DS2437S-3 Maxim Integrated Products, DS2437S-3 Datasheet - Page 4

• Manufacturer Part Number: DS2437S-3
• Description: IC MONITOR SMART BATTERY 16-SSOP
• Manufacturer: Maxim Integrated Products

Specifications of DS2437S-3

• Function: Battery Monitor
• Battery Type: Smart Batteries
• Voltage - Supply: 2.7 V ~ 10 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

OPERATION – MEASURING TEMPERATURE
The DS2437 measures temperatures through the use of an onboard proprietary temperature measurement
technique.
The temperature reading is provided in a 13-bit, two’s complement reading, which provides 0.03125°C of
resolution. Table 1 describes the exact relationship of output data to measured temperature. The data is
transmitted serially over the 1-Wire interface. The DS2437 can measure temperature over the range of
-55°C to +125°C in 0.03125°C increments. For Fahrenheit usage, a lookup table or conversion factor
must be used.
Note that temperature is represented in the DS2437 in terms of a 0.03125°C LSb, yielding the following
13-bit format. The 3 least significant bits of the temperature register will always be 0. The remaining 13
bits contain the two’s complement representation of the temperature in °C, with the MSb holding the sign
(S) bit. See “Memory Map” section for the TEMPERATURE REGISTER address location.
Temperature/Data Relationships Table 1
OPERATION – MEASURING BATTERY VOLTAGE
The on-board analog-to-digital converter (ADC) has 10 bits of resolution and will perform a conversion
when the DS2437 receives a command protocol (Convert V) instructing it to do so. The result of this
measurement is placed in the 2-byte VOLTAGE REGISTER. The range for the DS2437 ADC is 0V to
10V; this range is suitable for NiCd or NiMH battery packs up to six cells and for lithium ion battery
packs of two cells. The full-scale range of the ADC is scaled to 10.23V, resulting in a resolution of 10
mV.
While the ADC has a range that extends to 0V, it is important to note that the battery voltage can also be
the supply voltage to the DS2437. As such, the accuracy of the ADC begins to degrade below battery
voltages of 2.7V, and the ability to make conversions is limited by the operating voltage range of the
DS2437.
TEMPERATURE
+25.0625°C
-25.0625°C
+125°C
+1/2°C
-1/2°C
-55°C
0°C
DIGITAL OUTPUT (Binary)
01111101 00000000
00011001 00010000
00000000 10000000
00000000 00000000
11111111 10000000
11100110 11110000
11001001 00000000
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DIGITAL OUTPUT (Hex)
7D00h
E6F0h
C900h
FF80h
1910h
0080h
0000h
DS2437