Datasheet

3Maxim Integrated
Low-Current SPI/3-Wire RTCs
DS1343/DS1344
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= V
CC(MIN)
to +5.5V, V
BAT
= +1.3V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted.) (Notes 2, 3)
AC ELECTRICAL CHARACTERISTICS
(V
CC
= V
CC(MIN)
to V
CC(MAX)
, T
A
= -40°C to +85°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Backup Current
(Note 7)
DS1343
I
BAT2
V
BAT
= 3V 300
nA
V
BAT
= V
BAT(MAX)
600
DS1344
V
BAT
= 3V 400
V
BAT
= V
BAT(MAX)
700
Input Leakage (CE, SERMODE,
SCLK, SDI)
I
I
V
IN
= 0V to V
CC
-0.1 +0.1
FA
Output Leakage
(INT0, INT1, PF, SDO)
I
O
CE = V
IL
, no alarms -0.1 +0.1
FA
Output Logic 1 (PF, SDO)
I
OH
-3 or -33: V
OH
= 2.4V -1
mA
-18: V
OH
= 1V -0.5
Output Logic 0
(INT0, INT1, PF, SDO)
I
OL
-3 or -33: V
OL
= 0.4V 3.0
mA
-18: V
OL
= 0.4V 2.0
V
BAT
R 1.3V R V
CC
+ 0.2V, V
OL
= 0.2V
(Note 8)
0.25
Power-Fail Trip Point V
PF
-18 1.51 1.6 1.71
V
-3 2.45 2.6 2.70
-33 2.70 2.88 3.0
Switchover Voltage V
SW
V
BAT
> V
PF
V
PF
V
V
BAT
< V
PF
V
BAT
> V
CC
Trickle-Charger Resistors
R1 1
kI
R2 2
R3 4
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SCLK Frequency f
SCLK
-18 DC 1
MHz
-3 or -33 DC 4
Data to SCLK Setup t
DC
30 ns
SCLK to Data Hold t
CDH
30 ns
SCLK to Data Delay t
CDD
-18 240
ns
-3 or -33 80
SCLK Low Time t
CL
-18 400
ns
-3 or -33 110
SCLK High Time t
CH
-18 400
ns
-3 or -33 110