bq24700, bq24701
NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM
SLUS452A APRIL 2001
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
Dynamic Power Management, DPM
t
Minimizes Battery Charge Time
D
Integrated Selector Supports Battery
Conditioning and Smart Battery Learn
Cycle
D
Selector Feedback Circuit Insures
Break-Before-Make Transition
D
0.4% Charge Voltage Accuracy, Suitable
for Charging Li-Ion Cells
D
4% Charge Current Accuracy
D
300-kHz Integrated PWM Controller for
High-Efficiency Buck Regulation
D
Depleted Battery Detection and Indication
to Protect Battery from Over Discharge
D
15-
A Sleep Mode Current for Low Battery
Drain
D
Designed for Charge Management of
NiCd/NiMH and Li-Ion/Li-Pol Battery Packs
D
24-Pin TSSOP Package
description
The bq24700/bq24701 is a highly integrated battery charge controller and selector tailored for the notebook and
sub-notebook PC applications.
The bq24700/bq24701 uses Dynamic Power Management
t
(DPM) to minimize battery charge time by
maximizing use of available wall-adapter power. This is achieved by dynamically adjusting the battery charge
current based on the total system (adapter) current.
The bq24700/bq24701 uses a fixed frequency, pulse width modulator (PWM) to accurately control battery
charge current and voltage. Charge current limits can be programmed from a keyboard controller DAC or by
external resistor dividers from the precision 5-V,
0.6%, externally bypassed voltage reference (VREF),
supplied by the bq24700/bq24701.
The battery voltage limit can be programmed by using the internal 1.25-V,
0.5% precision reference, making
it suitable for the critical charging demands of lithium-ion cells. Also, the bq24700/bq24701 provides an option
to override the precision 1.25-V reference and drive the error amplifier either directly from an external reference
or from a resistor divider off the 5 V supplied by the integrated circuit.
The selector function allows the manual selection of the system power source, battery or wall-adapter power.
The bq24700 supports battery-conditioning and battery-lean cycles through the ACSEL function. The ACSEL
function allows manual selection of the battery or wall power as the main system power. It also provides
autonomous switching to the remaining source (battery or ac power) should the selected system power source
terminate (refer to Table 1 for the differences between the bq24700 and the bq24701). The bq24700/bq24701
also provides an alarm function to indicate a depleted battery condition.
The bq24700/bq24701 PWM controller is ideally suited for operation in a buck converter for applications when
the wall-adapter voltage is greater than the battery voltage.
Copyright
2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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.
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
ACDET
ACPRES
ACSEL
BATDEP
SRSET
ACSET
VREF
ENABLE
BATSET
COMP
ACN
ACP
ACDRV
BATDRV
VCC
PWM
VHSP
ALARM
VS
GND
SRP
SRN
IBAT
BATP
PW PACKAGE
(TOP VIEW)
Benchmarq US Patent # 5,352,970
bq24700, bq24701
NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM
SLUS452A APRIL 2001
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
AVAILABLE OPTIONS
Condition
Selector Operation
Condition
40
C
TA
85
C
bq24700PW
bq24701PW
Battery as Power Source
Battery removal
Automatically selects ac
Automatically selects ac
Battery re-inserted
Selection based on selector inputs
Selection based on selector inputs
ac as Power Source
ac removal
Automatically selects battery
Automatically selects battery
ac re-inserted
Selection based on selector inputs
Selection based on selector inputs
Depleted Battery Condition
Battery as power source
Sends ALARM signal
Automatically selects ac
Sends ALARM signal
ac as power source
Sends ALARM signal
Sends ALARM signal
ALARM Signal Active
Depleted battery condition
Depleted battery condition
Selector inputs do not match selector outputs
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
}
Supply voltage range: VCC
0.3 V to 32 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery voltage range: SRP, SRN
0.3 V to 19 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input voltage: ACN, ACP
0.3 V to 32 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Virtual junction temperature range, T
J
40
C to 85
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range T
stg
65
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (Soldering, 10 seconds)
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.
All voltages are with respect to ground. Currents are positive into and negative out of the specified terminals. Consult the Packaging section of
the databook for thermal limitations and considerations of the package.
