TI BQ24296

bq24296
bq24297
www.ti.com
SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
I2C Controlled 3A Single Cell USB Charger With Narrow VDC
Power Path Management and Adjustable Voltage USB OTG
Check for Samples: bq24296, bq24297
FEATURES
1
•
•
2
•
•
•
•
•
90% High Efficiency Switch Mode 3A Charger
3.9V-6.2V Single Input USB-compliant Charger
with 6.4V Over-Voltage Protection
– USB Host or Charging Port D+/D- Detection
Compatible to USB Battery Charger Spec
(BC1.2)
– Support Non-standard 2A/1A Adapters
detection (bq24297)
– Input voltage and current limit supports
USB2.0 and USB 3.0
– Input Current Limit: 100mA, 150mA, 500mA,
900mA, 1A, 1.5A, 2A, and 3A
USB OTG with Adjustable output [email protected] or 1.5A
– Fast OTG Startup (22ms typ.)
– 90% 5V Boost Mode Efficiency
– Accurate +/-15% Hiccup Mode Overcurrent
Protection
Narrow VDC (NVDC) Power Path Management
– Instant System On with No Battery or
Deeply Discharged Battery
– Ideal Diode Operation in Battery
Supplement Mode
1.5MHz Switching Frequency for Low Profile
1.2mm Inductor
I2C port for optimal system performance and
status reporting
Autonomous Battery Charging with or without
Host Management
– Battery Charge Enable
– Battery Charge Preconditioning
– Charge Termination and Recharge
•
•
•
•
•
•
•
High Accuracy
– ±0.5% Charge Voltage Regulation
– ±7% Charge Current Regulation
– ±7.5% Input Current Regulation
– ±3% Output Voltage Regulation in USB
OTG Boost Mode
High Integration
– Power Path Management
– Synchronous Switching MOSFETs
– Integrated Current Sensing
– Bootstrap Diode
– Internal Loop Compensation
Safety
– Battery Temperature Sensing for Charging
and Discharging in OTG Mode
– Battery Charging Safety Timer
– Thermal Regulation and Thermal Shutdown
– Input and System Over-Voltage Protection
– MOSFET Over-Current Protection
Charge Status Outputs for LED or Host
Processor
Maximum power tracking capability by input
voltage regulation
20µA Low Battery Leakage Current and
Support Shipping Mode
4mm x 4mm QFN-24 Package
APPLICATIONS
•
•
•
•
Tablet PC
Smart Phone
Portable Audio Speaker
Internet Devices
1
2
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2013, Texas Instruments Incorporated
bq24296
bq24297
SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
DESCRIPTION
The bq24296 and bq24297 are highly-integrated switch-mode battery charge management and system power
path management device for 1 cell Li-Ion and Li-polymer battery in a wide range of smartphone and tablet
applications. Its low impedance power path optimizes switch-mode operation efficiency, reduces battery charging
time and extends battery life during discharging phase. The I2C serial interface with charging and system
settings makes the device a truly flexible solution.
The device supports a 3.9V-6.2V USB input sources, including standard USB host port and USB charging port
with 6.4V over-voltage protection. The device is compliant with USB 2.0 and USB 3.0 power specifications with
input current and voltage regulation. To set the default input current limit, the bq24296 takes the result from the
detection circuit in the system, such as USB PHY device and the bq24297 detects the input source through
D+/D- detection following the USB battery charging spec 1.2. In addition, the bq24297 detects non-standard
2A/1A adapters. The device also supports USB On-the-Go operation by providing fast startup and supplying
adjustable voltage 4.55-5.5V (default 5V) on the VBUS with a accurate current limit up to 1.5A.
The power path management regulates the system slightly above battery voltage but does not drop below 3.5V
minimum system voltage (programmable). With this feature, the system keeps operating even when the battery
is completely depleted or removed. When the input source current or voltage limit is reached, the power path
management automatically reduces the charge current to zero and then starts discharges the battery until the
system power requirement is met. This supplement mode operation keeps the input source from getting
overloaded.
The device initiates and completes a charging cycle when host control is not available. It automatically charges
the battery in three phases: pre-conditioning, constant current and constant voltage. In the end, the charger
automatically terminates when the charge current is below a preset limit in the constant voltage phase. Later on,
when the battery voltage falls below the recharge threshold, the charger will automatically start another charging
cycle.
The charge device provides various safety features for battery charging and system operation, including negative
thermistor monitoring, charging safety timer and over-voltage/over-current protections. The thermal regulation
reduces charge current when the junction temperature exceeds 120°C (programmable).
The STAT output reports the charging status and any fault conditions. The INT immediately notifies host when
fault occurs.
The bq24296 and bq24297 are available in 24-pin, 4x4 mm2 thin QFN package.
bq24296/bq24297 Family Table
bq24296
bq24297
I2C Address
6BH
6BH
USB OTG
Yes
Adjustable [email protected] (max)
Yes
Adjustable [email protected] (max)
USB Detection
PSEL
D+/D–
Default Battery Voltage
4.208V
4.208V
2.048A
Default Charge Current
2.048A
Default Adapter Current Limit
3A
3A
Default Pre-charge Current / Max Pre-charge
Current
256mA / 2.048A
256mA / 2.048A
2
Default Termination Current
256mA
256mA
Charging Temperature Profile
Cold/Hot
Cold/Hot
Status Output
STAT, PG
STAT
Blinking @ 1Hz
STAT During Fault
Blinking @ 1Hz
Default Safety Timer
12hr
12hr
Default VINDPM
4.36V
4.36V
Default Pre-charge Timer
4hr
4hr
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Product Folder Links: bq24296 bq24297
bq24296
bq24297
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
ORDERING INFORMATION
PART NUMBER
PART MARKING
PACKAGE
bq24296
bq24296
24-pin 4mmx4mm QFN
bq24297
bq24297
24-pin 4mmx4mm QFN
ORDERING NUMBER
QUANTITY
bq24296RGER
3000
bq24296RGET
250
bq24297RGER
3000
bq24297RGET
250
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
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APPLICATION DIAGRAM
bq24296
5V USB
SDP/DCP
VBUS
PMID
1μF
1μH
10μF
BOOT
REGN
317W (1.5A max)
4.7μF
ILIM
SYS
PGND
2.2kW
SYS
PG
STAT
VREF
BAT
10μF
10kW
10kW
10μF
47nF
8.2μF
10kW
SYS: 3.5V-4.35V
SW
QON
SDA
SCL
INT
OTG
CE
Host
PHY
4.2V
Optional
REGN
5.52kW
TS
31.23kW
PSEL
10kW
Charge Enable (0°C - 45°C)
Power Pad
Figure 1. bq24296 with PSEL from PHY, charging from SDP/DCP, and Optional BATFET Enable Interface
bq24297
5V USB SDP/DCP
10μF
47nF
8.2μF
USB
SYS: 3.5V-4.35V
SW
VBUS
PMID
1μ F
1μH
10μF
BTST
REGN
D+
4.7μF
D–
SYS
PGND
2.2kW
SYS
STAT
BAT
317W (1.5A max)
10μF
ILIM
VREF
QON
10kW
10kW
Host
10kW
4.2V
Optional
REGN
SDA
SCL
INT
OTG
CE
5.52kW
TS
31.23kW
Power Pad
10kW
Charge Enable (0°C - 45°C)
Figure 2. bq24297 with USB D+/D- Detection, USB On-The-Go (OTG) and Optional BATFET Enable
Interface
4
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bq24297
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
FUNCTIONAL BLOCK DIAGRAM
VBUS
PMID
RBFET (Q1)
VVBUS_UVLOZ
UVLO
Q1 Gate
Control
VBATZ+VSLEEP
SLEEP
REGN
REGN
LDO
EN_HIZ
ACOV
VACOV
BTST
FBO
VBUS
VOTG_OVP
VINDPM
VBUS_OVP_BOOST
I(Q2)
IOTG_HSZCP
Q2_UCP_BOOST
I(Q3)
Q3_OCP_BOOST
SW
IOTG_LSOCP
IINDPM
BAT
IC TJ
CONVERTER
CONTROL
BATOVP
HSFET (Q2)
REGN
104%xVBAT_REG
BAT
TREG
VBAT_REG
LSFET (Q3)
ILSFET_UCP
UCP
Q2_OCP
I(Q3)
SYS
PGND
IHSFET_OCP
VSYSMIN
ICHG_REG
I(Q2)
EN_HIZ
EN_CHARGE
EN_BOOST
REFRESH
VBTST-SW
VBTST_REFRESH
SYS
ICHG
VBAT_REG
ICHG_REG
REF
DAC
BAD_SRC
CONVERTER
CONTROL
TSHUT
STATE
MACHINE
ILIM
D+ (bq24297)
D– (bq24297)
PSEL(bq24296)
USB Host
Adapter
Detection
BAT_GD
USB
Adapter
OTG
RECHRG
INT
I2C
Interface
SCL
SDA
BATSHORT
Q4 Gate
Control
BATFET (Q4)
IDC
BAT
IC TJ
TSHUT
BAT
QON
VBATGD
VBAT_REG - VRECHG
BAT
ICHG
TERMINATION
CHARGE
ITERM
CONTROL
SUSPEND
STATE
VBATLOWV
MACHINE BATLOWV
BAT
STAT
PG(bq24296)
IBADSRC
bq24296/297
BATTERY
THERMISTER
SENSING
TS
VSHORT
BAT
CE
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
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VBUS
PMID
REGN
BTST
SW
SW
VBUS
PMID
REGN
BTST
SW
SW
PINOUTS
24
23
22
21
20
19
24
23
22
21
20
19
VBUS
1
18
PGND
VBUS
1
18
PGND
PSEL
2
17
PGND
D+
2
17
PGND
16
SYS
D–
3
16
SYS
PG
3
bq24297
bq24296
STAT
15 SYS
14
BAT
SCL 5
14
SDA
6
13
BAT
SDA
13 BAT
7
8
9
10
11
12
QON
12
TS
11
ILIM
10
CE
9
6
OTG
8
4
INT
7
QON
5
TS
SCL
ILIM
SYS
CE
15
OTG
4
INT
STAT
BAT
PIN FUNCTIONS
PIN
TYPE
DESCRIPTION
NAME
NO.
VBUS
1,24
P
D+
(bq24297)
2
I
Analog
PSEL
(bq24296)
2
I
D–
(bq24297)
3
I
Analog
PG
(bq24296)
3
O
Open drain active low power good indicator. Connect to the pull up rail via 10kohm resistor. LOW indicates a good input
source if the input voltage is between UVLO and ACOV, above SLEEP mode threshold, and current limit is above 30mA.
STAT
4
O
Open drain charge status output to indicate various charger operation. Connect to the pull up rail via 10kohm. LOW
indicates charge in progress. HIGH indicates charge complete or charge disabled. When any fault condition occurs, STAT
pin in the charge blinks at 1Hz.
SCL
5
I
I2C Interface clock. Connect SCL to the logic rail through a 10kΩ resistor.
SDA
6
I/O
I2C Interface data. Connect SDA to the logic rail through a 10kΩ resistor.
INT
7
O
Open-drain Interrupt Output. Connect the INT to a logic rail via 10kΩ resistor. The INT pin sends active low, 256us pulse
to host to report charger device status and fault.
OTG
8
I
Digital
Charger Input Voltage. The internal n-channel reverse block MOSFET (RBFET) is connected between VBUS and PMID
with VBUS on source. Place a 1µF ceramic capacitor from VBUS to PGND and place it as close as possible to IC.
Positive line of the USB data line pair. D+/D– based USB host/charging port detection. The detection includes data
contact detection (DCD), primary detection in bc1.2, and non-standard adapters.
Power source selection input. High indicates a USB host source and Low indicates an adapter source.
