K4A4G165WF-BCTD datasheet: Performance breakdown & key specs
The K4A4G165WF-BCTD datasheet presents timing and electrical tables that list a nominal data rate of 2666 MT/s, a 1.2 V supply window, and a 4 Gb density in a 96-ball FBGA. This combination directly drives system bandwidth, power budgeting, and signal-integrity trade-offs, so designers must convert those numbers into actionable constraints when selecting memory for a target platform.
This analysis converts raw datasheet entries into practical design guidance: how to compute theoretical bandwidth for x16 organization, which DC/AC limits to validate against board rails, and what layout and thermal checks preserve the device’s published behavior under sustained traffic.
K4A4G165WF-BCTD datasheet at a glance
Package, density & organization
Point: The device is a 4 Gb DRAM organized as 256M x 16 in a 96-ball FBGA package. Evidence: the datasheet lists 4 Gb density and 16-bit die organization, implying two ranks of x8 devices per 32-bit ECC module or one x16 die per channel device. Explanation: designers should map die organization to module/channel population when estimating address bus width, rank count, and routing complexity for channel balancing.
Voltage, temperature & absolute max ratings
Point: Nominal core supply is 1.2 V with defined minimum/maximum margins and an operating temperature window. Evidence: the datasheet specifies Vcc = 1.2 V typical and lists absolute limits and operating temperature bounds. Explanation: validate board power rails against the Vcc min/max and ensure decoupling to maintain margin during transients; confirm the device’s operating temperature range is compatible with enclosure thermal assumptions.
Performance benchmarks & throughput characteristics
Effective bandwidth and throughput calculations
Point: Theoretical peak bandwidth at 2666 MT/s for x16 organization is straightforward to compute and sets an upper bound for subsystem throughput. Evidence: using the rate 2666 MT/s and a 16-bit data path yields a known formula. Explanation: use the table below to derive peak numbers and compare them to sustained expectations after accounting for protocol overhead and multi-die/channel arbitration.
| Parameter | Value | Calculation |
|---|---|---|
| Data rate | 2666 MT/s | — |
| Bus width | x16 | 16 bits = 2 bytes |
| Peak bandwidth per device | 5,332 MB/s | 2666 MT/s × 2 bytes |
| Example: two devices per channel | 10,664 MB/s | 5,332 × 2 |
Timing, frequency grades & real-world latency
Point: CAS latency and tRCD/tRP entries determine effective access latency and vary with speed grade. Evidence: timing tables list CL, tRCD, and tRP values for supported frequency/grade combinations. Explanation: multiply CL by clock period to get absolute CAS latency; for microbenchmarks (STREAM-like) report both raw latency and sustained bandwidth to show how timing choices affect real workloads.
Power, thermal behavior & signal integrity considerations
Power consumption breakdown (active vs. standby)
Point: IDD currents in the datasheet translate to milliwatts at the nominal supply and define idle vs. active power. Evidence: the datasheet provides IDD0, IDD1, IDD2 (standby/active/read/write) currents under specified Vcc and temperature. Explanation: compute mW = I (A) × 1.2 V and budget per device, add 20–30% margin for board-level losses, and place decoupling close to Vcc pins to limit transient droop during bursts.
| Mode | Example IDD (mA) | Approx. Power (mW) |
|---|---|---|
| Standby | 50 | 60 (50×1.2) |
| Active read/write | 500 | 600 (500×1.2) |
Thermal & SI implications for 2666 MT/s operation
Point: Sustained high-rate traffic raises die temperature and tightens SI margins, affecting eye height and jitter tolerance. Evidence: the datasheet identifies rated conditions and warns of derating outside specified temperature and supply ranges. Explanation: use thermal pads or local copper pours to dissipate heat, match trace lengths per channel, and reserve margin in the eye diagram by following recommended routing and termination strategies to avoid BER increases at 2666 MT/s.
How to read and validate the K4A4G165WF-BCTD datasheet
Decoding part numbers and speed grades
Point: Part fields encode organization, speed grade, package and temperature options—decode them before BOM freeze. Evidence: the part suffixes and marking correspond to die revision and grade in the datasheet’s ordering information. Explanation: correlate part-mark codes to your BOM spec sheet and confirm the speed-grade letter versus the controller capability to prevent mismatches at assembly.
