AO2P24HC8T1-BTBS Datasheet, Pinout, Equivalents, and Specs

The AO2P24HC8T1-BTBS is a high-performance DDR4 synchronous dynamic random-access memory (SDRAM) module manufactured by ADATA, engineered to meet stringent JEDEC JESD79-4 specifications. Operating at a nominal core voltage of 1.2V with a 2.5V wordline activation supply (VPP), this component delivers significant power efficiency improvements over legacy DDR3 architectures. It is designed for integration into enterprise servers, industrial computing platforms, and high-bandwidth embedded systems requiring reliable volatile memory with advanced signal integrity features such as Pseudo-Open Drain (POD) signaling and on-die termination (ODT).

What is the AO2P24HC8T1-BTBS?

The AO2P24HC8T1-BTBS represents a standard implementation of ADATA's DDR4 memory architecture, utilizing high-density synchronous DRAM components mounted on a multi-layer printed circuit board (PCB). At its core, the module leverages an 8n prefetch architecture, which allows it to transfer eight data words per clock cycle, effectively multiplying the internal core frequency to achieve high external data transfer rates. The internal architecture is divided into 16 distinct memory banks, which are further organized into four bank groups (four banks per group). This bank group topology is a critical advancement in DDR4, enabling the device to execute concurrent operations across different bank groups, thereby minimizing the timing penalties typically associated with consecutive read or write commands (tCCD_S vs. tCCD_L) and maximizing overall data throughput.

Power management within the AO2P24HC8T1-BTBS is handled through a dual-voltage system. The primary supply voltage (VDD) and the I/O voltage (VDDQ) are strictly regulated at 1.2V, representing a 20% reduction in power consumption compared to the 1.5V standard of DDR3. Furthermore, the module utilizes a dedicated 2.5V supply (VPP) specifically for wordline activation. By providing a direct, higher-voltage external supply for the wordline, the DDR4 architecture eliminates the need for inefficient internal charge pumps, significantly reducing the thermal footprint and active power dissipation of the memory ICs during row activation commands.

Signal integrity and data reliability are paramount in the AO2P24HC8T1-BTBS design. The module incorporates Pseudo-Open Drain (POD) I/O signaling, which differs fundamentally from the Series Stub Terminated Logic (SSTL) used in previous generations. POD signaling ensures that no current flows when a high logic level (1) is transmitted, drastically reducing I/O power consumption. Additionally, the device supports Data Bus Inversion (DBI), an algorithmic feature that minimizes the number of simultaneous switching outputs (SSO) by inverting the data byte if more than half the bits are driven low. This not only conserves power but also mitigates ground bounce and electromagnetic interference (EMI). For error detection, the module includes a Write Cyclic Redundancy Check (CRC) feature, which calculates and transmits a checksum alongside write data, allowing the memory controller to detect transmission errors across the high-speed data bus in real-time.

Pinout Configuration and Packaging

The AO2P24HC8T1-BTBS is typically packaged in a standard 288-pin Unbuffered Dual In-Line Memory Module (UDIMM) form factor, featuring a 0.85mm pin pitch. A defining mechanical characteristic of this DDR4 package is the curved edge connector. The PCB edge is contoured so that the central pins are longer than those at the extremities, reducing the insertion force required during assembly and minimizing mechanical stress on the motherboard's DIMM socket. The pinout is strictly defined by JEDEC standards to ensure interoperability across compatible motherboards and memory controllers.

The 288 pins are categorized into several functional groups. The Power and Ground pins include VDD (1.2V core/IO), VPP (2.5V wordline), VREFCA (reference voltage for command/address), and VSS (ground). The Data Bus consists of 64 bidirectional data pins (DQ0-DQ63) and corresponding differential data strobes (DQS_t/DQS_c) used for source-synchronous data capture. The Command and Address (CA) bus includes multiplexed address pins (A0-A17), Bank Address pins (BA0-BA1), and Bank Group pins (BG0-BG1). Critical control signals include the active-low Chip Select (CS_n), Clock Enable (CKE), On-Die Termination control (ODT), and the differential clock inputs (CK_t/CK_c). Furthermore, DDR4 introduces the ACT_n pin, which simplifies the command truth table by acting as a dedicated activation command signal, replacing the complex combination of RAS, CAS, and WE signals used in legacy DRAM for row activation.

Core Architectural Features

• Dual-Voltage Power Architecture: Operates with a primary VDD/VDDQ of 1.2V for core logic and I/O operations, paired with a 2.5V VPP supply for wordline activation, eliminating internal charge pumps and reducing active power consumption.
• Advanced Bank Group Topology: Features 16 internal banks organized into 4 bank groups, allowing for shorter timing parameters (tCCD_S) between accesses to different bank groups, thereby increasing overall memory bandwidth and efficiency.
• Pseudo-Open Drain (POD) Signaling: Utilizes POD12 I/O technology where the receiver is terminated to VDDQ. This ensures zero current draw when driving a logic high state, significantly lowering the I/O power budget compared to SSTL.
• Data Bus Inversion (DBI) & Write CRC: Implements DBI to minimize simultaneous switching outputs and reduce noise, alongside Write Cyclic Redundancy Check (CRC) to detect data transmission errors on the high-speed DQ bus.
• Programmable On-Die Termination (ODT): Features dynamically adjustable termination impedance (e.g., 34Ω, 40Ω, 48Ω, 60Ω, 120Ω, 240Ω) controlled via Mode Registers, optimizing signal integrity based on the specific system topology and loading conditions.

