Intel's 2.7V SmartVoltage Flash Memory Advances Low-Power High-Performance Mobile Applications

Mobile applications strive for longer battery life combined with the right system features.

This need for longer battery life drives system voltage lower. In contrast, the right system features often drive performance requirements higher. Intel's SmartVoltage technology advances Intel's leading NOR flash memory solutions to satisfy these requirements with the lowest voltage and highest performance solution at 2.7V and 120 ns. Available in upgradable 4- and 8-Mbit product families, these extended-temperature 2.7V SmartVoltage products set the pace for future trends in mobile applications.

Mobile Applications Drive the Need for Low Voltage and High Performance

Cellular phone users desire longer talk-time. Users, as well as cellular service providers, demand longer standby time when their phone is waiting to receive an incoming call. While research continues for a more cost-effective battery with longer life, today's clear directive is to lower the system voltage. Lowering the voltage from 5V to 2.7V more than doubles the battery life. In cellular phones, this translates to twice the talk time and four times the standby time. This improvement comes from discharging the battery to the lower voltage and reducing overall system power consumption at 2.7V. While lowering voltage extends precious battery life, it also reduces the current supplied to system components. Traditionally, this runs counter to maintaining performance. At the same time, high-performance remains critical since mobile applications execute all facets of operation directly out of high performance flash memory. Therefore, the right solution must meet both the voltage and performance requirements of the application.

Intel's 2.7V, 120 ns SmartVoltage Boot Block Products Advance Mobile Applications

Intel's new 2.7V, 4- and 8-Mbit SmartVoltage boot block flash memories, manufactured on Intel's advanced 0.6 ľ ETOX(TM) IV flash technology, lead the way in low-voltage read operation and high performance. The figure below provides a comparison of performance and voltage for 4-Mbit memory products from several manufacturers.

Comparison of 4-Mbit Flash Memory Products

Mobile Applications Require Low Voltage and High Performance

Mobile applications are represented by the shaded area in the lower left of the figure, bounded by 3.3V maximum voltage and 150 ns maximum performance. To use a memory outside these boundaries requires significant tradeoffs in battery life or the right system features.

Intel Leads in Low-Voltage Flash Memory

Intel has been developing low-voltage design techniques since its first 3.3V products, introduced in 1992. Intel's SmartVoltage technology incorporates three fundamental advances to enable 2.7V capability:

Address Transition Detection applies a circuit technique used for many years on high-speed SRAM to flash memory. On-chip circuitry detects address and control input transitions. An internal control pipe pre-charges read circuits ahead of address decoding logic. This speeds up array access once the complete address is decoded. This patented flash memory approach, first applied to Intel's high-volume boot block family at 5V, provides significant performance benefits when optimized for low-voltage operation.
Low-Voltage Margin Sensing increases performance while maintaining proper noise margins during array sensing. By increasing the array cell current, a greater differential is achieved during sensing which provides faster operation and greater noise margin.
Output Auto-detect circuitry determines optimal output drive characteristics for low voltage. This ensures high-speed switching while optimizing the supply current profile for optimal noise characteristics.

Building on Intel's Widely Adopted SmartVoltage Products

These 2.7V advancements build on the key attributes that make Intel's SmartVoltage technology the leading solution today for mobile applications. Intel's complete family of 2-, 4-, and 8-Mbit SmartVoltage boot block products deliver:

High speed parallel random access for direct code execution: Today's applications use flash memory predominantly for direct code execution. This requires that any random access to memory provide sustained high-performance, parallel access. Intel's NOR architecture provides parallel access for both x8 and x16 operation. Anything less, such as slow initial access featured on alternative architectures, will not meet the performance requirements of the application.
Low-voltage read using two supply pins for flexible, cost-effective solutions, including single-supply. By using two separate supply pins, SmartVoltage allows the read supply to be driven lower than the write/erase voltage. As a result, SmartVoltage delivers a cost-effective, low-voltage solution on a given technology sooner than a single supply-approach. As technology advances to allow cost-effective, low-voltage write and erase, this capability is easily integrated into SmartVoltage.
12V High-speed programming for fast production throughput: High-speed programming has proven to be invaluable for high-volume manufacturing, doubling production throughput. During the production process, high-volume manufacturers apply a readily available 12V supply to their system board using industry-standard production equipment. Accelerated write and erase times at 12V speed production throughput, thereby saving tester-equipment costs and improving time-to-market.
Optimal 5V in-system writes for updating the memory in-system: SmartVoltage also allows for the simplicity of 5V in-system reads and writes. For 5V applications the write/erase voltage (VPP) is simply shorted to the read voltage (VCC). On-chip circuitry automatically senses the write/erase voltage applied to the memory and implements internal write and erase operations. Dedicated control of the write/erase supply also provides absolute write protection by grounding the supply during normal read operation.
Automatic Power Savings (APS) for longer system battery life: APS mode reduces active current by automatically shutting down inactive circuits when the memory is not being accessed. This proves to be a key feature for further reducing system power consumption.

Conclusion

Mobile applications, such as cellular phones, are trending to lower voltages while maintaining their performance requirements. Intel's SmartVoltage technology advances Intel's leading NOR flash memory products to deliver the optimal solutions. Architectural advancements enable the lowest voltage, highest performance solution today with 120ns performance at 2.7V extended-temperature operation. This new capability builds on the key attributes that make Intel's SmartVoltage technology the right choice for mobile applications. Intel's SmartVoltage technology sets the pace for future trends to subsequent lower voltage and higher performance.