IEEE Solid-State Circuits Magazine - Winter 2015 - 22

HBM

Data Bandwidth for DRAMs

Data Bandwidth (Gb/s)

100

DDR
DDR2
DDR3
DDR4
GDDR3
GDDR4
GDDR5
LPDDR2
LPDDR3
LPDDR4
LPDDR5
HBM
WIO

)
R(x
GDD
(x)
WIO

10

(x)
DDR
x)
DR(
LPD

1

0.1
1997

1999

2001

2003

2005

2007
Year

2009

2011

2013

2015

Figure 18: The data bandwidth for DRAMs.

10,000

Cond.>1 Mb
ISSCC, VLSI Cir.
ASSCC (2001-2014)

Write Bandwidth (Mb/s)

1,000

Emerging NVRAM
FeRAM (ISSCC '09)

eMRAM (ASSCC '07)
MRAM
(ASSCC '06)

FeRAM, MRAM
(ISSCC '06)

NAND-SLC
(ISSCC '08)
NAND-MLC
(ISSCC '14)
VNAND-TLC
(ISSCC '15)
PRAM
(ISSCC '07, '10)

100

10

ReRAM
(ISSCC '11)

PRAM
(ISSCC '11)

NOR
(ISSCC '05, '07)

Flash
1
100

r

tte

Be

eNOR
(ISSCC '07)

1,000
Read Bandwidth (Mb/s)

10,000

Figure 19: Trends in NVM technologies comparing write bandwidths to read bandwidths.

year saw the first introduction of
14-nm/16-nm technology. This year, a
14-nm SRAM using second-generation
FinFET technology implements the
smallest SRAM bit cell ever reported
at just 0.050 µm2. As the transistor
feature size reduced below 20 nm,
device variation has made it very difficult to shrink the bit-cell size at the
desired 50% rate while maintaining or

22

W I N T E R 2 0 15

lowering VMIN between generations.
The introduction of high- l metal-gate
(45 nm) and FinFET or fully depleted
SOI transistors (22 nm) has reduced
VTH mismatch and has enabled further
device scaling. Design solutions such
as read/write-assist circuitry and
variation-tolerant sensing schemes
have been used to improve SRAM VMIN
performance starting at 32 nm and

IEEE SOLID-STATE CIRCUITS MAGAZINE

are now ubiquitous in high-density
SRAM designs at 14/16 nm. Dual-rail
SRAM design emerges as an effective
solution to enable dynamic voltagefrequency scaling by decoupling
logic-supply rails from SRAM arrays,
thus allowing a much wider operating window. The use of assist-circuit
techniques, FinFET transistors, and
dual-rail architectures is expected to



Table of Contents for the Digital Edition of IEEE Solid-State Circuits Magazine - Winter 2015

IEEE Solid-State Circuits Magazine - Winter 2015 - Cover1
IEEE Solid-State Circuits Magazine - Winter 2015 - Cover2
IEEE Solid-State Circuits Magazine - Winter 2015 - 1
IEEE Solid-State Circuits Magazine - Winter 2015 - 2
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IEEE Solid-State Circuits Magazine - Winter 2015 - Cover3
IEEE Solid-State Circuits Magazine - Winter 2015 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2023
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2022
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2021
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_spring2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_winter2020
https://www.nxtbook.com/nxtbooks/ieee/mssc_fall2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_summer2019
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2019winter
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018fall
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018summer
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018spring
https://www.nxtbook.com/nxtbooks/ieee/mssc_2018winter
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2017
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2016
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2015
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_winter2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_fall2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_summer2014
https://www.nxtbook.com/nxtbooks/ieee/solidstatecircuits_spring2014
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