DS2715BZ+ Maxim Integrated Products, DS2715BZ+ Datasheet - Page 12
DS2715BZ+
Manufacturer Part Number
DS2715BZ+
Description
IC CTRLR CHRG NIMH BATT 16-SOIC
Manufacturer
Maxim Integrated Products
Datasheet
1.DS2715Z.pdf
(17 pages)
Specifications of DS2715BZ+
Function
Charge Management
Battery Type
Nickel Metal Hydride (NiMH)
Voltage - Supply
4.5 V ~ 16 V
Operating Temperature
-20°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
16-SOIC (0.154", 3.90mm Width)
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
TEMPERATURE SENSE
Accurate temperature sensing is needed to determine end of charge by dT/dt and to detect over temperature fault
conditions. Connecting an external 10k NTC thermistor between THM and V
Div and THM allows the DS2715 to sense temperature. To sense the temperature of the cell pack, locate the
thermistor close to the body of a cell, preferably in the middle of the cell pack. Several recommended 10k
thermistors are shown in Table 3.
Min, Max Temperature Compare
The voltage thresholds of the THM input (V
temperature is between 0C and 45C when using the recommended 10k bias resistor and 10k thermistor
circuit. If pre-charging is in progress, and the voltage on THM reaches V
condition is generated. If the voltage on THM reaches V
stops and the DS2715 enters the DONE state. FAST_CHARGE will complete normally and TOPOFF will begin if
the voltage change on THM exceeds the equivalent T
Table 3. THM THRESHOLDS
Used with a 10k resistor, the Semitec 103AT-2 provides about 0.9% full scale per degree sensitivity. This linearity
is shown in the curve in Figure 4. The left axis is the ratio of the sensed voltage to the divider’s input voltage
(V
Figure 4. RATIO OF THM PIN TO CBIAS PIN OVER TEMPERATURE
Cbias
THRESHOLD
).
STOP
THM
MAX
MIN
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0.35
0.30
0
OF V
RATIO
0.73
0.33
0.29
CBIAS
THERMISTOR
RESISTANCE
10
27.04k
4.925k
4.085k
()
THM-MIN
Divider Output
Degrees Centigrade
, V
20
TERM
12 of 17
THM-MAX
103AT-2
Semitec
ºC per minute (dT/dt Detect specification).
45C
50C
THM-STOP
0C
) are set to allow charging to start if the thermistor
during FAST-CHARGE or TOPOFF, charging
30
TEMPERATURE (C)
THM-STOP
SS
, and a 10k bias resistor between
197-103LAG-A01
173-103LAF-301
, pre-charging stops and a fault
40
Fenwal
42C
47C
4C
50