TI BQ24103 Synchronous switchmode, li-ion and li-pol charge management ic with integrated powerfet Datasheet

bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
Actual Size
5,5 mm x 3,5 mm
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SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
SYNCHRONOUS SWITCHMODE, LI-ION AND LI-POLYMER CHARGE-MANAGEMENT
IC WITH INTEGRATED POWER FETs (bqSWITCHER™)
FEATURES
APPLICATIONS
•
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Ideal For Highly Efficient Charger Designs For
Single-, Two- or Three-Cell Li-Ion and
Li-Polymer
Battery Packs
Integrated Synchronous Fixed-Frequency
PWM Controller Operating at 1.1 MHz With
0% to 100% Duty Cycle
Integrated Power FETs For Up To 2-A Charge
Rate
High-Accuracy Voltage and Current
Regulation
Available In Both Stand-Alone (Built-In Charge
Management and Control) and
System-Controlled (Under System Command)
Versions
Status Outputs For LED or Host Processor
Interface Indicates Charge-In-Progress,
Charge Completion, Fault, and AC-Adapter
Present Conditions
20-V Maximum Voltage Rating on IN and OUT
Pins
High-Side Current Sensing
Optional Battery Temperature Monitoring
Automatic Sleep Mode for Low Power
Consumption
System-Controlled Version Can Be Used In
NiMH and NiCd Applications
Uses Ceramic Capacitors
Reverse Leakage Protection Prevents Battery
Drainage
Thermal Shutdown and Protection
Built-In Battery Detection
Handheld Products
Portable Media Players
Industrial and Medical Equipment
Portable Equipment
DESCRIPTION
The bqSWITCHER™ series are highly integrated
Li-ion
and
Li-polymer
switch-mode
charge
management devices targeted at a wide range of
portable applications. The bqSWITCHER™ series
offers integrated synchronous PWM controller and
power FETs, high-accuracy current and voltage
regulation, charge preconditioning, charge status, and
charge termination, in a small, thermally enhanced
QFN package. The system-controlled version
provides additional inputs for full charge management
under system control.
The bqSWITCHER charges the battery in three
phases: conditioning, constant current, and constant
voltage. Charge is terminated based on userselectable minimum current level. A programmable
charge timer provides a safety backup for charge
termination. The bqSWITCHER automatically restarts
the charge cycle if the battery voltage falls below an
internal threshold. The bqSWITCHER automatically
enters sleep mode when VCC supply is removed.
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.
bqSWITCHER, PowerPAD are trademarks 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 © 2004–2005, Texas Instruments Incorporated
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
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.
TYPICAL SINGLE CELL LI-ION STAND-ALONE CHARGER
LOUT
10 µH
bq24100RHL
VIN
3
IN
OUT 1
4
IN
OUT 20
6
VCC
PGND 17
2
STAT1
PGND 18
19 STAT2
SNS 15
PG
BAT 14
10 µF
5
R(SNS)
COUT
10 µF
PACK+
PACKR(ISET1)
7
TTC
+
VTSB
0.1 µF
ISET1 8
R(ISET2)
CTTC
ISET2 9
16 CE
RT1
TS 12
10 VSS
TEMP
PWR PAD VTSB 11
RT2
VIN
VIN
D1
Adapter
Present
BATTERY
PACK
VIN
D2
Done
D3
Charge
UDG-04033
ORDERING INFORMATION (1)
TJ
CHARGE REGULATION VOLTAGE (V)
4.2 V
–40°C to 125°C
(2)
(3)
2
Stand-alone
1 or 2 cells selectable (CELLS pin, 4.2 V or 8.4 V)
Stand-alone
Externally programmable (2.1 V to 15.5 V)
Stand-alone
4.2 (Blinking status pins)
Stand-alone
1 or 2 cells selectable (CELLS pin, 4.2 V or 8.4 V)
System-controlled
Externally programmable (2.1 V to 15.5 V)
(1)
INTENDED APPLICATION
System-controlled
PART NUMBER (2) (3)
MARKINGS
bq24100RHLR
CIA
bq24100RHLT
CIA
bq24103RHLR
CID
bq24103RHLT
CID
bq24105RHLR
CIF
bq24105RHLT
CIF
bq24108RHLR
CIU
bq24113RHLR
CIJ
bq24113RHLT
CIJ
bq24115RHLR
CIL
bq24115RHLT
CIL
For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
Web site at www.ti.com.
The RHL package is available in the following options:
T - taped and reeled in quantities of 3,000 devices per reel
R - taped and reeled in quantities of 250 devices per reel
This product is RoHS compatible, including a lead concentration that does not exceed 0.1% of total product weight, and is suitable for
use in specified lead-free soldering processes.
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
PACKAGE DISSIPATION RATINGS
(1)
PACKAGE
ΘJA
TA < 40°C
POWER RATING
DERATING FACTOR
ABOVE TA = 40°C
RHL (1)
46.87°C/W
1.81 W
0.021 W/°C
This data is based on using the JEDEC High-K board, and the exposed die pad is connected to a copper pad on the board. This is
connected to the ground plane by a 2x3 via matrix.
ABSOLUTE MAXIMUM RATINGS (1)
over operating free-air temperature range (unless otherwise noted)
UNIT
Supply voltage range (with respect to VSS)
IN, VCC
Input voltage range (with respect to VSS and PGND)
20 V
STAT1, STAT2, PG, CE, CELLS, SNS, BAT
–0.3 V to 20 V
OUT
–0.7 V to 20 V
CMODE, TS, TTC
7V
VTSB
3.6 V
ISET1, ISET2
3.3 V
Voltage difference between SNS and BAT inputs (VSNS - VBAT)
Output sink
STAT1, STAT2, PG
Output current (average)
OUT
±1 V
10 mA
2.2 A
TA
Operating free-air temperature range
–40°C to 85°C
TJ
Junction temperature range
–40°C to 125°C
Tstg
Storage temperature
–65°C to 150°C
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds
(1)
300°C
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.
RECOMMENDED OPERATING CONDITIONS
MIN
NOM
MAX
UNIT
Supply voltage, VCC and IN (Tie together)
4.35 (1)
16.0 (2)
V
Operating junction temperature range, TJ
–40
125
°C
(1)
(2)
The IC continues to operate below Vmin, to 3.5 V, but the specifications are not tested and not guaranteed.
The inherent switching noise voltage spikes should not exceed the absolute maximum rating on either the IN or OUT pins. A tight layout
minimizes switching noise.
