FEATURES
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LTC4101
Smart Battery
Charger Controller
DESCRIPTION
The LTC
®
4101 Smart Battery Charger is a single chip
charging solution that dramatically simplifies construction
of an SBS compliant system. The LTC4101 implements
a Level 2 charger function whereby the charger can be
programmed by the battery or by the host. A SafetySignal
on the battery being charged is monitored for temperature,
connectivity and battery type information. The SMBus
interface remains alive when the AC power adapter is
removed and responds to all SMBus activity directed to
it, including SafetySignal status (via the ChargerStatus
command). The charger also provides an interrupt to the
host whenever a status change is detected (e.g., battery
removal, AC adapter connection).
Charging current and voltage are restricted to chemistry-
specific limits for improved system safety and reliability.
Limits are programmable by two external resistors. Ad-
ditionally, the maximum average current from the AC
adapter is programmable to avoid overloading the adapter
when simultaneously supplying load current and charging
current. When supplying system load current, charg-
ing current is automatically reduced to prevent adapter
overload.
Single Chip Smart Battery Charger Controller
100% Compliant (Rev. 1.1) SMBus Support Allows
for Operation with or without Host
Up to 4A Charging Current Capability
High Efficiency Synchronous Buck Charger
V
BAT
Optimized 3V to 5.5V
SMBus Accelerator Improves SMBus Timing
Hardware Interrupt and SMBAlert Response
Eliminate Interrupt Polling
0.5V Dropout Voltage; Maximum Duty Cycle > 98%
AC Adapter Current Limit Maximizes Charge Rate
±0.8% Voltage Accuracy; ±4% Current Accuracy
10-Bit DAC for Charge Current Programming
11-Bit DAC for Charger Voltage Programming
User-Selectable Overvoltage and Overcurrent Limits
High Noise Immunity SafetySignal Sensor
Available in a 24-Pin SSOP Package
APPLICATIONS
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Portable Instruments and Computers
Data Storage Systems and Battery Backup Servers
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 6650174, 5723970.
TYPICAL APPLICATION
DCIN
9V to 12V, 2A
3V
TO 5.5V
1.21k
17
11
CHGEN
ACP
6
10
7
9
8
15
16
13
1.13k
10k
54.9k
0.068μF
0.12μF
SafetySignal
SMBCLK
SMBDAT
4101 F01a
6.04k
0.1μF
V
BAT
0.1μF
5k
< 5.5V
> 5.5V
PART
LTC4101
LTC4100
LTC4101
V
DD
DCDIV
CHGEN
ACP
SMBALERT
SCL
SDA
THB
THA
I
LIM
V
LIM
I
DC
DCIN
INFET
CLP
CLN
TGATE
BGATE
PGND
CSP
BAT
V
SET
I
TH
GND
5
4
24
23
1
3
2
21
22
18
19
12
6.04k
0.05Ω
SYSTEM LOAD
5μF
24μH
5μF
0.1Ω 1%
SMART BATTERY
14
20
0.03μF
0.0015μF
0.1μF
100Ω
SMBALERT#
SMBCLK
SMBDAT
Figure 1. 1A Smart Battery Charger
4101fa
1
LTC4101
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE/ORDER INFORMATION
TOP VIEW
TGATE
PGND
BGATE
INFET
DCIN
CHGEN
SMBALERT
SDA
SCL
1
2
3
4
5
6
7
8
9
24 CLP
23 CLN
22 BAT
21 CSP
20 I
DC
19 I
TH
18 V
SET
17 V
DD
16 THA
15 THB
14 V
LIM
13 I
LIM
