FEATURES
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LTC4009
LTC4009-1/LTC4009-2
High Efficiency,
Multi-Chemistry
Battery Charger
DESCRIPTION
The LTC4009 is a constant-current/constant-voltage battery
charger controller. It uses a synchronous quasi-constant
frequency PWM control architecture that will not generate
audible noise with ceramic bulk capacitors. Charge cur-
rent is set by the combination of external sense, input and
programming resistors. With no built-in termination, the
LTC4009 family charges a wide range of batteries under
external control.
The LTC4009 features a fully adjustable output voltage, while
the LTC4009-1 and LTC4009-2 can be pin-programmed for
lithium-ion/polymer battery packs of 1-, 2-, 3- or 4-series
cells. The LTC4009-1 provides output voltage of 4.1V/cell,
and the LTC4009-2 is a 4.2V/cell version.
The device includes AC adapter input current limiting which
maximizes the charge rate for a fixed input power level. An
external sense resistor programs the input current limit, and
the
ICL
status pin indicates when the battery charge current
is being reduced as a result of AC adapter current limiting.
The
CHRG
status pin is active during all charging modes,
including special indication for low charge current.
General Purpose Battery Charger Controller
Efficient 550kHz Synchronous Buck PWM Topology
±0.5% Output Float Voltage Accuracy
Programmable Charge Current: 4% Accuracy
Programmable AC Adapter Current Limit:
3% Accuracy
No Audible Noise with Ceramic Capacitors
Wide Input Voltage Range: 6V to 28V
Wide Output Voltage Range: 2V to 28V
Indicator Outputs for AC Adapter Present, Charging,
C/10 Current Detection and Input Current Limiting
Analog Charge Current Monitor
Micropower Shutdown
Thermally Enhanced 20-Pin 4mm
×
4mm
×
0.75mm
QFN Package
APPLICATIONS
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Notebook Computers
Portable Instruments
Battery Backup Systems
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5723970.
TYPICAL APPLICATION
FROM
ADAPTER
13V TO 20V
33mΩ
0.1μF
DCIN
14.3k
CLP
0.1μF
5.1k
100
20μF
POWER TO
SYSTEM
Efficiency at DCIN = 20V
10000
95
EFFICIENCY (%)
90
POWER LOSS
85
80
75
70
V
FLOAT
= 12.3V
R
SENSE
= 33mΩ
R
IN
= 3.01k
R
PROG
= 26.7k
D
IN
= SSB44
L = IHLP-2525CZ 6.8μH
0
0.5
1.0
1.5
2.0
CHARGE CURRENT (A)
2.5
100
3.0
1000
1.5k
CLN
DCDIV BOOST
LTC4009
TGATE
CHRG
SW
INTV
DD
BGATE
GND
0.1μF
EFFICIENCY
POWER LOSS (mW)
TO/FROM
MCU
ACP
ICL
SHDN
ITH
6.04k
0.1μF
2μF
6.8μH
3.01k
CSP
33mΩ
3.01k
CSN
BAT
PROG
4.7nF
26.7k
V
FB
32.8k
FBDIV
301k
20μF
CHARGE
CURRENT
MONITOR
+
12.3V
Li-Ion
BATTERY
4009 TA01a
4009 TA01b
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LTC4009
LTC4009-1/LTC4009-2
ABSOLUTE MAXIMUM RATINGS
(Note 1)
DCIN, CLP CLN or SW to GND ................... –0.3V to 30V
