bq2005

Features:

Sequential fast charge and con-ditioning of two NiCd or NiMH nickel cadmium or nickel-metal hydridebatterypacks
Hysteretic PWM switch-mode current regulation or gated controlofanexternalregulator
Easily integrated into systems orusedasastand-alonecharger
Pre-charge qualification of temperatureandvoltage
Direct LED outputs display batteryandchargestatus
Fast-chargeterminationby
temperature/? time, -V, maximum voltage, maximum temperature,andmaximumtime
Optional top-off and pulsetricklecharging


Pinout




Specifications

Symbol	Parameter	Minimum	Maximum	Unit	Notes
VCC	VCC relative to VSS	-0.3	+7.0	V
VT	DC voltage applied on any pin ex- cluding VCC relative to VSS	-0.3	+7.0	V
TOPR	Operating ambient temperature	-20	+70	°C	Commercial
TSTG	Storage temperature	-55	+125	°C
TSOLDER	Soldering temperature	-	+260	°C	10 sec. max.
TBIAS	Temperature under bias	-40	+85	°C

Description

The bq2005 Fast-Charge IC provides comprehensive fast charge control functions together with high-speed switching power control circuitry on a monolithicCMOS device for sequential charge management in dual battery packapplications.


Integration of closed-loop current control circuitry allows the bq2005 to be the basis of a cost-effective solution for stand-alone and system-integrated chargers for batteries of oneormorecells.


Switch-activated discharge-before charge allows bq2005-based chargers to support battery conditioning and capacitydetermination.


High-efficiency power conversion is accomplished using the bq2005 as a hysteretic PWM controller for switch-mode regulation of the charging current. The bq2005 may alterna-tively be used to gate an externally regulatedchargingcurrent.


Fast charge of bq2005 may begin on application of the charging supply, replacement of the battery, or switch depression. For safety, fast charge is inhibited unless/until the battery temperature and voltage are within configuredlimits.


Temperature, voltage, and time of bq2005 are monitored throughout fast charge.Fast charge is terminated by any of thefollowing:
Rateoftemperaturerise(T/t)
Negativedeltavoltage(-V)
Maximumvoltage
Maximumtemperature
Maximumtime


After fast charge, optional top-off and pulsed current maintenance phasesareavailable.