User's Manual

Description of TC-700 Desktop Charger
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Pin Names and Descriptions:
SNS: Current-sense input
Enables the bq2000T to sense the battery current via the voltage developed on this pin by an
external sense-resistor connected in series with the battery pack.
Vss: System ground
LED: Charge-status output
Open-drain output that indicates the charging status by turning on, turning off, or flashing an
external LED.
BAT: Battery-voltage input
Battery-voltage sense input. A simple resistive divider, across the battery terminals, generates
this input.
TS: Temperature-sense input
Input for an external battery-temperature monitoring circuit. An external resistive divider network
with a negative temperature-coefficient thermistor sets the lower and upper temperature
thresholds.
RC: Timer-program input
RC input used to program the maximum charge-time, hold-off period, and trickle rate during the
charge cycle, and to disable or enable top-off charge.
Vcc: Supply-voltage input
MOD: Modulation-control output
Push-pull output that controls the charging current to the battery. MOD switches high to enable
charging current to flow and low to inhibit charging current flow.