Guia completo do IS46TR16256A-125KBLA2: Especificações, pinagem, design-in e alternativas do SDRAM DDR3 de 4Gb

The IS46TR16256A-125KBLA2 is a 4Gb DDR3 SDRAM from ISSI (Integrated Silicon Solution Inc), organized as 256M x 16 and delivering a 1600 MT/s data rate at an 800 MHz clock from a 1.5V supply. It comes in a surface-mount 96-ball TWBGA package measuring 9x13 mm, provides 8 internal banks, a 20 ns tRCD, and 290 mA operating current, and is rated for 0°C to +95°C (Tc). The part is RoHS compliant, carries an active lifecycle status, and is in stock at XAIPART with 99,999 units available, MOQ 1, priced from $7.20 per unit at 1,000 pieces as of 2026-09-11. This pillar guide answers the most common buyer and engineer questions, walks through design-in best practices, compares drop-in alternatives, and explains supply and market positioning.

What Are the Quick Answers Engineers and Buyers Need About the IS46TR16256A-125KBLA2?

The IS46TR16256A-125KBLA2 is ISSI's high-density DDR3 DRAM for embedded processors, networking equipment, industrial PCs, telecom infrastructure, video processing, and data acquisition systems. Its headline specifications are a 4 Gbit density in 256M x 16 organization, a 1600 MT/s data rate (800 MHz clock), 1.5V nominal supply with 1.35V low-voltage backward compatibility, and a 96-TWBGA (9x13 mm) surface-mount package. Key timing and power figures include a 20 ns RAS-to-CAS delay (tRCD) and 290 mA operating current. The device uses a parallel interface with programmable CAS latency, burst length, and on-die termination (ODT) for signal integrity, plus a DLL for precise clock alignment and auto-refresh and self-refresh modes for power management. Per device peak bandwidth is 12.8 GB/s. The part is RoHS compliant, lifecycle status is active, and XAIPART lists 99,999 units in stock with an MOQ of 1 as of 2026-09-11.

How Do You Select and Design In the IS46TR16256A-125KBLA2?

Designing in this DDR3 SDRAM requires attention to power, timing, layout, and configuration. Follow these steps.

1. Confirm power architecture. The device requires 1.5V for both VDD and VDDQ, plus a separate VREF reference for address/command signals. Per the verified pinout, VDD appears on balls A1 and P3, VSS on B1, VDDQ on C1, VSSQ on D1, and VREF on E1. Budget at least 290 mA of operating current per device and follow JEDEC DDR3 guidelines for power supply decoupling [VERIFY_NEEDED: exact decoupling capacitor recommendation from JEDEC DDR3 guidelines]. If your rail is 1.35V, the part supports low-voltage operation at 1.35V while remaining backward compatible, giving flexibility in power-sensitive designs.

2. Verify timing closure against your memory controller. The verified tRCD is 20 ns. Program the controller for a data rate of 1600 MT/s at an 800 MHz clock, and use the device's programmable CAS latency, burst length, read latency, and write latency settings to match your controller. Detailed tRCD-derived cycle counts at your exact controller clock [DATA_NEEDED: full AC timing table including tRAS, tRP, tRC, CL values].

3. Plan the signal-integrity strategy. The device includes on-die termination (ODT) to improve signal quality on high-speed buses; enable controller-managed ODT on the data lines. Route address/command as a controlled-impedance group referenced to VREF, and keep fly-by or balanced topologies consistent with DDR3 layout practice [VERIFY_NEEDED: recommended routing topology and impedance values for this specific module].

4. Use the 16-bit organization to your advantage. The 256M x 16 organization simplifies bus design by reducing the number of devices needed for wide data paths. A single device gives a 16-bit data path and 12.8 GB/s peak bandwidth; two devices in parallel give 32 bits and 25.6 GB/s.

5. Manage reset and clocks. Per the verified pinout, the differential clock pair is CK (N3, positive) and CK# (P1, negative), CKE (N1) gates the clock, RESET# (P2) resets the device, and CS# (M3), RAS# (L3), CAS# (M1), and WE# (M2) form the command interface. A10/AP (H3) doubles as the auto-precharge control.

6. Account for thermal and environmental limits. The rated operating range is 0°C to +95°C (Tc). This covers commercial and typical industrial environments but does not extend to extended-temperature automotive or outdoor ranges; confirm your case temperature budget before finalizing the thermal design.

What Key Pins Should You Know When Working With the IS46TR16256A-125KBLA2?