,
CLP to CLN ............................................................±0.3V
CSP CSN or BAT to GND ............................ –0.3V to 28V
,
CSP to CSN ............................................................±0.3V
BOOST to GND ........................................... –0.3V to 36V
BOOST to SW............................................... –0.3V to 7V
DCDIV,
SHDN,
FVS0, FVS1 or V
FB
to GND .... –0.3V to 7V
ACP, CHRG
or
ICL
to GND ......................... –0.3V to 30V
Operating Temperature Range (Note 2)........ 0°C to 85°C
Junction Temperature (Note 3) ............................. 125°C
Storage Temperature Range................... –65°C to 150°C
PIN CONFIGURATION
LTC4009
BOOST
TOP VIEW
INTV
DD
BGATE
TGATE
SW
INTV
DD
BOOST
BGATE
15 CSP
14 CSN
21
13 PROG
12 ITH
11 BAT
6
SHDN
7
ACP
8
CHRG
9 10
FVS0
FVS1
TGATE
LTC4009-1
LTC4009-2
TOP VIEW
SW
20 19 18 17 16
CLN 1
CLP 2
DCIN 3
ICL
4
DCDIV 5
6
SHDN
7
ACP
8
CHRG
9 10
FBDIV
V
FB
21
15 CSP
14 CSN
13 PROG
12 ITH
11 BAT
CLN 1
CLP 2
DCIN 3
ICL
4
DCDIV 5
20 19 18 17 16
UF PACKAGE
20-LEAD (4mm 4mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 37°C/W
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB
UF PACKAGE
20-LEAD (4mm 4mm) PLASTIC QFN
T
JMAX
= 125°C,
θ
JA
= 37°C/W
EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC4009CUF#PBF
LTC4009CUF-1#PBF
LTC4009CUF-2#PBF
TAPE AND REEL
LTC4009CUF#TRPBF
LTC4009CUF-1#TRPBF
LTC4009CUF-2#TRPBF
PART MARKING
4009
40091
40092
PACKAGE DESCRIPTION
20-Lead (4mm
×
4mm) Plastic QFN
20-Lead (4mm
×
4mm) Plastic QFN
20-Lead (4mm
×
4mm) Plastic QFN
TEMPERATURE RANGE
0°C to 85°C
0°C to 85°C
0°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
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LTC4009
LTC4009-1/LTC4009-2
ELECTRICAL CHARACTERISTICS
SYMBOL
V
TOL
PARAMETER
V
BAT
Accuracy (See Test Circuits)
Charge Voltage Regulation
LTC4009
LTC4009-1/LTC4009-2
I
VFB
R
ON
I
LEAK-FBDIV
V
BOV
V
FB
Input Bias Current
FBDIV On-Resistance
FBDIV Output Leakage Current
V
FB
Overvoltage Threshold
BAT Overvoltage Threshold
Charge Current Regulation
I
TOL
Charge Current Accuracy with R
IN
= 3.01k,
5V < BAT < 18V
Current Sense Amplifier Gain (PROG
ΔI)
with
R
IN
= 3.01k, 5V < BAT < 18V
R
PROG
= 26.7k
V
SENSE
= 0mV, PROG = 1.2V
A
I
V
CS-MAX
V
C10
V
REV
V
CL
I
CLN
V
ICL
OVR
I
DCO
I
CLPO
V
CBT
V
CNT
V
OVP
Shutdown
V
ACP
V
ACP(HYST)
I
DCDIV
V
IL
V
IH
R
IN
I
DCS
I
CLPS
DCDIV AC Present Threshold Voltage
DCDIV ACP Threshold Hysteresis Voltage
DCDIV Input Current
SHDN
Input Voltage Low
SHDN
Input Voltage High
SHDN
Pull-Down Resistance
DCIN Shutdown Current
CLP Shutdown Current
SHDN
= 0V
CLP = 12V,
SHDN
= 0V or DCDIV = 0V
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. DCIN = 20V, BAT = 12V, GND = 0V unless otherwise noted.
