SLUS025F − MAY 2001 − REVISED JULY 2002
FEATURES
D Ideal for Single (4.1 V or 4.2 V) and Dual-Cell
D
D
D
D
D
D
D
D
D
D
D
D
D
DESCRIPTION
(8.2 V or 8.4 V) Li-Ion or Li-Pol Packs
Requires Small Number of External
Components
0.3 V Dropout Voltage for Minimizing Heat
Dissipation
Better Than ±1% Voltage Regulation Accuracy
With Preset Voltages
AutoCompt Dynamic Compensation of
Battery Pack’s Internal Impedance to Reduce
Charge Time
Optional Cell-Temperature Monitoring Before
and During Charge
Integrated Voltage and Current Regulation
With Programmable Charge-Current and Highor Low-Side Current Sensing
Integrated Cell Conditioning for Reviving
Deeply Discharged Cells and Minimizing Heat
Dissipation During Initial Stage Of Charge
Charge Status Output for Single or Dual Led
or Host Processor Interface
Automatic Battery-Recharge Feature
Charge Termination by Minimum Current
Automatic Low-Power Sleep Mode When VCC
Is Removed
EVMs Available for Quick Evaluation
Packaging: 8-Pin SOIC, 8-Pin TSSOP, 8-Pin
MSOP
The BENCHMARQ bq2057 series advanced
Lithium-Ion (Li-Ion) and Lithium-Polymer (Li-Pol) linear
charge-management ICs are designed for costsensitive and compact portable electronics. They
combine high-accuracy current and voltage regulation,
battery conditioning, temperature monitoring, charge
termination, charge-status indication, and AutoComp
charge-rate compensation in a single 8-pin IC. MSOP,
TSSOP, and SOIC package options are offered to fit a
wide range of end applications.
The bq2057 continuously measures battery
temperature using an external thermistor. For safety,
the bq2057 inhibits charge until the battery temperature
is within user-defined thresholds. The bq2057 then
charges the battery in three phases: conditioning,
constant current, and constant voltage. If the battery
voltage is below the low-voltage threshold, V(min), the
bq2057 precharges using a low current to condition the
battery. The conditioning charge rate is approximately
10% of the regulation current. The conditioning current
also minimizes heat dissipation in the external passelement during the initial stage of the charge. After
conditioning, the bq2057 applies a constant current to
the battery. An external sense-resistor sets the current.
The sense-resistor can be on either the high or low side
of the battery without additional components. The
constant-current phase continues until the battery
reaches the charge-regulation voltage.
bq2057xSN or bq2057xTS
SOIC (SN) or TSSOP (TS) PACKAGE
(TOP VIEW)
SNS
BAT
VCC
TS
1
8
2
7
3
6
4
5
COMP
CC
VSS
STAT
bq2057xDGK
MSOP (DGK) PACKAGE
(TOP VIEW)
VCC
TS
STAT
VSS
1
8
2
7
3
6
4
5
BAT
SNS
COMP
CC
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.
AutoComp is a trademark of Texas Instruments.
!"#$%! & '("")% $& ! *(+'$%! ,$%)"!,('%& '!!"# %! &*)''$%!& *)" %.) %)"#& ! )/$& &%"(#)%&
&%$,$", 0$""$%1- "!,('%! *"!')&&2 ,!)& !% )')&&$"+1 '+(,)
%)&%2 ! $++ *$"$#)%)"&-
Copyright 2002, Texas Instruments Incorporated
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1
SLUS025F − MAY 2001 − REVISED JULY 2002
DESCRIPTION (continued)
The bq2057 then begins the constant-voltage phase. The accuracy of the voltage regulation is better than ±1%
over the operating-temperature and supply-voltage ranges. For single and dual cells, the bq2057 is offered in
four fixed-voltage versions: 4.1 V, 4.2 V, 8.2 V, and 8.4 V. Charge stops when the current tapers to the charge
termination threshold, I(TERM). The bq2057 automatically restarts the charge if the battery voltage falls below
the V(RCH) threshold.
The designer also may use the AutoComp feature to reduce charging time. This proprietary technique allows
safe and dynamic compensation for the internal impedance of the battery pack during charge.
AVAILABLE OPTIONS
PACKAGE
TA
−20°C to 70°C
CHARGE REGULATION
VOLTAGE
SOIC
(SN)
MSOP†
(DGK)
4.1 V
Not available
bq2057TS
bq2057DGK
4.2 V
bq2057CSN
bq2057CTS
bq2057CDGK
8.2 V
Not available
bq2057TTS
8.4 V
bq2057WSN
bq2057WTS
† Note the difference in pinout for this package.
2
TSSOP
(TS)
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Not available
SLUS025F − MAY 2001 − REVISED JULY 2002
function block diagram
VCC
Internal Reference
VCC
_
DONE
+
Sleep Mode
_
BAT
V-Control
+
G(comp)
+
_
CC
I-Control
Voltage Regulation
COMP
Battery
Recharge
VCC
+
_
VCC
Battery
Conditioning
Control
Block
STAT
_
+
TS
TS2 Trip
_
+
TS1 Trip
I-Control
0.5 VCC
_
High/Low SNS Set
+
SNS
VCC−V(SNS)
+
_
Current Regulation
VSS−V(SNS)
+
_
Charge Termination
VSS
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3
SLUS025F − MAY 2001 − REVISED JULY 2002
Terminal Functions
TERMINAL
NO.
NAME
I/O
DESCRIPTION
SOIC (SN) and
TSSOP (TS)
MSOP
(DGK)
BAT
2
8
I
Voltage sense input
CC
7
5
O
Charge control output
COMP
8
6
I
Charge-rate compensation input (AutoComp)
SNS
1
7
I
Current sense input
STAT
5
3
O
Charge status output
TS
4
2
I
Temperature sense input
VCC
3
1
I
Supply voltage
VSS
6
4
Ground
detailed description
current-sense input
Battery current is sensed via the voltage developed on this pin by an external sense resistor. The external
resistor can be placed on either the high or low side of the battery. (See schematics for details.)
battery-voltage input
Voltage sense-input tied directly to the positive side of the battery.
temperature sense input
Input for an external battery-temperature monitoring circuit. Connecting this input to VCC/2 disables this feature.
charge-status output
3-state indication of charge in progress, charge complete, and temperature fault or sleep mode.
charge-control output
Source-follower output that drives an external pass-transistor (PNP or P-channel MOSFET) for current and
voltage regulation.
charge-rate compensation input
Sets the charge-rate compensation level. The voltage-regulation output may be programmed to vary as a
function of the charge current delivered to the battery.
supply voltage input
Power supply input and current reference for high-side sensing configuration.
4
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SLUS025F − MAY 2001 − REVISED JULY 2002
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Supply voltage (VCC with respect to GND) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to +18 V
Input voltage, SNS, BAT, TS, COMP (all with respect to GND) . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 V to VCC+0.3 V
Sink current (STAT pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Source current (STAT pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mA
Output current (CC pin) not to exceed PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 mA
Total power dissipation, PD (at 25°C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300mW
Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −20°C to 70°C
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40°C to 125°C
Lead temperature (soldering, 10 s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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.
DISSIPATION RATING TABLE
PACKAGE
DGK
DERATING FACTOR
ABOVE TA = 25°C
TA ≤ 25°C
POWER RATING
3.4 mW/°C
424 mW
TA = 70°C
POWER RATING
271 mW
recommended operating conditions
MIN
MAX
Supply voltage, VCC
4.5
15
UNIT
V
Operating free-air temperature range, TA
−20
70
°C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
PARAMETER
I(VCC)
VCC Current
I(VCCS)
VCC Sleep current
IIB(BAT)
IIB(SNS)
Input bias current on BAT pin
IIB(TS)
IIB(COMP)
Input bias current on TS pin
Input bias current on SNS pin
Input bias current on COMP pin
TEST CONDITIONS
MIN
VCC > VCC(min), Excluding external loads
For bq2057 and bq2957C,
V(BAT) ≥ V(min), V(BAT) – VCC ≥ 0.8 V
TYP
MAX
2
4
3
6
UNIT
