LTC1732-8.4
Lithium-Ion Linear
Battery Charger Controller
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DESCRIPTIO
FEATURES
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Complete Linear Charger Controller for 2-Cell
Lithium-Ion Batteries
Preset Charge Voltage with ±1% Accuracy
Programmable Charge Current
C/10 Charge Current Detection Output
Programmable Charge Termination Timer
Small, Thin 10-Pin MSOP Package
Input Supply (Wall Adapter) Detection Output
8.8V to 12V Input Voltage Range
Automatic Sleep Mode When Input Supply
Is Removed (Only 10µA Battery Drain)
Automatic Trickle Charging of Low Voltage Cells
Programmable for Constant-Current-Only Mode
Battery Insertion Detect and Automatic Charging
of Low-Battery
Automatic Battery Recharge
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APPLICATIO S
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The LTC ®1732-8.4 is a complete constant-current/constant-voltage linear charge controller for lithium-ion
(Li-Ion) batteries. Nickel-cadmium (NiCd) and nickel metalhydride (NiMH) batteries can also be charged with constant current using external termination. Charge current
can be programmed with ±7% accuracy using external
sense and program resistors. An internal resistor divider
and precision reference set the final float voltage with ±1%
accuracy.
When the input supply is removed, the LTC1732-8.4
automatically enters a low current sleep mode, dropping
the battery drain current to 10µA. An internal comparator
detects the end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the
total charge time. Fully discharged cells are automatically
trickle charged at 10% of the programmed current until
battery voltage exceeds 4.9V.
The LTC1732-8.4 begins a new charge cycle when a
discharged battery is connected to the charger or when the
input power is applied. In additon, if the battery remains
connected to the charger and the cell voltage drops below
8.05V, a new charge cycle will begin.
Cellular Phones
Handheld Computers
Charging Docks and Cradles
Digital Cameras and Camcorders
The LTC1732-8.4 is available in the 10-pin MSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
400mA 2-Cell 8.4V Li-Ion Battery Charger
Typical Li-Ion Charge Cycle
VIN = 10V
CONSTANT
CURRENT
R2
1k
2
8
SEL
VCC
SENSE
3
DRV
CHRG
RSENSE
0.25Ω
9
7
Q1
Si9430DY
LTC1732-8.4
10
4
CTIMER
0.1µF
ACPR
BAT
TIMER
PROG
GND
5
1µF
IBAT = 400mA
1
6
RPROG*
19.6k
10µF
*SHUTDOWN INVOKED BY FLOATING THE PROG PIN
+ 8.4V
Li-Ion
BATTERY
1732-8.4 TA01
9
CONSTANT
VOLTAGE
BATTERY VOLTAGE
400
8
400mA HR BATTERY
300
CHARGE CURRENT
200
CHRG
LED OFF
100
0
0
0.5
2.0
1.5
1.0
TIME (HOURS)
7
BATTERY VOLTAGE(V)
R1
1k
CHARGE CURRENT (mA)
MBRM120T3
TIMER
STOPS
2.5
6
3.0
1732-8.4 TA01b
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LTC1732-8.4
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ABSOLUTE MAXIMUM RATINGS
PACKAGE/ORDER INFORMATION
(Note 1)
Input Supply Voltage (VCC) ................................... 13.2V
SENSE, DRV, BAT, SEL,
TIMER, PROG, CHRG, ACPR ................. – 0.3V to 13.2V
Operating Temperature Range (Note 2) .... – 40° to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
TOP VIEW
BAT
SEL
CHRG
TIMER
GND
1
2
3
4
5
10
9
8
7
6
ACPR
SENSE
VCC
DRV
PROG
LTC1732EMS-8.4
MS10 PART MARKING
MS10 PACKAGE
10-LEAD PLASTIC MSOP
LTWW
