DS2788K Maxim Integrated, DS2788K Datasheet - Page 6

• Manufacturer Part Number: DS2788K
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Series: DS2788r

The DS2788 operates directly from 2.5V to 4.5V and
supports single-cell Li+ battery packs. As shown in
Figure 2, the DS2788 accommodates multicell applica-
tions by adding a trim resistor for calibration of an
external voltage-divider for V
for cell compensation and application parameters.
Host-side development of fuel-gauging algorithms is
eliminated. On-chip algorithms and convenient status
reporting of operating conditions reduce the serial
polling required of the host processor.
Additionally, 16 bytes of EEPROM memory are made
available for the exclusive use of the host system
and/or pack manufacturer. The additional EEPROM
memory can be used to facilitate battery lot and date
tracking and NV storage of system or battery usage
statistics.
A 1-Wire interface provides serial communication at the
standard 16kbps or overdrive 140kbps speeds, allow-
ing access to data registers, control registers, and user
memory. A unique, factory-programmed, 64-bit regis-
Stand-Alone Fuel-Gauge IC with
LED Display Drivers
Figure 2. Multicell Application Example
6
330Ω
LEDs
DATA
PK+
PK-
_______________________________________________________________________________________
330Ω
330Ω
150Ω
330Ω
5.6V
Detailed Description
330Ω
IN
. NV storage is provided
LED1
LED2
LED3
LED4
LED5
DQ
SNS
DS2788
20mΩ
R
SNS
DV
VMA
OVD
V
V
PIO
V
DD
SS
SS
IN
B3F-1000
tration number (8-bit family code + 48-bit serial number
+ 8-bit CRC) assures that no two parts are alike and
enables absolute traceability. The 1-Wire interface on
the DS2788 supports multidrop capability so that multi-
ple slave devices can be addressed with a single pin.
The DS2788 has two power modes: ACTIVE and
SLEEP. On initial power-up, the DS2788 defaults to
ACTIVE mode. While in ACTIVE mode, the DS2788 is
fully functional with measurements and capacity esti-
mation continuously updated. In SLEEP mode, the
DS2788 conserves power by disabling measurement
and capacity estimation functions, but preserves regis-
ter contents. SLEEP mode is entered under two differ-
ent conditions and an enable bit for each condition
makes entry into SLEEP optional. SLEEP mode can be
enabled using the power mode (PMOD) bit or the
undervoltage enable (UVEN) bit.
The PMOD type SLEEP is entered if the PMOD bit is set
and DQ is low for t
DQ low for t
RST
MAX6765TTLD2+
OUT
IN
10μF
TIMEOUT
ENABLE
SLEEP
GND
BSS84
can be used to detect a pack discon-
SLEEP
0.1μF
0.1μF
(2s nominal). The condition of
900kΩ
2N7002
100kΩ
Power Modes
10kΩ
10kΩ
PROTECTION
CIRCUIT
10-CELL
Li+ BATTERY