Specifications Parameter Table

AO2P24HC8T1-BTBS Equivalents, Cross Reference & Lifecycle

The AO2P24HC8T1-BTBS is part of ADATA's mature DDR4 product portfolio. As DDR4 remains a dominant standard in both legacy and contemporary computing architectures, the lifecycle status of this module is generally considered active, though specific binning variants may transition to Not Recommended for New Designs (NRND) as higher-speed grades (e.g., 3200 MT/s) become the baseline standard. Hardware engineers looking to source this exact module or validate its lifecycle status should consult authorized distributors. You can Check AO2P24HC8T1-BTBS Inventory & Pricing to verify current availability and procurement lead times.

In terms of cross-reference and equivalents, the AO2P24HC8T1-BTBS can typically be substituted with standard JEDEC-compliant DDR4 UDIMMs of matching density, speed grade (e.g., 2400 MT/s or 2666 MT/s), and CAS latency. Equivalent modules from manufacturers such as Micron (Crucial series), Samsung, and SK Hynix will offer drop-in pin compatibility and identical electrical characteristics. When selecting an equivalent, it is critical to ensure that the replacement module matches the unbuffered, non-ECC nature of the AO2P24HC8T1-BTBS, as mixing registered (RDIMM) or load-reduced (LRDIMM) modules on a motherboard designed for UDIMMs will result in system initialization failure.

Typical Applications & Circuit Considerations

The AO2P24HC8T1-BTBS is engineered for deployment in a wide array of computing environments, ranging from standard desktop workstations to industrial PCs (IPCs), edge computing nodes, and embedded networking appliances. In system-level applications, this DDR4 module provides the necessary volatile workspace for operating systems, real-time data processing, and high-speed caching. Because it operates at high frequencies, integrating the memory controller and the DIMM socket on a custom motherboard requires strict adherence to high-speed PCB design guidelines to maintain signal integrity and meet JEDEC timing specifications.

From a circuit design perspective, routing the DDR4 interface demands precise impedance control and length matching. The Command, Address, and Control (CAC) bus must be routed using a fly-by topology. This daisy-chain routing method reduces the number of stubs and improves signal integrity at high frequencies, but it introduces a flight-time skew between the clock and the data strobes at each DRAM component. To compensate for this, the system memory controller must support write leveling, a calibration process that aligns the DQS signal with the CK signal at each memory tier. The single-ended impedance for the CAC bus is typically targeted at 40Ω to 50Ω, while the differential clock (CK_t/CK_c) and data strobes (DQS_t/DQS_c) require an 80Ω to 100Ω differential impedance profile. To explore other memory options for your specific application, you can Browse DDR4 Series components.

Power delivery network (PDN) design is equally critical. The 1.2V VDD and 2.5V VPP rails must be heavily decoupled to handle rapid transient current spikes during read/write bursts and row activations. Engineers must place a mix of low-ESR ceramic capacitors (e.g., 0402 and 0201 package sizes) as close to the DIMM socket pins as possible. Furthermore, the VREFCA reference voltage must be exceptionally clean, often generated by a dedicated precision voltage divider or a specialized DDR termination regulator, and routed with adequate isolation from noisy switching signals to prevent command/address decoding errors.

Video Demonstration

Frequently Asked Questions (AO2P24HC8T1-BTBS FAQ)

Q: What is the purpose of the VPP voltage in the AO2P24HC8T1-BTBS DDR4 module?

A: The VPP voltage is a dedicated 2.5V power supply used exclusively for activating the wordlines within the DRAM internal array. By providing this higher voltage externally, the DDR4 architecture eliminates the need for internal charge pumps that were required in previous DDR generations. This architectural change significantly reduces the active power dissipation and thermal output of the memory module during operation.

Q: How does Pseudo-Open Drain (POD) signaling improve the performance of this ADATA DDR4 memory?

A: Pseudo-Open Drain (POD) signaling improves power efficiency by terminating the receiver to the VDDQ supply voltage rather than a midpoint voltage (VTT). In this configuration, no current flows through the termination resistor when the driver transmits a logic high (1) state. This drastically reduces the overall I/O power consumption of the module, especially when combined with Data Bus Inversion (DBI) which maximizes the transmission of logic high states.

Q: What are the specific routing requirements for the Command/Address bus when integrating this module?

A: The Command/Address (CA) bus for DDR4 modules like the AO2P24HC8T1-BTBS must be routed using a fly-by topology rather than a traditional T-branch topology. This daisy-chain routing minimizes signal reflections and stub lengths, ensuring cleaner signal integrity at high transfer rates. Consequently, the memory controller must utilize write leveling to compensate for the intentional timing skew introduced by the fly-by routing between the clock and data strobes.

Q: Can the AO2P24HC8T1-BTBS operate at 1.35V or 1.5V like older DDR generations?

A: No, the AO2P24HC8T1-BTBS is strictly designed to operate at the JEDEC DDR4 standard voltage of 1.2V for both VDD and VDDQ. Applying 1.35V (DDR3L) or 1.5V (DDR3) to the core power pins will exceed the absolute maximum ratings of the internal DRAM components. Overvoltaging the module in this manner will cause permanent electrical damage and catastrophic failure of the memory ICs.

Q: How does the Bank Group architecture enhance the data throughput of the AO2P24HC8T1-BTBS?

A: The Bank Group architecture divides the 16 internal memory banks into four distinct groups of four banks each. This allows the memory controller to interleave commands, accessing a bank in one group while another group is still processing a previous command. By alternating accesses between different bank groups, the module utilizes shorter timing delays (tCCD_S), thereby maximizing the data bus utilization and overall system bandwidth.

Alan Carter

Senior Hardware Engineer & Component Specialist

Alan has over 15 years of expertise in embedded systems design, FPGA architecture, and global semiconductor supply chains. He specializes in component cross-referencing, lifecycle management, and helping OEMs navigate supply shortages.