ELECTRICAL CHARACTERISTICS
TJ = 0°C to 125°C and recommended supply voltage range (unless otherwise stated)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
INPUT CURRENTS
VCC > VCC(min), PWM switching
IVCC(VCC)
I(SLP)
VCC supply current
Battery discharge sleep current, (SNS,
BAT, OUT, FB pins)
VCC > VCC(min), PWM NOT switching
10
5
VCC > VCC(min), CE = HIGH
315
0°C ≤ TJ ≤ 65°C, VI(BAT) = 4.2 V,
VCC < V(SLP) or VCC > V(SLP) but not in charge
3.5
0°C ≤ TJ ≤ 65°C, VI(BAT) = 8.4 V,
VCC < V(SLP) or VCC > V(SLP) but not in charge
5.5
0°C ≤ TJ ≤ 65°C, VI(BAT) = 12.6 V,
VCC < V(SLP) or VCC > V(SLP) but not in charge
7.7
mA
µA
µA
3
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
ELECTRICAL CHARACTERISTICS (continued)
TJ = 0°C to 125°C and recommended supply voltage range (unless otherwise stated)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
VOLTAGE REGULATION
VOREG
VIBAT
CELLS = Low, in voltage regulation
4.2
CELLS = High, in voltage regulation
8.4
Output voltage, bq24100/08
Operating in voltage regulation
4.2
Feedback regulation REF for bq24105/15
only (W/FB)
IIBAT = 25 nA typical into pin
2.1
Output voltage, bq24103/13
Voltage regulation accuracy
TA = 25°C
V
V
–0.5%
0.5%
–1%
1%
150
2000
–10%
10%
CURRENT REGULATION - FAST CHARGE
IOCHARGE
Output current range of converter
VLOWV ≤ VI(BAT) < VOREG,
V(VCC) - VI(BAT) > V(DO-MAX)
mA
100 mV ≤ VIREG≤ 200 mV,
V
IREG
1V 1000,
RSET1
VIREG
Voltage regulated across R(SNS) Accuracy
V(ISET1)
Output current set voltage
V(LOWV) ≤ VI(BAT) ≤ VO(REG),
V(VCC) ≥ VI(BAT) × V(DO-MAX)
1
K(ISET1)
Output current set factor
VLOWV ≤ VI(BAT) < VO(REG) ,
V(VCC) ≥ VI(BAT) + V(DO-MAX)
1000
Programmed Where
5 kΩ ≤ RSET1 ≤ 10 kΩ, Select RSET1 to
program VIREG,
VIREG(measured) = IOCHARGE + RSNS
(–10% to 10% excludes errors due to RSET1
and R(SNS) tolerances)
V
V/A
PRECHARGE AND SHORT-CIRCUIT CURRENT REGULATION
VLOWV
Precharge to fast-charge transition voltage
threshold, BAT, bq24100/03/05/08 ICs only
t
Deglitch time for precharge to fast charge
transition
IOPRECHG
V(ISET2)
K(ISET2)
Precharge current set factor
68
71.4
75
%VO(REG)
Rising voltage;
tRISE, tFALL = 100 ns, 2-mV overdrive
20
30
40
ms
Precharge range
VI(BAT) < VLOWV, t < tPRECHG
15
200
mA
Precharge set voltage, ISET2
VI(BAT) < VLOWV, t < tPRECHG
100
mV
1000
V/A
100 mV ≤ VIREG-PRE ≤ 100 mV,
V
VIREG-PRE
Voltage regulated across RSNS-Accuracy
IREGPRE
0.1V 1000,
RSET2
(PGM) Where
1.2 kΩ ≤ RSET2 ≤ 10 kΩ, Select RSET1
to program VIREG-PRE,
VIREG-PRE (Measured) = IOPRE-CHG × RSNS
(–20% to 20% excludes errors due to RSET1
and RSNS tolerances)
–20%
20%
15
200
CHARGE TERMINATION (CURRENT TAPER) DETECTION
ITERM
Charge current termination detection range
VI(BAT) > VRCH
VTERM
Charge termination detection set voltage,
ISET2
VI(BAT) > VRCH
K(ISET2)
Termination current set factor
tdg-TERM
100
mV
1000
Charger termination accuracy
VI(BAT) > VRCH
Deglitch time for charge termination
Both rising and falling,
2-mV overdrive tRISE, tFALL = 100 ns
–20%
mA
V/A
20%
20
30
40
ms
TEMPERATURE COMPARATOR AND VTSB BIAS REGULATOR
VLTF
Cold temperature threshold, TS
72.8
73.5
74.2
VHTF
Hot temperature threshold, TS
33.7
34.4
35.1
VTCO
Cutoff temperature threshold, TS
28.7
29.3
29.9
0.5
1.0
1.5
LTF hysteresis
4
%VO(VTSB)
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
ELECTRICAL CHARACTERISTICS (continued)
TJ = 0°C to 125°C and recommended supply voltage range (unless otherwise stated)
PARAMETER
TEST CONDITIONS
tdg-TS
Deglitch time for temperature fault, TS
Both rising and falling,
2-mV overdrive tRISE, tFALL = 100 ns
VO(VTSB)
TS bias output voltage
VCC > VIN(min),
I(VTSB) = 10 mA 0.1 µF ≤ CO(VTSB) ≤ 1 µF
VO(VTSB)
TS bias voltage regulation accuracy
VCC > IN(min),
I(VTSB) = 10 mA 0.1 µF ≤ CO(VTSB) ≤ 1 µF
MIN
TYP
MAX
20
30
40
3.15
–10%
UNIT
ms
V
10%
BATTERY RECHARGE THRESHOLD
VRCH
tdg-RCH
Recharge threshold voltage
Below VOREG
75
100
125
mV/cell
Deglitch time
VI(BAT) < decreasing below threshold,
tFALL = 100 ns 10-mV overdrive
20
30
40
ms
STAT1, STAT2, AND PG OUTPUTS
VOL(STATx)
Low-level output saturation voltage, STATx
IO = 5 mA
0.5
VOL(PG)
Low-level output saturation voltage, PG
IO = 10 mA
0.1
V
CE CMODE, CELLS INPUTS
VIL
Low-level input voltage
IIL = 5 µA
VIH
High-level input voltage
IIH = 20 µA
0
0.4
1.3
VCC
V
TTC INPUT
tPRECHG
Precharge timer
tCHARGE
Programmable charge timer range
t(CHG) = C(TTC) × K(TTC)
Charge timer accuracy
0.01 µF ≤ C(TTC) ≤ 0.18 µF
KTTC
Timer multiplier
