M41T94
DC and AC parameters
Table 13. DC characteristics
Symb.
Parameter
Test condition(1) Min
Typ
Max Unit
Battery current OSC on
IBAT
Battery current OSC off
TA = 25°C, VCC =
0V, VBAT = 3V
400
500 nA
50
nA
ICC1 Supply current
ICC2 Supply current (standby)
ILI(2)
ILO(3)
VIH
VIL
VBAT
VOH
VOL
Input leakage current
Output leakage current
Input high voltage
Input low voltage
Battery voltage
Output high voltage(5)
Output low voltage(5)
Output low voltage
(open drain)(6)
f = 2 MHz
SCL, SDI =
VCC – 0.3V
0V ≤VIN ≤VCC
0V ≤VOUT ≤VCC
IOH = –1.0mA
IOL = 3.0mA
IOL = 10mA
0.7VCC
–0.3
2.5
2.4
2
mA
1.4 mA
±1
µA
±1
µA
VCC + 0.3 V
0.3VCC V
3.5(4)
V
V
0.4
V
0.4
Pull-up supply voltage
(open drain)
RST, IRQ/FT/OUT
5.5
V
Power fail deselect (THS = VCC)
VPFD
Power fail deselect (THS = VSS)
4.20 4.40 4.50
V
2.55 2.60 2.70
VSO Battery back-up switchover
2.5
V
1. Valid for ambient operating temperature: TA = –40 to 85°C; VCC = 2.7 to 5.5V (except where noted).
2. RSTIN1 and RSTIN2 internally pulled-up to VCC through 100KΩ resistor. WDI internally pulled-down to VSS
through 100KΩ resistor.
3. Outputs deselected.
4. For rechargeable back-up, VBAT (max) may be considered VCC.
5. For SQW pin (CMOS).
6. For IRQ/FT/OUT, RST pins (open drain): if pulled-up to supply other than VCC, this supply must be equal
to, or less than 3.0V when VCC = 0V (during battery back-up mode).
Table 14. Crystal electrical characteristics (externally supplied)
Symbol
Parameter(1)(2)
Typ
Min
Max
Unit
f0
Resonant frequency
32.768
kHz
RS
Series resistance
50
kΩ
CL
Load capacitance
12.5
pF
1. Load capacitors are integrated within the M41T94. Circuit board layout considerations for the 32.768 kHz
crystal of minimum trace lengths and isolation from RF generating signals should be taken into account.
These characteristics are externally supplied.
2. STMicroelectronics recommends the KDS DT-38: 1TA/1TC252E127, Tuning Fork Type (thru-hole) or the
DMX-26S: 1TJS125FH2A212, (SMD) quartz crystal for industrial temperature operations. KDS can be
contacted at kouhou@kdsj.co.jp or http://www.kdsj.co.jp for further information on this crystal type.
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