MCP79512 datasheet, PDF - EEWORLD Datasheet

MCP7952X/MCP7951X

3V SPI Real-Time Clock Calendar with Battery Switchover

Device Selection Table

Part Number

MCP79520

MCP79510

MCP79521

MCP79511

MCP79522

MCP79512

SRAM

(Bytes)

64

EEPROM

(Kbits)

2

1

2

1

2

1

Unique ID

Blank

EUI-48

™

EUI-48

™

EUI-64

™

EUI-64

™

User Memory:

• 64-Byte Battery-Backed SRAM

• 2 Kbit and 1 Kbit EEPROM Memory:

- Software block write-protect (¼, ½, or entire

array)

- Write Page mode (up to 8 bytes)

- Endurance: 1M erase/write cycles

• 128-Bit Unique ID in Protected Area of EEPROM:

- Available blank or preprogrammed

- EUI-48™ or EUI-64™ MAC address

- Unlock sequence for user programming

Timekeeping Features:

• Real-Time Clock/Calendar:

- Hours, Minutes, Seconds, Hundredth of

Seconds, Day of Week, Month, Year, Leap

Year

• Crystal Oscillator requires External 32,768 kHz

Tuning Fork Crystal and Load Capacitors.

• Clock Out Function:

- 1Hz, 4.096 kHz, 8.192 kHz, 32.768 kHz

• 2 Programmable Alarms

• Programmable open drain output – Alarm or

Interrupt

• On-Chip Digital Trimming/Calibration:

- +/- 255 PPM range in 1 PPM steps

• Power-Fail Time-Stamp @ Battery Switchover:

- Logs time when V

CC

fails and V

CC

is restored

Operating Ranges:

• SPI Clock Speed up to 5 MHz

• Operating Temperature Ranges:

- Industrial (I Temp): -40°C to +85°C.

• Packages include 10-Lead MSOP and TDFN

Package Types (not to scale)

MSOP/TDFN

X1

X2

V

BAT

CS

V

SS

1

2

3

4

5

10

Vcc

MFP

SCK

SO

SI

MCP795XX

9

8

7

6

Low-Power Features:

• Wide Operating Voltage:

- V

CC

: 1.8V to 3.6V

- V

BAT

: 1.3V to 3.6V

• Low Operating Current:

- V

CC

Standby Current < 1uA @ 3V

- V

BAT

Timekeeping Current: <700nA @ 1.8V

• Automatic Battery Switchover from V

CC

to V

BAT

:

- Backup power for timekeeping and SRAM

retention

Note:

MCP795XX is used in this document as a

generic part number for the MCP7951X,

MCP7952X devices.



2012 Microchip Technology Inc.

Preliminary

DS22300A-page 1

MCP7952X/MCP7951X

Description:

The MCP795XX is a low-power Real-Time Clock/

Calendar (RTCC) that uses digital trimming compen-

sation for an accurate clock/calendar, an interrupt out-

put to support alarms and events, a power sense

circuit that automatically switches to the backup sup-

ply, nonvolatile memory for safe data storage and sev-

eral enhanced features that support system

requirements.

Along with a low-cost 32,768 kHz crystal, this RTCC

tracks time using several internal registers and then

communicates the data over a 5 MHz SPI bus that is

fast enough to support a programmable millisecond

alarm.

The device is fully accessible through the serial inter-

face, while V

CC

is between 1.8V and 3.6V, but can

operate down to 1.3V through the backup supply con-

nected to the V

BAT

input for timekeeping and SRAM

retention only.

As part of the power sense circuit, a time saver

function is implemented to store the time when main

power is lost and again, when power is restored to log

the duration of a power failure.

Along with the on-board serial EEPROM and battery-

backed SRAM, a 128-bit protected space is available

for a unique ID. This space can be ordered

preprogrammed with a MAC address, or blank for the

user to program.

This clock/calendar automatically adjusts for months

with fewer than 31 days including corrections for leap

years. The clock operates in either 24-hour or 12-hour

format with AM/PM indicator and settable alarm(s).

Using the external crystal, the MFP pin can be set to

generate a number of output frequencies.

FIGURE 1-1:

BLOCK DIAGRAM

X1

CLKOUT Divider

OSC

X2

V

BAT

SWITCHOVER

V

CC

MFP

V

BAT

EEPROM

SCK

ID

SO

CS

ALARMS

SRAM

SPI

TIME-STAMP

V

SS

SI

DS22300A-page 2

Preliminary



2012 Microchip Technology Inc.

MCP7952X/MCP7951X

1.0

ELECTRICAL CHARACTERISTICS

Absolute Maximum Ratings

(†)

V

CC

.............................................................................................................................................................................6.5V

All inputs and outputs w.r.t. V

SS

................................................................................................................. -0.6V to +6.5V

Storage temperature ...............................................................................................................................-65°C to +150°C

Ambient temperature under bias............................................................................................................... -40°C to +85°C

ESD protection on all pins.......................................................................................................................................... 4 kV

† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the

device. This is a stress rating only and functional operation of the device at those or any other conditions above those

indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for

extended periods may affect device reliability.