Interpreting timing tables, AC/DC specs and test conditions
Point: Datasheet values are given under defined Vcc and temperature test conditions and may not represent worst-case in-system results. Evidence: timing and IDD numbers are qualified at specified Vcc and ambient ranges. Explanation: when reporting performance, capture test conditions (Vcc, temp, termination) and avoid extrapolating nominal numbers to different board conditions without validation.
System integration: real-world use cases & design notes
Integrating into a 2666 MT/s memory subsystem
Point: Controller compatibility and channel population directly determine achievable lane throughput per module. Evidence: per-device peak bandwidth at 2666 MT/s sets the theoretical per-DIMM ceiling; controller arbitration and ranks reduce sustained rates. Explanation: use the bandwidth table above to estimate how many devices saturate a controller channel and verify expected lane throughput with targeted microbenchmarks.
PCB layout & power-sequencing notes
Point: Proper placement, decoupling, and power-up sequencing preserve data integrity and meet reset timing. Evidence: the datasheet specifies recommended power sequencing and Vref relationships. Explanation: follow the recommended power-up order, place bulk and high-frequency decoupling close to the package, and match address/command trace lengths to minimize timing skew between devices.
Quick verification checklist & procurement tips
Key specs to verify before selection
Point: A short procurement checklist prevents specification mismatches at procurement and assembly. Evidence: confirm density, organization, speed (MT/s), CAS family, Vcc min/max, operating temp, package ball count and footprint, and ECC compatibility. Explanation: include the K4A4G165WF-BCTD datasheet reference in BOM notes and require matching part-mark and test-condition confirmation from suppliers before acceptance.
Testing & validation steps
Point: Validation should demonstrate both functional correctness and sustained performance under target conditions. Evidence: recommended tests include read/write throughput, sustained bandwidth runs, power measurements under load, eye-diagram SI captures, and thermal soak. Explanation: log expected vs. measured deviations, update BOM acceptance criteria, and iterate hardware changes based on measurable SI or thermal issues rather than nominal datasheet values alone.
Summary
- Peak bandwidth at 2666 MT/s for x16 is 5,332 MB/s per device; designers must account for protocol overhead to get sustained performance.
- Verify Vcc = 1.2 V margins, IDD currents, operating temperature windows and package footprint against board rails and layout constraints.
- Follow routing, termination, and thermal recommendations to protect eye margins and limit jitter at high data rates.
- Use the provided testing checklist to validate read/write throughput, power under load, SI eye diagrams, and thermal soak before BOM approval; always consult the full K4A4G165WF-BCTD datasheet when finalizing selection.
Frequently Asked Questions
How should one calculate theoretical bandwidth for a 2666 MT/s device?
Multiply the transfer rate (MT/s) by bytes per transfer (for x16, 2 bytes). For 2666 MT/s × 2 bytes = 5,332 MB/s peak per device. Subtract protocol and training overhead to estimate realistic sustained throughput and validate with microbenchmarks.
What power-budget margin is recommended based on datasheet IDD values?
Convert IDD currents to power using P = I × Vcc (use 1.2 V). Add a 20–30% margin for board-level losses and transient peaks. Ensure decoupling near the package and verify rail regulation under worst-case simultaneous switching to avoid undervoltage events.
Which layout checks most impact signal integrity at 2666 MT/s?
Match trace lengths within specified skew, maintain controlled impedance, use proper termination, and separate address/command routing from data lanes to reduce crosstalk. Capture eye diagrams under representative loads to confirm margin and iterate layout if jitter or closure issues appear.
How does the x16 configuration of K4A4G165WF-BCTD affect channel density compared to x8?
A x16 configuration uses fewer physical DRAM chips per channel to achieve a target bus width, reducing trace complexity and power routing. However, it provides fewer banks per rank compared to x8 modules, which can slightly impact bank-interleaving performance in multi-threaded workloads.
