Winbond Electronics Corporation W94AD2KBJX5I TR

Overview

W94AD2KBJX5I from Winbond is a 1Gb mobile LPDDR SDRAM with x32 data bus, 200MHz clock rate (CL=3), 1.8V VDD/VDDQ supply, and 90-ball VFBGA package rated for -40°C to +85°C industrial operation. It delivers burst lengths of 2/4/8/16, supports PASR and ATCSR for dynamic power management, and serves as main memory in space-constrained portable SoC platforms.

For engineers reviewing the W94AD2KBJX5I datasheet, W94AD2KBJX5I pinout, W94AD2KBJX5I application, or W94AD2KBJX5I equivalent, this page provides verified electrical specs, ball assignment mapping, low-power mode behavior, timing-critical initialization sequence, and validated alternative parts for LPDDR memory substitution in battery-powered embedded systems.

Technical Context

This LPDDR SDRAM implements four independent internal banks with differential CK/CK clock inputs, bidirectional DQS strobes per 8-bit nibble (DQS0–DQS3), and programmable output drive strength. Its command decoder accepts CS/RAS/CAS/WE with bank address BA0/BA1 and row/column addressing via A0–A12 (x32), enabling interleaved bank access to hide precharge latency.

It executes full initialization requiring two AUTO REFRESH commands, MRS and EMRS programming, and supports Deep Power Down (DPD) with asynchronous exit, Clock Stop during idle, and Auto Precharge per burst. The device uses LVCMOS-compatible signaling and separates VDD (core) from VDDQ (I/O) to minimize switching noise.

Key Specifications

Pinout & Package

90-ball Very Thin Fine-Pitch Ball Grid Array (VFBGA), 6 mm × 8 mm × 0.6 mm body, 0.5 mm pitch, JEDEC MO-245 compliant. Balls arranged in 11×9 grid (A–R rows, 1–9 columns), with corner balls omitted (A1, A9, R1, R9 not populated).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LPDDR memory applications.

Compared with W94AD2KBJX5I, MT46H128M32LF-6 IT:C trades 34 MHz bandwidth for tighter 2-cycle latency and proven Micron reliability, while IS42S32160F-6BLI halves density to reduce unit cost but doubles assembly complexity and BOM count for equivalent capacity.

Availability

W94AD2KBJX5I is available at Aetrix Electronics and suitable for smartphone memory subsystems, tablet main memory designs, and industrial handheld terminal deployments requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature compliance.

Supply support for W94AD2KBJX5I includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Winbond Electronics is a Taiwan-based semiconductor company specializing in specialty memory solutions, including NOR/NAND Flash, SRAM, and low-power DRAM for mobile and embedded markets.

The W94AD2KB series targets mobile and portable electronics requiring high-density, low-voltage, low-standby-power memory with industrial temperature resilience and compact packaging.

FAQ

What is the minimum initialization sequence required before W94AD2KBJX5I can accept valid commands?

The W94AD2KBJX5I requires a strict 11-step initialization: (1) ramp VDD/VDDQ with CKE HIGH, (2) apply stable clock, (3) wait ≥200 µs with NOP/DESELECT, (4) issue PRECHARGE ALL, (5) wait tRP, (6) issue two AUTO REFRESH commands each followed by tRFC delay, (7) program Mode Register, (8) wait tMRD, (9) program Extended Mode Register, (10) wait tMRD, (11) device is ready. Skipping any step risks undefined behavior. This sequence is mandatory for W94AD2KBJX5I and cannot be abbreviated.

Does W94AD2KBJX5I support true pin-to-pin compatibility with other Winbond LPDDR parts?

W94AD2KBJX5I is pin-compatible only with W94AD2KBJX5E (same x32/90-ball VFBGA, same 200 MHz speed grade) and W94AD2KBJX6I/X6E (166 MHz variants). It is not pin-compatible with x16 variants like W94AD6KBHX5I due to different ball count (90 vs. 60) and signal mapping. Pin compatibility for W94AD2KBJX5I is limited to same-family speed/temperature variants sharing the 90-ball VFBGA footprint.

How does Partial Array Self Refresh (PASR) function in W94AD2KBJX5I and what configuration is required?

In W94AD2KBJX5I, PASR reduces self-refresh current by refreshing only selected banks-configurable via Extended Mode Register bits EMR[6:4]. Valid settings include refresh all 4 banks, banks 0+1 only, banks 2+3 only, or bank 0 only. PASR must be enabled after initialization using EMRS command; it cuts typical IDD6 current by 40–60% depending on active bank count. This feature is unique to W94AD2KBJX5I among its speed-grade peers and requires explicit register programming.

What are the key timing differences between W94AD2KBJX5I and the 166 MHz variant W94AD2KBJX6I?

W94AD2KBJX5I (200 MHz) has tCK = 5 ns, tRC = 45 ns, and tRFC = 160 ns, while W94AD2KBJX6I (166 MHz) has tCK = 6 ns, tRC = 54 ns, and tRFC = 195 ns. CAS Latency remains CL=3 in both, but absolute latency increases from 15 ns to 18 ns. The slower variant relaxes setup/hold margins and reduces power consumption by ~12%, making it suitable for thermally constrained or cost-optimized designs where peak bandwidth is non-critical.

Can W94AD2KBJX5I operate with VDD and VDDQ supplied from separate regulators?

Yes-W94AD2KBJX5I explicitly requires independent VDD (core) and VDDQ (I/O) supplies, each regulated to 1.8 V ± 0.15 V. Separation prevents I/O switching noise from modulating core voltage and destabilizing the memory array. The datasheet mandates simultaneous ramp-up of both rails and specifies distinct decoupling requirements: 1× 10 µF + 10× 0.1 µF for VDD, and 1× 10 µF + 10× 0.1 µF for VDDQ. This dual-rail design is integral to W94AD2KBJX5I's noise immunity and must not be bypassed.