BQ24030 Datasheet, PDF (16/20 Pages) Texas Instruments – SINGLE-CHIP CHARGE AND SYSTEM POWER-PATH MANAGEMENT IC (bqTINYI)

bq24030, bq24032, bq24035
SLUS618 – AUGUST 2004
www.ti.com
Charge Status Outputs
The open-drain STAT1 and STAT2 outputs indicate various charger operations as shown in Table 2. These
status pins can be used to drive LEDs or communicate to the host processor. Note that OFF indicates the
open-drain transistor is turned off. Note this assumes CE=HIGH..
CHARGE STATE
Precharge in progress
Fast charge in progress
Charge done
Charge suspend (temperature), timer fault,
and sleep mode
Table 2. Status Pins Summary
STAT1
ON
ON
OFF
OFF
STAT2
ON
OFF
ON
OFF
ACPG, USBPGOutputs (Power Good)
The two open-drain pins, ACPG, USBPG (AC and USB Power Good) indicate when the AC adapter or USB port
is present and above the battery voltage. The corresponding output turns ON (low) when exiting sleep mode
(input voltage above battery voltage). This output is turned off in the sleep mode (open drain). The ACPG,
USBPG pins can be used to drive an LED or communicate to the host processor. Note that OFF indicates the
open-drain transistor is turned off.
CE Input (Chip Enable)
The CE (chip enable) digital input is used to disable or enable the IC. A high-level signal on this pin enables the
chip and a low-level signal disables the device and initiates the standby mode. The bqTINY-III enters the
low-power standby mode when the CE input is low with either AC or USB present. In this suspend mode, internal
PowerFETs Q1 and Q3 (refer to block diagram) are turned off, the battery (BAT pin) is used to power the system
via Q2 and the OUT pin which also powers the LDO. This feature is designed to limit the power drawn from the
input supplies (such as USB suspend mode).
Charge Disable Functions
The DPPM input can be used to disable the charge process. This can be accomplished by floating the DPPM
mode. Note that this applies to both AC and USB charging.
TImer Fault Recovery
As shown in Figure 3, bqTINY-III provides a recovery method to deal with timer fault conditions. The following
summarizes this method:
Condition 1: Charge voltage above recharge threshold (V_(RCH)) and timeout fault occurs.
Recovery Method: bqTINY-III waits for the battery voltage to fall below the recharge threshold. This could
happen as a result of a load on the battery, self-discharge or battery removal. Once the battery falls below the
recharge threshold, the bqTINY-III clears the fault and starts a new charge cycle. A POR or CE toggle also clears
the fault.
Condition 2: Charge voltage below recharge threshold (V_(RCH)) and timeout fault occurs.
Recovery Method:Under this scenario, the bqTINY-III applies the I_(FAULT) current. This small current is used to
detect a battery removal condition and remains on as long as the battery voltage stays below the recharge
threshold. If the battery voltage goes above the recharge threshold, then the bqTINY-III disables the I_(FAULT)
current and executes the recovery method described for condition #1. Once the battery falls below the recharge
threshold, the bqTINY-III clears the fault and starts a new charge cycle. A POR or CE toggle also clears the fault.
16