Negative line of the USB data line pair. D+/D– based USB host/charging port detection. The detection includes data
contact detection (DCD), primary detection in bc1.2, and non-standard adapters.
USB current limit selection pin during buck mode, and active high enable pin during boost mode.
For bq24296, when in buck mode with USB host (PSEL=High), when OTG = High, IIN limit = 500mA and when OTG =
Low, IIN limit = 100mA.
For bq24297, when in buck mode with USB host, when OTG = High, IIN limit = 500mA and when OTG = Low, IIN limit =
100mA.
The boost mode is activated when the REG01[4]=1 and OTG pin is High.
6
CE
9
I
Active low Charge Enable pin. Battery charging is enabled when REG01[5:4]=01 and CE pin = Low. CE pin must be
pulled high or low.
ILIM
10
I
ILIM pin sets the maximum input current limit by regulating the ILIM voltage at 1V. A resistor is connected from ILIM pin to
ground to set the maximum limit as IINMAX = (1V/RILIM) × KILIM. The actual input current limit is the lower one set by ILIM
and by I2C REG00[2:0]. The minimum input current programmed on ILIM pin is 500mA.
TS
11
I
Analog
Temperature qualification voltage input #1. Connect a negative temperature coefficient thermistor. Program temperature
window with a resistor divider from REGN to TS1 to GND. Charge suspends or Boost disable disable when TS pin is out
of range. Recommend 103AT-2 thermistor.
QON
12
I
BATFET enable control in shipping mode. A logic low to high transition on this pin with minimum 2ms high level turns on
BATFET to exit shipping mode. It has internal 1MΩ (typ.) pull down. For backward compatibility, when BATFET enable
control function is not used, the pin can be no connect or tied to TS pin. (Please refer to Shipping Mode for detail
description).
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
PIN FUNCTIONS (continued)
PIN
TYPE
DESCRIPTION
13,14
P
Battery connection point to the positive terminal of the battery pack. The internal BATFET is connected between BAT and
SYS. Connect a 10uF closely to the BAT pin.
SYS
15,16
I
System connection point. The internal BATFET is connected between BAT and SYS. When the battery falls below the
minimum system voltage, switch-mode converter keeps SYS above the minimum system voltage.
PGND
17,18
P
Power ground connection for high-current power converter node. Internally, PGND is connected to the source of the nchannel LSFET. On PCB layout, connect directly to ground connection of input and output capacitors of the charger. A
single point connection is recommended between power PGND and the analog GND near the IC PGND pin.
SW
19,20
O
Switching node connecting to output inductor. Internally SW is connected to the source of the n-channel HSFET and the
drain of the n-channel LSFET. Connect the 0.047µF bootstrap capacitor from SW to BTST.
BTST
21
P
PWM high side driver positive supply. Internally, the BTST is connected to the anode of the boost-strap diode. Connect
the 0.047µF bootstrap capacitor from SW to BTST.
REGN
22
P
PWM low side driver positive supply output. Internally, REGN is connected to the cathode of the boost-strap diode.
Connect a 4.7-μF (10V rating) ceramic capacitor from REGN to analog GND. The capacitor should be placed close to the
IC. REGN also serves as bias rail of TS pin.
PMID
23
O
Connected to the drain of the reverse blocking MOSFET and the drain of HSFET. Given the total input capacitance,
connect a 1-µF capacitor on VBUS to PGND, and the recommended 8.2uF or more on PMID to PGND.
PowerPAD
–
P
Exposed pad beneath the IC for heat dissipation. Always solder PowerPAD™ to the board, and have vias on the
PowerPAD plane star-connecting to PGND and ground plane for high-current power converter.
NAME
NO.
BAT
ABSOLUTE MAXIMUM RATINGS (1)
VALUE
VBUS (converter not switching)
–2 V – 15 V (2)
PMID (converter not switching)
–0.3 V – 15 V (2)
STAT, PG
–0.3 V – 12 V
BTST
–0.3 V – 12 V
SW
–2 V – 7 V
8V (Peak for 20ns
duration)
Voltage range (with respect to GND)
Output sink current
BAT, SYS (converter not switching)
–0.3 V – 6 V
SDA, SCL, INT, OTG, ILIM, REGN, TS, QON CE , D+, D–, PSEL
–0.3 V – 7 V
BTST TO SW
–0.3 V – 7 V
PGND to GND
–0.3 V – 0.3 V
INT, STAT, PG
6mA
Junction temperature
–40°C to 150°C
Storage temperature
–65°C to 150°C
(1)
(2)
Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating
conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage
values are with respect to the network ground terminal unless otherwise noted.
VBUS is specified up to 16V for a maximum of 24 hours under no load conditions.
RECOMMENDED OPERATING CONDITIONS
MIN
Input voltage
IIN
Input current (VBUS)
3
A
ISYS
Output current (SYS)
3.5
A
VBAT
Battery voltage
4.4
V
3
A
TA
(1)
Fast charging current
Discharging current with internal MOSFET
Operating free-air temperature range
–40
6.2
UNIT
(1)
VIN
IBAT
3.9
MAX
V
5.5
A
85
°C
The inherent switching noise voltage spikes should not exceed the absolute maximum rating on either the BTST or SW pins. A tight
layout minimizes switching noise.
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THERMAL INFORMATION
RGE PACKAGE
THERMAL METRIC (1)
24-PIN
θJA
Junction-to-ambient thermal resistance
32.2
θJCtop
Junction-to-case (top) thermal resistance
29.8
θJB
Junction-to-board thermal resistance
9.1
ψJT
Junction-to-top characterization parameter
0.3
ψJB
Junction-to-board characterization parameter
9.1
θJCbot
Junction-to-case (bottom) thermal resistance
2.2
(1)
UNITS
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
space
ELECTRICAL CHARACTERISTICS
VVBUS_UVLOZ < VVBUS < VACOV and VVBUS > VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values unless other
noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
QUIESCENT CURRENTS
VVBUS < VUVLO, VBAT = 4.2 V, leakage between
BAT and VBUS
IBAT
Battery discharge current (BAT, SW, SYS)
IVBUS
Input supply current (VBUS)
IBOOST
Battery Discharge Current in boost mode
5
µA
High-Z Mode, or no VBUS, BATFET disabled
(REG07[5] = 1), –40°C – 85°C
16
20
µA
High-Z Mode, or no VBUS, BATFET enabled
(REG07[5] = 0), –40°C – 85°C
32
55
µA
VVBUS = 5 V, High-Z mode, No battery
15
30
µA
VVBUS > VUVLO, VVBUS > VBAT, converter not
switching
1.5
3
mA
VVBUS > VUVLO, VVBUS > VBAT, converter switching,
VBAT=3.2V, ISYS=0A
4
mA
VVBUS > VUVLO, VVBUS > VBAT, converter switching,
charge disable, VBAT=3.8V, ISYS=100µA
3.5
mA
VBAT=4.2V, Boost mode, IVBUS = 0A, converter
switching
3.5
mA
VBUS/BAT POWER UP
VVBUS_OP
VBUS operating range
VVBUS_UVLOZ
VBUS for active I2C, no battery
VVBUS rising
3.6
VSLEEP
Sleep mode falling threshold
VVBUS falling, VVBUS-VBAT
35
VSLEEPZ
Sleep mode rising threshold
VVBUS rising, VVBUS-VBAT
170
VACOV
VBUS over-voltage rising threshold
VVBUS rising
6.2
VACOV_HYST
VBUS Over-Voltage Falling Hysteresis
VVBUS falling
VBAT_UVLOZ
Battery for active I2C, no VBUS
VBAT rising
VBAT_DPL
Battery depletion threshold
VBAT falling
2.4
VBAT_DPL_HY
Battery depletion rising hysteresis
VBAT rising
200
VVBUSMIN
Bad adapter detection threshold
VVBUS falling
3.8
V
IBADSRC
Bad adapter detection current source
30
mA
tBADSRC
Bad source detection duration
30
ms
8
3.9
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6.2
V
80
120
mV
250
350
mV
V
6.6
250
V
mV
2.3
V
2.6
V
mV
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
ELECTRICAL CHARACTERISTICS (continued)
VVBUS_UVLOZ < VVBUS < VACOV and VVBUS > VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values unless other
noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
4.35
V
POWER PATH MANAGEMENT
VSYS_RANGE
Typical system regulation voltage
Isys = 0A, BATFET (Q4) off, VBAT up to 4.2 V,
REG01[3:1]=101, VSYSMIN = 3.5 V
3.5
VSYS_MIN
System voltage output
REG01[3:1]=101, VSYSMIN = 3.5 V
3.5
RON(RBFET)
Top reverse blocking MOSFET onresistance between VBUS and PMIID
RON(HSFET)
Internal top switching MOSFET onresistance between PMID and SW
RON(LSFET)
Internal bottom switching MOSFET onresistance between SW and PGND
VFWD
3.65
V
28
41
mΩ
TJ = –40°C – 85°C
39
51
TJ = -40°C – 125°C
39
58
TJ = –40°C – 85°C
61
82
TJ = -40°C – 125°C
61
90
BATFET forward voltage in supplement
mode
BAT discharge current 10mA
30
mV
VSYS_BAT
SYS/BAT Comparator
VSYS falling
70
mV
VBATGD
Battery good comparator rising threshold
VBAT rising
3.55
V
VBATGD_HYST
Battery good comparator falling threshold
VBAT falling
100
mV
mΩ
mΩ
BATTERY CHARGER
VBAT_REG_ACC
Charge voltage regulation accuracy
VBAT = 4.112V and 4.208V
VBAT = 3.8V, ICHG = 1024mA, TJ = 25°C
IICHG_REG_ACC
Fast charge current regulation accuracy
–0.5
0.5
%
-4
4
%
VBAT = 3.8V, ICHG = 1024mA, TJ = -20°C – 125°C
-7
7
%
VBAT = 3.8V, ICHG = 2112mA, TJ = -20°C – 125°C
–10
10
%
75
175
mA
ICHG_20pct
Charge current with 20% option on
VBAT = 3.1V, ICHG = 104mA, REG02=03 and
REG02[0]=1
VBATLOWV
Battery LOWV falling threshold
Fast charge to precharge, REG04[1] = 1
2.6
2.8
2.9
V
VBATLOWV_HYST
Battery LOWV rising threshold
Precharge to fast charge, REG04[1] = 1
(Typical 200mV hysteresis)
2.8
3.0
3.1
V
IPRECHG_ACC
Precharge current regulation accuracy
VBAT = 2.6V, ICHG = 256mA
–20
ITYP_TERM_ACC
Typical Termination current
ITERM = 256mA, ICHG = 2048mA
ITERM_ACC
Termination current accuracy
ITERM = 256mA, ICHG = 2048mA
VSHORT
Battery Short Voltage
VBAT falling
2.0
V
VSHORT_HYST
Battery Short Voltage hysteresis
VBAT rising
200
mV
ISHORT
Battery short current
VBAT<2.2V
100
mA
VRECHG
Recharge threshold below VBAT_REG
VBAT falling, REG04[0] = 0
100
mV
tRECHG
Recharge deglitch time
VBAT falling, REG04[0]=0
20
TJ = 25°C
24
28
TJ = –40°C – 125°C
24
35
RON_BATFET
SYS-BAT MOSFET on-resistance
20
265
–22.5
%
mA
22.5
%
ms
mΩ
INPUT VOLTAGE/CURRENT REGULATION
VINDPM_REG_ACC
Input voltage regulation accuracy
-2
2
USB100
85
100
mA
USB150
125
150
mA
USB500
440
500
mA
mA
IUSB_DPM
USB Input current regulation limit, VBUS =
5V, current pulled from SW
USB900
750
900
IADPT_DPM
Input current regulation accuracy
IADP=1.5A, REG00[2:0]=101
1.3
1.5
IIN_START
Input current limit during system start up
VSYS<2.2V
KILIM
IIN = KILIM/RILIM
IINDPM = 1.5A
100
395
435
%
A
mA
475
AxΩ
D+/D- DETECTION (bq24297)
VD+_SRC
D+ voltage source
ID+_SRC
D+ connection check current source
ID–_SINK
D– current sink
ID_LKG
Leakage current into D+/D–
VD+_LOW
D+ Low comparator threshold
0.5
0.7
V
7
14
µA
150
µA
D–, switch open
50
–1
100
1
µA
D+, switch open
–1
1
µA
0.8
V
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ELECTRICAL CHARACTERISTICS (continued)
VVBUS_UVLOZ < VVBUS < VACOV and VVBUS > VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values unless other
noted.
