bq2004E

The bq2004E and bq2004H Fast Charge ICs provide comprehensive fast charge control functions together with high-speed switching power control circuitry on a monolithic CMOS device.


Integration of closed-loop current control circuitry allows the bq2004 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 bq2004E/H-based chargers to support battery conditioning andcapacitydetermination.


High-efficiency power conversion is accomplished using the bq2004E/H as a hysteretic PWM controller for switch-mode regulation of the charging current. The bq2004E/H may alternatively be used to gate an externallyregulatedchargingcurrent.


Fast charge 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 tempera-ture and voltage are within config-uredlimits.


Temperature, voltage, and time of bq2004E are monitored throughout fast charge. Fast charge is terminated by any of thefollowing:
Rateoftemperaturerise(T/t)
Peakvoltagedetection(PVD)
Negativedeltavoltage(-V)
Maximumvoltage
Maximumtemperature
Maximumtime


After fast charge of bq2004E, optional top-off and pulsed current maintenance phases with appropriate display modeselections areavailable.


The bq2004H differs from the bq2004E only in that fast charge, hold-off, and top-off time units have been scaled up by a factor of two, and the bq2004H provides different display selections. Timing differences between the two ICs are illustrated in Table 1. Display differ-encesareshowninTable2.