How we graded 53 Tianma standard parts for engineering cross-reference
A part number is not a specification. When an OEM buyer sends a Tianma standard module code, the first engineering task is to decide whether a RONEN module can be published as an engineering cross-reference, offered only as an engineering candidate, or explicitly recorded with no published match. This article states the checks and the resulting distribution for the 53 Tianma standard parts we evaluated.
Why grades instead of one yes-or-no answer
An original module maker sells a fixed assembly. RONEN builds display modules to the project: capacitive or resistive touch, cover lens, FPC routing and backlight configuration can all be specified. A meaningful cross-reference therefore compares the display cell and the electrical and mechanical envelope rather than promising that two assemblies are interchangeable in every design. Publishing the grade keeps that distinction visible to the buyer and to the engineer who owns the host board.
Touch is the clearest example. Because touch is a selectable option on an ODM/OEM build, a difference in the original touch configuration is recorded as a project choice, not as a reason to reject the module. Connector pin assignment, timing, backlight drive and firmware initialisation are still reviewed per project on every grade.
The checks applied to every part number
Each of the 53 Tianma parts was compared against the 197 modules in the RONEN catalog. The rules below are deterministic; a part either passes a check or the difference is recorded and shown on its own page.
| Check | Rule used in the grading | Why it matters |
|---|---|---|
| Display size | Same nominal diagonal within 0.06 inch | Keeps the module inside the existing mechanical envelope. |
| Resolution | Exact pixel matrix match (for example 800x480) | Avoids host firmware and scaling changes. |
| Active area | Width and height each within 0.35 mm | Protects bezel opening, visible image position and touch alignment. |
| Interface family | Normalised to LVDS, MIPI, RGB or MCU/SPI | The interface name alone never defines the electrical path. |
| Luminance | Relative difference no more than 30 percent | Flags optical differences that need a project-level decision. |
| Panel mode | IPS (including SFT) versus TN; unstated values do not block | Viewing angle and colour behaviour are application dependent. |
| Touch | Project option, not a blocking check | Capacitive, resistive or no touch is specified on the ODM/OEM build. |
The first three checks form the core: size, resolution and active area. A module that misses any of them is not published as a cross-reference. Interface, luminance and panel mode then decide whether the result is a published engineering cross-reference or an engineering candidate with recorded differences.
Result across the 53 standard parts
| Grade published | Parts | What the customer sees |
|---|---|---|
| Published engineering cross-reference | 20 | RONEN module, parameter table and a documented engineering cross-reference. |
| Engineering candidate | 25 | RONEN module plus each published parameter difference; final fit confirmed per project. |
| No published cross-reference | 7 | An explicit no-match statement, nearby catalog modules for evaluation only, and an ODM/OEM review request. |
| Legacy dedicated page | 1 | TM070DDHG03-40 already had its own page before this grading was published. |
All 53 part numbers have their own indexable page. The full Tianma part-number index links every one of them, and the alternative source finder accepts any of these codes directly.
What each grade means in practice
Published engineering cross-reference (20 parts)
The core checks and the interface, luminance and panel-mode checks all pass. Examples: TM043NDH02-40, TM050RDH03-41, TM070JDHG30-00. Each page lists the published parameters of both modules and the checks still required before production.
Engineering candidate (25 parts)
The core checks pass but at least one published parameter differs. Examples: TM024HDHP49-00, TM035KDGP01-00, TM035KDH03-79. The difference is stated item by item, for example luminance, interface family, panel mode or active area, and the page says that final fit is confirmed per project. These parts are never labelled as verified cross-references.
No published cross-reference (7 parts)
TM035KDGP01-02, TM065QDGP03-00, TM070RDHG34-01, TM097TDHG04-66, TM104SDGP01-00, TM104SDGP01-01, TM123XDGP01-00. No RONEN module is forced into a match for these codes. The page explains what is missing, shows the closest catalog modules strictly as evaluation material, and offers an ODM/OEM engineering evaluation with the part number already filled in.
What a published cross-reference does not claim
- It does not claim identical connector pin assignment. Pin mapping, FPC exit direction, contact side and mating connector are verified against the host board per project.
- It does not claim firmware or timing reuse. Pixel clock, sync polarity, lane mapping, initialisation commands and backlight dimming are checked against the host platform.
- It does not assume a fixed backlight drive. LED string arrangement, forward voltage, current and dimming method are reviewed against the existing driver.
- It does not state commercial conditions. Configuration, touch, cover lens and project terms are confirmed in writing for each build.
For the full verification sequence see the LCD replacement compatibility verification checklist. The companion article what to send for a Tianma alternative source evaluation lists the documents that let our engineers close these open items.
FAQ
Does a published cross-reference mean the module can be fitted without any design check?
No. It means the published display parameters were compared side by side and no blocking difference was found. Connector, timing and backlight checks are still performed per project.
Why is touch not part of the pass or fail decision?
Because RONEN builds to the project. Capacitive touch, resistive touch or no touch is specified on the ODM/OEM module, so the original touch configuration is a project choice rather than a blocking parameter.
What if my Tianma part number is not in the 53?
Use the alternative source finder. Any code not in the published list is still accepted as an engineering evaluation request with the part number pre-filled; we compare it against the 197 catalog modules by size, resolution, interface and mechanical envelope.
Request an engineering review
Send the original Tianma part number together with the interface, mechanical envelope and backlight conditions of your design. RONEN engineering compares the published parameters, lists every open item and confirms the recommended module per project before any order is placed.
Contact RONEN engineering → · Search by part number →
This is an engineering cross-reference, not an unconditional interchangeability commitment. Final fit is confirmed per project.