PARAMETER
TEST CONDITIONS
MIN
MAX
UNITS
250
TYP
400
mV
14.25
24.8
kΩ
VD–_LOWdatref
D– Low comparator threshold
RD–_DWN
D– Pulldown for connection check
tSDP_DEFAULT
Charging timer with 100mA USB host in
default mode
Vadpt1_lo
D+ Low Comparator Threshold for Nonstandard adapter Divider-1
As Percentage of REGN, 0°C – 85°C (1)
46.5
48
49.5
%
Vadpt1_hi
D+ Low Comparator Threshold for Nonstandard adapter Divider-1
As Percentage of REGN, 0°C – 85°C (1)
58.5
60
61.5
%
Vadpt2_lo
D+ Low Comparator Threshold for Nonstandard adapter Divider-2
As Percentage of REGN, 0°C – 85°C (1)
15.5
17
18.5
%
Vadpt2_hi
D+ Low Comparator Threshold for Nonstandard adapter Divider-2
As Percentage of REGN, 0°C – 85°C (1)
28.5
30
31.5
%
Vadpt3_lo
D- Low Comparator Threshold for Nonstandard adapter Divider-3
As Percentage of REGN, 0°C – 85°C (1)
46.5
48
49.5
%
Vadpt3_hi
D- High Comparator Threshold for Nonstandard adapter Divider-3
As Percentage of REGN, 0°C – 85°C (1)
58.5
60
61.5
%
45
mins
BAT OVER-VOLTAGE PROTECTION
VBATOVP
Battery over-voltage threshold
VBAT rising, as percentage of VBAT_REG
104
%
VBATOVP_HYST
Battery over-voltage hysteresis
VBAT falling, as percentage of VBAT_REG
2
%
tBATOVP
Battery over-voltage deglitch time to disable
charge
1
µs
THERMAL REGULATION AND THERMAL SHUTDOWN
TJunction_REG
Junction temperature regulation accuracy
REG06[1:0] = 11
120
°C
TSHUT
Thermal shutdown rising temperature
Temperature increasing
160
°C
TSHUT_HYS
Thermal shutdown hysteresis
30
°C
Thermal shutdown rising deglitch
Temperature increasing delay
1
ms
Thermal shutdown falling deglitch
Temperature decreasing delay
1
ms
COLD/HOT THERMISTER COMPARATOR
VLTF
Cold temperature threshold, TS pin voltage
rising threshold
Charger suspends charge. As Percentage to VREGN
VLTF_HYS
Cold temperature hysteresis, TS pin voltage
falling
As Percentage to VREGN
VHTF
Hot temperature TS pin voltage falling
threshold
As Percentage to VREGN
46.6
47.7
48.8
%
VTCO
Cut-off temperature TS pin voltage falling
threshold
As Percentage to VREGN
44.2
44.7
45.2
%
Deglitch time for temperature out of range
detection
VTS > VLTF, or VTS < VTCO, or VTS < VHTF
Cold Temperature Threshold, TS pin
Voltage Rising Threshold
As Percentage to VREGN REG02[1]=0
(Approx. -10◦C w/ 103AT)
VBCOLD0
Cold Temperature Threshold 1, TS pin
Voltage Rising Threshold
Hot Temperature Threshold, TS pin Voltage
falling Threshold
Hot Temperature Threshold 1, TS pin
Voltage falling Threshold
(1)
10
As Percentage to VREGN REG06[3:2]= 00
(Approx. 60◦C w/ 103AT)
Hot Temperature Threshold 2, TS pin
Voltage falling Threshold
As Percentage to VREGN REG06[3:2]= 10
(Approx. 65◦C w/ 103AT)
76
78.5
79
ms
76.5
36
79.5
33
36.5
30
%
%
33.5
3
29.5
%
%
3
32.5
%
%
1
35.5
%
%
1
As Percentage to VREGN REG06[3:2]= 00
(Approx. 3◦C w/ 103AT)
VBHOT1_HYS
VBHOT2
75.5
As Percentage to VREGN REG06[3:2]= 01
(Approx. 3◦C w/ 103AT)
VBHOT0_HYS
VBHOT1
As Percentage to VREGN REG06[3:2]= 01
(Approx. 55◦C w/ 103AT)
74
10
As Percentage to VREGN REG02[1]=1
(Approx. 1◦C w/ 103AT)
VBCOLD1_HYS
VBHOT0
As Percentage to VREGN REG02[1]=1
(Approx. -20◦C w/ 103AT)
73.5%
0.4
As Percentage to VREGN REG02[1]=0
(Approx. 1◦C w/ 103AT)
VBCOLD0_HYS
VBCOLD1
73
%
%
30.5
%
REGN LDO is configured in drop-out mode. VBUS is close to REGN when IREGN= 0mA.
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ELECTRICAL CHARACTERISTICS (continued)
VVBUS_UVLOZ < VVBUS < VACOV and VVBUS > VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values unless other
noted.
PARAMETER
TEST CONDITIONS
MIN
As Percentage to VREGN REG06[3:2]= 10
(Approx. 3◦C w/ 103AT)
VBHOT2_HYS
TYP
MAX
UNITS
3
%
CHARGE OVER-CURRENT COMPARATOR
IHSFET_OCP
HSFET cycle by cycle over-current
threshold
5.3
7.5
A
IBATFET_OCP
System over load threshold
5.5
6.6
A
VLSFET_UCP
LSFET charge under-current falling
threshold
100
mA
FSW
PWM Switching frequency, and digital clock
DMAX
Maximum PWM duty cycle
VBTST_REFRESH
From sync mode to non-sync mode
Bootstrap refresh comparator threshold
1300
VBTST-VSW when LSFET refresh pulse is
requested, VBUS=5V
1500
1700
%
3.6
V
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ELECTRICAL CHARACTERISTICS (continued)
VVBUS_UVLOZ < VVBUS < VACOV and VVBUS > VBAT + VSLEEP, TJ = –40°C to 125°C and TJ = 25°C for typical values unless other
noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
BOOST MODE OPERATION
VOTG_REG_ACC
OTG output voltage
I(VBUS)=0, REG06[7:4]=0111 (4.998V)
VOTG_REG_ACC
OTG output voltage accuracy
I(VBUS) = 0, REG06[7:4]=0111 (4.998V)
VOTG_BAT
Battery voltage exiting OTG mode
BAT falling, REG04[1]=1
5
-3
V
3
%
2.9
V
REG01[0] = 0
1
A
REG01[0] = 1
1.5
5.8
IOTG
OTG mode output current
VOTG_OVP
OTG over-voltage threshold
Rising Threshold
VOTG_OVP_HYS
OTG over-voltage threshold hysteresis
Falling Threshold
IOTG_LSOCP
LSFET cycle by cycle current limit
IOTG_HSZCP
HSFET under current falling threshold
IRBFET_OCP
RBFET over-current threshold
tOTG_OCP_OFF
OTG mode over-current protection off cycle
time
32
ms
tOTG_OCP_ON
OTG mode over-current protection on cycle
time
260
µs
A
6
V
300
mV
100
mA
5
A
REG01[0] = 0
1.00
1.15
1.30
REG01[0] = 1
1.50
1.70
1.90
A
REGN LDO
VREGN
REGN LDO output voltage
IREGN
REGN LDO current limit
VVBUS = 6V, IREGN = 40mA
4.8
5
VVBUS = 5V, IREGN = 20mA
4.7
4.8
5.5
V
VVBUS = 5V, VREGN = 3.8V
50
mA
2
ms
V
QON Timing
tQON
QON pin high time to turn on BATFET
LOGIC I/O PIN CHARACTERISTICS (OTG, CE, STAT, QON, PSEL, PG)
VILO
Input low threshold
VIH
Input high threshold
0.4
VOUT_LO
Output low saturation voltage
Sink current = 5 mA
IBIAS
High level leakage current (OTG, CE,
STAT , PSEL, PG)
IBIAS
High level leakage current (QON)
1.3
V
V
0.4
V
Pull up rail 1.8V
1
µA
Pull up rail 3.6V
8
µA
I2C INTERFACE (SDA, SCL, INT)
VIH
Input high threshold level
VPULL-UP = 1.8V, SDA and SCL
VIL
Input low threshold level
VPULL-UP = 1.8V, SDA and SCL
1.3
0.4
V
V
VOL
Output low threshold level
Sink current = 5mA
0.4
V
IBIAS
High-level leakage current
VPULL-UP = 1.8V, SDA and SCL
fSCL
SCL clock frequency
1
µA
400
kHz
DIGITAL CLOCK AND WATCHDOG TIMER
fHIZ
Digital crude clock
REGN LDO disabled
15
35
50
kHz
fDIG
Digital clock
REGN LDO enabled
1300
1500
1700
kHz
REGN LDO disabled
112
160
REGN LDO enabled
136
160
tWDT
12
REG05[5:4]=11
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SLUSBP6A – SEPTEMBER 2013 – REVISED OCTOBER 2013
Figure 3. I2C-Compatible Interface Timing Diagram
TYPICAL CHARACTERISTICS
Table 1. Tables of Figures
FIGURE NO.
CHARGING EFFICIENCY vs. CHARGING CURRENT (DCR = 10mΩ)
Figure 4
SYSTEM EFFICIENCY vs. SYSTEM LOAD CURRENT (DCR = 10mΩ)
Figure 5
BOOST MODE EFFICIENCY vs VBUS LOAD CURRENT (DCR = 10mΩ)
Figure 6
SYS VOLTAGE REGULATION vs SYSTEM LOAD CURRENT
Figure 7
BOOST MODE VBUS VOLTAGE REGULATION (Typical Output = 4.998V ; REG06[7:4]=0111) vs VBUS
LOAD CURRENT
Figure 8
SYS VOLTAGE vs TEMPERATURE
Figure 9
BAT VOLTAGE vs TEMPERATURE
Figure 10
INPUT CURRENT LIMIT vs TEMPERATURE
Figure 11
CHARGE CURRENT vs PACKAGE TEMPERATURE
Figure 12
bq24296 Power Up with Charge Enabled (VBAT =3.2V)
Figure 13
bq24297 Power Up with Charge Enabled (VBAT =3.2V)
Figure 14
bq24297 Power Up with Charge Disabled (VBAT =3.2V)
Figure 15
Charge Enable (VBUS = 5V)
Figure 16
Charge Disable
Figure 17
PWM Switching in Buck Mode (VBUS = 5V, No Battery, ISYS = 40mA, Charge Disable)
Figure 18
PFM Switching in Buck Mode (VBUS = 5V, VBAT = 3.6V, ICHG = 2.5A)
Figure 19
Input Current DPM Response Without Battery (VBUS = 5V, IIN = 3A, No Battery, Charge Disable
Figure 20
Load Transient During Supplement Mode (VBUS = 5V, IIN = 1.5A, VBAT = 3.8V)
Figure 21
Boost Mode Switching (VBAT = 3.8V, ILOAD = 1A)
Figure 22
Boost Mode Load Transient (VBAT = 3.8V)
Figure 23
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CHARGE EFFICIENCY
vs
CHARGE CURRENT
SYSTEM EFFICIENCY
vs
SYSTEM LOAD CURRENT
95
95
90
85
Efficiency (%)
Efficiency (%)
90
80
75
85
80
75
70
VBUS = 5V
VBUS = 5V
65
70
0
0.5
1
1.5
2
2.5
3
3.5
0
0.5
1
BOOST MODE EFFICIENCY
vs
VBUS LOAD CURRENT
SYS VOLTAGE REGULATION
vs
SYSTEM LOAD CURRENT
4
95
3.9
90
3.8
85
80
75
60
0.5
3
1
3.7
3.6
SYSMIN = 3.5
SYSMIN = 3.2
SYSMIN = 3.7
3.5
3.4
VBAT = 3.2V
VBAT = 3.5V
VBAT = 3.8V
65
3.3
3.2
1.5
0
0.5
1
VBUS Load Current (A)
1.5
2
2.5
3
3.5
System Load Current (A)
Figure 6.
