DS2720 Datasheet, PDF (1/21 Pages) Dallas Semiconductor – Efficient, Addressable Single-Cell Rechargeable Lithium Protection IC

www.maxim-ic.com
FEATURES
§ Rechargeable Lithium-Ion (Li+) Safety
Circuit
- Overvoltage Protection
- Overcurrent/Short-Circuit Protection
- Undervoltage Protection
- Overtemperature Protection
§ Controls High-Side N-Channel Power
MOSFETs Driven from 9V Charge Pump
§ System Power Management and Control
Feature Support
§ Eight Bytes of Lockable EEPROM
§ Dallas 1-Wire^® Interface with Unique 64-Bit
Device Address
§ 8-Pin mSOP Package
§ Low Power Consumption:
- Active Current: 12.5mA typ
- Sleep Current: 1.5mA typ
DS2720
Efficient, Addressable Single-Cell
Rechargeable Lithium Protection IC
PIN CONFIGURATION
PLS 1
PS 2
DQ 3
VSS
4
8 CP
7 DC
6 CC
5
VDD
DS2720U
mSOP
PIN DESCRIPTION
PLS - Battery-Pack Positive Terminal Input
PS - Power-Switch Sense Input
DQ - Data Input/Output
V_SS - Device Ground
V_DD - Power-Supply Input
CP - Reservoir Capacitor
CC - Charge Control Output
DC - Discharge Control Output
DESCRIPTION
The DS2720 single-cell rechargeable Li+ protection IC provides electronic safety functions required for
rechargeable Li+ applications including protecting the battery during charge, protection of the circuit
from damage during periods of excess current flow and maximization of battery life by limiting the level
of cell depletion. Protection is facilitated by electronically disconnecting the charge and discharge
conduction path with switching devices such as low-cost N-channel power MOSFETs.
Since the DS2720 provides high-side drive to external N-channel protection MOSFETs from a 9V charge
pump, superior on-resistance performance results compared to common low-side protector circuits using
the same FETs. The FET on-resistance actually decreases as the battery discharges.
Adding to the uniqueness of the DS2720 is the ability of the system to control the FETs from either the
data interface or a dedicated input thereby eliminating the power-switch control redundancy of
rechargeable Li+ battery systems.
Through its 1-Wire interface, the DS2720 gives the host system read/write access to status and control
registers, instrumentation registers, and general-purpose data storage. Each device has a factory-
programmed 64-bit net address that allows it to be individually addressed by the host system.
1-Wire is a registered trademark of Dallas Semiconductor.
1 of 21
112602