The full ball-map for the 96-ball TWBGA lives on the IS46TR16256A-125KBLA2 product page and in the official ISSI datasheet. Functionally, the critical balls are the power group (VDD on A1/P3, VSS on B1, VDDQ on C1, VSSQ on D1, VREF on E1), the differential clock CK/CK# on N3/P1, the control strobes RAS#/CAS#/WE#/CS# on L3/M1/M2/M3, CKE on N1, ODT on N2, RESET# on P2, the bank-select pins BA0–BA2 on K3/L1/L2, and the address pins A0–A15 with A10/AP on H3 serving auto-precharge. The DQ0–DQ7 data bits occupy A2, A3, B2, B3, C2, C3, D2, and D3, with DQ8–DQ15 on the remaining balls per the datasheet ball diagram.

Which Alternatives Can Drop In for the IS46TR16256A-125KBLA2?

Per ISSI's product family and verified FAQ data, the closest drop-in replacement is the IS46TR16256B-125KBLA2, a newer revision with the same package and pinout and potentially improved timing or features. Pin-compatible cross-brand options named in verified data include Micron's MT41K256M16HA-125:E and Samsung's K4B4G1646D-BYK0, both 4Gb DDR3 in the same 96-TWBGA footprint. ISSI's IS43TR16256AL-125KBL and IS43TR16256AL-107MBLI are also listed as pin-compatible alternatives. Note that the IS46TR16256BL-125KBLA2 DDR3L variant (1.35V native) can also replace the A-version in 1.5V systems thanks to backward compatibility.

Detailed electrical specifications for each alternative [DATA_NEEDED: full product_specs for IS46TR16256B-125KBLA2, IS43TR16256AL-125KBL, IS43TR16256AL-107MBLI, MT41K256M16HA-125:E, K4B4G1646D-BYK0, IS46TR16256BL-125KBLA2]. The table below lists only what verified data confirms:

Selection guidance from verified FAQ data: choose the B-version for the latest revision improvements; choose the BL DDR3L variant if your system is power-sensitive or needs native 1.35V operation; choose the A-version for standard 1.5V DDR3 designs where its active status and deep stock at XAIPART (99,999 units as of 2026-09-11) simplify sourcing.

What Is the Market Position, Lifecycle, and Supply Situation for the IS46TR16256A-125KBLA2?

Lifecycle status is active per the verified product database, and the part is RoHS compliant for lead-free manufacturing. On the supply side, XAIPART lists 99,999 units in stock with MOQ 1 and pricing of $12.50 (qty ≥1), $11.20 (qty ≥10), $9.80 (qty ≥100), $8.50 (qty ≥500), and $7.20 (qty ≥1,000) as of 2026-09-11. Verified FAQ data also notes availability from major distributors such as DigiKey and Mouser, with lead times typically 2–4 weeks depending on stock. Broader market-share, demand-forecast, and DDR3 end-of-life roadmap data [DATA_NEEDED: industry market analysis and DDR3 EOL roadmap].

What Trends Should Buyers Watch, Anchored to Verified Specs?

Three points matter for procurement and design teams. First, density and bandwidth economics: at 4Gb per device and 12.8 GB/s peak bandwidth per 16-bit device, the IS46TR16256A-125KBLA2 lets a single package serve frame-buffer and packet-buffer roles that previously needed multiple lower-density parts, cutting BOM count. Second, voltage flexibility is increasingly valuable: because the part supports both 1.5V and 1.35V operation with backward compatibility, designs can migrate toward DDR3L power levels without a redesign, or accept either the standard or BL variant on the same footprint. Third, supply continuity: with lifecycle status active and 99,999 units on hand at XAIPART as of 2026-09-11, near-term sourcing risk is low, but buyers building long-lifetime industrial and networking systems should qualify the pin-compatible IS46TR16256B-125KBLA2 second source now. Price per unit drops from $12.50 at single units to $7.20 at 1,000+ pieces as of 2026-09-11, so consolidating orders into the 500–1,000+ tiers yields 32–42% savings.

Key Takeaways

The IS46TR16256A-125KBLA2 delivers 4Gb DDR3 density in a compact 96-TWBGA (9x13 mm) with 1600 MT/s performance, dual 1.5V/1.35V voltage support, and active lifecycle status. Verify your controller timing against the 20 ns tRCD, budget 290 mA per device, and use ODT plus proper VREF decoupling for signal integrity. The B-revision is the natural drop-in successor, and DDR3L BL and cross-brand 96-TWBGA parts give voltage and sourcing options. With deep stock and tiered pricing from $12.50 down to $7.20 as of 2026-09-11, this is a well-supplied part for embedded, networking, industrial, telecom, video, and data-acquisition designs.