Figure 7.
BOOST MODE VBUS VOLTAGE REGULATION
(Typical Output = 4.998V ; REG06[7:4]=0111)
vs
VBUS LOAD CURRENT
SYS VOLTAGE
vs
TEMPERATURE
3.7
5.1
5
3.65
SYS Voltage (V)
BOOST Mode Output Voltage (V)
2.5
Figure 5.
70
4.9
4.8
4.7
0
0.5
1
3.6
3.55
VBAT = 3.2V
VBAT = 3.5V
VBAT = 3.8V
4.6
4.5
SYSMIN = 3.5V
3.5
1.5
-50
-25
0
25
50
75
100
125
150
Temperature (oC)
VBUS Load Current (A)
Figure 8.
14
2
Figure 4.
100
0
1.5
Load Current (A)
SYS Voltage (V)
Efficiency (%)
Charge Current (A)
Figure 9.
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BAT VOLTAGE
vs
TEMPERATURE
INPUT CURRENT LIMIT
vs
TEMPERATURE
4.4
2.5
Input Current Limit (A)
BAT Voltage (V)
4.35
4.3
4.25
4.2
1.5
IIN = 500mA
IIN = 1.5A
IIN = 2A
1
0.5
VREG = 4.208V
4.15
2
VREG = 4.35V
4.1
0
-50
-25
0
25
50
75
100
125
150
-50
-25
Temperature (oC)
2.5
25
50
75
100
125
150
Temperature (oC)
Figure 10.
Figure 11.
CHARGE CURRENT
vs
PACKAGE TEMPERATURE
bq24296 Power Up with Charge Enabled (VBAT =3.2V)
TREG = 120C
TREG = 80C
2
Charge Current (A)
0
VBUS
5V/div
1.5
REGN
5V/div
1
SYS
2V/div
0.5
IVBUS
100mA/div
0
100ms/div
60
80
100
120
140
160
Package Temperature (oC)
Figure 12.
Figure 13.
bq24297 Power Up with Charge Enabled (VBAT =3.2V)
bq24297 Power Up with Charge Disabled (VBAT =3.2V)
VBUS
5V/div
VBUS
5V/div
REGN
5V/div
REGN
5V/div
SYS
2V/div
SYS
2V/div
IBAT
2A/div
IBAT
2A/div
100ms/div
100ms/div
Figure 14.
Figure 15.
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PWM Switching in Buck Mode
(VBUS = 5V, No Battery, ISYS = 40mA, Charge Disable)
Charge Disable
STAT
2V/div
CE
5V/div
IL
1A/div
SW
5V/div
SW
2V/div
IBAT
1A/div
4ms/div
400ns/div
Figure 17.
Figure 18.
PFM Switching in Buck Mode
(VBUS = 5V, VBAT = 3.6V, ICHG = 2.5A)
Input Current DPM Response Without Battery
(VBUS = 5V, IIN = 3A, No Battery, Charge Disable)
SYS3p5
500mV/div
SYS3p7
100mV/div
ISYS
2A/div
SW
2V/div
IL
1A/div
IVBUS
2A/div
4ms/div
2ms/div
Figure 19.
Figure 20.
Load Transient During Supplement Mode
(VBUS = 5V, IIN = 1.5A, VBAT = 3.8V)
Boost Mode Switching
(VBAT = 3.8V, ILOAD = 1A)
SYS3p8
500mV/div
ISYS
2A/div
SW
2V/div
IBAT
2A/div
IVBUS
2A/div
IL
1A/div
20ms/div
400ns/div
Figure 21.
16
Figure 22.
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Boost Mode Load Transient
(VBAT = 3.8V)
VBUS
200mV/div
IBAT
1A/div
IVBUS
1A/div
4ms/div
Figure 23.
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I2C Registers
Address: 6BH. REG00-07 support Read and Write. REG08-0A are read only.
Input Source Control Register REG00 (default 00110xxx, or 3x)
BIT
DESCRIPTION
Bit 7
EN_HIZ
0 – Disable, 1 – Enable
Input Voltage Limit
Bit 6
VINDPM[3]
640mV
Bit 5
VINDPM[2]
320mV
Bit 4
VINDPM[1]
160mV
Bit 3
VINDPM[0]
80mV
Input Current Limit (Actual input current limit is the lower of I2C and ILIM)
Bit 2
IINLIM[2]
000 – 100mA, 001 – 150mA, 010 – 500mA,
011 – 900mA, 100 – 1A, 101 – 1.5A,
Bit 1
IINLIM[1]
110 – 2A, 111 – 3A
Bit 0
IINLIM[0]
Default: Disable (0)
Offset 3.88V, Range: 3.88V-5.08V
Default: 4.36V (0110)
bq24296
PSEL=Lo : 3A (111)
PSEL=Hi : 100mA (000) (OTG pin =Lo) or 500mA (OTG pin=Hi)
bq24297
Default SDP : 100mA (000) (OTG pin =Lo) or 500mA (OTG
pin=Hi)
Default DCP/CDP: 3A (111)
Default Divider 1 & 2 : 2A (110)
Default Divider 3 : 1A (100)
Power-On Configuration Register REG01 (default 00011011, or 1B)
BIT
Bit 7
Bit 6
Register Reset
DESCRIPTION
0 – Keep current register setting,
1 – Reset to default
I2C Watchdog
Timer Reset
0 – Normal ; 1 – Reset
Charger Configuration
Bit 5
OTG_CONFIG
0 – OTG Disable; 1 – OTG Enable
Bit 4
CHG_CONFIG
0- Charge Disable; 1- Charge Enable
Minimum System Voltage Limit
Bit 3
SYS_MIN[2]
0.4V
Bit 2
SYS_MIN[1]
0.2V
Bit 1
SYS_MIN[0]
0.1V
Boost Mode Current Limit
Bit 0
BOOST_LIM
0 – 1A, 1 – 1.5A
18
NOTE
Default: Keep current register setting (0)
Note: Register Reset bit does not reset device to default
mode
Default: Normal (0)
Note: Consecutive I2C watchdog timer reset requires
minimum 20uS delay
Default: OTG disable (0)
Note: OTG_CONFIG would over-ride Charge Enable
Function in CHG_CONFIG
Default: Charge Battery (1)
Offset: 3.0V, Range 3.0V-3.7V
Default: 3.5V (101)
Default: 1.5A (1)
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Charge Current Control Register REG02 (default 01100000, or 60)
BIT
Fast Charge Current Limit
Bit 7
ICHG[5]
Bit 6
ICHG[4]
Bit 5
ICHG[3]
Bit 4
ICHG[2]
Bit 3
ICHG[1]
Bit 2
ICHG[0]
Bit 1
BCOLD
Bit 0
FORCE_20PCT
DESCRIPTION
NOTE
2048mA
1024mA
512mA
256mA
128mA
64mA
Set Boost Mode temperature monitor threshold
voltage to disable boost mode
0 – Vbcold0 (Typ. 76% of REGN or -10◦C w/ 103AT
thermistor )
1 – Vbcold1 (Typ. 79% of REGN or -20◦C w/ 103AT
thermistor)
0 – ICHG as Fast Charge Current (REG02[7:2])
and IPRECH as Pre-Charge Current (REG03[7:4])
programmed
1 – ICHG as 20% Fast Charge Current
(REG02[7:2]) and IPRECH as 50% Pre-Charge
Current (REG03[7:4]) programmed
Offset: 512mA
Range: 512-3008mA (000000 - 100111)
Default: 2048mA (011000)
Note: ICHG higher than 3008mA is not suported
Default: Vbcold0 (0)
Default: ICHG as Fast Charge Current (REG02[7:2]) and
IPRECH as Pre-Charge Current (REG03[7:4])
programmed (0)
Pre-Charge/Termination Current Control Register REG 03 (default 00010001, or 0x11)
BIT
DESCRIPTION
Pre-Charge Current Limit
Bit 7
IPRECHG[3] 1024mA
Bit 6
IPRECHG[2] 512mA
Bit 5
IPRECHG[1] 256mA
Bit 4
IPRECHG[0] 128mA
Termination Current Limit
Bit 3
ITERM[3]
1024mA
Bit 2
ITERM[2]
512mA
Bit 1
ITERM[1]
256mA
Bit 0
ITERM[0]
128mA
NOTE
Offset: 128mA,
Range: 128mA – 2048mA
Default: 256mA (0001)
Offset: 128mA
Range: 128mA – 2048mA
Default: 256mA (0001)
Charge Voltage Control Register REG04 (default 10110010, or 0xB2)
BIT
DESCRIPTION
Charge Voltage Limit
Bit 7
VREG[5]
512mV
Bit 6
VREG[4]
256mV
Bit 5
VREG[3]
128mV
Bit 4
VREG[2]
64mV
Bit 3
VREG[1]
32mV
Bit 2
VREG[0]
16mV
Bit 1
BATLOWV
0 – 2.8V, 1 – 3.0V
Battery Recharge Threshold (below battery regulation voltage)
Bit 0
VRECHG
0 – 100mV, 1 – 300mV
NOTE
Offset: 3.504V
Range: 3.504V – 4.400V
Default: 4.208V
Default: 3.0V (1) (pre-charge to fast charge)
Default: 100mV (0)
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Charge Termination/Timer Control Register REG05 (default 10011010, or 0x9A)
BIT
DESCRIPTION
Charging Termination Enable
Bit 7
EN_TERM
0 – Disable, 1 – Enable
Bit 6
Reserved
0 - Reserved
I2C Watchdog Timer Setting
Bit 5
WATCHDOG[1] 00 – Disable timer, 01 – 40s, 10 – 80s, 11 –
Bit 4
WATCHDOG[0] 160s
Charging Safety Timer Enable
Bit 3
EN_TIMER
0 – Disable, 1 – Enable
Fast Charge Timer Setting
Bit 2
CHG_TIMER[1] 00 – 5 hrs, 01 – 8 hrs, 10 – 12 hrs, 11 – 20
Bit 1
CHG_TIMER[0] hrs
Bit 0
Reserved
0 - Reserved
NOTE
Default: Enable termination (1)
Default: 40s (01)
Default: Enable (1)
Default: 12 hrs (10)
(See Charging Safety Timer for details)
Boost Voltage/Thermal Regulation Control Register REG06 (default 01110011, or 0x73)
BIT
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
DESCRIPTION
512mV
256mV
128mV
64mV
Set Boost Mode temperature monitor
threshold voltage to disable boost mode
Voltage to disable boost mode
00 – Vbhot1 (33% of REGN or 55◦C w/ 103AT
thermistor)
01 – Vbhot0 (36% of REGN or 60◦C w/ 103AT
thermistor)
10 – Vbhot2 (30% of REGN or 65◦C w/ 103AT
thermistor)
11 – Disable boost mode thermal protection.