Voltage from V
DD
to GND ................................. 7V/–0.3V
Voltage from CHGEN, DCDIV, SDA,
SCL and
SMBALERT
to GND ............................ 7V/–0.3V
Voltage from DCIN, CLP CLN to GND............. 32V/–0.3V
,
Voltage from CLP to CLN .......................................±0.3V
PGND wrt. GND..................................................... ±0.3V
CSP BAT to GND ............................................... 28V/–5V
,
Operating Ambient Temperature Range (Note 4)
.................................................................–40°C to 85°C
Junction Temperature Range ................ –40°C to 125°C
Storage Temperature Range...................–65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
ACP 10
DCDIV 11
GND 12
G PACKAGE
24-LEAD PLASTIC SSOP
T
JMAX
= 125°C,
θ
JA
= 90°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC4101EG#PBF
LEAD BASED FINISH
LTC4101EG
TAPE AND REEL
LTC4101EG#TRPBF
TAPE AND REEL
LTC4101EG#TR
PART MARKING
LTC4101EG
PART MARKING
LTC4101EG
PACKAGE DESCRIPTION
24-Lead Plastic SSOP
PACKAGE DESCRIPTION
24-Lead Plastic SSOP
TEMPERATURE RANGE
–40°C to 85°C
TEMPERATURE RANGE
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 20V, V
DD
= 3.3V, V
BAT
= 4V unless otherwise noted. (Note 4)
SYMBOL PARAMETER
DCIN Operating Range
I
DCIN
V
TOL
I
TOL
V
DD
Shutdown
Battery Leakage Current
UVLO
Undervoltage Lockout Threshold
V
DD
Power-Fail
DCIN Current in Shutdown
DCIN = 0V, V
CLP
= V
CLN
= V
CSP
= V
BAT
DCIN Rising, V
BAT
= 0V
Part Held in Reset Until this V
DD
Present
V
CHGEN
= 0V
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ELECTRICAL CHARACTERISTICS
CONDITIONS
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MIN
6
TYP
3
MAX
28
5
1.1
1.3
6
7
5.5
UNITS
V
mA
%
%
%
%
V
μA
V
V
mA
4101fa
DCIN Operating Current
Charge Voltage Accuracy
Charge Current Accuracy (Note 3)
V
DD
Operating Voltage
Charging, Sum of Currents on
DCIN, CLP and CLN
(Note 2)
V
CSP
– V
BAT
Target = 102.3mV
I
DAC
= 0xFFFF
0V ≤ V
DCIN
≤ 28V
l
l
l
–1.1
–1.3
–2
–3
3
15
4.2
4.7
2
35
5.5
3
3
2
LTC4101
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Current Sense Amplifier, CA1
Input Bias Current into BAT Pin
CMSL
CMSH
I
TREV
CA1/I
1
Input Common Mode Low
CA1/I
1
Input Common Mode High
Reverse Current Threshold (V
CSP
-V
BAT
)
Transconductance
Source Current
Sink Current
Current Limit Amplifier
Transconductance
V
CLP
I
CLN
Current Limit Threshold
CLN Input Bias Current
Transconductance
Sink Current
OVSD
Overvoltage Shutdown Threshold as a Percent
of Programmed Charger Voltage
DCIN Detection Threshold (V
DCIN
-V
CLP
)
Forward Regulation Voltage (V
DCIN
-V
CLP
)
Reverse Voltage Turn-Off Voltage (V
DCIN
-V
CLP
)
INFET ON Clamping Voltage (V
DCIN
-V
INFET
)
INFET OFF Clamping Voltage (V
DCIN
-V
INFET
)
Oscillator
f
OSC
f
MIN
DC
MAX
Regulator Switching Frequency
Regulator Switching Frequency in Drop Out
Regulator Maximum Duty Cycle
V
TGATE
High (V
CLP
-V
TGATE
)
V
BGATE
High
V
TGATE
Low (V
CLP
-V
TGATE
)
V
BGATE
Low
TGTR
TGTF
BGTR
