linear charger for most battery chemistry types including
Li-Ion/Polymer, Lead-Acid or NiMH battery stacks up to
60V. The maximum charge current is adjustable from
10mA to 250mA with an external resistor. The battery
charge voltage is set using an external resistor divider.
With an integrated power device, current sensing and
reverse current protection, a complete charging solution
using the LTC4079 requires very few external components.
Thermal regulation ensures maximum charge current up to
the specified limit without the risk of overheating. Charging
can be terminated by either C/10 or adjustable timer.
Input voltage regulation reduces charge current when
the input voltage falls to an adjustable level or the battery
voltage, making it well suited for energy harvesting
applications. Other features include temperature qualified
charging, bad battery detection, automatic recharge with
sampled feedback in standby for negligible battery drain,
and an open-drain
CHRG
status output. The device is
offered in a compact, thermally enhanced 10-lead (3mm
×
3mm) DFN package.
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.
n
n
n
n
n
n
n
n
Wide Input Voltage Range: 2.7V to 60V
Adjustable Battery Voltage: 1.2V to 60V
Adjustable Charge Current: 10mA to 250mA
Low Quiescent Current While Charging: I
IN
= 4µA
Ultralow Battery Drain When Shutdown or Charged:
I
BAT
< 0.01µA
Auto Recharge
Input Voltage Regulation for High Impedance Sources
Thermal Regulation Maximizes Output Current
without Overheating
Constant Voltage Feedback with ±0.5% Accuracy
NTC Thermistor Input for Temperature Qualified
Charging
Adjustable Safety Timer
Charging Status Indication
Thermally Enhanced 10-Lead (3mm
×
3mm)
DFN Package
applicaTions
n
n
n
n
Embedded Automotive and Industrial
Backup Battery Charging from Another Battery
Energy Harvesting Charger
Thin Film Battery Products
Typical applicaTion
Charging a Backup Battery
9V TO 60V
1µF
EN
CHRG
3.01k
TIMER
NTC
GND
T 10k
IN
LTC4079
FB
249k
FBG
10k
PROG NTCBIAS
BAT
1.54M
8.4V
140
120
100
I
BAT
(mA)
80
60
40
Li-Ion Battery Charge Cycle
8.6
500mAh 2-CELL LI-ION
I
BAT
V
BAT
8.4
8.2
V
BAT
(V)
8.0
7.8
C/10
7.6
TERMINATION
7.4
0
1
2
3
4
5
TIME (HOURS)
6
7
8
7.2
+
20
Li-Ion
0
4079 TA01a
4079 TA01b
For more information
www.linear.com/LTC4079
1
4079f
LTC4079
absoluTe MaxiMuM raTings
(Notes 1, 2)
pin conFiguraTion
TOP VIEW
IN
EN
PROG
NTCBIAS
NTC
1
2
3
4
5
11
GND
10 BAT
9 FB
8 FBG
7
CHRG
6 TIMER
IN, BAT, EN,
CHRG,
FB, FBG Voltage .......... –0.3V to 62V
PROG TIMER Voltage ..................................................3V
BAT Current....................................................... –400mA
PROG Current ..................................................... –1.6mA
FBG Current .............................................................2mA
CHRG
Current ..........................................................2mA
Operating Junction Temperature Range
(Notes 3, 5) ................................................ –40 to 125°C
Storage Temperature Range ......................–65 to 150°C
DD PACKAGE
10-LEAD (3mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
orDer inForMaTion
LEAD FREE FINISH
LTC4079EDD#PBF
LTC4079IDD#PBF
TAPE AND REEL
LTC4079EDD#TRPBF
LTC4079IDD#TRPBF
PART MARKING*
LGNQ
LGNQ
PACKAGE DESCRIPTION
10-Lead (3mm
×
3mm) Plastic DFN
10-Lead (3mm
×
3mm) Plastic DFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard 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/
2
4079f
For more information
www.linear.com/LTC4079
LTC4079
elecTrical characTerisTics
SYMBOL
V
IN
V
BAT
V
UVLO
V
DUVLO
V
DVREG
I
Q(IN)
I
Q(BAT)
PARAMETER
Operating Supply Voltage
Battery Voltage Range
V
IN
Undervoltage Lockout
Differential Undervoltage Lockout
Differential Voltage Regulation
Input Supply Quiescent Current
V
IN
Rising
Hysteresis
V
IN
-V
BAT
Rising
Hysteresis
Minimum V
IN
-V
BAT
for Charge Current
Charging (Note 4)
Charging Terminated (V
FB
= 1.210V)
Shutdown (EN = 0)
Charging Terminated (V
FB
=1.210V)
Shutdown (EN = 0)
V
IN
= 0 or IN open
1.165
1.156
The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at