recommended operating conditions (T
A
= T
OPR
) all voltages relative to Vss
MIN
MAX
UNIT
Supply voltage (VCC)
Analog and PWM operation
7.0
30
V
Supply voltage, (VCC)
Selector operation
4.5
30
V
Negative ac current Sense, (ACN)
7.0
30
V
Positive ac current Sense, (ACP)
7.0
30.2
V
Negative battery current sense, (SRN)
5.0
18
V
Positive battery current sense, (SRP)
5.0
18.2
V
Operating freeair temperature, TA
40
85
C
bq24700, bq24701
NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM
SLUS452A APRIL 2001
3
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
block diagram
UDG00137
20
VHSP
VCC/2
22
VCC
VCC > 15 V
7
VREF
VOLTAGE
REFERENCE
VREF = 5 V
0.5%
ACPRES
REF1 = 1.22 V
2
ACPRES
+
1
ACDET
REF1 = 1.22 V
ACPRES
HYST = 6%
LEVEL
SHIFT
S
Q
Q
R
PWM
LOGIC
OSC
21
HIGHSIDE
DRIVE
300 kHz
+
3
ACSEL
8
ENABLE
VCC
VHSP
10
COMP
5 V
100
A
+
+
5 V
SRN
+
2 k
12
ACP
11
ACN
+
ACSET
25 k
VCC
ac
CURRENT
ERROR
AMPLIFIER
BATTERY
CURRENT
ERROR
AMPLIFIER
BATTERY
VOLTAGE
ERROR
AMPLIFIER
+
13
PWM
BATP
9
BATSET
16
SRP
2 k
15
SRN
5
SRSET
50 k
0.25 V
BATTERY
SELECT
DRIVE
ADAPTER
SELECT
DRIVE
+
24
VCC
VHSP
VCC
23
BATDRV
BATTERY SELECT
LOGIC
AND
ANTICROSS
CONDUCT
+
NO BATTERY
COMPARATOR
17
GND
+
A=20
SRN
VREF
14
IBAT
SRP
SRN
ACSEL
ACPRES
+
SWITCH TO
BATTERY
4
BATDEP
+
DEPLETED
BATTERY
COMPARATOR
BATP
18
VS
2
2
1
1
ACDRV
ACDRV
ACSEL
bq24700 ONLY
bq24701 ONLY
19
ALARM
0.8 x REF1
REF2 = 1.25 V
0.5%
1.25 V
0.5%
2 V
REF1=1.22 V
6
bq24700, bq24701
NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM
SLUS452A APRIL 2001
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics (T
A
=T
OPR
, 7.0 Vdc V
CC
30.0 Vdc, all voltages relative to Vss) (unless
otherwise specified)
quiescent current
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
IDDOP
Total chip operating current, switching and no load on
PWMB
ACPRES = High, PWM
ON,
VCC = 30 V
1
3
6
mA
ISLEEP Total battery sleep current, ac not present
ACPRES = Low,
VCC = SRN = 18 V
15
22
A
logic interface dc characteristics
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
VOL
Lowlevel output voltage (ACPRES, ALARM)
IOL = 1 mA
0.4
V
VIL
Lowlevel input voltage (ACSEL, ENABLE)
0.8
V
VIH
Highlevel input voltage (ACSEL, ENABLE)
1.8
V
ISINK1 Sink current (ACPRES)
VOL = 0.4
2
5
8
mA
ISINK2 Sink current (ALARM)
VOL = 0.4
0.75
1.5
3.5
mA
pwm oscillator
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
f
Oscillator freq enc
0
C
TA
85
C
260
300
340
kH
fOSC(PWM) Oscillator frequency
40
C
TA
0
C
240
300
340
kHz
Maximum duty cycle
100%
Input voltage for maximum dc (COMP)
3.8
V
Minimum duty cycle
0%
Input voltage for minimum dc (COMP)
0.8
V
Oscillator ramp oltage (peak to peak)
0
C
TA
85
C
1.85
2.15
2.30
VRAMP
Oscillator ramp voltage (peak-to-peak)
40
C
TA
0
C
1.60
2.15
2.30
V
VIK(COMP)
Internal input clamp voltage
(tracks COMP voltage for maximum dc)
3.8
4.5
IS(COMP)
Internal source current (COMP)
Error amplifier = OFF,
VCOMP = 1 V
70
110
140
A
bq24700, bq24701
NOTEBOOK PC BATTERY CHARGE CONTROLLER AND SELECTOR WITH DPM
SLUS452A APRIL 2001
5
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics (T
A
=T
OPR
, 7.0 Vdc V
CC
30.0 Vdc, all voltages relative to Vss) (unless
otherwise specified)
battery current-sense amplifier
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
gm
Transconductance gain
90
150
210
mA/V
CMRR
Common-mode rejection ratio
See Note 1
90
dB
VICR
Common-mode input (SRP) voltage
range
VCC = SRN + 2 V
5
18.2
V
ISINK
Sink current (COMP)
COMP = 1 V,
(SRP SRN) = 10 mV
0.5
1.5
2.5
mA
I
Input bias current (SRP)
VSRP = 16 V,
SRSET = 0 V,
VCC = 20
6
10
A
IIB
Input bias current (SRN)
VSRP = 16 V,
SRSET = 0 V,
VCC = 20
200
300
A
VSET
Battery current programming voltage
(SRSET)
0
2.5
V
AV
Battery current set gain
0.65 V
SRSET
2.5 V,
8 V
SRN
16 V,
40
C
TA
85
C,
See Note 2
24
25
26
V/V
Total battery current-sense mid-scale
SRSET = 1.25 V
TA = 25
C,
See Note 3
5%
5%
Total battery current-sense mid-scale
accuracy
SRSET = 1.25 V
40
C
TA
85
C,
See Note 3
6%
6%
Total battery current-sense full-scale
SRSET = 2.5 V
TA = 25
C,
See Note 3
3%
3%
Total battery current-sense full-scale
accuracy
SRSET = 2.5 V
40
C
TA
85
C,
See Note 3
4%
4%
NOTES: 1. Ensured by design. Not production tested.
2. I
BAT
+
SRSET
R
SENSE
1
A
V
3. Total battery-current set is based on the measured value of (SRPSRN) =
m, and the calculated value of (SRPSRN) =
C, using
the measured gain, AV.
D
C
+
SRSET
A
V
, Total accuracy in %
+
(
D
m
* D
c)
D
c
100
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