M41T256Y

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Table 8. DC Characteristics

2. Outputs deselected.

3. For RST and FT pin (Open Drain).

Table 9. Crystal Electrical Characteristics (Externally Supplied)

Note: 1. 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 ht-

tp://www.kdsj.co.jp for further information on this crystal type.

2. Load capacitors are integrated within the M41T256Y. Circuit board layout considerations for the 32.768kHz crystal of minimum trace

lengths and isolation from RF generating signals should be taken into account.

Sym

Parameter

Min

Typ

Max

Unit

Battery Current OSC ON

1.5

1.9

µA

Battery Current OSC OFF

1.0

1.4

µA

Supply Current

f = 400kHz

1.4

3.0

mA

Supply Current (Standby)

1.0

2.5

mA

Input Leakage Current

0V

±1

µA

(2)

Output Leakage Current

0V

±1

µA

Input High Voltage

V

Input High Voltage in Battery Back-

up for Tamper Pin

Vdiode

V

Input Low Voltage

–0.3

V

Battery Voltage

2.5

3.5

V

Output High Voltage

V

Output Low Voltage

0.4

V

0.4

V

Power Fail Deselect

4.20

4.50

V

Battery Back-up Switchover

V

Switch Resistance on Tamper Pin

500

Ω

Symbol

Typ

Min

Max

Unit

Resonant Frequency

32.768

kHz

Series Resistance

35

k

Ω

Load Capacitance

12.5

pF