Texas Instruments BQ24055 Evaluation Module: 0.8-A, Single-Input, Single-Cell Li-Ion Battery Charger BQ24052EVM BQ24052EVM 데이터 시트
제품 코드
BQ24052EVM
Introduction
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1
Introduction
The bq2405x series of devices are highly integrated Li-ion linear chargers devices targeted at
space-limited portable applications. The devices operate from either a USB port or AC adapter.
space-limited portable applications. The devices operate from either a USB port or AC adapter.
The bq2405x has a single power output that charges the battery. A system load can be placed in parallel
with the battery as long as the average system load does not keep the battery from charging fully during
the 10 hour safety timer.
with the battery as long as the average system load does not keep the battery from charging fully during
the 10 hour safety timer.
The bq24050/2/5 have an integrated USB detect routine that looks for an USB connection on power-up
and initially sets the charge input control to either the programmed ISET level, if an adaptor is detected, or
to USB100 mode if an USB port is detected. This aides in a faster charge if the battery is discharged and
the USB device transceiver is not powered and an adaptor is connected.
and initially sets the charge input control to either the programmed ISET level, if an adaptor is detected, or
to USB100 mode if an USB port is detected. This aides in a faster charge if the battery is discharged and
the USB device transceiver is not powered and an adaptor is connected.
The battery is charged in three phases: conditioning, constant current and constant voltage. In all charge
phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an
internal temperature threshold is exceeded.
phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an
internal temperature threshold is exceeded.
The charger power stage and charge current sense functions are fully integrated. The charger function
has high accuracy current and voltage regulation loops, charge status display, and charge termination.
The pre-charge current and termination current threshold are programmed via an external resistor on the
bq24050/2/5. The fast charge current value is also programmable via an external resistor
has high accuracy current and voltage regulation loops, charge status display, and charge termination.
The pre-charge current and termination current threshold are programmed via an external resistor on the
bq24050/2/5. The fast charge current value is also programmable via an external resistor
2
Considerations With Evaluating the bq24050/2/5
Refer to the data sheet for specific details on the charger ICs. The main differences between the
bq24050/2/5 spins is: (1) The '50 uses a 10k NTC thermistor, (2) the '52 uses a 100k NTC thermistor, and
(3) the '55 uses a 10k NTC thermistor and has a PG pin.
bq24050/2/5 spins is: (1) The '50 uses a 10k NTC thermistor, (2) the '52 uses a 100k NTC thermistor, and
(3) the '55 uses a 10k NTC thermistor and has a PG pin.
The ISET current control loop sets the maximum charge current. This maximum programmed current level
can be further reduced by entering a USB mode, selected by the ISET2 pin.
can be further reduced by entering a USB mode, selected by the ISET2 pin.
A system load may be connected to the OUT pin which will take away some of the charge current.
Normally it is not recommended to operate the system in pre-charge mode since the system load keeps
the battery from recovering, but since the PRE_TERM pin can program a higher pre-charge current this
restriction is not necessary.
Normally it is not recommended to operate the system in pre-charge mode since the system load keeps
the battery from recovering, but since the PRE_TERM pin can program a higher pre-charge current this
restriction is not necessary.
3
Performance Specification Summary
Specificaton
Test Conditions
Min
Typ
Max
Units
Input DC voltage, Vin
Recommended input voltage range
4.45
6.45
V
Reduced Performance, Vin
(1)
Will not charge with Over Voltage input condition. Limited
3.5
28
V
charging with under voltage input.
Power Dissipation
(2)
P
DISS
= (V
IN
– V
OUT
) × I
OUT
1.5
W
I
OUT
RISET = 1k
0.54
0.8
A
(1)
Input voltage range is specified for normal operation. Input voltage between UVLO and 4.75 V has limited functionality, but does not
damage the IC nor present any safety issue with the battery. Input voltage above OVP and less than 30 Vdc has no operation and will
not damage the IC. Lower input voltage (closer to dropout operation) produces less heat dissipation and potentially better performance.
damage the IC nor present any safety issue with the battery. Input voltage above OVP and less than 30 Vdc has no operation and will
not damage the IC. Lower input voltage (closer to dropout operation) produces less heat dissipation and potentially better performance.
(2)
The junction temperature rise above ambient is proportional to the power dissipation. Once the junction temperature reaches ~125°C,
thermal regulations reduces the programmed charge current.
thermal regulations reduces the programmed charge current.
4
Test Summary
The bq24050/2/5 EVM board requires a 5-VDC, 1-A power source to provide input power and a single-cell
Li-ion or Li-polymer battery pack. The test setup connections and jumper setting selections are configured
for a stand-alone evaluation but can be changed to interface with external hardware such as a
microcontroller.
Li-ion or Li-polymer battery pack. The test setup connections and jumper setting selections are configured
for a stand-alone evaluation but can be changed to interface with external hardware such as a
microcontroller.
2
0.8-A, Single-Input, Single-Cell Li-Ion Battery Charger
SLUU378 – September 2009
Copyright © 2009, Texas Instruments Incorporated