DC and AC parameters

M41T81

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DocID007529 Rev 11

Figure 15. Power down/up mode AC waveforms

Table 9. DC characteristics

Sym

Parameter

Test condition(1)

1. Valid for ambient operating temperature: TA = –40 to 85°C; VCC = 2.0 to 5.5 V (except where noted).

Min

Typ

Max

Unit

ILI

Input leakage current

0V

 VIN  VCC

±1

μA

ILO

Output leakage current

0V

 VOUT  VCC

±1

μA

ICC1

Supply current

Switch freq = 400 kHz

400

μA

ICC2

Supply current (standby)

SCL,SDA = VCC – 0.3V

100

μA

VIL

Input low voltage

–0.3

0.3VCC

V

VIH

Input high voltage

0.7VCC

VCC + 0.3

V

VOL

Output low voltage

IOL = 3.0 mA

0.4

V

Output low voltage (open

drain)(2)

2. For IRQ/FT/OUT/SQW pin (open drain)

IOL = 10 mA

0.4

V

Pull-up supply voltage

(open drain)

IRQ/OUT/FT/SQW

5.5

V

VBAT(3)

3. STMicroelectronics recommends the RAYOVAC BR1225 or BR1632 (or equivalent) as the battery supply.

Battery supply voltage

2.5(4)

4. After switchover (VSO), VBAT (min) can be 2.0 V for crystal with RS = 40 k.

3

3.5(5)

5. For rechargeable backup, VBAT (max) may be considered VCC.

V

IBAT

Battery supply current

TA = 25 °C, VCC = 0 V

oscillator on, VBAT = 3 V

0.6

1

μA

Table 10. Crystal electrical characteristics

Sym

Parameter(1)(2)

1. Externally supplied. 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.

2. Load capacitors are integrated within the M41T81. 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.

Min

Typ

Max

Units

fO

Resonant frequency

-

32.768

kHz

RS

Series resistance

-

60

k



CL

Load capacitance

-

12.5

pF

AI00596

VCC

trec

tPD

VSO

SDA

SCL

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