DS1646 Datasheet, PDF (7/11 Pages) Dallas Semiconductor – Nonvolatile Timekeeping RAM

AC ELECTRICAL CHARACTERISTICS
PARAMETER
SYMBOL
Read Cycle Time
t_RC
Address Access Time
t_AA
CE Access Time
t_CEA
CE Data Off Time
t_CEZ
Output Enable Access Time
t_OEA
Output Enable Data Off Time
t_OEZ
Output Enable to DQ Low-Z
t_OEL
CE to DQ Low-Z
t_CEL
Output Hold from Address
t_OH
Write Cycle Time
t_WC
Address Setup Time
t_AS
CE Pulse Width
t_CEW
Address Hold from End of Write
Write Pulse Width
WE Data Off Time
t_AH1
t_AH2
t_WEW
t_WEZ
WE or CE Inactive Time
t_WR
Data Setup Time
t_DS
Data Hold Time High
t_DH1
t_DH2
MIN
120
5
5
5
120
0
100
5
30
75
10
85
0
25
AC TEST CONDITIONS
Input Levels:
0V to 3V
Transition Times: 5 ns
DS1646/DS1646P
(Over the Operating Range)
TYP
MAX
120
120
UNITS
ns
ns
ns
NOTES
40
ns
100
ns
40
ns
ns
ns
ns
ns
ns
ns
ns
5
ns
6
ns
40
ns
ns
ns
ns
5
ns
6
CAPACITANCE
PARAMETER
Capacitance on all pins (except DQ)
Capacitance on DQ pins
SYMBOL
C_I
C_DQ
MIN
TYP
MAX
7
10
(t_A = 25°C)
UNITS NOTES
pF
pF
AC ELECTRICAL CHARACTERISTICS
(POWER-UP/DOWN TIMING)
PARAMETER
SYMBOL
CE or WE at V_IH before Power-Down
t_PD
V_PF (Max) to V_PF (Min) V_CC Fall Time
t_F
V_PF (Min) to V_SO V_CC Fall Time
t_FB
V_SO to V_PF (Min) V_CC Rise Time
t_RB
V_PF (Min) to V_PF (Max) V_CC Rise Time
t_R
Power-Up
t_REC
Expected Data Retention Time
t_DR
(Oscillator On)
MIN
0
300
10
1
0
15
10
(Over the Operating Range)
TYP MAX UNITS NOTES
µs
µs
µs
µs
µs
35
ms
years
4
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