DS2726G+ Maxim Integrated Products, DS2726G+ Datasheet - Page 13

• Manufacturer Part Number: DS2726G+
• Description: IC PROT LI+ 5-10CELL 32-TQFP
• Manufacturer: Maxim Integrated Products

Specifications of DS2726G+

• Function: Over/Under Voltage Protection
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 5 V ~ 50 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The DS2726 allows the selection of a short-circuit cur-
rent threshold. This threshold is set using a resistor
from the RSC pin to the positive terminal of the cell
stack. The RSC pin sinks 1µA (nominal). The short-cir-
cuit comparator triggers when the voltage on the SNS
pin is less than the voltage on the RSC pin. For exam-
ple, assume a 500kΩ resistor is used on RSC, along
with a DC FET with an R
sponds to an RSC voltage of 500kΩ x 1µA = 0.5V.
Because the FET is 10mΩ, the short-circuit threshold is
0.5V/10mΩ = 50A:
The DS2726 allows for a delayed reaction to a short-cir-
cuit event. The short threshold must persist for the
entire delay time before the DC FET begins to turn off
(actual turn-off time varies based on the gate capaci-
tance of the DC FET; see the DC pin drive capabilities
in the DC Electrical Characteristics table for more
details). The short-circuit delay time is set using a
capacitor on the CSCD pin. The short-circuit delay time
can be calculated by the equation:
Be sure to select threshold and delay times that fall
within the safe operating area of the FETs chosen for
DC and CC.
The DS2726 allows the selection of a discharge over-
current threshold. This threshold is set using a resistor
from the RDOC pin to the positive terminal of the cell
stack. The RDOC pin sinks 1µA (nominal). The overcur-
Threshold and Delay Time
Setting the Short-Circuit
t
SCD
______________________________________________________________________________________
I
Overcurrent Threshold
SC
Setting the Discharge
= C
=
1
SCD
R
DS_ON
µA RSC
DS ON
×
_
x 500kΩ
and Delay Time
5-Cell to 10-Cell Li+ Protector with
of 10mΩ. This corre-
rent circuit comparator triggers when the voltage on the
SNS pin is less than the voltage on the RDOC pin. For
example, assume a 200kΩ resistor is used on RDOC,
along with a DC FET with an R
corresponds to a voltage on RDOC of 200kΩ x 1µA =
0.2V. Because the FET is 10mΩ, the discharge overcur-
rent threshold is 0.2V/10mΩ = 20A:
The DS2726 allows for a delayed reaction to a dis-
charge overcurrent event. The discharge overcurrent
threshold must persist for the entire delay time before
the DC FET begins to turn off (actual turn-off time varies
based on the gate capacitance of the DC FET; see DC
pin drive capabilities in the DC Electrical
Characteristics table for more details). The discharge
overcurrent delay time is set using a capacitor on the
CDOCD pin. The discharge overcurrent delay can be
calculated by the equation:
Be sure to select threshold and delay times that fall
within the safe operating area for the FETs chosen for
DC and CC.
If the voltage on the CDOCD pin is within approximately
1V of V
fault, and the CC and DC outputs are disabled. This
results in a delay before enabling the FETs when the
part awakens from Sleep Mode. This delay occurs until
the voltage on CDOCD reaches an acceptable level.
This is a function of the capacitor on CDOCD. The
CDOCD startup delay is in addition to a typical regulator
startup of 100µs, and is given by the equation:
Be sure to select threshold and delay times that fall
within the safe operating area for the FETs chosen for
DC and CC.
STARTUP DELAY ≈ 100µs + C
CC
or GND, the condition is considered to be a
t
DOCD
I
DOC
Cell Balancing
= C
=
1
DOCD
µA R
R
DS ON
×
_
x 32MΩ
DOC
DS_ON
DOCD
of 10mΩ. This
x 1.65MΩ
13