BQ25060_1 Datasheet, PDF (14/24 Pages) Texas Instruments – 1A, Single-Input, Single Cell Li-Ion Battery Charger with 50-mA LDO, and External Power Path Control

bq25060
SLUSA32 – MAY 2010
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Input Current Limit Control (EN)
The bq25060 contains a 3-state that controls the input current limit. Drive EN low to program the input current
limit to the user defined value programmed using ISET. Drive EN high to place the bq25060 in USB suspend
mode. In USB suspend mode, the input current into bq25060 is reduced and the external battery FET is held on
(BGATE pulled to GND). Leaving EN unconnected or connected to a high impedance source programs the
USB500 input current limit.
Table 1. EN Input Definition
EN
MODE
Low
ISET
Hi-Z
USB500
Hi
USB Suspend
Input Over Voltage Protection
The bq25060 contains an input over voltage protection circuit that disables the LDO output and charging when
the input voltage rises above V_OVP. This prevents damage from faulty adapters. The OVP circuitry contains an
deglitch that prevents ringing on the input from line transients from tripping the OVP circuitry falsely. If an adapter
with an output greater than V_OVP is plugged in, the IC completes power up and then shuts down if the voltage
remains above V_OVP after the deglitch. The LDO remains off and charging remains disabled until the input
voltage falls below V_OVP.
Under-Voltage Lockout (UVLO)
The bq25060 remains in power down mode when the input voltage is below the under-voltage lockout threshold
(VUVLO). During this mode, the control input (EN) is ignored. The LDO, the charge FET connected between IN
and OUT are off and the status output (CHG) is high impedance. Once the input voltage rises above V_UVLO, the
internal circuitry is turned on and the normal operating procedures are followed.
Input DPM Mode (V_IN-DPM)
The input current into the bq25060 includes all load currents, i.e. the system load, LDO load, and battery charge
current. The total input current is regulated by the input current limit of the bq25060. The bq25060 utilizes the
V_IN-DPM mode for operation from current-limited input sources.
WIth V_IN-DPM enabled, the input voltage is monitored. If V_IN falls to V_IN-DPM, the input current limit is reduced to
prevent the input voltage from falling further. This prevents the bq25060 from crashing poorly designed or
incorrectly configured USB sources. Figure 20 shows the V_IN-DPM behavior to a current limited source. In this
figure the input source has a 200mA current limit and the device has started up with the 285mA current limit.
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