DS2764AXSLASHT datasheet(10/20 Pages) MAXIM

10 / 20 page

DS2764 High-Precision Li+ Battery Monitor With 2-Wire Interface

10 of 20

Overcurrent, Charge Direction. The voltage difference between the IS1 pin and the IS2 pin (VIS = VIS1 - VIS2) is the

filtered voltage drop across the current-sense resistor. If VIS exceeds overcurrent threshold VOC for a period longer

than overcurrent delay tOCD, the DS2764 shuts off both external FETs and sets the COC flag in the protection

DS2764 provides a test current of value ITST from PLS to VSS to pull PLS down to detect the removal of the

offending charge current source.

Overcurrent, Discharge Direction. If VIS is less than -VOC for a period longer than tOCD, the DS2764 shuts off the

external discharge FET and sets the DOC flag in the protection register. The discharge current path is not re-

established until the voltage on PLS rises above VDD - VTP. The DS2764 provides a test current of value ITST from

VDD to PLS to pull PLS up to detect the removal of the offending low-impedance load.

Short Circuit. If the voltage on the SNS pin with respect to VSS exceeds short-circuit threshold VSC for a period

longer than short-circuit delay tSCD, the DS2764 shuts off the external discharge FET and sets the DOC flag in the

protection register. The discharge current path is not re-established until the voltage on PLS rises above VDD - VTP.

The DS2764 provides a test current of value ITST from VDD to PLS to pull PLS up to detect the removal of the short

circuit.

Figure 4. Li+ Protection Circuitry Example Waveforms

Summary. All of the protection conditions described above are OR’ed together to affect the

CC and DC outputs.

DC = (Undervoltage) or (Overcurrent, Either Direction) or (Short Circuit) or (Protection Register Bit DE = 0)

or (Sleep Mode)

CC = (Overvoltage and VIS ≥ -2mV) or (Undervoltage) or (Overcurrent, Charge Direction) or (Protection

Soft Startup. The discharge protection FET is turned on slowly when the DS2764 enters Active mode from Sleep.

The soft startup reduces the inrush current that normally occurs when a battery pack is inserted into an un-powered

host system. Soft Startup does not reduce inrush currents if the DS2764 is already in Active mode when the

battery pack is connected to the un-powered system.

MODE

VOV

VCE

VUV

VCELL

VIS

CHARGE

DISCHARGE

-VSC

VOC

-VOC

tSCD

tOCD

tUVD

tOVD

VPLS

VDD

ACTIVE

VSS

SLEEP

tOVD

(NOTE 1)

NOTE 1: TO ALLOW THE DEVICE TO REACT QUICKLY TO SHORT CIRCUITS, DETECTION OCCURS ON THE SNS PIN RATHER THAN ON THE

FILTERED IS1 AND IS2 PINS. THE ACTUAL SHORT-CIRCUIT DETECT CONDITION IS VSNS > VSC.

DS2764AX/T Datasheet(PDF) 10 Page - Maxim Integrated Products

DS2764AX/T Datasheet(HTML) 10 Page - Maxim Integrated Products

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL