Datasheet

36. The refresh period is 64ms when T
C
is less than or equal to 85°C. This equates to an aver-
age refresh rate of 7.8125μs. However, nine REFRESH commands should be asserted at
least once every 70.3μs. When T
C
is greater than 85°C, the refresh period is 32ms.
37. Although CKE is allowed to be registered LOW after a REFRESH command when
t
REFPDEN (MIN) is satisfied, there are cases where additional time such as
t
XPDLL (MIN)
is required.
38. ODT turn-on time MIN is when the device leaves High-Z and ODT resistance begins to
turn on. ODT turn-on time maximum is when the ODT resistance is fully on. The ODT
reference load is shown in Figure 20 (page 53). This output load is used for ODT timings
(see Figure 27 (page 65)).Designs that were created prior to JEDEC tightening the maxi-
mum limit from 9ns to 8.5ns will be allowed to have a 9ns maximum.
39. Half-clock output parameters must be derated by the actual
t
ERR10per and
t
JITdty when
input clock jitter is present. This results in each parameter becoming larger. The parame-
ters
t
ADC (MIN) and
t
AOF (MIN) are each required to be derated by subtracting both
t
ERR10per (MAX) and
t
JITdty (MAX). The parameters
t
ADC (MAX) and
t
AOF (MAX) are
required to be derated by subtracting both
t
ERR10per (MAX) and
t
JITdty (MAX).
40. ODT turn-off time minimum is when the device starts to turn off ODT resistance. ODT
turn-off time maximum is when the DRAM buffer is in High-Z. The ODT reference load is
shown in Figure 20 (page 53). This output load is used for ODT timings (see Figure 27
(page 65)).
41. Pulse width of a input signal is defined as the width between the first crossing of
V
REF(DC)
and the consecutive crossing of V
REF(DC)
.
42. Should the clock rate be larger than
t
RFC (MIN), an AUTO REFRESH command should
have at least one NOP command between it and another AUTO REFRESH command. Ad-
ditionally, if the clock rate is slower than 40ns (25 MHz), all REFRESH commands should
be followed by a PRECHARGE ALL command.
43. DRAM devices should be evenly addressed when being accessed. Disproportionate ac-
cesses to a particular row address may result in a reduction of REFRESH characteristics or
product lifetime.
44. When two V
IH(AC)
values (and two corresponding V
IL(AC)
values) are listed for a specific
speed bin, the user may choose either value for the input AC level. Whichever value is
used, the associated setup time for that AC level must also be used. Additionally, one
V
IH(AC)
value may be used for address/command inputs and the other V
IH(AC)
value may
be used for data inputs.
For example, for DDR3-800, two input AC levels are defined: V
IH(AC175),min
and
V
IH(AC150),min
(corresponding V
IL(AC175),min
and V
IL(AC150),min
). For DDR3-800, the address/
command inputs must use either V
IH(AC175),min
with
t
IS(AC175) of 200ps or V
IH(AC150),min
with
t
IS(AC150) of 350ps; independently, the data inputs must use either V
IH(AC175),min
with
t
DS(AC175) of 75ps or V
IH(AC150),min
with
t
DS(AC150) of 125ps.
8Gb: x4, x8, x16 DDR3L SDRAM
Electrical Characteristics and AC Operating Conditions
92
Rev 2.0 June 2016
© 2015 Alliance Memory, Inc. All rights reserved.
Alliance Memory Inc. reserves the right to change products or specification without notice
Alliance Memory Inc. 511 Taylor Way, San Carlos, CA 94070
TEL: [phone] FAX: [phone]