M48T35 View Datasheet(PDF) - STMicroelectronics

Part Name

Description

MFG CO.

M48T35

5V, 256 Kbit (32 Kb x8) TIMEKEEPER® SRAM

STMicroelectronics 

M48T35, M48T35Y

Figure 14. Power Down/Up Mode AC Waveforms

VCC

VPFD (max)

VPFD (min)

VSO

tF

tFB

tPD

INPUTS

RECOGNIZED

tRB

tDR

DON'T CARE

OUTPUTS

VALID

(PER CONTROL INPUT)

HIGH-Z

tR

trec

RECOGNIZED

VALID

(PER CONTROL INPUT)

AI01168C

Table 10. Power Down/Up AC Characteristics

Symbol

Parameter(1)

Min

Max

Unit

tPD

E or W at VIH before Power Down

0

µs

tF(2)

VPFD (max) to VPFD (min) VCC Fall Time

300

µs

M48T35

10

µs

tFB(3)

VPFD (min) to VSS VCC Fall Time

M48T35Y

10

µs

tR

VPFD (min) to VPFD (max) VCC Rise Time

10

µs

tRB

VSS to VPFD (min) VCC Rise Time

1

µs

trec(4)

VPFD (max) to Inputs Recognized

40

200

ms

Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70 or –40 to 85°C; VCC = 4.75 to 5.5V or 4.5 to 5.5V (except where noted).

2. VPFD (max) to VPFD (min) fall time of less than tF may result in deselection/write protection not occurring until 200µs after VCC pass-

es VPFD (min).

3. VPFD (min) to VSS fall time of less than tFB may cause corruption of RAM data.

4. trec (min) = 20ms for industrial temperature Grade 6 device.

Table 11. Power Down/Up Trip Points DC Characteristics

Symbol

Parameter(1,2)

Min

Typ

Max

Unit

VPFD Power-fail Deselect Voltage

M48T35

4.5

M48T35Y

4.2

4.6

4.75

V

4.35

4.5

V

M48T35

3.0

V

VSO Battery Back-up Switchover Voltage

M48T35Y

3.0

V

tDR(5) Expected Data Retention Time

Grade 1

Grade 6

10(3)

10(4)

YEARS

YEARS

Note: 1. Valid for Ambient Operating Temperature: TA = 0 to 70 or –40 to 85°C; VCC = 4.75 to 5.5V or 4.5 to 5.5V (except where noted).

2. All voltages referenced to VSS.

3. CAPHAT and M4T32-BR12SH1 SNAPHAT only, M4T28-BR12SH1 SNAPHAT top tDR = 7 years (typ).

4. Using larger M4T32-BR12SH6 SNAPHAT top (recommended for Industrial Temperature Range - Grade 6 device).

5. At 25°C, VCC = 0V.

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