Technical review: October 19, 2026.
MT41K256M16TW-107:P is a Micron 4Gb DDR3L SDRAM component, organized as 256 Meg × 16. It supplies external working memory for a suitable processor or FPGA memory controller. Selecting it requires agreement between the exact ordering code, controller configuration, board layout and operating conditions. This reference covers identification, specification interpretation, pinout checks and replacement review.
Identify the complete ordering code
The Micron part page for MT41K256M16TW-107:P identifies the exact device. The TW package is a 96-ball FBGA with an 8 × 14 mm body; Micron's catalog labels it TFBGA. In the manufacturer's ordering diagram, :P identifies the device revision. Preserve the colon and revision in the BOM and quotation request.
This ordering string has the commercial temperature selection: 0 to +95°C case temperature, TC. The industrial selection uses an IT designation. The unsuffixed temperature selection does not inherit a −40°C lower limit from another family entry. When reviewing a quotation, check the entire order code rather than matching only the density and package prefix.
Read the speed rating in the correct units
| Characteristic | Verified selection |
|---|---|
| Density and organization | 4Gb; 256 Meg × 16 |
| Nominal supply | 1.35 V DDR3L |
| Speed selection | −107: DDR3-1866, CL13 |
| Clock and transfers | Approximately 933 MHz; 1866 MT/s |
| Clock period | Approximately 1.07 ns for this speed selection |
| Package | 96-ball TW, 8 × 14 mm |
| Temperature selection | Commercial; 0 to +95°C TC |
Clock frequency and transfer rate describe different quantities. For a theoretical x16 transfer calculation, 1866 million transfers per second × 16 bits ÷ 8 gives 3.732 GB/s in decimal units. This assumes uninterrupted payload transfers on the full bus. Refresh, commands, direction changes and controller scheduling reduce usable bandwidth. The result is calculated, not a measured system performance figure.
Similarly, 4Gb corresponds to 512 MiB of raw storage. It does not mean a 4GB memory device. Keep capacity units explicit when converting a system memory requirement into device quantities.
Check supply and temperature conditions together
Micron specifies nominal 1.35 V DDR3L operation, with a headline VDD/VDDQ range of 1.283–1.45 V. Apply the accompanying conditions: Table 23 on page 47 of the linked datasheet limits the long-term DC average to 1.425 V and requires the supplies to track, with VDDQ no higher than VDD. The headline maximum is not a standalone regulator target. The documentation also supports 1.5 V compatibility subject to the applicable DDR3 specifications. Review the controller, PHY, references and timing mode before changing the supply configuration.
Case temperature is distinct from the temperature of the air around the board and from die junction temperature. Define where and under what workload the case condition will be assessed. An enclosure may be within its ambient target while the package is hotter, so a component temperature selection alone cannot establish an enclosure rating.
The upper temperature range also changes refresh requirements. Above +85°C and up to +95°C case temperature, the datasheet requires twice the external refresh rate, reducing the refresh window from 64 ms to 32 ms. Its extended-temperature guidance also requires appropriate SRT or ASR settings during self refresh. Include both active-operation and self-refresh behavior in the controller review; see page 30 and the extended-temperature discussion on page 184.
A useful power estimate needs the operating voltage, transfer activity, idle behavior and termination settings. Compare equivalent workloads instead of assuming a fixed percentage saving from the voltage label, then check the selected board under its intended conditions.
Use the x16 ball map and the TW drawing
The Micron 4Gb DDR3L datasheet, 2016 revision, provides the x16 ball map in Figure 7 on page 17, ball descriptions in Table 4 on pages 20–21, and the TW drawing in Figure 13 on page 27. This accessible copy is hosted by Texas Instruments. Use the TW drawing when checking a footprint; other 96-ball package codes in the document have different body dimensions.
Review the data bus and its byte strobes, address and bank-address inputs, clock pair, command/control pins, power, references and calibration connection. Check the top-view convention and ball-A1 orientation before comparing a symbol with a footprint. Read the function assigned to each ball, including address pins with command-dependent functions.
Create a worksheet linking each memory signal to the controller pin, byte group, power domain and schematic net. Include unused and no-connect positions explicitly. Pin-count agreement alone cannot detect an orientation error, incorrect byte assignment or an unsuitable footprint library entry.
Confirm the controller and initialization plan
A system using an FPGA needs a suitable DDR3L controller and PHY implementation, along with supported I/O resources and board timing. The memory component supplies storage; it does not supply the host-side controller. Confirm the target FPGA's support for the proposed width and rate before committing the schematic.
Record the selected timing set, mode-register settings, initialization sequence, refresh behavior and reset handling. A speed label is not a substitute for those settings. If an existing controller configuration was built for another memory, compare it against this exact part before reuse.
For validation, separate capacity checks from interface-margin checks. A simple memory test can find obvious faults, but it does not demonstrate adequate timing margin across every operating condition. Plan tests that exercise sustained traffic, changing data patterns, reset recovery and the intended temperature range.
Review layout as part of the memory interface
Use the controller vendor's routing requirements alongside the memory documentation. Determine topology, impedance and skew budgets for the actual stackup. A universal trace-impedance value or a single length-matching rule cannot define the complete interface.
Check power distribution, reference routing, termination and decoupling together with signal escape. Ask the fabricator and assembler to confirm their capabilities against the selected footprint and process. Component values and via placement should follow the board's electrical and assembly review, not a generic capacitor list.
Evaluate replacements without assuming equivalence
Treat another 4Gb x16 DDR3L part as a candidate for review. Compare the complete ball map, package drawing, operating voltage, temperature selection, timing tables, refresh requirements and controller initialization. A shared JEDEC memory type or nominal transfer rate does not establish a drop-in replacement.
Keep a written comparison against the original BOM and record the engineering disposition. Where a controller setting or board change is needed, identify it before procurement approves the substitution. Do not carry over an industrial rating, certification or lifecycle assumption from a differently suffixed part.
Prepare a precise purchase request
Specify MT41K256M16TW-107:P, quantity, accepted shipping format, required delivery date and lot documentation. Ask the supplier to confirm the actual offered ordering code and applicable manufacturer notices. Catalog status does not establish current inventory, shipment condition or a delivery commitment.
The linked Micron catalog is the reference for current part identification. The linked 2016 datasheet explains the ordering structure and technical details; its revision date is not the device's launch date or an offered lot's manufacture date. Obtain applicable current documentation for a production design and retain the reviewed revision with the engineering release.