CTTC
Charge time capacitor range
VTTC_EN
TTC enable threshold voltage
1440
1800
25
-10%
2160
s
572
minutes
10%
2.6
0.01
V(TTC) rising
min/nF
0.22
200
µF
mV
SLEEP COMPARATOR
VSLP-ENT
Sleep-mode entry threshold
VSLP-EXIT
Sleep-mode exit hysteresis,
tdg-SLP
Deglitch time for sleep mode
2.3 V ≤ VI(OUT) ≤ VOREG, for 1 or 2 cells
VCC ≤ VIBAT
+5 mV
VCC ≤ VIBAT
+75 mV
VI(OUT) = 12.6 V, RIN = 1 kΩ
bq24105/15 (1)
VCC ≤ VIBAT
-4 mV
VCC ≤ VIBAT
+73 mV
40
160
2.3 V ≤ VI(OUT)≤ VOREG
VCC decreasing below threshold,
tFALL = 100 ns, 10-mV overdrive,
PMOS turns off
VCC decreasing below threshold,
tFALL = 100 ns, 10-mV overdrive,
STATx pins turn off
5
V
mV
µs
20
30
40
3.50
ms
UVLO
VUVLO-ON
IC active threshold voltage
VCC rising
3.15
3.30
IC active hysteresis
VCC falling
120
150
V
mV
PWM
Internal P-channel MOSFET on-resistance
Internal N-channel MOSFET on-resistance
fOSC
7 V ≤ VCC ≤ VCC(max)
400
4.5 V ≤ VCC ≤ 7 V
500
7 V ≤ VCC ≤ VCC(max)
130
4.5 V ≤ VCC ≤ 7 V
150
Oscillator frequency
Frequency accuracy
mΩ
1.1
–9%
MHz
9%
DMAX
Maximum duty cycle
DMIN
Minimum duty cycle
tTOD
Switching delay time (turn on)
20
ns
tsyncmin
Minimum synchronous FET on time
60
ns
Synchronous FET minimum current-off
threshold (2)
(1)
(2)
100%
0%
50
400
mA
For bq24105 and bq24115 only. RIN is connected between IN and PGND pins and needed to ensure sleep entry.
N-channel always turns on for ~60 ns and then turns off if current is too low.
5
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
ELECTRICAL CHARACTERISTICS (continued)
TJ = 0°C to 125°C and recommended supply voltage range (unless otherwise stated)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
BATTERY DETECTION
IDETECT
Battery detection current during time-out
fault
VI(BAT) < VOREG – VRCH
IDISCHRG1
Discharge current
tDISCHRG1
Discharge time
IWAKE
tWAKE
2
mA
VSHORT < VI(BAT) < VOREG – VRCH
400
µA
VSHORT < VI(BAT) < VOREG – VRCH
1
s
Wake current
VSHORT < VI(BAT) < VOREG – VRCH
2
mA
Wake time
VSHORT < VI(BAT) < VOREG – VRCH
0.5
s
IDISCHRG2
Termination discharge current
Begins after termination detected,
VI(BAT) ≤ VOREG
400
µA
tDISCHRG2
Termination time
262
ms
OUTPUT CAPACITOR
COUT
Required output ceramic capacitor range
from SNS to PGND, between inductor and
RSNS
CSNS
Required SNS capacitor (ceramic) at SNS
pin
4.7
10
47
0.1
µF
µF
PROTECTION
Threshold over VOREG to turn off P-channel
MOSFET, STAT1, and STAT2 during charge
or termination states
110
117
2.6
3.6
4.5
A
Short-circuit voltage threshold, BAT
VI(BAT) falling
1.95
2
2.05
V/cell
ISHORT
Short-circuit current
VI(BAT) ≤ VSHORT
TSHTDWN
Thermal trip
VOVP
OVP threshold voltage
ILIMIT
Cycle-by-cycle current limit
VSHORT
35
121
65
165
Thermal hysteresis
10
%VO(REG)
mA
°C
19 20
1
2
18
3
17
4
16
5
15
6
14
7
8
13
10 9
STAT1
IN
IN
PG
VCC
TTC
ISET1
ISET2
VSS
12 11
VTSB
STAS2
PGND
PGND
CE
SNS
BAT
NC
TS
OUT
OUT
RHL PACKAGE
(BOTTOM VIEW)
TERMINAL FUNCTIONS
TERMINAL
I/O
DESCRIPTION
bq24100,
bq24108
bq24103
bq24105
bq24113
bq24115
BAT
14
14
14
14
14
I
Battery voltage sense input. Bypass it with a capacitor to PGND if there are
long inductive leads to battery.
CE
16
16
16
16
16
I
Charger enable input. This active low input, if set high, suspends charge and
places the device in the low-power sleep mode. Do not pull up this input to
VTSB.
NAME
6
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
TERMINAL FUNCTIONS (continued)
TERMINAL
NAME
bq24100,
bq24108
CELLS
bq24103
bq24105
13
7
FB
bq24115
13
I/O
DESCRIPTION
I
Available on parts with fixed output voltage. Ground or float for single-cell
operation (4.2 V). For two-cell operation (8.4 V) pull up this pin with a resistor
to VCC.
7
I
Charge mode selection: low for precharge as set by ISET2 pin and high (pull
up to VTSB or <7 V) for fast charge as set by ISET1.
13
I
Output voltage analog feedback adjustment. Connect the output of a resistive
voltage divider powered from the battery terminals to this node to adjust the
output battery voltage regulation.
Charger input voltage.
13
CMODE
IN
bq24113
3, 4
3, 4
3, 4
3, 4
3, 4
I
ISET1
8
8
8
8
8
I/O
Charger current set point 1 (fast charge). Use a resistor to ground to set this
value.
ISET2
9
9
9
9
9
I/O
Charge current set point 2 (precharge and termination), set by a resistor
connected to ground. A low-level CMODE signal selects the ISET2 charge
rate, but if the battery voltage reaches the regulation set point, bqSWITCHER
changes to voltage regulation regardless of CMODE input.
