ds2760bx-025-t-r Maxim Integrated Products, Inc., ds2760bx-025-t-r Datasheet - Page 6

• Manufacturer Part Number: ds2760bx-025-t-r
• Description: Ds2760 High-precision Li+ Battery Monitor
• Manufacturer: Maxim Integrated Products, Inc.

POWER MODES
The DS2760 has two power modes: Active and Sleep. While in Active Mode, the DS2760 continually
measures current, voltage and temperature to provide data to the host system and to support current
accumulation and Li+ safety monitoring. In Sleep Mode, the DS2760 ceases these activities. The
DS2760 enters Sleep Mode when any of the following conditions occurs:
§ the PMOD bit in the Status Register has been set to 1 and the DQ line is low for longer than
§ the voltage on VIN drops below undervoltage threshold V
§ the pack is disabled through the issuance of a SWAP command (SWEN bit =1)
The DS2760 returns to Active Mode when any of the following occurs:
§ the PMOD bit has been set to 1 and the SWEN bit is set to 0 and the DQ line is pulled high
§ the
§ the voltage on PLS becomes greater than the voltage on VIN (charger connection) with the SWEN bit
§ the pack is enabled through the issuance of a SWAP command (SWEN bit =1)
The DS2760 defaults to Sleep Mode when power is first applied.
LI+ PROTECTION CIRCUITRY
During Active Mode, the DS2760 constantly monitors cell voltage and current to protect the battery from
overcharge (overvoltage), overdischarge (undervoltage) and excessive charge and discharge currents
(overcurrent, short circuit). Conditions and DS2760 responses are described in the sections below and
summarized in Table 2 and Figure 3.
LI+ PROTECTION CONDITIONS AND DS2760 RESPONSES Table 2
V
references current delivered from pin SNS.
(1) If V
(2) for the internal sense resistor configuration, the overcurrent thresholds are expressed in terms of
(3) with test current I
(4) with test current I
Overvoltage. If the voltage of the cell exceeds overvoltage threshold V
overvoltage delay t
Protection Register. When the cell voltage falls below charge enable threshold V
Overcurrent, Discharge
Short Circuit
Condition
Name
Overvoltage
Undervoltage
Overcurrent, Charge
IS
2 seconds (pack disconnection)
(pack connection)
set to 0
charges the battery and allows V
current: I
= V
PS
IS1
DD
– V
pin is pulled low (power switch)
<2.2V, release is delayed until the recovery charge current (I
SNS
IS2
. Logic high = V
> I
OC
OVD
TST
TST
for charge direction and I
, the DS2760 shuts off the external charge FET and sets the OV flag in the
current flowing from PLS to VSS (pull-down on PLS)
current flowing from V
V
V
V
VIN > V
VIN < V
Threshold
IS
IS
SNS
PLS
< -V
> V
> V
DD
for
OC
OC
OV
UV
to exceed 2.2V.
SC
(2)
(2)
CC
and V
Delay
t
t
t
t
t
OVD
UVD
OCD
OCD
SCD
Activation
SNS
DD
DD
to PLS (pull-up on PLS)
< -I
6
for
OC
DC
for discharge direction
CC
CC
Sleep Mode
.
UV
Response
All voltages are with respect to VSS. I
CC
DC
DC
,
,
for t
DC
DC
high
high
high
high,
UVD
high
RC
(cell depletion)
) passed from PLS to V
OV
for a period longer than
CE
(charger connected)
V
V
V
, the DS2760 turns the
PLS
PLS
PLS
V
Threshold
VIN < V
PLS
< V
> V
> V
Release
> V
DD
DD
DD
– V
– V
– V
DD
CE
DD
(1)
TP
TP
TP
(3)
(4)
(4)
SNS