in handheld PC and portable product applications. The
device monitors current through an external sense resistor
between the battery’s positive terminal and the battery’s
load or charger. A voltage-to-frequency converter trans-
forms the current sense voltage into a series of output
pulses at the interrupt pin. These pulses correspond to a
fixed quantity of charge flowing into or out of the battery.
The part also indicates charge polarity as the battery is
depleted or charged.
The LTC4150 is intended for 1-cell or 2-cell Li-Ion and
3-cell to 6-cell NiCd or NiMH applications.
L,
LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode are registered trademarks and
ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Indicates Charge Quantity and Polarity
±50mV Sense Voltage Range
Precision Timer Capacitor or Crystal Not Required
2.7V to 8.5V Operation
High Side Sense
32.55Hz/V Charge Count Frequency
1.5μA Shutdown Current
10-Pin MSOP Package
APPLICATIONS
n
n
n
Battery Chargers
Palmtop Computers and PDAs
Cellular Telephones and Wireless Modems
TYPICAL APPLICATION
Integral Nonlinearity, % of Full Scale
0.5
R
SENSE
CHARGER
LOAD
ERROR (% FULL SCALE)
4.7μF
R
L
SENSE
–
SENSE
+
C
F+
4.7μF
C
F–
LTC4150
V
DD
INT
CLR
POL
GND
SHDN
4150 TA01a
0.4
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
–50
–25
0
25
CURRENT SENSE VOLTAGE (mV)
50
4150 TA01b
+
R
L
CHG
DISCHG
μP
4150fc
1
LTC4150
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
SENSE
+
SENSE
–
C
F+
C
F–
1
2
3
4
SHDN
5
10
9
8
7
6
INT
CLR
V
DD
GND
POL
Supply Voltage (V
DD
) .................................. –0.3V to 9V
Input Voltage Range
Digital Inputs (CLR,
SHDN)
........–0.3V to (V
DD
+ 0.3)
SENSE
–
, SENSE
+
, C
F–
, C
F+
.........–0.3V to (V
DD
+ 0.3)
Output Voltage Range
Digital Outputs (INT, POL) ....................... –0.3V to 9V
Operating Temperature Range
LTC4150CMS ........................................... 0°C to 70°C
LTC4150IMS .......................................–40°C TO 85°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
MS PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 160°C/W
ORDER INFORMATION
LEAD FREE FINISH
LTC4150CMS#PBF
LTC4150IMS#PBF
TAPE AND REEL
LTC4150CMS#TRPBF
LTC4150IMS#TRPBF
PART MARKING*
LTQW
LTQW
PACKAGE DESCRIPTION
10-Lead Plastic MSOP
10-Lead Plastic MSOP
TEMPERATURE RANGE
0°C to 70°C
–40°C to 85°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 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/
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IL
V
IH
V
OL
I
LEAK
V
OS
PARAMETER
Digital Input Low Voltage,
CLR, SHDN
Digital Input High Voltage,
CLR, SHDN
Digital Output Low Voltage,
INT,
POL
Digital Output Leakage Current,
INT,
POL
Differential Offset Voltage (Note 4)
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
DD
= 2.7V and 8.5V unless otherwise noted.
CONDITIONS
l
l
MIN
1.9
TYP
MAX
0.7
0.5
UNITS
V
V
V
μA
μV
μV
μV
μV
μV
μV
V
V
kΩ
V
I
OL
= 1.6mA, V
DD
= 2.7V
V
INT
= V
POL
= 8.5V
V
DD
= 4.0V
V
DD
= 8.0V
V
DD
= 2.7V to 8.5V
l
l
l
l
l
l
0.01
1
±100
±150
±100
±150
±150
±200
V
SENSE(CM)
Sense Voltage Common Mode Input Range
V
SENSE
R
IDR
V
UVLO
Sense Voltage Differential Input Range
Average Differential Input Resistance,
Across SENSE
+
and SENSE
–
Undervoltage Lockout Threshold
SENSE
+
– SENSE
–
V
DD
= 4.1V (Note 3)
V
DD
Rising
V
DD
– 0.06
–0.05
155
270
2.5
V
DD
+ 0.06
0.05
390
2.7
l
l
4150fc
2
LTC4150
ELECTRICAL CHARACTERISTICS
SYMBOL
I
DD
I
DD(SD)
PARAMETER
Supply Current, Operating
Supply Current, Shutdown
Power Supply Current
V
DD
= 8.5V
V
DD
= 2.7V
V
DD
= 8.5V
V
DD
= 5.5V
V
DD
= 2.7V
V
SENSE
= 50mV to –50mV,
2.7V ≤ V
DD
≤ 8.5V
2.7V ≤ V
DD
≤ 8.5V
(Note 2)
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
DD
= 2.7V and 8.5V unless otherwise noted.
CONDITIONS
MIN
TYP
115
80
10
MAX
140
100
22
10
1.5
33.1
33.3
0.5
0.03
0.4
0.5
UNITS
μA
μA
μA
μA
μA
Hz/V
Hz/V
%/V
%/ºC
%
%
μs
μs
AC Characteristics
G
VF
ΔG
VF(VDD)
INL
t
CLR
t
INT
Voltage to Frequency Gain
Gain Variation with Supply
Integral Nonlinearity
CLR
Pulse Width to Reset
INT,
INT
and
CLR
Not Connected
INT
Low Time,
INT
Connected to
CLR
Figure 2
Figure 3, C
L
= 15pF
l
l
32.0
31.8
0
–0.03
–0.4
–0.5
20
1
32.55
ΔG
VF(TEMP)
Gain Variation with Temperature
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:
Guaranteed by design and not tested in production.