BGTF
TGATE Transition Time
TGATE Rise Time
TGATE Fall Time
BGATE Transition Time
BGATE Rise Time
BGATE Fall Time
V
TGATE
at Shutdown (V
CLN
-V
TGATE
)
Duty Cycle ≥ 98%
V
CSP
= V
BAT
I
TGATE
= –1mA
C
LOAD
= 3000pF
C
LOAD
= 3000pF
I
BGATE
= 1mA
C
LOAD
= 3000pF, 10% to 90%
C
LOAD
= 3000pF, 10% to 90%
C
LOAD
= 3000pF, 10% to 90%
C
LOAD
= 3000pF, 10% to 90%
I
TGATE
= –1μA
50
50
40
40
4.5
4.5
5.6
5.6
255
20
98
300
25
99
50
10
10
50
110
100
90
80
100
345
kHz
kHz
%
mV
V
V
mV
ns
ns
ns
ns
mV
4101fa
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 20V, V
DD
= 3.3V, V
BAT
= 4V unless otherwise noted. (Note 4)
CONDITIONS
MIN
TYP
11.66
l
MAX
UNITS
μA
V
0
V
CLN
–0.2
–30
1
V
DCIN
≤ 28V
l
V
mV
mmho
μA
μA
mmho
Current Comparators I
REV
Current Sense Amplifier, CA2
Measured at I
TH
, V
ITH
= 1.4V
Measured at I
TH
, V
ITH
= 1.4V
–40
40
1.5
l
93
100
50
1
107
mV
nA
mmho
μA
Voltage Error Amplifier, EA
Measured at I
TH,
V
ITH
= 1.4V
l
36
102
107
110
%
Input P-Channel FET Driver (INFET)
DCIN Voltage Ramping Up
from V
CLP
-0.05V
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0
0.17
25
0.25
50
6.5
0.25
V
mV
mV
V
V
–60
5
–25
5.8
I
INFET
= 1μA
I
INFET
= –25μA
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Gate Drivers (TGATE, BGATE)
3
LTC4101
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
V
BGATE
at Shutdown
AC Present Comparator
V
ACP
DCDIV Threshold
DCDIV Hysteresis
DCDIV Input Bias Current
ACP V
OH
ACP V
OL
DCDIV to ACP Delay
SafetySignal Decoder
SafetySignal Trip (RES_COLD/RES_OR)
SafetySignal Trip (RES_IDEAL/RES_COLD)
SafetySignal Trip (RES_HOT/RES_IDEAL)
SafetySignal Trip (RES_UR/RES_HOT)
Time Between SafetySignal Measurements
DACs
Charging Current Resolution
Charging Current Granularity
Guaranteed Monotonic Above I
MAX
/16
R
ILIM
= 0
R
ILIM
= 10k ±1%
R
ILIM
= 33k ±1%
R
ILIM
= Open (or Short to V
DD
)
All Values of R
ILIM
All Values of R
VLIM
R
ILIM
= 0 (0-1A)
Charging Current = 0x03FF (0x0400 Note 7)
R
ILIM
= 10k ±1% (0-2A)
Charging Current = 0x07FE (0x0800 Note 7)
R
ILIM
= 33k ±1% (0-3A)
Charging Current = 0x0BFC (0x0C00 Note 7)
R
ILIM
= 0pen (or Short to V
DD
) (0-4A)
Charging Current = 0x0FFC (0x1000 Note 7)
Charging Voltage Resolution
Charging Voltage Granularity
Charging Voltage Limit
R
VLIM
= 0
Charging Voltage = 0x1090 (Note 7)
R
VLIM
= 10k ±1%
Charging Voltage = 0x10D0 (Note 7)
R
VLIM
= 33k ±1%
Charging Voltage = 0x1150 (Note 7)
R
VLIM
= 100k ±1%
Charging Voltage = 0x11A0 (Note 7)
R
VLIM
= 0pen (or Short to V
DD
)
Charging Voltage = 0x1580 (Note 7)
4.206
4.270
4.397
4.476
5.460
Guaranteed Monotonic (2.9V ≤ V
BAT
≤ 5.6V)
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 20V, V
DD
= 3.3V, V
BAT
= 4V unless otherwise noted. (Note 4)
CONDITIONS
I
TGATE
= 1μA
V
DCDIV
Rising from 1V to 1.4V
V
DCDIV
= 1.2V
I
ACP
= –2mA
I
ACP
= 1mA
V
DCDIV
= 1.3V
R
THA
= 1130Ω ±1%, C
TH
= 1nF (Note 6)
R
THB
= 54.9Ω ±1%
R
THA
= 1130Ω ±1%, C
TH
= 1nF (Note 6)
R
THB
= 54.9Ω ±1%
R
THA
= 1130Ω ±1%, C
TH
= 1nF (Note 6)
R
THB
= 54.9Ω ±1%
R
THA
