MT41K256M16TW-107:P

The MT41K256M16TW-107:P is a 4Gbit (512MB) DDR3L SDRAM device manufactured by Micron Technology, organized as 256 Meg x 16 bits. It belongs to the MT41K series of low-voltage DDR3 SDRAM devices, operating at VDD = VDDQ = 1.35V (range: 1.283V to 1.45V) while maintaining backward compatibility with 1.5V DDR3 applications. The device uses an 8n-prefetch architecture with a double data rate interface that transfers two data words per clock cycle at the I/O pins.

The -107 speed grade supports a maximum clock frequency of 933 MHz (1866 MT/s data rate) with CL = 13 timing (tRCD = 13.91ns, tRP = 13.91ns). The device incorporates 8 internal banks for concurrent operation, enabling high bandwidth by hiding row precharge and activation time. It features nominal and dynamic on-die termination (ODT) for data, strobe, and mask signals, differential bidirectional data strobe (DQS/DQS#), and differential clock inputs (CK/CK#).

Fabricated in 20nm process technology, the device is packaged in a 96-ball FBGA (8mm x 14mm, height 0.92mm) with commercial temperature range (0°C to 95°C). Key features include programmable CAS latency (CL), programmable posted CAS additive latency (AL), programmable CAS write latency (CWL), fixed burst length of 8 (BL8) and burst chop of 4 (BC4) with on-the-fly selection, self-refresh mode with temperature-compensated auto-refresh, write leveling, multipurpose register, and output driver calibration via ZQ pin. The device supports refresh intervals of 64ms at 0-85°C and 32ms at 85-95°C with 8192 refresh cycles.

The MT41K256M16TW-107:P employs a double data rate (DDR) architecture based on an 8n-prefetch scheme. A single read or write operation consists of a single 8n-bit-wide, four-clock-cycle data transfer at the internal DRAM core, paired with eight corresponding n-bit-wide, one-half-clock-cycle data transfers at the I/O pins. This architecture enables high bandwidth while keeping the internal DRAM core frequency at one-eighth of the external data rate.

Clock and Command Subsystem: The device operates from differential clock inputs (CK and CK#). All control, command, and address signals are registered at the positive edge of CK. Commands are decoded from the CS#, RAS#, CAS#, WE#, and ACT# pins to initiate operations such as ACTIVATE, READ, WRITE, PRECHARGE, REFRESH, and mode register access.

Memory Array Subsystem: The 4Gbit density is organized as 256 Meg x 16 with 8 internal banks. Each bank contains 32K rows (A[14:0]), 1K columns (A[9:0]), and a 2KB page size. The 8-bank architecture allows concurrent bank operations, hiding row access latency through bank interleaving and improving overall throughput.

Data Path Subsystem: Data is transferred via the 16-bit DQ bus with differential data strobe signals (DQS/DQS#). During WRITE operations, DQS is center-aligned with data for reliable capture. During READ operations, the DRAM transmits data edge-aligned to DQS. The device supports BL8 (burst length 8) and BC4 (burst chop 4) with on-the-fly selection via the mode register.

On-Die Termination (ODT) Subsystem: The device supports both nominal and dynamic ODT for DQ, DQS, DQS#, and DM signals. ODT values are programmable through mode registers (RTT_NOM, RTT_WR), providing signal integrity optimization without external termination components. Dynamic ODT allows the termination value to change on-the-fly during write operations.

Refresh Subsystem: The device requires 8192 refresh commands every 64ms (0-85°C) or 32ms (85-95°C). Self-refresh mode with auto-refresh (SRT) enables autonomous refresh operation during low-power standby. The ZQ calibration subsystem performs periodic output driver impedance calibration against an external 240-ohm resistor to maintain signal integrity over temperature and voltage variations.