N/C
13
19
19
-
1
1
1
1
1
O
20
20
20
20
20
O
5
5
5
5
5
O
17,18
17,18
17,18
17,18
17, 18
SNS
15
15
15
15
15
I
Charge current-sense input. Battery current is sensed via the voltage drop
developed on this pin by an external sense resistor in series with the battery
pack. A 0.1-µF capacitor to PGND is required.
STAT1
2
2
2
2
2
O
Charge status 1 (open-drain output). When the transistor turns on indicates
charge in process. When it is off and with the condition of STAT2 indicates
various charger conditions (See Table 1)
STAT2
19
19
19
O
Charge status 2 (open-drain output). When the transistor turns on indicates
charge is done. When it is off and with the condition of STAT1 indicates
various charger conditions (See Table 1)
TS
12
12
12
I
Temperature sense input. This input monitors its voltage against an internal
threshold to determine if charging is allowed. Use an NTC thermistor and a
voltage divider powered from VTSB to develop this voltage. (See Figure 7)
TTC
7
7
7
I
Timer and termination control. Connect a capacitor from this node to GND to
set the bqSWITCHER timer. When this input is low, the timer and termination
detection are disabled.
I
Analog device input
OUT
PG
PGND
12
12
VCC
6
6
6
6
6
VSS
10
10
10
10
10
VTSB
11
11
11
11
11
Exposed
Thermal
Pad
Pad
Pad
Pad
Pad
Pad
No connection. This pin must be left floating in the application.
Charge current output inductor connection.
Power-good status output (open drain). The transistor turns on when a valid
VCC is detected. It is turned off in the sleep mode. PG can be used to drive a
LED or communicate with a host processor.
Power ground input
Analog ground input
O
TS internal bias regulator voltage. Connect capacitor (with a value between a
0.1-µF and 1-µF) between this output and VSS.
There is an internal electrical connection between the exposed thermal pad
and VSS. The exposed thermal pad must be connected to the same potential
as the VSS pin on the printed circuit board. The power pad can be used as a
star ground connection between VSS and PGND. A common ground plane may
be used. VSS pin must be connected to ground at all times.
7
8
VCC
Term &
Timer
Disable
VCC
VTSB
VCC
VSS
TTC
STAT2
STAT1
CE
PG
VTSB
VCC
IN
IN
0.5V
1V
CE
CHARGE
50 mV
BAT
TERM
OVP
Charge
(STATE
MACHINE)
TIMER
FF CHAIN
PRE-CHG
TIMEOUT
TIMER CLK
*Patent Pending #36889
TG
CONTROL
LOGIC
DSABL_TERM
PRE-CHARGE
WAKE
DISCHARGE
0.75V
bq2410x
VCC
V(3.6A)
Icntrl
Sense FET
VCC-6V
Poff VCC PG
2.1V
0.25V
SLEEP
VCC-6V
bqSWITCHER
VCC
VTSB
Voltage
Reference
Vuvlo UVLO/POR
POR
CHARGE
SLEEP
+
-
VIN
Protection PMOS FET is OFF when not charging
or in SLEEP to prevent discharge of battery
when IN < BAT
MOD
SYNCH
SLEEP
SYNCH
PkILim
VSHORT
BAT_PRS_
disch
LowV
Term_Det
Vrch
UVLO/
POR
SUSPEND
TIMEOUT
OVP
FAST CHG
TIMEOUT
RESET
PkILim
6V
VCC-6V
VCC
VSHORT
LowV 30ms
Dgltch
BAT_PRS_dischg
Vovp
Q R
Q S
I
2.1V
BAT
VCC
+
-
SNS+
1V
TS
SPIN
SUSPEND
FASTCHG
Disable
BAT
20uA
VCC
Ibat Reg
+
-
+
-
2.1V
+
-
TCO
HTF
LTF
30ms
dgltch
PRE-CHG
Disable
0.1V
FASTCHG
Disable
TEMP
SUSPEND
0.1V
SNS
+
1k
-
TERM
SLEEP
SUSPEND
1V
Vbat Reg
+
-
20uA
VCC
VCC
RAMP
(Vpp=VCC/10)
VCC
RAMP
OSC
VCC/10
COMPENSATION
Discharge
Charge
Wake
Vrch 30ms
Dgltch
Vreg
BAT
CLAMP
BG
*
Synch
Gate
Drive
TG
+
V(150 mA)
Isynch
PkILim or OVP
TIMEOUT FAULT
SUSPEND
TERM
UVLO/POR
MOD
OVP
BG
Sense FET
1C
2C
FB
SPIN
BAT
1k
Term_Det
VTSB
+
-
Co
10 F
10 H
Lo
Rsns
TS
ISET2
ISET1
VTSB
RSET2
RSET1
FB
CELLS (bq24103/13)
FB (bq24105/15)
N/C (bq24100)
VTSB
BAT
SNS
PGND
PGND
OUT
OUT
to FB
FB
SPIN
ONLY
Temp
Pack-
+
Pack+
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bq24113, bq24115
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
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FUNCTIONAL BLOCK DIAGRAM
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bq24105, bq24108
bq24113, bq24115
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SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
TYPICAL CHARACTERISTICS
EFFICIENCY
vs
OUTPUT CHARGE CURRENT
EFFICIENCY
vs
OUTPUT CHARGE CURRENT
100
100
90
90
80
80
70
70
η - Efficiency - %
η - Efficiency - %
VIN = 9 V
VIN = 4.5 V
60
VIN = 16 V
50
40
50
40
30
30
20
20
V(BAT) = 4.2 V
1 Cell
TA = 25°C
10
0
0
0.5
1
1.5
VIN = 16 V
60
V(BAT) = 8.4 V
2 Cell
TA = 25°C
10
0
2
0
IO(CHARGE) = Output Charge Current - A
0.5
1
1.5
IO(CHARGE) = Output Charge Current - A
Figure 1.
Figure 2.
bq24113RHL
VIN
10 µF
3 IN
OUT 1
4 IN
OUT 20
6 VCC
PGND 17
2 STAT1
PGND 18
5 PG
SNS 15
7 CMODE
BAT 14
LOUT
10 µH
16 CE
ISET1 8
10 VSS
ISET2 9
PACK+
+
R(ISET2)
TS 12
VTSB 11
R(SNS)
COUT
10 µF
R(ISET1)
13 CELLS
2
0.1 µF
PACK-
RT1
TEMP
RT2
BATTERY
PACK
To System
UDG-04035
Figure 3. Typical Application Circuit (System-Controlled Version)
9
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APPLICATION INFORMATION
POR
Check for Battery
Presence
Battery
Detect?