= 1130Ω ±1%, C
TH
= 1nF (Note 6)
R
THB
= 54.9Ω ±1%
DCDIV = 1.3V
DCDIV = 1V
10
1
2
4
4
80 (Note
5)
97.3
97.3
72.3
97.3
11
16
4.240
4.304
4.432
4.512
5.504
4.274
4.338
4.467
4.548
5.548
107.3
107.3
82.3
107.3
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l
MIN
TYP
MAX
100
UNITS
mV
V
mV
μA
V
V
μs
kΩ
kΩ
kΩ
Ω
ms
ms
Bits
mA
mA
mA
mA
mA
mV
mV
mV
mV
Bits
mV
V
V
V
V
V
4101fa
1.14
–1
2
1.20
25
1.26
1
0.5
10
95
28.5
2.85
425
100
30
3
500
32
105
31.5
3.15
575
250
Wake-Up Charging Current (I
WAKE-UP
)
Charging Current Limit
CSP – BAT
4
LTC4101
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER
Logic Levels
V
IL
V
IH
V
OL
I
IL
I
IH
V
OL
I
LEAK
V
OL
V
IL
V
IH
SCL/SDA Input Low Voltage
SCL/SDA Input High Voltage
SDA Output Low Voltage
SCL/SDA Input Current
SCL/SDA Input Current
SMBALERT
Output Low Voltage
SMBALERT
Output Pull-Up Current
SDA/SCL/SMBALERT Power Down Leakage
CHGEN Output Low Voltage
CHGEN Output Pull-Up Current
CHGEN Input Low Voltage
CHGEN Input High Voltage
Power-On Reset Duration
t
HIGH
t
LOW
t
R
t
F
t
SU:STA
t
HD:STA
t
HD:DAT
t
TIMEOUT
SCL Serial Clock High Period
SCL Serial Clock Low Period
SDA/SCL Rise Time
SDA/SCL Fall Time
Start Condition Setup Time
Start Condition Hold Time
SDA to SCL Falling-Edge Hold Time,
Slave Clocking in Data
Time Between Receiving Valid
ChargingCurrent() and
ChargingVoltage() Commands
V
DD
= 3V
V
DD
= 5.5V
V
DD
Ramp from 0V to >3V in <5μs
I
PULL-UP
= 350μA, C
LOAD
= 250pF, R
PU
= 9.31k,
V
DD
= 3V and V
DD
= 5.5V
I
PULL-UP
= 350μA, C
LOAD
= 250pF, R
PU
= 9.31k,
V
DD
= 3V and V
DD
= 5.5V
C
LOAD
= 250pF R
PU
= 9.31k, V
DD
= 3V
,
and V
DD
= 5.5V
C
LOAD
= 250pF R
PU
= 9.31k, V
DD
= 3V
,
and V
DD
= 5.5V
V
DD
= 3V and V
DD
= 5.5V
V
DD
= 3V and V
DD
= 5.5V
V
DD
= 3V and V
DD
= 5.5V
V
DD
= 3V and V
DD
= 5.5V
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DCIN
= 20V, V
DD
= 3.3V, V
BAT
= 4V unless otherwise noted. (Note 4)
CONDITIONS
V
DD
= 3V and V
DD
= 5.5V
V
DD
= 3V and V
DD
= 5.5V
I
PULL-UP
= 350μA
V
SDA
, V
SCL
= V
IL
V
SDA
, V
SCL
= V
IH
I
PULL-UP
= 500μA
V
SMBALERT
= V
OL
V
SDA
, V
SCL
, V
SMBALERT
= 5.5V, V
DD
= OV
I
OL
= 100μA
V
CHGEN
= V
OL
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l
l
l
l
l
l
l
MIN
TYP
MAX
0.8
UNITS
V
V
V
μA
μA
V
μA
μA
V
μA
V
V
V
μs
μs
2.1
0.4
–1
–1
–17.5
–2
–17.5
2.5
3.9
100
4
4.7
15000
1000
300
4.7
4
300
140
175
210
–10
–10
1
1
0.4
–3.5
2
0.5
–3.5
0.9
SMBus Timing (Refer to System Management Bus Specification, Revision 1.1, Section 2.1 for Timing Diagrams)
μs
ns
ns
μs
μs
ns
sec
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
See Test Circuit.
Note 3:
Does not include tolerance of current sense resistor.
Note 4:
The LTC4101E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 5:
Current accuracy dependent upon circuit compensation and sense
resistor.
Note 6:
C
TH
is defined as the sum of capacitance on THA, THB and
SafetySignal.
Note 7:
The corresponding overrange bit will be set when a HEX value
greater than or equal to this value is used.
4101fa
5