Maxim DS1672U-2, DS1672U-3, DS1672U-33, DS1672-2, DS1672-3 Schematic

R

www.maxim-ic.com

DS1672

2

C 32-Bit Binary Counter RTC

I

GENERAL DESCRIPTION

The DS1672 incorporates a 32-bit counter and power-monitoring functions. The 32-bit counter is designed to count seconds and can be used to derive time-of-day, week, month, month, and year by using a software algorithm. A precision, temperature-compensated reference and comparator circuit monitors the status of VCC. When an out-of-tolerance condition occurs, an internal power-fail signal is generated that forces the reset to the active state. When VCC returns to an in-tolerance condition, the reset signal is kept in the active state for a period of time to allow the power supply and processor to stabilize.

TYPICAL OPERATING CIRCUIT

FEATURES

 32-Bit Counter

 I2C* Serial Interface

 Automatic Power-Fail Detect and Switch

Circuitry

 Power-Fail Reset Output

 Low-Voltage Oscillator Operation

(1.3V min)

 Trickle-Charge Capability

 Underwriters Laboratory (UL) Recognized

 -40°C to +85°C Operating Temperature

Range

PIN CONFIGURATION

TOP VIEW

V

BACKUP

X1

X2

GND

*Purchase of I2C components from Maxim Integrated Products, Inc., or one of its sublicensed Associated Companies, conveys a license under the Philips I components in an I to the I

2

C Standard Specification defined by Philips.

1

DS1672

2

3

4

µSOP

2

C system, provided that the system conforms

8

7

6

5

DIP

SO

C Patent Rights to use these

V

CC

ST

SCL

SDA

1 of 15 REV: 031406

ORDERING INFORMATION

PART TEMP RANGE VOLTAGE (V) PIN-PACKAGE TOP MARK*

DS1672-2 -40°C to +85°C 2.0 8 DIP (300 mils) DS1672-2

DS1672-3 -40°C to +85°C 3.0 8 DIP (300 mils) DS1672-3

DS1672-33 -40°C to +85°C 3.3 8 DIP (300 mils) DS1672-33

DS1672S-2 -40°C to +85°C 2.0 8 SO (150 mils) DS1672-2

DS1672S-2+ -40°C to +85°C 2.0 8 SO (150 mils) D1672-2

DS1672S-3 -40°C to +85°C 3.0 8 SO (150 mils) DS1672-3

DS1672S-3+ -40°C to +85°C 3.0 8 SO (150 mils) D1672-3

DS1672S-33 -40°C to +85°C 3.3 8 SO (150 mils) DS167233

DS1672S-33+ -40°C to +85°C 3.3 8 SO (150 mils) D167233

DS1672

DS1672S-3/T&R -40°C to +85°C 3.0

DS1672S-3+T&R -40°C to +85°C 3.0

DS1672S-33/T&R -40°C to +85°C 3.3

DS1672S-33+T&R -40°C to +85°C 3.3

DS1672U-2 -40°C to +85°C 2.0

DS1672U-2+ -40°C to +85°C 2.0

DS1672U-3 -40°C to +85°C 3.0

DS1672U-3+ -40°C to +85°C 3.0

DS1672U-33 -40°C to +85°C 3.3

DS1672U-33+ -40°C to +85°C 3.3

DS1672U-33/T&R -40°C to +85°C 3.3

DS1672U-33+T&R -40°C to +85°C 3.3

8 SO (150 mils)/Tape and Reel 8 SO (150 mils)/Tape and Reel 8 SO (150 mils)/Tape and Reel 8 SO (150 mils)/Tape and Reel

8 µSOP (3mm)

8 µSOP (3mm)/Tape and Reel

DS1672-3

D1672-3

DS167233

D167233

1672 rr -2 1672 rr -2 1672 rr -3 1672 rr -3 1672 rr -33 1672 rr -33

1672 rr -33

+ Denotes a lead-free/RoHS-compliant device. * A “+” anywhere on the top mark denotes a lead-free device. rr = 2-digit alphanumeric revision code.

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DS1672

ABSOLUTE MAXIMUM RATINGS

Voltage Range on Any Pin Relative to Ground……………………………………………..-0.5V to +6.0V Operating Temperature Range (noncondensing) ...…………………………………………-40°C to +85°C Storage Temperature Range……………………………………………………………….-55°C to +125°C Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification

This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect device reliability.