No
Indicate BATTERY
ABSENT
Yes
Suspend Charge
TS Pin
in LTF to HTF
Range?
No
Indicate CHARGE
SUSPEND
Yes
VBAT <VLOWV
Yes
Regulate
IPRECHG
Reset and Start
T30min timer
Indicate ChargeIn-Progress
No
Suspend Charge
Reset and Start
FSTCHG timer
TS pin
in LTF to TCO
range?
Regulate
Current or Voltage
Yes
No
Indicate CHARGE
SUSPEND
No
TS pin
in LTF to HTF
range?
Indicate ChargeIn-Progress
No
VBAT <VLOWV
Suspend Charge
TS Pin
in LTF to TCO
Range?
Yes
Yes
No
Indicate CHARGE
SUSPEND
Yes
No
T30min
Expired?
No
TS pin
in LTF to HTF
range?
FSTCHG Timer
Expired?
No
Yes
Yes
Yes
VBAT <VLOWV
Yes
No
- Fault Condition
- Enable I DETECT
No
ITERM detection?
Indicate Fault
No
Yes
Battery
Replaced?
(Vbat < Vrch?)
- Turn Off Charge
- Enable I DISCHG for
tDISCHG2
Indicate ChargeIn-Progress
*NOTE: If the TTC pin is
pulled low, the safety timer
and termination are
disabled; the charger
continues to regulate, and
the STAT pins indicate
charge in progress.
If the TTC pin is pulled high
(VTSB), only the safety
timer is disabled
(termination is normal).
Yes
Charge Complete
VBAT < VRCH ?
No
Indicate DONE
*
Battery Removed
Yes
Indicate BATTERY
ABSENT
Figure 4. Stand-Alone Version Operational Flow Chart
10
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APPLICATION INFORMATION (continued)
POR
SLEEP MODE
No
Vcc > VI(BAT)
Checked at All
Times
No
Indicate SLEEP
MODE
Yes
/CE=Low
Yes
Regulate
IO(PRECHG)
CMODE=Low
Yes
Indicate ChargeIn-Progress
No
Yes
/CE=High
No
Regulate Current
or Voltage
Indicate ChargeIn-Progress
Yes
Yes
CMODE=High
or
VIBAT in VREG
Yes
No
CMODE=Low
No
No
/CE=High
Yes
Turn Off Charge
Indicate DONE
Yes
No
/CE=Low
Yes
Figure 5. System-Controlled Operational Flow Chart
11
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FUNCTIONAL DESCRIPTION FOR STAND-ALONE VERSION (bq2410x)
The bqSWITCHER™ supports a precision Li-ion or Li-polymer charging system for single-, two- or three-cell
applications. See Figure 4 and Figure 5 for operational flow charts and Figure 6 for a typical charge profile.
Precharge
Phase
Voltage Regulation and
Charge Termination Phase
Current Regulation Phase
Regulation Voltage
Regulation Current
Charge Voltage
VLOW
VSHORT
Charge Current
Precharge
and Termination
ISHORT
UDG-04037
Precharge
Timer
Programmable
Safety Timer
Figure 6. Typical Charging Profile
Temperature Qualification
The bqSWITCHER continuously monitors battery temperature by measuring the voltage between the TS pin and
VSS pin. A negative temperature coefficient thermistor (NTC) and an external voltage divider typically develop
this voltage. The bqSWITCHER compares this voltage against its internal thresholds to determine if charging is
allowed. To initiate a charge cycle, the battery temperature must be within the V(LTF)-to-V(HTF) thresholds. If
battery temperature is outside of this range, the bqSWITCHER suspends charge and waits until the battery
temperature is within the V(LTF)-to-V(HTF) range. During the charge cycle (both precharge and fast charge), the
battery temperature must be within the V(LTF)-to-V(TCO) thresholds. If battery temperature is outside of this range,
the bqSWITCHER suspends charge and waits until the battery temperature is within the V(LTF)-to-V(HTF) range.
The bqSWITCHER suspends charge by turning off the PWM and holding the timer value (i.e., timers are not
reset during a suspend condition). Note that the bias for the external resistor divider is provided from the VTSB
output. Applying a constant voltage between the V(LTF)-to-V(HTF) thresholds to the TS pin disables the
temperature-sensing feature.
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FUNCTIONAL DESCRIPTION FOR STAND-ALONE VERSION (bq2410x) (continued)
VCC
Charge Suspend
Charge Suspend
V(LTF)
Temperature Range
to Initiate Charge
V(HTF)
V(TCO)
Charge Suspend
Temperature Range
During Charge Cycle
Charge Suspend
VSS
Figure 7. TS Pin Thresholds
Battery Preconditioning (Precharge)
On power up, if the battery voltage is below the VLOWV threshold, the bqSWITCHER applies a precharge current,
IPRECHG, to the battery. This feature revives deeply discharged cells. The bqSWITCHER activates a safety timer,
tPRECHG, during the conditioning phase. If the VLOWV threshold is not reached within the timer period, the
bqSWITCHER turns off the charger and enunciates FAULT on the STATx pins. In the case of a FAULT
condition, the bqSWITCHER reduces the current to IDETECT. IDETECT is used to detect a battery replacement
condition. Fault condition is cleared by POR or battery replacement.
The magnitude of the precharge current, IO(PRECHG), is determined by the value of programming resistor, R(ISET2),
connected to the ISET2 pin.
K (ISET2) V (ISET2)
I O(PRECHG) R(ISET2) R(SNS)
(1)
where
RSNS is the external current-sense resistor
V(ISET2) is the output voltage of the ISET2 pin
K(ISET2) is the V/A gain factor
V(ISET2) and K(ISET2) are specified in the Electrical Characteristics table.
Battery Charge Current
The battery charge current, IO(CHARGE), is established by setting the external sense resistor, R(SNS), and the
resistor, R(ISET1), connected to the ISET1 pin.
In order to set the current, first choose R(SNS) based on the regulation threshold VIREG across this resistor. Let
VIREG = 100 mV to start and calculate the RSNS value needed.
V IREG
R (SNS) I OCHARGE
(2)
If this value is not a standard sense resistor value, choose the next larger value. Using the selected standard
value, solve for VIREG.
13
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FUNCTIONAL DESCRIPTION FOR STAND-ALONE VERSION (bq2410x) (continued)
V IREG R(SNS) I OCHARGE
(3)
The value of R(ISET1) is then calculated based on the following equation:
K
VISET1
R SET1 ISET1
1000 V
I OCHARGE RSNS
V IREG
(4)
where
VIREG is the voltage regulated across RSNS
IOCHARGE is the battery charge current
RSNS is the external current sense resistor
V(ISET1) is the output voltage of the ISET1 pin
K(ISET1) is the V/A gain factor (see Electrical Characteristics table)
The following provide a more detailed design procedure and example for this parameter:
1.
Select the charge current.
Example:
2.
•
IOCHARGE = 2 A
•
IOPRECHG = 200 mA
Select the sense resistor value. Ensure that the power rating of the sense resistor is not exceeded
Example:
•
Let VIREG = 100 mV (S/B from 100–200 mV
•
Solve for
R (SNS) V IREG
I OCHARGE
100 mV 50 m
2A
(5)
•
Check availability for R(SNS). Use value that is equal (next larger value if not available).
•
Check for power dissiaption
2
2
P (SNS) R(SNS) I OCHARGE 0.05 (2 A) 0.2 W
•
3.
Select 0805 or 1206 size rated at 0.25 W
Determine R(ISET1)
•
V(ISET1) = 1 V
•
K(ISET1) = 1000 V/A
R (ISET1) 4.
14
(6)
K(ISET1) V(ISET1)
R(SNS) I OCHARGE
Determine R(ISET2)
•
V(ISET2) = 0.1 V
•
K(ISET2) = 1000 V/A
1000 VA 1 V
10 k
0.05 2 A
(7)
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FUNCTIONAL DESCRIPTION FOR STAND-ALONE VERSION (bq2410x) (continued)
R (ISET2) K(ISET2) V(ISET2)
R(SNS) I OPRECHG
1000 VA 0.1 V
10 k
0.05 0.2 A
(8)
RSENSE
SNS
BAT
V(ISET1) = 1 V
ISET1
R(ISET1)
I(ISET1)
V(ISET2) = 0.1 V
ISET2
VSS
R(ISET2)
I(ISET2)
UDG-04036
Figure 8. Program Charge Current with R(ISET1) and R(ISET2)
Battery Voltage Regulation
The voltage regulation feedback occurs through the BAT pin. This input is tied directly to the positive side of the
battery pack. The bqSWITCHER monitors the battery-pack voltage between the BAT and VSS pins. The
bqSWITCHER is offered in two fixed-voltage versions: 4.2 V and 8.4 V as selected by the CELLS input. A low or
floating input on the CELLS selects single-cell mode (4.2 V) while a high-input selects two-cell mode.
For device options that include adjustable output voltage, the voltage regulation feedback is through the FB pin.
A resistor divider is used from the battery output voltage to GND. The BAT pin remains connected directly to the
battery output voltage for current sensing with respect to SNS.
Charge Termination and Recharge
The bqSWITCHER monitors the charging current during the voltage regulation phase. Once the termination
threshold, ITERM, is detected, the bqSWITCHER terminates charge. The termination current level is selected by
the value of programming resistor, R(ISET2), connected to the ISET2 pin.
K (ISET2) V TERM
I TERM R(ISET2) R(SNS)
(9)
where
R(SNS) is the external current-sense resistor
VTERM is the output of the ISET2 pin
K(ISET2) is the A/V gain factor
VTERM and K(ISET2) are specified in the Electrical Characteristics table
As a safety backup, the bqSWITCHER also provides a programmable charge timer. The charge time is
programmed by the value of a capacitor connected between the TTC pin and GND by the following formula:
t CHARGE C(TTC) K(TTC)
(10)
where
C(TTC) is the capacitor connected to the TTC pin
K(TTC) is the multiplier
15
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FUNCTIONAL DESCRIPTION FOR STAND-ALONE VERSION (bq2410x) (continued)
A new charge cycle is initiated when one of the following conditions is detected:
• The battery voltage falls below the VRCH threshold.
• Power-on reset (POR), if battery voltage is below the VRCH threshold
• CE toggle
• TTC pin, described as follows.
In order to disable the charge termination and safety timer, the user can pull the TTC input below the VTTC_EN
threshold. Going above this threshold enables the termination and safety timer features and also resets the timer.
Tying TTC high to VTSB disables the safety timer only.
Sleep Mode
The bqSWITCHER enters the low-power sleep mode if the VCC pin is removed from the circuit. This feature
prevents draining the battery during the absence of VCC.
Charge Status Outputs
The open-drain STAT1 and STAT2 outputs indicate various charger operations as shown in Table 1 and Table 2.
These status pins can be used to drive LEDs or communicate to the host processor. Note that OFF indicates that
the open-drain transistor is turned off.
Table 1. Status Pins Summary
STAT1
STAT2
Charge-in-progress
Charge State
ON
OFF
Charge complete
OFF
ON
Charge suspend, timer fault, overvoltage, sleep mode, battery absent (1)
OFF
OFF
(1)
bq2411x ICs do not have timer-fault or battery-absent modes
Table 2. Status Pins Summary (bq24108 only)
STAT1
STAT2
Battery absent
Charge State
OFF
OFF
Charge-in-progress
ON
OFF
Charge complete
OFF
ON
Battery over discharge, VI(BAT) < V(SC)
ON/OFF (0.5 Hz)
OFF
Charge suspend, (due to TS pin and internal thermal protection)
ON/OFF (0.5 Hz)
OFF
Precharge timer fault
ON/OFF (0.5 Hz)
OFF
Fast-charge timer fault
ON/OFF (0.5 Hz)
OFF
OFF
OFF
Sleep mode
PG Output
The open-drain PG (power good) indicates when the AC-to-DC adapter (i.e., VCC) is present. The output turns on
when sleep-mode exit threshold, VSLP-EXIT, is detected. This output is turned off in the sleep mode. The PG pin
can be used to drive an LED or communicate to the host processor.
CE Input (Charge Enable)
The CE digital input is used to disable or enable the charge process. A low-level signal on this pin enables the
charge and a high-level VCC signal disables the charge. A high-to-low transition on this pin also resets all timers
and fault conditions. Note that the CE pin cannot be pulled up to VTSB voltage. This may create power-up
issues.
16
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Battery Absent Detection
For applications with removable battery packs, bqSWITCHER provides a battery absent detection scheme to
reliably detect insertion and/or removal of battery packs.
POR or VRCH
Detection routine runs on power up
and if VBAT drops below refresh
threshold due to removing battery
or discharging battery.
Yes
Enable
I(DETECT)
for t(DETECT)
VI(BAT)<V(LOWV)
No
BATTERY
PRESENT,
Begin Charge
No
BATTERY
PRESENT,
Begin Charge
Yes
Apply I(WAKE)
for t(WAKE)
VI(BAT) >
VO(REG)
-VRCH
Yes
BATTERY
ABSENT
Figure 9. Battery Absent Detection for bq2410x ICs only
The voltage at the BAT pin is held above the battery recharge threshold, VRCH, by the charged battery following
fast charging. When the voltage at the BAT pin falls to the recharge threshold, either by a load on the battery or
due to battery removal, the bqSWITCHER begins a battery absent detection test. This test involves enabling a
detection current, IDETECT, for a period of tDETECT and checking to see if the battery voltage is below the precharge
threshold, VLOWV. Following this, the precharge current, IOPRECHG is applied for a period of tDETECT and the battery
voltage is checked again to ensure that it is above the recharge threshold. The purpose of this current is to
attempt to close a battery pack with an open protector, if one is connected to the bqSWITCHER.
Passing both of the discharge and charging tests indicates a battery absent fault at the STAT pins. Failure of
either test starts a new charge cycle. For the absent battery condition, the voltage on the BAT pin rises and falls
between the VLOWV and VOREG thresholds indefinitely.
Timer Fault Recovery
As shown in Figure 5, bqSWITCHER provides a recovery method to deal with timer fault conditions. The
following summarizes this method.
Condition 1 VI(BAT) above recharge threshold (VOREG - VRCH) and timeout fault occurs.
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Recovery method: bqSWITCHER waits for the battery voltage to fall below the recharge threshold. This could
happen as a result of a load on the battery, self-discharge or battery removal. Once the battery falls below the
recharge threshold, the bqSWITCHER clears the fault and enters the battery absent detection routine. A POR or
CE or TTE toggle also clears the fault.
Condition 2 Charge voltage below recharge threshold (VRCH) and timeout fault occurs
Recovery method: Under this scenario, the bqSWITCHER applies the IDETECT current. This small current is used
to detect a battery removal condition and remains on as long as the battery voltage stays below the recharge
threshold. If the battery voltage goes above the recharge threshold, then the bqSWITCHER disables the IDETECT
current and executes the recovery method described for Condition 1. Once the battery falls below the recharge
threshold, the bqSWITCHER clears the fault and enters the battery absent detection routine. A POR or CE toggle
also clears the fault.
Output Overvoltage Protection (Applies To All Versions)
The bqSWITCHER provides a built-in overvoltage protection to protect the detect and other components against
damages if the battery voltage gets too high, as when the battery is suddenly removed. When an overvoltage
condition is detected, this feature turns off the PWM and STATx pins. The fault is cleared once VIBAT drops to the
recharge threshold (VOREG - VRCH).
FUNCTIONAL DESCRIPTION FOR SYSTEM-CONTROLLED VERSION (bq2411x)
For applications requiring charge management under the host system control, the bqSWITCHER (bq2411x)
offers a number of control functions. The following section describes these functions.
Precharge And Fast-Charge Control
A low-level signal on the CMODE pin forces the bqSWITCHER to charge at the precharge rate set on the ISET2
pin. A high-level signal forces charge at fast-charge rate as set by the ISET1 pin. If the battery reaches the
voltage regulation level, VOREG, the bqSWITCHER transitions to voltage regulation phase regardless of the status
of the CMODE input.
Charge Termination And Safety Timers
The charge timers and termination are disabled in the system-controlled versions of the bqSWITCHER. The host
system can use the CE input to enable or disable charge. When an overvoltage condition is detected, the
charger process stops, and all power FETs are turned off.
Inductor, Capacitor, and Sense Resistor Selection Guidelines
The bqSWITCHER provides internal loop compensation. With this scheme, best stability occurs when LC
resonant frequency, fo is approximately 16 kHz (8 kHz to 32 kHz). Equation 11 can be used to calculate the
value of the output inductor and capacitor. Table 3 provides a summary of typical component values for various
charge rates.
1
f0 2 L OUT C OUT
(11)
Table 3. Output Components Summary
CHARGE CURRENT
0.5 A
1A
Output inductor, LOUT
22 µH
10 µH
4.7 µH
Output capacitor, COUT
4.7 µF
10 µF
22 µF (or 2 × 10 µH) ceramic
Sense resistor, R(SNS)
0.2 Ω
0.1 Ω
0.05 Ω
18
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THERMAL CONSIDERATIONS
The SWITCHER is packaged in a thermally enhanced MLP package. The package includes a thermal pad to
provide an effective thermal contact between the IC and the printed circuit board (PCB). Full PCB design
guidelines for this package are provided in the application report entitled: QFN/SON PCB Attachment
(SLUA271).
The most common measure of package thermal performance is thermal impedance (ΘJA) measured (or modeled)
from the chip junction to the air surrounding the package surface (ambient). The mathematical expression for ΘJA
is:
T TA
(JA) J
P
(12)
Where:
TJ = chip junction temperature
TA = ambient temperature
P = device power dissipation
Factors that can greatly influence the measurement and calculation of ΘJA include:
• Whether or not the device is board mounted
• Trace size, composition, thickness, and geometry
• Orientation of the device (horizontal or vertical)
• Volume of the ambient air surrounding the device under test and airflow
• Whether other surfaces are in close proximity to the device being tested
The device power dissipation, P, is a function of the charge rate and the voltage drop across the internal power
FET. It can be calculated from the following equation:
P = [Vin × lin - Vbat × Ibat]
Due to the charge profile of Li-xx batteries, the maximum power dissipation is typically seen at the beginning of
the charge cycle when the battery voltage is at its lowest. (See Figure 6.)
PCB LAYOUT CONSIDERATION
It is important to pay special attention to the PCB layout. The following provides some guidelines:
• To obtain optimal performance, the power input capacitors, connected from input to PGND, should be placed
as close as possible to the bqSWITCHER. The output inductor should be placed directly above the IC and
the output capacitor connected between the inductor and PGND of the IC. The intent is to minimize the
current path loop area from the OUT pin through the LC filter and back to the GND pin. The sense resistor
should be adjacent to the junction of the inductor and output capacitor. Route the sense leads connected
across the R(SNS) back to the IC, close to each other (minimize loop area) or on top of each other on adjacent
layers (do not route the sense leads through a high-current path). Use an optional capacitor downstream
from the sense resistor if long (inductive) battery leads are used.