TABLE 1-1:

DC CHARACTERISTICS

Industrial (I):

Min.

.7 V

CC

-0.3

—

V

CC

-0.5

T

AMB

= -40°C to +85°C

Max.

V

CC

+1

0.3V

CC

0.2V

CC

0.4

0.2

—

±1

—

7

Units

V

A

pF

V

CC

2.5V

V

CC

< 2.5V

I

OL

= 2.1 mA

I

OL

= 1.0 mA, V

CC

< 2.5V

I

OH

= -400

A

CS = V

CC

, V

IN

= V

SS TO

V

CC

CS = V

CC

, V

OUT

= V

SS TO

V

CC

T

AMB

= 25°C, CLK = 1.0 MHz

V

CC

= 5.0V

(Note

1)

V

CC

= 3.6V; F

CLK

= 5 MHz

SO = Open

V

CC

= 3.6V

V

BAT

= 1.8V @ 25°C

(Note

2)

1.5V typical at T

AMB

= 25°C

From V

TRIP

(max) to V

TRIP

(min)

From V

TRIP

(min) to V

TRIP

(max)

—

V

CC

= 1.8V to 3.6V

Test Conditions

DC CHARACTERISTICS

Param.

No.

D001

D002

D003

D004

D005

D006

D007

D008

D009

Sym.

V

IH1

V

IL1

V

IL2

V

OL

V

OL

V

OH

I

LI

I

LO

C

INT

Characteristic

High-level input

voltage

Low-level input

voltage

Low-level output

voltage

High-level output

voltage

Input leakage current

Output leakage

current

Internal Capacitance

(all inputs and

outputs)

D010

D011

D012

D013

D014

D015

D016

D017

I

CC

Read Operating Current

I

DD

write Write Current

I

BAT

V

TRIP

VCCFT

VCCRT

V

BAT

I

CCS

V

BAT

Current

V

BAT

Change Over

V

CC

Fall Time

V

CC

Rise Time

V

BAT

Voltage Range

Standby Current

—

1.3

300

0

1.3

—

3

5

700

1.7

mA

nA

V

s

3.6

1

V

A

Note 1:

This parameter is periodically sampled and not 100% tested.

2:

With oscillator running.



2012 Microchip Technology Inc.

Preliminary

DS22300A-page 3

MCP7952X/MCP7951X

TABLE 1-2:

Param.

No.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

AC CHARACTERISTICS

Industrial (I):

Min.

—

100

150

100

150

50

20

30

40

50

—

100

150

100

150

50

—

0

—

1,000,000

T

AMB

= -40°C to +85°C V

CC

= 1.8V to 3.6V

Max.

5

3

—

100

—

100

160

—

80

160

5

—

Units

MHz

ns

ms

Test Conditions

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

—

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

(Note

1)

(Note

1)

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

—

2.5V

Vcc 

3.6V

1.8V

Vcc 

2.5V

(Note

1)

2.5V

Vcc 

3.6V

(Note

1)

1.8V

Vcc 

2.5V

(Note

1)

(Note

3)

AC CHARACTERISTICS

Sym.

F

CLK

T

CSS

T

CSH

T

CSD

Tsu

T

HD

T

R

T

F

T

HI

T

LO

T

CLD

T

CLE

T

V

T

HO

T

DIS

T

WC

—

Characteristic

Clock Frequency

CS Setup Time

CS Hold Time

CS Disable Time

Data Setup Time

Data Hold Time

CLK Rise Time

CLK Fall Time

Clock High Time

Clock Low Time

Clock Delay Time

Clock Enable Time

Output Valid from Clock

Low

Output Hold Time

Output Disable Time

Internal Write Cycle Time

Endurance

E/W

(Note

2)

Cycles

Note 1:

This parameter is periodically sampled and not 100% tested.

2:

This parameter is not tested but ensured by characterization. For endurance estimates in a specific

application, please consult the Total Endurance™ Model which can be obtained from Microchip’s web site:

www.microchip.com.

3:

T

WC

begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle

is complete.

DS22300A-page 4

Preliminary



2012 Microchip Technology Inc.

MCP7952X/MCP7951X

FIGURE 1-1:

SERIAL INPUT TIMING

4

CS

2

SCK

5

SI

MSB In

10

9

6

LSB In

7

8

3

11

12

SO

High-Impedance

FIGURE 1-2:

CS

SERIAL OUTPUT TIMING

9

SCK

10

3

13

SO

MSB Out

Don’t Care

14

15

LSB Out

SI



2012 Microchip Technology Inc.

Preliminary

DS22300A-page 5

MCP79512

MCP79512 Overview

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