Thermal Regulation Threshold
Bit 1
TREG[1]
00 – 60°C, 01 – 80°C, 10 – 100°C, 11 –
120°C
Bit 0
TREG[0]
BOOSTV[3]
BOOSTV[2]
BOOSTV[1]
BOOSTV[0]
BHOT[1]
BHOT[0]
NOTE
Offset: 4.55V
Range: 4.55V – 5.51V
Default:4.998V(0111)
Default: Vbhot1 (00)
Note: For BHOT[1:0]=11, boost mode operates without
temperature monitor and the NTC_FAULT is generated based
on Vbhot1 threshold
Default: 120°C (11)
Misc Operation Control Register REG07 (default 01001011, or 4B)
BIT
Force DPDM detection
Bit 7
DPDM_EN
DESCRIPTION
0 – Not in D+/D– detection;
1 – Force D+/D– detection when VBUS power is
presence
Safety Timer Setting during Input DPM and Thermal Regulation
Bit 6
TMR2X_EN
0 – Safety timer not slowed by 2X during input DPM
or thermal regulation,
1 – Safety timer slowed by 2X during input DPM or
thermal regulation
Force BATFET Off
Bit 5
BATFET_Disable
0 – Allow BATFET (Q4) turn on, 1 – Turn off
BATFET (Q4)
Bit 4
Reserved
0 - Reserved
Bit 3
Reserved
1 - Reserved
Bit 2
Reserved
0 - Reserved
Bit 1
INT_MASK[1]
0 – No INT during CHRG_FAULT, 1 – INT on
CHRG_FAULT
Bit 0
INT_MASK[0]
0 – No INT during BAT_FAULT, 1 – INT on
BAT_FAULT
20
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NOTE
Default: Not in D+/D– detection (0), Back to 0
after detection complete
Default: Safety timer slowed by 2X (1)
Default: Allow BATFET (Q4) turn on(0)
Default: INT on CHRG_FAULT (1)
Default: INT on BAT_FAULT (1)
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System Status Register REG08
BIT
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
VBUS_STAT[1]
VBUS_STAT[0]
CHRG_STAT[1]
CHRG_STAT[0]
DPM_STAT
PG_STAT
THERM_STAT
VSYS_STAT
DESCRIPTION
00 – Unknown (no input, or DPDM detection incomplete), 01 – USB host, 10 – Adapter port, 11 – OTG
00 – Not Charging, 01 – Pre-charge (<VBATLOWV), 10 – Fast Charging, 11 – Charge Termination Done
0 – Not DPM, 1 – VINDPM or IINDPM
0 – Not Power Good, 1 – Power Good
0 – Normal, 1 – In Thermal Regulation
0 – Not in VSYSMIN regulation (BAT>VSYSMIN), 1 – In VSYSMIN regulation (BAT<VSYSMIN)
New Fault Register REG09 (1) (2) (3)
BIT
Bit 7
Bit 6
WATCHDOG_FAULT
OTG_FAULT
Bit
Bit
Bit
Bit
Bit
CHRG_FAULT[1]
CHRG_FAULT[0]
BAT_FAULT
Reserved
NTC_FAULT[1]
5
4
3
2
1
Bit 0
(1)
(2)
(3)
NTC_FAULT[0]
DESCRIPTION
0 – Normal, 1- Watchdog timer expiration
0 – Normal, 1 – VBUS overloaded in OTG, or VBUS OVP, or battery is too low (any conditions that we
cannot start boost function)
00 – Normal, 01 – Input fault (OVP or bad source), 10 - Thermal shutdown,
11 – Charge Timer Expiration
0 – Normal, 1 – System OVP
Reserved – 0
0-Normal 1–Cold Note: Cold temperature threshold is different based on device operates in buck or
boost mode
0-Normal 1–Hot Note: Hot temperature threshold is different based on device operates in buck or boost
mode
REG09 only supports single byte i2c read.
All register bits in REG09 are latched fault. First time read of REG09 will clear the previous fault and second read will update fault
register to any fault that still presents.
When adapter is unplugged, input fault (bad source) in CHRG_FAULT bits[5:4] will be set to 01 once.
Vender / Part / Revision Status Register REG0A
BIT
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PN[2]
PN[1]
PN[0]
Reserved
Reserved
Rev[2]
Rev[1]
Rev[0]
DESCRIPTION
001 (bq24296)
011 (bq24297)
0 – Reserved
0 – Reserved
000
DETAILED DESCRIPTION
The bq24296, bq24297 is an I2C controlled power path management device and a single cell Li-Ion battery
charger. It integrates the input reverse-blocking FET (RBFET, Q1), high-side switching FET (HSFET, Q2), lowside switching FET (LSFET, Q3), and battery FET (BATFET, Q4) between system and battery. The device also
integrates the bootstrap diode for the high-side gate drive.
Device Power Up
Power-On-Reset (POR)
The internal bias circuits are powered from the higher voltage of VBUS and BAT. When VBUS or VBAT rises
above UVLOZ, the sleep comparator, battery depletion comparator and BATFET driver are active. I2C interface
is ready for communication and all the registers are reset to default value. The host can access all the registers
after POR.
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Power Up from Battery without DC Source
If only battery is present and the voltage is above depletion threshold (VBAT_DEPL), the BATFET turns on and
connects battery to system. The REGN LDO stays off to minimize the quiescent current. The low RDSON in
BATFET and the low quiescent current on BAT minimize the conduction loss and maximize the battery run time.
During both boost and charge mode, the device always monitors the discharge current through BATFET. When
the system is overloaded or shorted, the device will immediately turn off BATFET and keep BATFET off until the
input source plugs in again.
BATFET Turn Off
The BATFET can be forced off by the host through I2C REG07[5]. This bit allows the user to independently turn
off the BATFET when the battery condition becomes abnormal during charging. When BATFET is off, there is no
path to charge or discharge the battery. When battery is not attached, the BATFET should be turned off by
setting REG07[5] to 1 to disable charging and supplement mode.
Shipping Mode
To extend battery life and minimize power when system is powered off during system idle, shipping, or storage,
the device can turn off BATFET so that the system voltage is zero to minimize the leakage. The BATFET can be
turned off by setting REG07[5] (BATFET_DISABLE) bit.
In order to keep BATFET off during shipping mode, the host has to disable the watchdog timer (REG05[5:4]=00)
and disable BATFET (REG07[5]=1) at the same time. Once the BATFET is disabled, one of the following events
can turn on BATFET and clear REG07[5] (BATFET_DISABLE) bit.
1. Plug in adapter
2. Write REG07[5]=0
3. watchdog timer expiration
4. Register reset (REG01[7]=1)
5. A logic low to high transition on QON pin (refer to Figure 24 for detail timing)
Min. 2ms
QON
BATFET Status
Turn on by QON
REG07[5]=0
Turn off by i2c command
REG07[5]=1
Figure 24. QON Timing
Power Up from DC Source
When the DC source plugs in, the charger device checks the input source voltage to turn on REGN LDO and all
the bias circuits. It also checks the input current limit before starts the buck converter.
REGN LDO
The REGN LDO supplies internal bias circuits as well as the HSFET and LSFET gate drive. The LDO also
provides bias rail to TS external resistors. The pull-up rail of STAT and PG (bq24296) can be connected to
REGN as well.
The REGN is enabled when all the conditions are valid.
1. VBUS above VVBUS_UVLOZ
2. VBUS above VBAT + VSLEEPZ in buck mode or VBUS below VBAT + VSLEEP in boost mode
22
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3. After typical 220ms delay (100ms minimum) is complete
If one of the above conditions is not valid, the device is in high impedance mode (HIZ) with REGN LDO off. The
device draws less than IVBUS (15µA typical) from VBUS during HIZ state. The battery powers up the system when
the device is in HIZ.
Input Source Qualification
After REGN LDO powers up, the device checks the current capability of the input source. The input source has
to meet the following requirements to start the buck converter.
1. VBUS voltage below VACOV (not in VBUS over-voltage)
2. VBUS voltage above VBADSRC (3.8V typical) when pulling IBADSRC (30mA typical) (poor source detection)
Once the input source passes all the conditions above, the status register REG08[2] goes high and the PG pin
(bq24296) goes low. An INT is asserted to the host.
If the device fails the poor source detection, it will repeat the detection every 2 seconds.
Input Current Limit Detection
The USB ports on personal computers are convenient charging source for portable devices (PDs). If the portable
device is attached to a USB host, the USB specification requires the portable device to draw limited current
(100mA/500mA in USB 2.0, and 150mA/900mA in USB 3.0). If the portable device is attached to a charging port,
it is allowed to draw up to 3A.
After the PG is LOW (bq24296) or REG08[2] goes HIGH, the charger device always runs input current limit
detection when a DC source plugs in unless the charger is in HIZ during host mode.
The bq24297 follows Battery Charging Specification 1.2 (BC1.2) to detect input source through USB D+/D- lines.
The bq24296 sets input current limit through PSEL and OTG pins. After the input current limit detection is done,
the detection result is reported in VBUS_STAT registers (REG08[7:6]) and input current limit is updated in IINLIM
register (REG00[2:0]). In additon, host can write to REG00[2:0] to change the input current limit.
D+/D– Detection Sets Input Current Limit (bq24297)
The bq24297 contains a D+/D– based input source detection to program the input current limit. The D+/Ddetection has three steps: data contact detect (DCD), primary detection, and non-standard adapter detection.
When the charging source passes data contact detect, the device would proceed to run primary detection.
Otherwise the charger would proceed to run non-standard adapter detection.
D+
VDP_SRC
VLGC_HI
IDP_SRC
CHG_DET
VDAC_REF
IDM_SINK
D-
RDM_DWN
Figure 25. USB D+/D- Detection
DCD (Data Contact Detection) uses a current source to detect when the D+/D– pins have made contact during
an attach event. The protocol for data contact detect is as follows:
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Detect VBUS present and REG08[2]=1 (power good)
Turn on D+ IDP_SRC and the D– pull-down resistor RDM_DWN for 40ms
If the USB connector is properly attached, the D+ line goes from HIGH to LOW, wait up to 0.5 sec.
Turn off IDP_SRC and disconnect RDM_DWN
The primary detection is used to distinguish between USB host (Standard Down Stream Port, or SDP) and
different type of charging ports (Charging Down Stream Port, or CDP, and Dedicated Charging Port, or DCP).
The protocol for primary detection is as follows:
• Turn on VDP_SRC on D+ and IDM_SINK on D– for 40ms
• If PD is attached to a USB host (SDP), the D– is low. If PD is attached to a charging port (CDP or DCP), the
D– is high
• Turn off VDP_SRC and IDM_SINK
Table 2 shows the input current limit setting after D+/D– detection.
Table 2. bq24297 USB D+/D– Detection
D+/D– DETECTION
OTG
INPUT CURRENT LIMIT
REG08[7:6]
0.5 sec timer expired in DCD
(D+/D- floating)
—
Proceed to Non-standard
adapter detection
00
USB Host
LOW
100 mA
01
USB Host
HIGH
500 mA
01
Charging Port
—
3A
10
When DCD 0.5 sec timer expires, the non-standard adapter detection is used to distinguish three different divider
bias conditions on D+/D- pins. When non-standard adapter is detected, the input current limit (REG0[2:0]) is set
based on the table shown below and REG08[7:6] is set to 10 (Adapter port). If non-standard adapter is not
detected, REG08[7:6] is set to 00 (Unknown) and the input current limit is set in REG0[2:0] to 500mA by default.
Table 3. bq24297 Non-Standard Adapter Detection
Non-Standard
Adapter
Input
Current
Limit
D+ Threshold
D- Threshold
Divider 1
Vadpt1_lo < VD+ < Vadpt1_hi
For VBUS=5V, typical range 2.4V < VD+ < 3.1V
Vadpt1_lo > VD- or VD- < Vadpt1_hi
For VBUS=5V, typical range 2.4V > VD- or VD- > 3.1V
2A
Divider 2
Vadpt2_lo < VD+ < Vadpt2_hi
For VBUS=5V, typical range 0.85V < VD+ < 1.5V
NA
2A
Divider 3
Vadpt3_lo < VD+ < Vadpt3_hi
For VBUS=5V, typical range 2.4V > VD+ or VD+ >
3.1V
Vadpt3_lo < VD- < Vadpt3_hi
For VBUS=5V, typical range 2.4V < VD- < 3.1V
1A
PSEL/OTG Pins Set Input Current Limit
The bq24296 has PSEL instead of D+/D-. It directly takes the USB PHY device output to decide whether the
input is USB host or charging port.
Table 4. bq24296 Input Current Limit Detection
24
PSEL
OTG
INPUT CURRENT LIMIT
REG08[7:6]
HIGH
LOW
100 mA
01
HIGH
HIGH
500 mA
01
LOW
—
3A
10
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HIZ State wth 100mA USB Host
In battery charging spec, the good battery threshold is the minimum charge level of a battery to power up the
portable device successfully. When the input source is 100mA USB host, and the battery is above bat-good
threshold (VBATGD), the device follows battery charging spec and enters high impedance state (HIZ). In HIZ state,
the device is in the lowest quiescent state with REGN LDO and the bias circuits off. The charger device sets
REG00[7] to 1, and the VBUS current during HIZ state will be less than 30µA. The system is supplied by the
battery.
Once the charger device enters HIZ state in host mode, it stays in HIZ until the host writes REG00[7]=0. When
the processor host wakes up, it is recommended to first check if the charger is in HIZ state.
In default mode, the charger IC will reset REG00[7] back to 0 when input source is removed. When another
source plugs in, the charger IC will run detection again, and update the input current limit.
Force Input Current Limit Detection
While adapter is plugged-in, the host can force the charger device to run input current limit detection by setting
REG07[7]=1 or when watchdog timeout. During the forced detection, the input current limit is set to 100mA. After
the detection is completed, REG07[7] will return to 0 by itself and new input current limit is set based on D+/D(bq24297) or PSEL/OTG (bq24296).
Converter Power-Up
After the input current limit is set, the converter is enabled and the HSFET and LSFET start switching. If battery
charging is disabled, BATFET turns off. Otherwise, BATFET stays on to charge the battery.
The device provides soft-start when ramp up the system rail. When the system rail is below 2.2V, the input
current limit is forced to 100mA. After the system rises above 2.2V, the charger device sets the input current limit
set by the lower value between register and ILIM pin.
As a battery charger, the charger deploys a 1.5MHz step-down switching regulator. The fixed frequency oscillator
keeps tight control of the switching frequency under all conditions of input voltage, battery voltage, charge current
and temperature, simplifying output filter design.
A type III compensation network allows using ceramic capacitors at the output of the converter. An internal sawtooth ramp is compared to the internal error control signal to vary the duty cycle of the converter. The ramp
height is proportional to the PMID voltage to cancel out any loop gain variation due to a change in input voltage.
In order to improve light-load efficiency, the device switches to PFM control at light load when battery is below
minimum system voltage setting or charging is disabled. During the PFM operation, the switching duty cycle is
set by the ratio of SYS and VBUS.
Boost Mode Operation from Battery
The device supports boost converter operation to deliver power from the battery to other portable devices
through USB port. The boost mode output current rating meets the USB On-The-Go 1A output requirement. The
maximum output current is 1.5A. The boost operation can be enabled if the following conditions are valid:
1. BAT above BATLOWV threshold (VBATLOWV set by REG04[1])
2. VBUS less than VBAT + VSLEEP (in sleep mode)
3. Boost mode operation is enabled (OTG pin HIGH and REG01[5:4]=10)
4. Thermistor Temperature is within boost mode temperature monitor threshold unless BHOT[1:0] is set to 11
(REG06[1:0]) to disable this monitor function
5. After 30ms delay from boost mode enable
In boost mode, the device employs a 1.5MHz step-up switching regulator. Similar to buck operation, the device
switches from PWM operation to PFM operation at light load to improve efficiency.
During boost mode, the status register REG08[7:6] is set to 11, the VBUS output is 5V and the output current
can reach up to 1A or 1.5A, selected via I2C (REG01[0]). In addition, the device provides adjustable boost
voltage from 4.55V to 5.5V by changing BOOSTV bits in REG06[7:4]
Any fault during boost operation, including VBUS over-voltage or over-current, sets the fault register REG09[6] to
1 and an INT is asserted.
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Power Path Management
The device accommodates a wide range of input sources from USB, wall adapter, to car battery. The device
provides automatic power path selection to supply the system (SYS) from input source (VBUS), battery (BAT), or
both.
Narrow VDC Architecture
The device deploys Narrow VDC architecture (NVDC) with BATFET separating system from battery. The
minimum system voltage is set by REG01[3:1]. Even with a fully depleted battery, the system is regulated above
the minimum system voltage (default 3.5V).
When the battery is below minimum system voltage setting, the BATFET operates in linear mode (LDO mode),
and the system is 150mV above the minimum system voltage setting. As the battery voltage rises above the
minimum system voltage, BATFET is fully on and the voltage difference between the system and battery is the
VDS of BATFET.
When the battery charging is disabled or terminated, the system is always regulated at 150mV above the
minimum system voltage setting. The status register REG08[0] goes high when the system is in minimum system
voltage regulation.
4.5
4.3
Charge Enabled
4.1
SYS
(V)
Charge Disabled
3.9
3.7
3.5
Minimum System Voltage
3.3
3.1
2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3
BAT (V)
Figure 26. V(SYS) vs V(BAT)
Dynamic Power Management
To meet maximum current limit in USB spec and avoid over loading the adapter, the device features Dynamic
Power Management (DPM), which continuously monitors the input current and input voltage.
When input source is over-loaded, either the current exceeds the input current limit (REG00[2:0]) or the voltage
falls below the input voltage limit (REG00[6:3]). The device then reduces the charge current until the input current
falls below the input current limit and the input voltage rises above the input voltage limit.
When the charge current is reduced to zero, but the input source is still overloaded, the system voltage starts to
drop. Once the system voltage falls below the battery voltage, the device automatically enters the supplement
mode where the BATFET turns on and battery starts discharging so that the system is supported from both the
input source and battery.
During DPM mode (either VINDPM or IINDPM), the status register REG08[3] will go high.
Figure 27 shows the DPM response with 5V/1.2A adapter, 3.2V battery, 2.0A charge current and 3.4V minimum
system voltage setting.
26
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Voltage
VBUS
5V
SYS
3.6V
3.4V
3.2V
3.18V
BAT
Current
3A
ICHG
2.3A
2.0A
ISYS
1.5A
1.0A
0.5A
IIN
-0.7A
DPM
DPM
Supplement
Figure 27. DPM Response
Supplement Mode
When the system voltage falls below the battery voltage, the BATFET turns on and the BATFET gate is
regulated the gate drive of BATFET so that the minimum BATFET VDS stays at 30mV when the current is low.
This prevents oscillation from entering and exiting the supplement mode. As the discharge current increases, the
BATFET gate is regulated with a higher voltage to reduce RDSON until the BATFET is in full conduction. At this
point onwards, the BATFET VDS linearly increases with discharge current. Figure 28 shows the V-I curve of the
BATFET gate regulation operation. BATFET turns off to exit supplement mode when the battery is below battery
depletion threshold.
4.5
4.0
CURRENT (A)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0
5
10
15
20
25
30
35
40
45
50
55
V(BAT-SYS) (mV)
Figure 28. BATFET V-I Curve
Battery Charging Management
The device charges 1-cell Li-Ion battery with up to 3A charge current for high capacity tablet battery. The 24mΩ
BATFET improves charging efficiency and minimizes the voltage drop during discharging.
Autonomous Charging Cycle
With battery charging enabled at POR (REG01[5:4]=01), the charger device complete a charging cycle without
host involvement. The device default charging parameters are listed in the following table.
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Table 5. Charging Parameter Default Setting
(1)
A
•
•
•
•
•
DEFAULT MODE
bq24296 / bq24297
Charging Voltage
4.208 V
Charging Current
2.048A
Pre-charge Current
256 mA
Termination Current
256 mA
Temperature Profile
Hot/Cold
Safety Timer
12 hours (1)
See section Charging Safety Timer for more information.
new charge cycle starts when the following conditions are valid:
Converter starts
Battery charging is enabled by I2C register bit (REG01[5:4]) = 01 and CE is low
No thermistor fault on TS
No safety timer fault
BATFET is not forced to turn off (REG07[5])
The charger device automatically terminates the charging cycle when the charging current is below termination
threshold and charge voltage is above recharge threshold. When a full battery voltage is discharged below
recharge threshold (REG04[0]), the device automatically starts another charging cycle.After the charge done,
either toggle /CE pin or REG01[5:4] will initiate a new charging cycle.
The STAT output indicates the charging status of charging (LOW), charging complete or charge disable (HIGH)
or charging fault (Blinking). The status register REG08[5:4] indicates the different charging phases: 00-charging
disable, 01-precharge, 10-fast charge (constant current) and constant voltage mode, 11-charging done. Once a
charging cycle is complete, an INT is asserted to notify the host.
The host can always control the charging operation and optimize the charging parameters by writing to the
registers through I2C.
Battery Charging Profile
The device charges the battery in three phases: preconditioning, constant current and constant voltage. At the
beginning of a charging cycle, the device checks the battery voltage and applies current.
Table 6. Charging Current Setting
28
VBAT
CHARGING CURRENT
REG DEFAULT SETTING
REG08[5:4]
VBAT < VSHORT
(Typical 2V)
100mA
–
01
VSHORT ≤ VBAT < VBATLOWV
(Typical 2V ≤ VBAT < 3V)
REG03[7:4]
256mA
01
VBAT ≥ VBATLOWV
(Typical VBAT ≥ 3V)
REG02[7:2]
2048mA
10
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If the charger device is in DPM regulation or thermal regulation during charging, the actual charging current will
be less than the programmed value. In this case, termination is temporarily disabled and the charging safety
timer is counted at half the clock rate.
Regulation Voltage
(3.5V – 4.4V)
Battery Voltage
Fast Charge Current
(500mA-3008mA)
Charge Current
VBAT_LOWV (2.8V/3V)
VBAT_SHORT (2V)
IPRECHARGE (128mA-2048mA)
ITERMINATION (128mA-2048mA)
IBATSHORT (100mA)
Trickle Charge
Pre-charge
Fast Charge and Voltage Regulation
Safety Timer
Expiration
Figure 29. Battery Charging Profile
Thermistor Qualification
The charger device provides a single thermistor input for battery temperature monitor.
Cold/Hot Temperature Window
The device continuously monitors battery temperature by measuring the voltage between the TS pin and ground,
typically determined by a negative temperature coefficient thermistor and an external voltage divider. The device
compares this voltage against its internal thresholds to determine if charge or boost is allowed.
To initiate a charge cycle, the battery temperature must be within the VLTF to VHTF thresholds. During the charge
cycle the battery temperature must be within the VLTF to VTCO thresholds, else the device suspends charging and
waits until the battery temperature is within the VLTF to VHTF range.
For battery protection during boost mode, the device monitors the battery temperature to be within the VBCOLDx
to VBHOTx thresholds unless boost mode temperature is disabled by setting BHOT bits (REG06[3:2]) to 11.
When temperature is outside of the temperature thresholds, the boost mode is suspended and REG08[7:6] bits
(VBUS_STAT) are set to 00. Once temperature returns within thresholds, the boost mode is recovered.
REGN
bq24296
bq24297
RT1
TS
RT2
RTH
103AT
Figure 30. TS Resistor Network
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When the TS fault occurs, the fault register REG09[2:0] indicates the actual condition on each TS pin and an INT
is asserted to the host. The STAT pin indicates the fault when charging is suspended.
TEMPERATURE RANGE
DURING A CHARGE CYCLE
TEMPERATURE RANGE TO
INITIATE CHARGE
VREF
VREF
CHARGE SUSPENDED
CHARGE SUSPENDED
VLTF
VLTF
VLTFH
VLTFH
CHARGE at full C
CHARGE at full C
VHTF
VTCO
CHARGE SUSPENDED
CHARGE SUSPENDED
AGND
AGND
Figure 31. TS Pin Thermistor Sense Thresholds in Charge Mode
Temperature Range to
Boost
VREF
V BCOLDx
Boost Disable
( - 10ºC / 20ºC)
Boost Enable
V
BHOTx
(55ºC / 60ºC / 65ºC)
Boost Disable
AGND
Figure 32. TS Pin thermistor Sense Thresholds in Boost Mode
Assuming a 103AT NTC thermistor is used on the battery pack Figure 31, the value RT1 and RT2 can be
determined by using the following equation:
æ 1
1 ö
VVREF ´ RTHCOLD ´ RTHHOT ´ ç
÷
V
V
TCO ø
è LTF
RT2 =
æV
ö
æV
ö
RTHHOT ´ ç VREF - 1÷ - RTHCOLD ´ ç VREF - 1÷
V
V
è LTF
ø
è TCO
ø
VVREF
-1
VLTF
RT1 =
1
1
+
RT2 RTHCOLD
(1)
Select 0°C to 45°C range for Li-ion or Li-polymer battery,
RTHCOLD = 27.28 kΩ
RTHHOT = 4.911 kΩ
30
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RT1 = 5.52 kΩ
RT2 = 31.23 kΩ
Charging Termination
The device terminates a charge cycle when the battery voltage is above recharge threshold, and the current is
below termination current. After the charging cycle is complete, the BATFET turns off. The converter keeps
running to power the system, and BATFET can turn back on to engage supplement mode.
When termination occurs, the status register REG08[5:4] is 11, and an INT is asserted to the host. Termination is
temporarily disabled if the charger device is in input current/voltage regulation or thermal regulation. Termination
can be disabled by writing 0 to REG05[7].
Termination when REG02[0] = 1
When REG02[0] is HIGH to reduce the charging current by 80%, the charging current could be less than the
termination current. The charger device termination function should be disabled. When the battery is charged to
fully capacity, the host disables charging through CE pin or REG01[5:4].
Charging Safety Timer
The device has safety timer to prevent extended charging cycle due to abnormal battery conditions. The safety
timer is 4 hours when the battery is below batlowv threshold. The user can program fast charge safety timer
(default 12 hours)through I2C (REG05[2:1]). When safety timer expires, the fault register REG09[5:4] goes 11
and an INT is asserted to the host. The safety timer feature can be disabled via I2C (REG05[3]).
The following actions restart the safety timer after safety timer expires:
• Toggle the CE pin HIGH to LOW to HIGH (charge enable)
• Write REG01[5:4] from 00 to 01 (charge enable)
• Write REG05[3] from 0 to 1 (safety timer enable)
During input voltage/current regulation, thermal regulation, or FORCE_20PCT bit (REG02[0]) is set , the safety
timer counting at half clock rate since the actual charge current is likely to be below the register setting. For
example, if the charger is in input current regulation (IINDPM) throughout the whole charging cycle, and the
safety time is set to 5 hours, the safety timer will expire in 10 hours. This feature can be disabled by writing 0 to
REG07[6].
Safety Timer Configuration Change
When safety timer value needs to be changed, it is recommended that the timer is disabled first before new
configuration is written to REG05[2:1]. The safety timer can be disable by writing 1 to REG05[3]. This ensures
the safety timer restart counting after new value is configured.
USB Timer when Charging from USB100mA Source
The total charging time in default mode from USB100mA source is limited by a 45-min max timer. At the end of
the timer, the device stops the converter and goes to HIZ.
Host Mode and Default Mode
The device is a host controlled device, but it can operate in default mode without host management. In default
mode, the device can be used as an autonomous charger with no host or with host in sleep.
When the charger is in default mode, REG09[7] is HIGH. When the charger is in host mode, REG09[7] is LOW.
After power-on-reset, the device starts in watchdog timer expiration state, or default mode. All the registers are in
the default settings. The device keeps charging the battery by default with 12-hour fast charging safety timer. At
the end of the 12 hours, the charging is stopped and the buck converter continues to operate to supply system
load.
Any write command to device transitions the device from default mode to host mode. All the device parameters
can be programmed by the host. To keep the device in host mode, the host has to reset the watchdog timer by
writing 1 to REG01[6] before the watchdog timer expires (REG05[5:4]), or disable watchdog timer by setting
REG05[5:4]=00.
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When the host changes watchdog timer configuration (REG05[5:4]), it is recommended to first disable watchdog
by writing 00 to REG05[5:4] and then change the watchdog to new timer values. This ensures the watchdog
timer is restarted after new value is written.
POR
watchdog timer expired
Reset registers
I2C interface enabled
Host Mode
Y
I2C Write?
Start watchdog timer
Host programs registers
N
Default Mode
Reset watchdog timer
Reset registers
N
Reset REG01
bit[6]?
Y
Y
N
I2C Write?
Y
Watchdog Timer
Expired?
N
Figure 33. Watchdog Timer Flow Chart
Plug in USB100mA Source with Good Battery
When the input source is detected as 100mA USB host, and the battery voltage is above batgood threshold
(VBATGD), the charger device enters HIZ state to meet the battery charging spec requirement.
If the charger device is in host mode, it will stay in HIZ state even after the USB100mA source is removed, and
the adapter plugs in. During the HIZ state, REG00[7] is set HIGH and the system load is supplied from battery. It
is recommended that the processor host always checks if the charger IC is in HIZ state when it wakes up. The
host can write REG00[7] to 0 to exit HIZ state.
If the charger is in default mode, when the DC source is removed, the charger device will get out of HIZ state
automatically. When the input source plugs in again, the charger IC runs detection on the input source and
update the input current limit.
USB Timer when Charging from USB100mA Source
The total charging time in default mode from USB100mA source is limited by a 45-min max timer. At the end of
the timer, the device stops the converter and goes to HIZ.
Status Outputs (PG, STAT, and INT)
Power Good Indicator (PG) (bq24296)
In bq24296, PG goes LOW to indicate a good input source when:
1. VBUS above VBUS_UVLO
2. VBUS above battery (not in sleep)
3. VBUS below VACOV threshold
4. VBUS above VBUS_MIN when IBADSRC current is applied (not a poor source)
Charging Status Indicator (STAT)
The device indicates charging state on the open drain STAT pin. The STAT pin can drive LED as the application
diagram shows.
32
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Table 7. STAT Pin State
CHARGING STATE
STAT
Charging in progress (including recharge)
LOW
Charging complete
HIGH
Sleep mode, charge disable
HIGH
Charge suspend (Input over-voltage, TS fault, timer fault, input
or system over-voltage)
blinking at 1Hz
Interrupt to Host (INT)
In some applications, the host does not always monitor the charger operation. The INT notifies the system on the
device operation. The following events will generate 256us INT pulse.
1. USB/adapter source identified (through PSEL or DPDM detection, and OTG pin)
2. Good input source detected
– not in sleep
– VBUS below VACOV threshold
– current limit above IBADSRC
3. Input removed or VBUS above VACOV threshold
4. Charge Complete
5. Any FAULT event in REG09
For the first four events, INT pulse is always generated. For the last event, when a fault occurs, the charger
device sends out INT and latches the fault state in REG09 until the host reads the fault register. If a prior fault
exists, the charger device would not send any INT upon new faults except NTC fault (REG09[2:0]). The NTC
fault is not latched and always reports the current thermistor conditions. In order to read the current fault status,
the host has to read REG09 two times consecutively. In order to read the current fault status, the host has to
read REG09 two times consecutively. The 1st reads fault register status from the last read and the 2nd reads the
current fault register status.
Protections
Input Current Limit on ILIM
For safe operation, the device has an additional hardware pin on ILIM to limit maximum input current on ILIM pin.
The input maximum current is set by a resistor from ILIM pin to ground as:
1V
I INMAX =
´ KLIM
RILIM
(2)
The actual input current limit is the lower value between ILIM setting and register setting (REG00[2:0]). For
example, if the register setting is 111 for 3A, and ILIM has a 316Ω resistor to ground for 1.5A, the input current
limit is 1.5A. ILIM pin can be used to set the input current limit rather than the register settings.
The device regulates ILIM pin at 1V. If ILIM voltage exceeds 1V, the device enters input current regulation (Refer
to Dynamic Power Path Management section).
The voltage on ILIM pin is proportional to the input current. ILIM pin can be used to monitor the input current
following Equation 3:
V
I IN = ILIM ´ IINMAX
(3)
1V
For example, if ILIM pin sets 2A, and the ILIM voltage is 0.75V, the actual input current 1.5A. If ILIM pin is open,
the input current is limited to zero since ILIM voltage floats above 1V. If ILIM pin is short, the input current limit is
set by the register.
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Thermal Regulation and Thermal Shutdown
During charge operation, the device monitors the internal junction temperature TJ to avoid overheat the chip and
limits the IC surface temperature. When the internal junction temperature exceeds the preset limit (REG06[1:0]),
the device lowers down the charge current. The wide thermal regulation range from 60°C to 120°C allows the
user to optimize the system thermal performance.
During thermal regulation, the actual charging current is usually below the programmed battery charging current.
Therefore, termination is disabled, the safety timer runs at half the clock rate, and the status register REG08[1]
goes high.
Additionally, the device has thermal shutdown to turn off the converter. The fault register REG09[5:4] is 10 and
an INT is asserted to the host.
Voltage and Current Monitoring in Buck Mode
The device closely monitors the input and system voltage, as well as HSFET and LSFET current for safe buck
mode operation.
Input Over-Voltage (ACOV)
The maximum input voltage for buck mode operation is VVBUS_OP. If VBUS voltage exceeds VACOV, the device
stops switching immediately. During input over voltage (ACOV), the fault register REG09[5:4] will be set to 01. An
INT is asserted to the host.
System Over-Voltage Protection (SYSOVP)
The charger device clamps the system voltage during load transient so that the components connect to system
would not be damaged due to high voltage. When SYSOVP is detected, the converter stops immediately to
clamp the overshoot.
Voltage and Current Monitoring in Boost Mode
The charger device closely monitors the VBUS voltage, as well as HSFET and LSFET current to ensure safe
boost mode operation.
Over-Current Protection
The charger device closely monitors the RBFET (Q1), HSFET (Q2), and LSFET (Q3) current to ensure safe
boost mode operation. During over-current condition, the device will operate in hiccup mode for protection. While
in hiccup mode cycle, the device turns off RBFET for tOTG_OCP_OFF (32ms typical) and turns on RBFET for
tOTG_OCP_ON (260us typical) in an attempt to restart. If the over-current condition is removed, the boost converter
will maintain the RBFET on state and the VBUS OTG output will operate normally. When over-current condition
continues to exist, the device will repeat the hiccup cycle until over-current condition is removed. When overcurrent condition is detected, the fault register bit BOOST_FAULT (REG09[6]) is set high to indicate fault in boost
operation. An INT is asserted to the host.
VBUS Over-Voltage Protection
When an adapter plugs in during boost mode, the VBUS voltage will rise above regulation target. Once the
VBUS voltage exceeds VOTG_OVP, the device stops switching and the device exits boost mode. During the overvoltage, the fault register bit BOOST_FAULT (REG09[6]) is set high to indicate fault in boost operation. An INT is
asserted to the host.