Note 3:
Measured at least 20ms after power on.
Note 4:
Tested in feedback loop to SENSE
+
and SENSE
–
.
4150fc
3
LTC4150
TYPICAL PERFORMANCE CHARACTERISTICS
T
A
= 25°C, unless otherwise noted.
Voltage to Frequency Gain
vs Supply Voltage
+1.00
+0.75
G
VF
ERROR (% OF TYPICAL)
+0.50
+0.25
V
SENSE
= 25mV
0
–0.25
–0.50
–0.75
–1.00
2
3
4
5
6
V
DD
(V)
7
8
9
4150 G01
Voltage to Frequency Gain
vs Temperature
+1.00
+0.75
G
VF
ERROR (% OF TYPICAL)
+0.50
+0.25
0
–0.25
–0.50
–0.75
–1.00
-50
60
-25
0
25
50
75
TEMPERATURE (°C)
100
125
80
V
DD
= 2.7V
I
DD
(μA)
V
DD
= 8.5V
100
120
V
SENSE
= 50mV
140
Operating I
DD
vs V
DD
V
SENSE
= 50mV
2
3
4
5
6
V
DD
(V)
7
8
9
10
4150 G02
4150 G03
Shutdown I
DD
vs V
DD
6
5
4
V
OL
(mV)
I
DD
(μA)
3
2
1
0
2
3
4
5
6
V
DD
(V)
4150 G04
Digital Output Low Voltage vs V
DD
400
350
300
UVLO (V)
250
200
150
100
50
0
7
8
9
10
2
3
4
5
6
V
DD
(V)
7
8
9
4150 G05
Undervoltage Lockout Threshold
vs Temperature
2.60
2.59
2.58
RISING EDGE
I
OL
= 1.6mA
POL PIN
INT PIN
2.57
2.56
2.55
2.54
2.53
2.52
-50
-25
0
25
50
75
TEMPERATURE (°C)
100
125
4150 G06
4150fc
4
LTC4150
PIN FUNCTIONS
SENSE
+
(Pin 1):
Positive Sense Input. This is the nonin-
verting current sense input. Connect SENSE
+
to the load
and charger side of the sense resistor. Full-scale current
sense input is 50mV. SENSE
+
must be within 60mV of
V
DD
for proper operation.
SENSE
–
(Pin 2):
Negative Sense Input. This is the inverting
current sense input. Connect SENSE
–
to the positive bat-
tery terminal side of the sense resistor. Full-scale current
sense input is 50mV. SENSE
–
must be within 60mV of V
DD
for proper operation.
C
F+
(Pin 3):
Filter Capacitor Positive Input. A capacitor
connected between C
F+
and C
F –
filters and averages
noise and fast battery current variations. A 4.7μF value
is recommended. If filtering is not desired, leave C
F+
and
C
F –
unconnected.
C
F
(Pin 4):
Filter Capacitor Negative Input. A capacitor
connected between C
F+
and C
F –
filters and averages
noise and fast battery current variations. A 4.7μF value
is recommended. If filtering is not desired, leave C
F+
and
C
F –
unconnected.
SHDN
(Pin 5):
Shutdown Digital Input. When asserted low,
SHDN
forces the LTC4150 into its low current consumption
power-down mode and resets the part. In applications
with logic supply V
CC
> V
DD
, a resistive divider must be
used between
SHDN
and the logic which drives it. See the
Applications Information section.
–
POL (Pin 6):
Battery Current Polarity Open-Drain Output.
POL indicates the most recent battery current polarity when
INT
is high. A low state indicates the current is flowing out
of the battery while high impedance means the current
is going into the battery. POL latches its state when
INT
is asserted low. POL is an open-drain output and can be
pulled up to any logic supply up to 9V. In shutdown, POL
is high impedance.
GND (Pin 7):
Ground. Connect directly to the negative
battery terminal.
V
DD
(Pin 8):
Positive Power Supply. Connect to the load
and charger side of the sense resistor. SENSE
+
also con-
nects to V
DD
. V
DD
operating range is 2.7V to 8.5V. Bypass
V
DD
with 4.7μF capacitor.
CLR
(Pin 9):
Clear Interrupt Digital Input. When asserted
low for more than 20μs,
CLR
resets
INT
high. Charge
counting is unaffected.
INT
may be directly connected to
CLR.
In this case the LTC4150 will capture each assertion
of
INT
and wait at least 1μs before resetting it. This ensures
that
INT
pulses low for at least 1μs but gives automatic
INT
reset. In applications with a logic supply V
CC
> V
DD
,
a resistive divider must be used between
INT
and
CLR.
See the Applications Information section.
INT
(Pin 10):
Charge Count Interrupt Open-Drain Output.
INT
latches low every 1/(V
SENSE
• G
VF
) seconds and is
reset by a low pulse at
CLR. INT
is an open-drain output
and can be pulled up to any logic supply of up to 9V. In