3
Maxim Integrated
Low-Current SPI/3-Wire RTCs
DS1343/DS1344
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = VCC(MIN) to +5.5V, VBAT = +1.3V to +5.5V, TA = -40°C to +85°C, unless otherwise noted.) (Notes 2, 3)
AC ELECTRICAL CHARACTERISTICS
(VCC = VCC(MIN) to VCC(MAX), TA = -40°C to +85°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Backup Current
(Note 7)
DS1343
IBAT2
VBAT = 3V
300
nA
VBAT = VBAT(MAX)
600
DS1344
VBAT = 3V
400
VBAT = VBAT(MAX)
700
Input Leakage (CE, SERMODE,
SCLK, SDI)
II
VIN = 0V to VCC
-0.1
+0.1
F
A
Output Leakage
(INT0, INT1, PF, SDO)
IO
CE = VIL, no alarms
-0.1
+0.1
F
A
Output Logic 1 (PF, SDO)
IOH
-3 or -33: VOH = 2.4V
-1
mA
Output Logic 0, VOL = 0.4V
(INT0, INT1, PF, SDO)
IOL
VCC R VCC(MIN)
3.0
mA
VBAT R 1.3V R VCC + 0.2V (Note 8)
250
F
A
Power-Fail Trip Point
VPF
-18
1.51
1.6
1.71
V
-3
2.45
2.6
2.70
-33
2.70
2.88
3.0
Switchover Voltage
VSW
VBAT > VPF
VPF
V
VBAT < VPF
VBAT > VCC
Trickle-Charger Resistors
R1
1
kI
R2
2
R3
4
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SCLK Frequency
fSCLK
-18
DC
1
MHz
-3 or -33
DC
4
Data to SCLK Setup
tDC
30
ns
SCLK to Data Hold
tCDH
30
ns
SCLK to Data Delay
tCDD
-18
160
ns
-3 or -33
80
SCLK Low Time
tCL
-18
400
ns
-3 or -33
110
SCLK High Time
tCH
-18
400
ns
-3 or -33
110
SCLK Rise and Fall
tR, tF
200
ns
CE to SCLK Setup
tCC
400
ns
SCLK to CE Hold
tCCH
100
ns
CE Inactive Time
tCWH
-18
500
ns
-3 or -33
400
CE to Output High-Z
tCDZ
40
ns
Oscillator Stop Flag (OSF) Delay
tOSF
(Note 9)
25
100
ms