RECOMMENDED DC OPERATING CONDITIONS

(TA = -40°C to +85°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Supply Voltage

Logic 1 VIH 0.7 x VCC V

DS1672-2 VCC 1.8 2.0 2.2 DS1672-3 VCC 2.7 3.0 3.3 DS1672-33 V

2.97 3.3 3.63

CC

+ 0.5 V 1

CC

V 1

Logic 0 VIL -0.5 +0.3 x VCC V 1 Backup Supply Voltage V

1.3 3.0 3.63 V 1

BACKUP

DC ELECTRICAL CHARACTERISTICS

(V

Active Supply Current I Standby Current I

Power-Fail Voltage VPF

CCMIN

< VCC < V

CCMAX, TA

= -40°C to +85°C.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

600

CCA

500

CCS

µA µA

2 3

2.70 2.88 2.97

2.45 2.6 2.7

V

1.58 1.7 1.8

V

Leakage Current I

BACKUP

BACKUPLKG

25 50 nA

Logic 0 Output (VOL = 0.4V) IOL 3 mA 1, 4

Logic 0 Output (DS1672-2)

Note 1: All voltages referenced to ground.

Note 2: I

Note 3: I

Note 4: SDA and RST.

specified with SCL clocking at max frequency (400kHz), trickle charger disabled.

CCA

specified with VCC = V

CCS

(VCC > 2V; V

= 0.4V)

OL

< 2V;

(V

CC

V

= 0.2 x VCC)

OL

CCTYP

I

OL

and SDA, SCL = V

CCTYP

3

mA 1, 4

3

, trickle charger disabled.

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DS1672

DC ELECTRICAL CHARACTERISTICS

(VCC = 0V, TA = -40°C to +85°C.)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

V V

Note 5: Using the recommended crystal on X1 and X2.

Current (Oscillator On) I

BACKUP

Current (Oscillator Off) I

BACKUP

BACKUPOSC

BACKUP

0.425 1

µA

5

200 nA

CRYSTAL SPECIFICATIONS

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Nominal Frequency fO 32.768 kHz Series Resistance ESR 45 kΩ Load Capacitance CL 6 pF

*The crystal, traces, and crystal input pins should be isolated from RF generating signals. Refer to Application Note 58: Crystal Considerations for Dallas Real-Time Clocks for additional specifications

*

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DS1672

AC ELECTRICAL CHARACTERISTICS

(VCC = 0V, TA = -40°C to +85°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS NOTES

SCL Clock Frequency

Bus Free Time Between a STOP and START Condition Hold Time (Repeated) START Condition

LOW Period of SCL Clock

HIGH Period of SCL Clock

Setup Time for a Repeated START Condition

Data Hold Time t

Data Setup Time t

Rise Time of Both SDA and SCL Signals Fall Time of Both SDA and SCL Signals

Setup Time for STOP Condition

f

SCL

t

BUF

t

HD:STA

t

LOW

t

HIGH

t

SU:STA

HD:DAT

SU:DAT

t

R

t

F

t

SU:STO

Fast mode 100 400

kHz

Standard mode 100

Fast mode 1.3

µs

Standard mode 4.7

Fast mode 0.6

µs

6

Standard mode 4.0

Fast mode 1.3

Standard mode 4.7

µs

Fast mode 0.6

µs

Standard mode 4.0

Fast mode 0.6

µs

Standard mode 4.7

Fast mode 0 0.9

µs

7, 8

Standard mode 0

Fast mode 100

ns 9

Standard mode 250

Fast mode 20 + 0.1CB 300

ns 10

Standard mode 1000

Fast mode 20 + 0.1CB 300

ns 10

Standard mode 300

Fast mode 0.6

µs

Standard mode 4.0

Capacitive Load for Each Bus Line

I/O Capacitance C

Note 6: After this period, the first clock pulse is generated.

Note 7: A device must internally provide a hold time of at least 300ns for the SDA signal (referenced to the V

order to bridge the undefined region of the falling edge of SCL.

Note 8:The maximum t

Note 9: A fast-mode device can be used in a standard-mode system, but the requirement t

automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW

period of the SCL signal, it must output the next data bit to the SDA line t

line is released.

Note 10: C

–Total capacitance of one bus line in pF.

B

has only to be met if the device does not stretch the LOW period (t

HD:DAT

400 pF 10

C

B

10 pF

I/O

) of the SCL signal.

LOW

≥ to 250ns must then be met. This will

SU:DAT

max + t

R

= 1000 + 250 = 1250ns before the SCL

SU:DAT

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of the SCL signal) in

IHMIN

Maxim DS1672U-2, DS1672U-3, DS1672U-33, DS1672-2, DS1672-3 Schematic [ru]

GENERAL DESCRIPTION

TYPICAL OPERATING CIRCUIT

FEATURES

PIN CONFIGURATION

ORDERING INFORMATION

ABSOLUTE MAXIMUM RATINGS

RECOMMENDED DC OPERATING CONDITIONS

DC ELECTRICAL CHARACTERISTICS

DC ELECTRICAL CHARACTERISTICS

AC ELECTRICAL CHARACTERISTICS