mA
µA
A
For bq2057T and bq2957W,
V(BAT) ≥ V(min), V(BAT) – VCC ≥ 0.8 V
10
V(BAT) = V(REG)
V(SNS)= 5 V
1
µA
5
µA
V(TS) = 5 V
V(COMP) = 5 V
5
µA
5
µA
BATTERY VOLTAGE REGULATION
VO(REG)
Output voltage
bq2057, See Notes 1, 2, 3
4.059
4.10
4.141
bq2057C, See Notes 1, 2, 3
4.158
4.20
4.242
bq2057T, See Notes 1, 2, 3
8.119
8.20
8.282
bq2057W, See Notes 1, 2, 3
8.317
8.40
8.484
V
NOTES: 1. For high-side current sensing configuration
2. For low-side current sensing configuration, the tolerance is ±1% for TA = 25°C and ±1.2% for −20°C ≥ TA ≥ 70°C
3. V(BAT)+0.3 V ≤ VCC ≤ VCC(max)
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5
SLUS025F − MAY 2001 − REVISED JULY 2002
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted) (continued)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
bq2057 and bq2057C,
High-side current sensing configuration
95.4
105
115.5
bq2057T and bq2057W,
High-side current sensing configuration
113.6
125
137.5
bq2057 and bq2057C,
Low-side current sensing configuration
100
110
121
bq2057T and bq2057W,
Low-side current sensing configuration
118.1
130
143
−24
−14
−4
29.1
30
30.9
58.3
60
61.8
bq2057
2.94
3
3.06
bq2057C
3.04
3.1
3.16
bq2057T
5.98
6.1
6.22
bq2057W
6.18
6.3
6.43
UNIT
CURRENT REGULATION
V(SNS)
Current regulation
threshold
mV
CHARGE TERMINATION DETECTION
I(TERM)
Charge termination
current detect
threshold
Voltage at pin SNS, relative to VCC for high-side
sensing, and to Vss for low-side sensing,
0°C ≤ TA ≤ 50°C
mV
TEMPERATURE COMPARATOR
V(TS1)
V(TS2)
Lower temperature
threshold
Upper temperature
threshold
TS pin voltage
%VCC
PRECHARGE COMPARATOR
V(min)
Precharge
threshold
V
PRECHARGE CURRENT REGULATION
I(PRECHG)
Precharge current
regulation
Voltage at pin SNS, relative to VCC for high-side
sensing, and to VSS for low-side sensing,
0°C ≤ TA ≤ 50°C
Voltage at pin SNS, relative to VCC for high-side
sensing, 0°C ≤ TA ≤ 50°C, VCC = 5 V
13
mV
3
13
22
bq2057 and bq2057C
VO(REG)−
98 mV
VO(REG)−
100 mV
VO(REG)−
102 mV
bq2057T and bq2057W
VO(REG)−
196 mV
VO(REG)−
200 mV
VO(REG)−
204 mV
V(BAT)+0.3 V ≤ VCC ≤ VCC(max), bq2057, bq2057C,
bq2057T, bq2057W
1.87
2.2
2.53
V(BAT)+0.3 V ≤ VCC ≤ VCC(max), bq2057T and
bq2057W in low-side sensing configuration
2.09
2.4
2.76
mV
VRCH COMPARATOR (Battery Recharge Threshold)
V(RCH)
Recharge
threshold
V
CHARGE-RATE COMPENSATION (AutoComp)
G(COMP)
AutoComp gain
V/V
STAT PIN
VOL(STAT)
Output (low)
voltage
IOL = 10 mA
VOH(STAT)
Output (high)
voltage
IOH = 5 mA
0.7
V
VCC-0.5
CC PIN
VOL(CC)
IO(CC)
6
Output low voltage
Sink current
IO(CC) = 5 mA (sink)
Not to exceed power rating specification (PD)
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5
1.5
V
40
mA
SLUS025F − MAY 2001 − REVISED JULY 2002
APPLICATION INFORMATION
RSNS
0.2 Ω
Q1
FZT788B
PACK+
DC+
C1
0.1 µF
VCC
R1
1 kΩ
PACK−
NTC
VCC
bq2057
CC
C2
0.1 µF
COMP
SNS
BAT
VCC
TS
VSS
STAT
RT1
TEMP
D1
GND
RT2
Battery
Pack
R2
2 kΩ
Figure 1. Low Dropout Single- or Two-Cell Li-Ion/Li-Pol Charger
functional description
The bq2057 is an advanced linear charge controller for single or two-cell Li-Ion or Li-Pol applications. Figure 1
shows the schematic of charger using a PNP pass transistor. Figure 2 is an operational state diagram, and
Figure 3 is a typical charge profile. Figure 4 shows the schematic of a charger using P-channel MOSFET.
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7
SLUS025F − MAY 2001 − REVISED JULY 2002
APPLICATION INFORMATION
POR
Sleep Mode
VCC > V(BAT)
Checked at All
Times
Indicate SLEEP
MODE
(STAT = Hi-Z)
No
Yes
Suspend Charge
TS Pin
in TS1 to TS2
Range
Indicate CHARGE
SUSPEND
(STAT = Hi-Z)
No
Yes
Regulate
I(PRECHG)
V(BAT)