Features: Fast charge and conditioning of nickel cadmium or nickel-metal hydridebatteries
Hysteretic PWM switch-mode current regulation or gated controlofanexternalregulator
Easily integrated into systems or usedasastand-alonecharger
Pre-charge qualification of temperatureandvoltage
Configurable, direct LED outputs displaybatteryandchargestatus
Fast-charge termination by temperature/ time, peak volume detection, -V, maximum voltage,maximum temperature, and maxi-mumtime
Optional top-off charge and pulsed current maintenance charging
Logic-level controlled low-power mode(<5Astandbycurrent)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 |
|
DescriptionThe bq2004 Fast Charge IC provides comprehensive fast charge control functions together with high-speed switching power control circuitry on a monolithicCMOSdevice.
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 bq2004-based chargers to support battery conditioning and capacitydetermination.
High-efficiency power conversion is accomplished using the bq2004 as a hysteretic PWM controller for switch-mode regulation of the charg-ing current. The bq2004 may alterna-tively be used to gate an externally regulatedchargingcurrent.
Fast charge may begin on application of the charging supply, replacementof 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 bq2004 are monitored throughout fast charge. Fast charge is terminated by any of thefollowing:
Rateoftemperaturetime (T/t)
Peakvoltagedetection(PVD)
Negativedeltavoltage(-V)
Maximumvoltage Maximumtemperature
Maximumtime
After fast charge, optional top-off and pulsed current maintenance phasesareavailable.
bq2004 Data Sheet
