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070600

FEATURES

Unique 1-Wire

port pin for communication

Provides unique 64-bit serial number to

battery packs

Eliminates thermistors by sensing battery

temperature on-chip

On-board A/D converter allows monitoring of

battery voltage for end-of-charge and end-of-

discharge determination

On-board integrated current accumulator

facilitates gas gauging

Real-time clock in binary format

40-byte nonvolatile user memory available for

storage of user data such as gas gauge and

manufacturing information

Operating range -40

°C to +85°C

Applications include portable computers,

portable/cellular phones, consumer

electronics, and handheld instrumentation

PIN ASSIGNMENT

PIN DESCRIPTION

DQ

- Data In/Out

VAD

- General A/D input

VSENS+

- Battery current monitor input (+)

VSENS-

- Battery current monitor input (-)

NC

- No connect

GND

- Digital Ground

AGND

- Analog Ground

X2

- Connection for 32.768 kHz XTAL

X1

- Connection for 32.768 kHz XTAL

- Power Supply (2.7V to 10.0V)

DESCRIPTION

The DS2437 Smart Battery Monitor provides several functions that are desirable to carry in a battery

pack: a means of tagging a battery pack with a unique serial number; a direct-to-digital temperature

sensor which eliminates the need for thermistors in the battery pack; an A/D converter which measures

the battery voltage and current; an integrated current accumulator, which keeps a running total of all

current going into and out of the battery; a real-time clock; and 40 bytes of nonvolatile EEPROM

memory for storage of important parameters such as battery capacity, capacity remaining, and indication

of battery cycling.

Information is sent to/from the DS2437 over a 1-Wire interface, so that only one wire (and ground) needs

to be connected from a central microprocessor to a DS2437. This means that battery packs need only

have three output connectors: battery power, ground, and the 1-Wire interface.

Because each DS2437 contains a unique silicon serial number, multiple DS2437s can exist on the same

1-Wire bus. This allows multiple battery packs to be charged or used in the system simultaneously.

DS2437

Smart Battery Monitor

www.dalsemi.com

16-PIN SSOP

See Mech. Drawings Section

15

VAD

VSENS+

NC

AGND

VDD

X1

NC

X2

NC

GND

1

2

3

4

5

6

7

8

16

14

13

12

11

10

9

NC

NC

VSENS-

DQ

NC

NC