• Place all small-signal components (CTTC, RSET1/2 and TS) close to their respective IC pin (do not place
components such that routing interrupts power stage currents). All small control signals should be routed
away from the high current paths.
• The PCB should have a ground plane (return) connected directly to the return of all components through vias
(3 vias per capacitor for power-stage capacitors, 3 vias for the IC PGND, 1 via per capacitor for small-signal
components). A star ground design approach is typically used to keep circuit block currents isolated
(high-power/low-power small-signal) which reduces noise-coupling and ground-bounce issues. A single
ground plane for this design gives good results. With this small layout and a single ground plane, there is not
a ground-bounce issue, and having the components segregated minimizes coupling between signals.
• The high-current charge paths into IN and from the OUT pins must be sized appropriately for the maximum
charge current in order to avoid voltage drops in these traces. The PGND pins should be connected to the
ground plane to return current through the internal low-side FET. The thermal vias in the IC PowerPAD™
provide the return-path connection.
• The bqSWITCHER is packaged in a thermally enhanced MLP package. The package includes a thermal pad
19
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PCB LAYOUT CONSIDERATION (continued)
•
to provide an effective thermal contact between the IC and the PCB. Full PCB design guidelines for this
package are provided in the application report entitled: QFN/SON PCB Attachment (SLUA271). Six 10-13 mil
vias are a minimum number of recommended vias, placed in the IC's power pad, connecting it to a ground
thermal plane on the opposite side of the PWB. This plane must be at the same potential as VSS and PGND
of this IC.
See user guide SLUU200 for an example of good layout.
WAVEFORMS: All waveforms are taken at Lout (IC Out pin). VIN = 7.6 V and the battery was set to 2.6 V, 3.5 V,
and 4.2 V for the three waveforms. When the top switch of the converter is on, the waveform is at ~7.5 V, and
when off, the waveform is near ground. Note that the ringing on the switching edges is small. This is due to a
tight layout (minimized loop areas), a shielded inductor (closed core), and using a low-inductive scope ground
lead (i.e., short with minimum loop) .
Precharge: The current is low in precharge; so, the bottom synchronous FET turns off after its minimum on-time
which explains the step between ~0 V and -0.5 V. When the bottom FET and top FET are off, the current
conducts through the body diode of the bottom FET which results in a diode drop below the ground potential.
The initial negative spike is the delay turning on the bottom FET, which is to prevent shoot-through current as the
top FET is turning off.
20
www.ti.com
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
PCB LAYOUT CONSIDERATION (continued)
Fast Charge: This is captured during the constant-current phase. The two negative spikes are the result of the
short delay when switching between the top and bottom FETs. The break-before-make action prevents current
shoot-through and results in a body diode drop below ground potential during the break time.
Charge during Voltage Regulation and Approaching Termination: Note that this waveform is similar to the
precharge waveform. The difference is that the battery voltage is higher so the duty cycle is slightly higher. The
bottom FET stays on longer because there is more of a current load than during precharge; it takes longer for the
inducator current to ramp down to the current threshold where the synchronous FET is disabled.
21
bq24100, bq24103
bq24105, bq24108
bq24113, bq24115
www.ti.com
SLUS606C – JUNE 2004 – REVISED SEPTEMBER 2005
Application Note: Charging Battery and Powering System Without Affecting Battery Charge and
Termination.
LOUT
10 µH
bq24100RHL
VIN
3
IN
OUT 1
4
IN
OUT 20
6
VCC
PGND 17
2
STAT1
PGND 18
19 STAT2
SNS 15
PG
BAT 14
10 µF
5
VTSB
TTC
R(SYS)
COUT
10 µF
PACK+
+
R(ISET1)
7
R(SNS)
ISET1 8
0.1 µF
PACK-
VTSB
R(ISET2)
CTTC
ISET2 9
16 CE
RT1
TS 12
10 VSS
TEMP
PWR PAD VTSB 11
RT2
VIN
VIN
D1
Adapter
Present
BATTERY
PACK
VIN
D2
Done
D3
Charge
UDG-04033
The bqSWITCHER was designed as a stand-alone battery charger but can be easily adapted to power a system
load, while considering a few minor issues.
Advantages:
1. The charger controller is based only on what current goes through the current-sense resistor (so precharge,
constant current, and termination all work well), and is not affected by the system load.
2. The input voltage has been converted to a usable system voltage with good efficiency from the input.
3. Extra external FETs are not needed to switch power source to the battery.
4. The TTC pin can be grounded to disable termination and keep the converter running and the battery fully
charged, or let the switcher terminate when the battery is full and then run off of the battery via the sense
resistor.
Other Issues:
1. If the system load current is large (≥ 1 A), the IR drop across the battery impedance causes the battery
voltage to drop below the refresh threshold and start a new charge. The charger would then terminate due to
low charge current. Therefore, the charger would cycle between charging and termination. If the load is
smaller, the battery would have to discharge down to the refresh threshold resulting in a much slower
cycling. Note that grounding the TTC pin keeps the converter on continuously.
2. If TTC is grounded, the battery is kept at 4.2 V (not much different than leaving a fully charged battery set
unloaded).
3. Eefficiency declines 2-3% hit when discharging through the sense resistor to the system.
22
PACKAGE OPTION ADDENDUM
www.ti.com
18-Oct-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
50
TBD
Lead/Ball Finish
BQ24100RHL
PREVIEW
QFN
RHL
20
BQ24100RHLR
ACTIVE
QFN
RHL
20
3000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
BQ24103RHLR
ACTIVE
QFN
RHL
20
3000
Pb-Free
(RoHS)
CU NIPDAU
Level-1-260C-UNLIM
BQ24105RHLR
ACTIVE
QFN
RHL
20
3000
Pb-Free
(RoHS)
CU NIPDAU
Level-1-260C-UNLIM
BQ24108RHLR
ACTIVE
QFN
RHL
20
3000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
BQ24113RHLR
ACTIVE
QFN
RHL
20
3000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
BQ24113RHLRG4
ACTIVE
QFN
RHL
20
3000 Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
BQ24115RHLR
ACTIVE
QFN
RHL
20
3000
CU NIPDAU
Level-1-260C-UNLIM
Pb-Free
(RoHS)
Call TI
MSL Peak Temp (3)
Call TI
(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) 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.
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.
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Addendum-Page 1
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