CONDITIONS
MIN
–0.5
–0.8
–0.6
–0.8
±20
85
–1
1.235
103
0
1.281
106
190
1
1.32
109
TYP
MAX
0.5
0.8
0.6
0.8
UNITS
%
%
%
%
nA
Ω
μA
V
%
V
FB
= 1.2V
I
LOAD
= 100μA
SHDN
= 0V, FBDIV = 0V
LTC4009
LTC4009-1/LTC4009-2, Relative to
Selected Output Voltage
–4
–5
–12.75
–1.78
–11.67
–1.66
185
325
400
253
100
100
±100
–8
6
1.5
0.5
–5
4
5
–10.95
–1.54
235
430
460
295
103
104
–2
28
2
0.8
60
60
1.9
%
%
μA
μA
mV
mV
mV
mV
mV
mV
nA
mV
V
mA
mA
mV
mV
V
mV
V
SENSE
Step from 0mV to 5mV,
PROG = 1.2V
l
l
Maximum Peak Current Sense Threshold Voltage ITH = 2V
per Cycle (R
IN
= 3.01k)
ITH = 5V
C/10 Indicator Threshold Voltage
Reverse Current Threshold Voltage
Current Limit Threshold
CLN Input Bias Current
ICL
Indicator Threshold
Operating Voltage Range
DCIN Operating Current
CLP Operating Current
CLP Boost Threshold Voltage
CLP Normal Threshold Voltage (Note 5)
DCDIV Overvoltage Protection Threshold
PROG Falling
PROG Falling
CLP – CLN
CLN = CLP
(CLP – CLN) – V
CL
DCIN and CLP
No Gate Loads
CLP = 20V, No Gate Loads
CLP – DCIN, CLP Rising
DCIN – CLP CLP Falling
,
DCDIV Rising
140
340
180
97
96
Input Current Regulation
l
DCIN, CLP Supplies
l
l
10
10
1.75
25
25
1.825
110
V
OVP(HYST)
DCDIV OVP Threshold Hysteresis
DCDIV Rising
DCDIV = 1.2V
l
l
l
1.145
–1
1.4
1.2
50
0
1.255
1
300
V
mV
μA
mV
V
kΩ
μA
50
215
9
18
μA
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LTC4009
LTC4009-1/LTC4009-2
ELECTRICAL CHARACTERISTICS
SYMBOL
I
LEAK-BAT
I
LEAK-CSN
I
LEAK-CSP
I
LEAK-SW
PARAMETER
BAT Leakage Current
CSN Leakage Current
CSP Leakage Current
SW Leakage Current
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. DCIN = 20V, BAT = 12V, GND = 0V unless otherwise noted.
CONDITIONS
SHDN
= 0V or DCDIV = 0V,
0V ≤ CSP = CSN = BAT ≤ 20V
SHDN
= 0V or DCDIV = 0V,
0V ≤ CSP = CSN = BAT ≤ 20V
SHDN
= 0V or DCDIV = 0V,
0V ≤ CSP = CSN = BAT ≤ 20V
SHDN
= 0V or DCDIV = 0V,
0V ≤ SW ≤ 20V
No Load
I
DD
= 20mA
INTV
DD
= 0V
CLP – BAT, CLP Rising
ITH = 1.4V
467
C
LOAD
= 3.3nF
C
LOAD
= 3.3nF
C
LOAD
= 3.3nF 10% – 90%
,
C
LOAD
= 3.3nF 90% – 10%
,
C
LOAD
= 3.3nF 10% – 90%
,
C
LOAD
= 3.3nF 90% – 10%
,
C
LOAD
= 3.3nF 10% – 10%
,
20
98
l
l
l
l
l
MIN
–1
–1
–1
–1
TYP
0
0
0
0
MAX
1
1
1
2
UNITS
μA
μA
μA
μA
INTV
DD
Regulator
INTV
DD
ΔV
DD
I
DD
V
CE
I
ITH
f
TYP
f
MIN
DC
MAX
t
R-TG
t
F-TG
t
R-BG
t
F-BG
t
NO
V
IL
V
IH
I
IN
V
OL
I
LEAK
I
C10
Output Voltage
Load Regulation
Short-Circuit Current (Note 6)
Charge Enable Threshold Voltage
ITH Current
Typical Switching Frequency
Minimum Switching Frequency
Maximum Duty Cycle
TGATE Rise Time
TGATE Fall Time
BGATE Rise Time
BGATE Fall Time
TGATE, BGATE Non-Overlap Time
Input Voltage Low
Input Voltage High
Input Current
Output Voltage Low
Output Leakage
CHRG
C/10 Current Sink
0V ≤ V
IN
≤ 5V
I
LOAD
= 100μA, PROG = 1.2V
SHDN
= 0V, DCDIV = 0V, V
OUT
= 20V
CHRG
= 2.5V
l
l
l
4.85
50
65
5
–0.4
85
100
–40/+90
550
25
99
60
50
60
60
110
5.15
–1
120
135
633
V
%
mA
mV
μA
kHz
kHz
%
Switching Regulator
110
90
90
110
ns
ns
ns
ns
ns
Float Voltage Select Inputs (LTC4009-1/LTC4009-2 Only)
0.5
3.5
–10
10
500
–10
15
25
10
38
V
V
μA
mV
μA
μA
Indicator Outputs
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:
The LTC4009 is guaranteed to meet performance specifications
over the 0°C to 85°C operating temperature range.