Battery Protection
Battery Over-Voltage Protection (BATOVP)
The battery over-voltage limit is clamped at VBAT_OVP (4% nominal) above the battery regulation voltage. When
battery over voltage occurs, the charger device immediately disables charge. The fault register REG09[5] goes
high and an INT is asserted to the host.
34
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Battery Short Protection
If the battery voltage falls below Vshort (2V typical), the device immediately turns off BATFET to disable the
battery charging or supplement mode. 1ms later, the BATFET turns on and charge the battery with 100mA
current. The device does not turn on BATFET to discharge a battery that is below 2.5V.
System Over-Current Protection
If the system is shorted or exceeds the over-current limit, the device latches off BATFET. DC source insertion on
VBUS is required to reset the latch-off condition and turn on BATFET.
Serial Interface
The device uses I2C compatible interface for flexible charging parameter programming and instantaneous device
status reporting. I2CTM is a bi-directional 2-wire serial interface developed by Philips Semiconductor (now NXP
Semiconductors). Only two bus lines are required: a serial data line (SDA) and a serial clock line (SCL). Devices
can be considered as masters or slaves when performing data transfers. A master is the device which initiates a
data transfer on the bus and generates the clock signals to permit that transfer. At that time, any device
addressed is considered a slave.
The device operates as a slave device with address 6BH, receiving control inputs from the master device like
micro controller or a digital signal processor. The I2C interface supports both standard mode (up to 100kbits), and
fast mode (up to 400kbits).
Both SDA and SCL are bi-directional lines, connecting to the positive supply voltage via a current source or pullup resistor. When the bus is free, both lines are HIGH. The SDA and SCL pins are open drain.
Data Validity
The data on the SDA line must be stable during the HIGH period of the clock. The HIGH or LOW state of the
data line can only change when the clock signal on the SCL line is LOW. One clock pulse is generated for each
data bit transferred.
SDA
SCL
Data line stable;
Data valid
Change
of data
allowed
Figure 34. Bit Transfer on the I2C Bus
START and STOP Conditions
All transactions begin with a START (S) and can be terminated by a STOP (P). A HIGH to LOW transition on the
SDA line while SCl is HIGH defines a START condition. A LOW to HIGH transition on the SDA line when the
SCL is HIGH defines a STOP condition.
START and STOP conditions are always generated by the master. The bus is considered busy after the START
condition, and free after the STOP condition.
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SDA
SDA
SCL
SCL
STOP (P)
START (S)
Figure 35. START and STOP conditions
Byte Format
Every byte on the SDA line must be 8 bits long. The number of bytes to be transmitted per transfer is
unrestricted. Each byte has to be followed by an Acknowledge bit. Data is transferred with the Most Significant
Bit (MSB) first. If a slave cannot receive or transmit another complete byte of data until it has performed some
other function, it can hold the clock line SCL low to force the master into a wait state (clock stretching). Data
transfer then continues when the slave is ready for another byte of data and release the clock line SCL.
Acknowledgement
signal from receiver
Acknowledgement
signal from slave
MSB
SDA
SCL
S or Sr
2
1
7
8
START or
Repeated
START
2
1
9
ACK
8
9
ACK
P or Sr
STOP or
Repeated
START
Figure 36. Data Transfer on the I2C Bus
Acknowledge (ACK) and Not Acknowledge (NACK)
The acknowledge takes place after every byte. The acknowledge bit allows the receiver to signal the transmitter
that the byte was successfully received and another byte may be sent. All clock pulses, including the
acknowledge 9th clock pulse, are generated by the master.
The transmitter releases the SDA line during the acknowledge clock pulse so the receiver can pull the SDA line
LOW and it remains stable LOW during the HIGH period of this clock pulse.
When SDA remains HIGH during the 9th clock pulse, this is the Not Acknowledge signal. The master can then
generate either a STOP to abort the transfer or a repeated START to start a new transfer.
Slave Address and Data Direction Bit
After the START, a slave address is sent. This address is 7 bits long followed by the eighth bit as a data direction
bit (bit R/W). A zero indicates a transmission (WRITE) and a one indicates a request for data (READ).
SDA
SCL
S
1-7
8
9
START
ADDRESS
R/W
ACK
8
1-7
DATA
9
ACK
8
1-7
DATA
9
P
ACK
STOP
Figure 37. Complete Data Transfer
36
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Single Read and Write
1
7
1
1
8
1
8
1
1
S
Slave Address
0
ACK
Reg Addr
ACK
Data Addr
ACK
P
Figure 38. Single Write
1
7
1
1
8
1
1
7
1
1
S
Slave Address
0
ACK
Reg Addr
ACK
S
Slave Address
1
ACK
8
1
1
Data
NCK
P
Figure 39. Single Read
If the register address is not defined, the charger IC send back NACK and go back to the idle state.
Multi-Read and Multi-Write
The charger device supports multi-read and multi-write on REG00 through REG08.
1
7
1
1
8
1
S
Slave Address
0
ACK
Reg Addr
ACK
8
1
8
1
8
1
1
Slave Address
ACK
Data to Addr+1
ACK
Data to Addr+1
ACK
P
Figure 40. Multi-Write
1
7
1
1
8
1
1
7
1
1
S
Slave Address
0
ACK
Reg Addr
ACK
S
Slave Address
1
ACK
8
Data @ Addr
1
8
1
8
1
1
ACK
Data @ Addr+1
ACK
Data @ Addr+1
ACK
P
Figure 41. Multi-Read
The fault register REG09 locks the previous fault and only clears it after the register is read. For example, if
Charge Safety Timer Expiration fault occurs but recovers later, the fault register REG09 reports the fault when it
is read the first time, but returns to normal when it is read the second time. To verify real time fault, the fault
register REG09 should be read twice to get the real condition. In addition, the fault register REG09 does not
support multi-read or multi-write.
REG09 is a fault register. It keeps all the fault information from last read until the host issues a new read. For
example, if there is a TS fault but gets recovered immediately, the host still sees TS fault during the first read. In
order to get the fault information at present, the host has to read REG09 for the second time. REG09 doesn’t
support multi-read and multi-write.
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APPLICATION INFORMATION
Inductor Selection
The device has 1.5 MHz switching frequency to allow the use of small inductor and capacitor values. The
Inductor saturation current should be higher than the charging current (ICHG) plus half the ripple current (IRIPPLE):
ISAT ³ ICHG + (1/ 2 ) IRIPPLE
(4)
The inductor ripple current depends on input voltage (VBUS), duty cycle (D = VBAT/VVBUS), switching frequency
(fs) and inductance (L):
V ´ D ´ (1 - D)
IRIPPLE = IN
¦s ´ L
(5)
The maximum inductor ripple current happens with D = 0.5 or close to 0.5. Usually inductor ripple is designed in
the range of (20–40%) maximum charging current as a trade-off between inductor size and efficiency for a
practical design.
Input Capacitor
Input capacitor should have enough ripple current rating to absorb input switching ripple current. The worst case
RMS ripple current is half of the charging current when duty cycle is 0.5. If the converter does not operate at
50% duty cycle, then the worst case capacitor RMS current ICIN occurs where the duty cycle is closest to 50%
and can be estimated by the following equation:
I CIN = ICHG ´ D ´ (1 - D)
(6)
For best performance, VBUS should be decouple to PGND with 1μF capacitance. The remaining input capacitor
should be place on PMID.
Low ESR ceramic capacitor such as X7R or X5R is preferred for input decoupling capacitor and should be
placed to the drain of the high side MOSFET and source of the low side MOSFET as close as possible. Voltage
rating of the capacitor must be higher than normal input voltage level. 25V rating or higher capacitor is preferred
for 15V input voltage. 22μF capacitance is suggested for typical of 3-4A charging current.
Output Capacitor
Output capacitor also should have enough ripple current rating to absorb output switching ripple current. The
output capacitor RMS current ICOUT is given:
I
I COUT = RIPPLE » 0.29 ´ IRIPPLE
2´ 3
(7)
The output capacitor voltage ripple can be calculated as follows:
VOUT æç
VOUT ö÷
1
DVO =
VIN ÷
8LC¦ s2 çè
ø
(8)
At certain input/output voltage and switching frequency, the voltage ripple can be reduced by increasing the
output filter LC.
The charger device has internal loop compensator. To get good loop stability, the resonant frequency of the
output inductor and output capacitor should be designed between 15kHz and 25kHz. The preferred ceramic
capacitor is 6V or higher rating, X7R or X5R.
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PCB Layout
The switching node rise and fall times should be minimized for minimum switching loss. Proper layout of the
components to minimize high frequency current path loop (see Figure 42) is important to prevent electrical and
magnetic field radiation and high frequency resonant problems. Here is a PCB layout priority list for proper
layout. Layout PCB according to this specific order is essential.
1. Place input capacitor as close as possible to PMID pin and GND pin connections and use shortest copper
trace connection or GND plane.
2. Place inductor input terminal to SW pin as close as possible. Minimize the copper area of this trace to lower
electrical and magnetic field radiation but make the trace wide enough to carry the charging current. Do not
use multiple layers in parallel for this connection. Minimize parasitic capacitance from this area to any other
trace or plane.
3. Put output capacitor near to the inductor and the IC. Ground connections need to be tied to the IC ground
with a short copper trace connection or GND plane.
4. Route analog ground separately from power ground. Connect analog ground and connect power ground
separately. Connect analog ground and power ground together using power pad as the single ground
connection point. Or using a 0Ω resistor to tie analog ground to power ground.
5. Use single ground connection to tie charger power ground to charger analog ground. Just beneath the IC.
Use ground copper pour but avoid power pins to reduce inductive and capacitive noise coupling.
6. Decoupling capacitors should be placed next to the IC pins and make trace connection as short as possible.
7. It is critical that the exposed power pad on the backside of the IC package be soldered to the PCB ground.
Ensure that there are sufficient thermal vias directly under the IC, connecting to the ground plane on the
other layers.
8. The via size and number should be enough for a given current path.
See the EVM design for the recommended component placement with trace and via locations. For the QFN
information, refer to SCBA017 and SLUA271.
Figure 42. High Frequency Current Path
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REVISION HISTORY
Changes from Original (September 2013) to Revision A
•
40
Page
Deleted H from bq24297 ORDERING NUMBER ................................................................................................................. 3
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PACKAGE OPTION ADDENDUM
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1-Oct-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
BQ24296RGER
ACTIVE
VQFN
RGE
24
3000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
24296
BQ24296RGET
ACTIVE
VQFN
RGE
24
250
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
24296
BQ24297RGER
ACTIVE
VQFN
RGE
24
3000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
24297
BQ24297RGET
ACTIVE
VQFN
RGE
24
250
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
BQ
24297
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation
of the previous line and the two combined represent the entire Device Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
1-Oct-2013
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
1-Oct-2013
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
BQ24296RGER
VQFN
RGE
24
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
3000
330.0
12.4
4.25
4.25
1.15
8.0
12.0
Q2
BQ24296RGET
VQFN
RGE
24
250
180.0
12.4
4.25
4.25
1.15
8.0
12.0
Q2
BQ24297RGER
VQFN
RGE
24
3000
330.0
12.4
4.25
4.25
1.15
8.0
12.0
Q2
BQ24297RGET
VQFN
RGE
24
250
180.0
12.4
4.25
4.25
1.15
8.0
12.0
Q2
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
1-Oct-2013
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
BQ24296RGER
VQFN
RGE
24
3000
367.0
367.0
35.0
BQ24296RGET
VQFN
RGE
24
250
210.0
185.0
35.0
BQ24297RGER
VQFN
RGE
24
3000
367.0
367.0
35.0
BQ24297RGET
VQFN
RGE
24
250
210.0
185.0
35.0
Pack Materials-Page 2
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