M48T212V-85MH1F Datasheet M48T212V-85MH1E, M48T212V-85MH1F | P4-P6

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List of figures M48T212V

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List of figures

Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. SOIC connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 3. Hardware hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 4. Chip enable control and bank select timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 5. Read cycle timing: RTC control signal waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 6. Write cycle timing: RTC control signal waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 7. Alarm interrupt reset waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 8. Back-up mode alarm waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 9. (RSTIN1

& RSTIN2) timing waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 10. Crystal accuracy across temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 11. Calibration waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 12. Supply voltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 13. AC testing load circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 14. Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 15. SOH44 – 44-lead plastic small outline, SNAPHAT, package outline . . . . . . . . . . . . . . . . . 30

Figure 16. SH – 4-pin SNAPHAT housing for 48 mAh battery & crystal, package outline. . . . . . . . . . 31

Figure 17. SH – 4-pin SNAPHAT housing for 120mAh battery & crystal, package outline . . . . . . . . . 32

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M48T212V Description

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1 Description

The M48T212V is a self-contained device that includes a real-time clock (RTC),

programmable alarms, a watchdog timer, and two external chip enable outputs which

provide control of up to four (two in parallel) external low-power static RAMs.

Access to all TIMEKEEPER

functions and the external RAM is the same as conventional

byte-wide SRAM. The 16 TIMEKEEPER Registers offer Century, Year, Month, Date, Day,

Hour, Minute, Second, Calibration, Alarm, Watchdog, and Flags. Externally attached static

RAMs are controlled by the M48T212V via the E1

CON

and E2

CON

signals (see Ta ble 3 on

page 10).

The 44-pin, 330mil SOIC provides sockets with gold plated contacts at both ends for direct

connection to a separate SNAPHAT

housing containing the battery and crystal. The

unique design allows the SNAPHAT battery package to be mounted on top of the SOIC

package after the completion of the surface mount process.

Insertion of the SNAPHAT housing after reflow prevents potential battery and crystal

damage due to the high temperatures required for device surface-mounting. The SNAPHAT

housing is keyed to prevent reverse insertion.

The SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or

in Tape & Reel form. For the-44 lead SOIC, the battery/crystal package (e.g., SNAPHAT)

part number is “M4TXX-BR12SH” (see Table 20 on page 33).

Caution: Do not place the SNAPHAT battery/crystal top in conductive foam, as this will drain the

lithium button-cell battery.

Figure 1. Logic diagram

AI03019

A0-A3

DQ0-DQ7

M48T212V

CON

RSTIN2

RSTIN1

RST

IRQ/FT

OUT

WDI

CCSW

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Description M48T212V

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Table 1. Signal names

A0-A3 Address inputs

DQ0-DQ7 Data inputs/outputs

RSTIN1 Reset 1 input

RSTIN2 Reset 2 input

RST Reset output (open drain)

WDI Watchdog input

A Bank select input

E Chip enable input

EX External chip enable input

G Output enable input

W WRITE enable input

CON

RAM chip enable 1 output

CON

RAM chip enable 2 output

IRQ/FT Int/freq test output (open drain)

CCSW

switch output

OUT

Supply voltage output

Supply voltage

Ground

NC Not connected internally

P1-P3 P4-P6 P7-P9 P10-P12 P13-P15 P16-P18 P19-P21 P22-P24 P25-P27 P28-P30 P31-P33 P34-P35

M48T212V-85MH1F

Mfr. #:

Buy M48T212V-85MH1F

Manufacturer:

STMicroelectronics

Description:

IC RTC CLK/CALENDAR PAR 44-SOH

Lifecycle:

New from this manufacturer.

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M48T212V-85MH1F

M48T212V-85MH1F

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