−4°F) |
| Operating max | +70°C (+158°F) |
| Storage min | −30°C (−22°F) |
| Storage max | +80°C (+176°F) |
| Humidity (operating) | 0–90% non-condensing |
Backlight Power Management
For sealed IP-rated enclosures, implement backlight PWM dimming as a standard feature rather than an option. Dimming the backlight to 50% in a well-lit factory environment is invisible to the operator and cuts backlight thermal dissipation by half. Most industrial operators prefer slightly dimmer displays in bright ambient environments anyway — the transmissive TFT panel does not have the reflective mode fallback of the CFAG12864B’s transflective polarizer, so ambient light management is handled entirely through backlight level and panel brightness settings.
| Thermal Design Warning The CFAF320240F-035T is a transmissive panel and requires the backlight to be on for any display visibility. Design your power budget for continuous backlight operation. Do not use backlight shutdown as a power-save mode in applications where the display must remain readable. |
Section 08 — Supply Chain and Lifecycle
Long-Term Availability for Industrial Production Programs
The three PCNs issued to date all maintained backward compatibility with existing firmware and mechanical designs. No re-certification was required for any of the changes.
| ● CFAF320240F-035T — Availability and Sourcing Summary | |
| Stocked in USA | Yes — Spokane Valley, WA — check site for current availability |
| Min order quantity | 1 unit |
| Volume pricing breaks | 5 / 10 / 20 / 50 / 100 / 200 / 300 / 500 / 1,000 units |
| Compliance | RoHS compliant |
| PCN subscription | Email and RSS — per part number, no account required |
| PCNs issued to date | 3 — all backward compatible, no re-certification required |
| Quality system | ISO 9001:2015 certified — Spokane Valley, WA |
Section 09 — Design Checklist
Pre-Integration Checklist for Industrial Color TFT Display Selection
Use the following checklist when evaluating the CFAF320240F-035T family for an IEC 61010 design.
- →Integration path selected: Bare module (custom PCB), carrier board (fast prototype or production), or EVE board (complex UI / low MCU load) chosen based on program timeline and firmware resources
- →Interface selected: 16-bit parallel for highest throughput, SPI for pin-constrained MCU, DOTCLK for Linux SoC — confirmed against MCU peripheral availability
- →Power supply: 3.3 V single rail confirmed; no separate panel voltage required; backlight LED current driver included (carrier board) or designed on host PCB (bare module)
- →Initialization register: SSD2119 Power Control 5 register (0x001E) set to 0x00BE for all units post-PCN #10403 — verified in firmware initialization sequence
- →Temperature margin: Worst-case internal enclosure temperature remains at least 10°C below +70°C module max; backlight dimming implemented to reduce thermal load in sealed enclosures
- →Backlight always-on: Transmissive panel requires backlight for any visibility — power budget accounts for continuous backlight operation; no ambient-light readability without backlight
- →EMC layout: FFC cable run kept short and routed over ground plane; parallel bus traces matched in length; DOTCLK line impedance-controlled if RGB interface used
- →Orientation confirmed: Portrait or landscape orientation set in SSD2119 address counter direction registers — verified in firmware before panel cutout finalized
- →PCN subscription: Email or RSS PCN subscription active for CFAF320240F-035T (and -CB / -A1-1 if applicable) before production release
- →Technical file: Module datasheet, SSD2119 datasheet, PCN history (#10403, #10423, #11027), and RoHS certificate included in product technical file for IEC 61010-1 certification
Start Your EvaluationThe CFAF320240F-035T ships from Spokane Valley, WA. Choose the integration path that fits your program timeline. Bare module for custom PCB integration · Carrier board for rapid prototyping · EVE board for GPU-accelerated UI |
Jeffrey Nystrom is an engineering technician at Crystalfontz. He graduated from ITT Technical Institute of Technology with his B.S. in Electronics Engineering. In his position, Jeff engages in customer technical support, works on engineering projects, and supports Crystalfontz’s manufacturing operations. Outside of the office, Jeff enjoys working in his shop, tinkering with his 3D printer, and going on new adventures with his family.