Texas Instruments bq24072RGTR, User Manual

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Introduction
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1 Introduction
The bq2407x and bq2432x powers the system while independently charging the battery. This feature
reduces the charge and discharge cycles on the battery, allows for proper charge termination, and allows
the system to run with an absent or defective battery pack. This feature also allows for the system to
instantaneously turn on from an external power source even when using a deeply discharged battery
pack.
This charger has one input and can be programmed to be used with an adapter or USB port as the power
source for the system. In the USB configuration, the host can select from the two preset input maximum
rates of 100 mA and 500 mA. The charger dynamically adjusts the charge rate based on the system load
to stay within the 100-mA or 500-mA maximum limits. An external resistor, RSET1, sets the magnitude of
the charge current. If the charge current exceeds the available input current, the voltage on the OUT pin
drops to the DPPM threshold or the battery voltage, whichever is higher. The charging current is reduced
to what current is available (I
BAT
= I
IN
–I
OUT
).
The integrated circuit (IC) charges the battery in three phases: conditioning, constant current, and
constant voltage. Charge is terminated based on minimum current. A resistor-programmable charge timer
provides a backup safety for charge termination. The charge automatically re-starts if the battery voltage
falls below an internal threshold. Sleep mode is entered when the supply is removed (Vin drops to the
battery voltage).
2 Considerations When Testing and Using bq24072/3/4/5/9(T) and bq24230/2 ICs
Consider the following noteworthy items while testing and using the bq2403x ICs.
The bq24072/3/4/5/9(T) series targets current above a nominal 500 mA (>350 mA) and the difference are
listed in
Table 1 .
Table 1. Ordering Information
Optional
Part Number V
OVP
V
BAT
V
OUT(REG)
V
DPM
Marking
Function
bq24072RGTR 6.6 V 4.2 V V
BAT
+ 200 mV V
O(REG)
– 100 mV TD CKP
bq24072RGTT 6.6 V 4.2 V V
BAT
+ 200 mV V
O(REG)
– 100 mV TD CKP
bq24072TRGTR 6.6 V 4.2 V V
BAT
+ 225 mV V
O(REG)
– 100 mV TD PAP
bq24072TRGTT 6.6 V 4.2 V V
BAT
+ 225 mV V
O(REG)
– 100 mV TD PAP
bq24073RGTR 6.6 V 4.2 V 4.4 V V
O(REG)
– 100 mV TD CKQ
bq24073RGTT 6.6 V 4.2 V 4.4 V V
O(REG)
– 100 mV TD CKQ
bq24074RGTR 10.5 V 4.2 V 4.4 V V
O(REG)
– 100 mV ITERM BZF
bq24074RGTT 10.5 V 4.2 V 4.4 V V
O(REG)
– 100 mV ITERM BZF
bq24075RGTR 6.6 V 4.2 V 5.5 V 4.3 V SYSOFF CDU
bq24075RGTT 6.6 V 4.2 V 5.5 V 4.3 V SYSOFF CDU
bq24075TRGTR 6.6 V 4.2 V 5.5 V 4.3 V SYSOFF OEC
bq24075TRGTT 6.6 V 4.1 V 5.5 V 4.3 V SYSOFF OEC
bq24079RGTR 6.6 V 4.1 V 5.5 V 4.3 V SYSOFF ODI
bq24079RGTT 6.6 V 4.1 V 5.5 V 4.3 V SYSOFF ODI
bq24079TRGTR 6.6 V 4.1 V 5.5 V 4.3 V SYSOFF OED
bq24079TRGTT 6.6 V 4.1 V 5.5 V 4.3 V SYSOFF OED
The bq24079(T) ICs are regulated to 4.1 V. The "T" version uses a voltage-based TS bias, which allows
more flexibility in setting the temperature range, whereas the bq24072/3/4/5 ICs use current-biased TS.
The bq24230/2 family is identical to the bq24073/4 ICs except that they are trimmed and their target
current values nominally are at 300 mA (<450 mA). This family is suited for headset designs. The pinout of
each IC is the same across both families except pin 15 (JMP2 on the EVM); the pin 15 function is listed in
Table 1 under the Optional Function column.
bqTINY-III is a trademark of Texas Instruments.
2 bq24072/3/4/5/9(T) and bq24230/2 1.5-A Single-Chip Li-Ion —and Li-Polymer SLVU274C – November 2008 – Revised May 2010
Charge Management IC EVM
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