Note 3:
Operating junction temperature T
J
(in °C) is calculated from
the ambient temperature T
A
and the total continuous package power
dissipation P
D
(in watts) by the formula T
J
= T
A
+ (θ
JA
• PD). Refer to the
Applications Information section for details.
Note 4:
All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to GND, unless otherwise
specified.
Note 5:
This threshold is guaranteed to be satisfied if CLP = DCIN when
the LTC4009 exits shutdown.
Note 6:
Output current may be limited by internal power dissipation. Refer
to the Applications Information section for details.
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LTC4009
LTC4009-1/LTC4009-2
TEST CIRCUITS
LTC4009
FROM ICL
(CLP = CLN)
LTC4009-1
LTC4009-2
FROM ICL
(CLP = CLN)
1.2085V
–
–
–
+
EA
1.2085V
–
–
–
+
EA
PROG
13
V
FB
10
1.2085V
TARGET
ITH
12
PROG
13
BAT
11
TARGET VARIES
WITH FVS0,1
ITH
12
+
LTC1055
+
LTC1055
–
4009 TC01
0.6V
–
4009 TC02
0.6V
TYPICAL PERFORMANCE CHARACTERISTICS
(T
A
= 25°C unless otherwise noted. D
IN
= SSB44, L = IHLP-2525 6.8μH)
Efficiency at DCIN = 20V, BAT = 8V
100
R
SENSE
= 33mΩ
R
IN
= 3.01k
10000
100
Efficiency at DCIN = 20V, BAT = 12V
R
SENSE
= 33mΩ
R
IN
= 3.01k
POWER LOSS
EFFICIENCY
90
1000
10000
95
EFFICIENCY (%)
POWER LOSS
90
EFFICIENCY
85
1000
95
EFFICIENCY (%)
POWER LOSS (mW)
POWER LOSS (mW)
85
80
0
0.5
1.0
1.5
2.0
CHARGE CURRENT (A)
2.5
100
3.0
4009 G01
80
0
0.5
1.0
1.5
2.0
CHARGE CURRENT (A)
2.5
100
3.0
4009 G02
Efficiency at DCIN = 20V, BAT = 16V
100
R
SENSE
= 33mΩ
R
IN
= 3.01k
EFFICIENCY
10000
0.10
0.08
0.06
POWER LOSS (mW)
V
FB
ERROR (%)
0.04
V
FB
Line Regulation
LTC4009 TEST CIRCUIT
300
275
250
225
R
ON
(Ω)
200
175
150
125
100
5
10
20
15
CLP (V)
25
30
4009 G04
FBDIV R
ON
vs BAT
CLP = BAT + 3V
(CLP ≥ 6V)
95
EFFICIENCY (%)
POWER LOSS
90
1000
0.02
0
–0.02
–0.04
–0.06
–0.08
85
80
0
0.5
1.0
1.5
2.0
CHARGE CURRENT (A)
2.5
100
3.0
4009 G03
–0.10
75
0
5
15
10
BAT (V)
20
25
4009 G05
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