TJMAX = 140°C, θJA = 180°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 9V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
VCC
Input Supply Voltage
ICC
Input Supply Current
Charger On, Current Mode
Shutdown Mode
Sleep Mode (Battery Drain Current)
●
●
VBAT
Regulated Output Float Voltage
9V ≤ VCC ≤ 12V, VSEL = VCC
●
IBAT
Current Mode Charge Current
RPROG = 19.6k, RSENSE = 0.2Ω
RPROG = 19.6k, RSENSE = 0.2Ω
●
●
RPROG = 97.6k, RSENSE = 0.2Ω
TYP
8.8
MAX
UNITS
12
V
1
1
10
3
3
30
mA
mA
µA
8.316
8.4
8.484
465
415
500
535
585
mA
mA
60
100
140
mA
V
ITRIKL
Trickle Charge Current
VBAT = 4V, RPROG = 19.6k, ITRIKL = (VCC – VSENSE)/0.2Ω ●
30
50
125
mA
VTRIKL
Trickle Charge Threshold Voltage
From Low to High
●
4.7
4.9
5.1
V
VUV
VCC Undervoltage Lockout Voltage
From Low to High
●
8.2
8.7
V
∆VUV
VCC Undervoltage Lockout Hysteresis
VMSD
Manual Shutdown Threshold Voltage
PROG Pin Low to High
PROG Pin High to Low
VASD
Automatic Shutdown Threshold Voltage
(VCC – VBAT) High to Low
(VCC – VBAT) Low to High
VDIS
Voltage Mode Disable Threshold Voltage
VDIS = VCC – VTIMER
IPROG
PROG Pin Current
Internal Pull-Up Current, No RPROG
PROG Pin Source Current, ∆VPROG ≤ 5mV
400
VPROG
PROG Pin Voltage
RPROG =19.6k
VACPR
ACPR Pin Output Low Voltage
IACPR = 5mA
ICHRG
CHRG Pin Weak Pull-Down Current
VCHRG = 1V
VCHRG
CHRG Pin Output Low Voltage
IDRV
Drive Pin Current
mV
2.457
2.446
30
40
54
69
V
V
90
100
mV
mV
0.4
V
300
µA
µA
2.5
●
2.457
V
0.6
1.2
V
35
55
µA
ICHRG = 5mA
0.6
1.2
V
VDRV = VCC – 2V
26
15
µA
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LTC1732-8.4
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 9V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
IC/10
10% Charge Current Indication Level
RPROG = 19.6k, RSENSE = 0.2Ω
tTIMER
TIMER Accuracy
CTIMER = 0.1µF
VRECHRG
Recharge Threshold Voltage
VBAT from High to Low
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
●
25
7.85
TYP
MAX
UNITS
50
100
mA
10
%
8.05
V
Note 2: The LTC1732EMS-8.4 is guaranteed to meet performance
specifications from 0°C to 70°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls.
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TYPICAL PERFOR A CE CHARACTERISTICS
Trickle Charge Current vs
Temperature
60
60
RPROG = 19.6K
RSENSE = 0.2Ω
VBAT = 4V
TA = 25°
55
ITRKL (mA)
ITRKL (mA)
55
50
Trickle Charge Threshold Voltage
vs VCC
4.96
RPROG = 19.6K
RSENSE = 0.2Ω
VBAT = 4V
VCC = 9V
RPROG = 19.6K
TA = 25°
4.95
4.94
VTRKL (V)
Trickle Charge Current vs VCC
50
4.93
4.92
4.91
45
45
4.90
4.89
40
9
10
11
12
40
–50 –25
0
25
50
75
100
125
1732-8.4 G01
9
10
11
12
VCC (V)
TEMPERATURE (°C)
VCC (V)
4.88
1732-8.4 G02
1732-8.4 G03
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TYPICAL PERFOR A CE CHARACTERISTICS
Trickle Charge Threshold Voltage
vs Temperature
110
110
VCC = 9V
4.93
CTIMER = 0.1µF
VCC = 9V
CTIMER = 0.1µF
VBAT = 6V
TA = 25°
105
4.92
4.91
tTIMER (%)
105
tTIMER (%)
VTRKL (V)
Timer Accuracy vs Temperature
Timer Accuracy vs VCC
4.94
100
95
95
4.90
–50 –25
25
0
50
75
100
90
125
9
10
11
25
75
50
Battery Charge Current vs
Temperature
540
530
IBAT (mA)
520
500
RPROG = 19.6K
RSENSE = 0.2Ω
VBAT = 6V
VCC = 9V
RPROG = 19.6K
VBAT = 6V
TA = 25°
2.47
510
500
490
480
490
125
Program Pin Voltage vs VCC
2.48
VPROG (V)
RPROG = 19.6K
RSENSE = 0.2Ω
VBAT = 6V
TA = 25°
100
1732-8.4 G06
1732-8.4 G05
Battery Charge Current vs VCC
510
0
TEMPERATURE (°C)
1732-8.4 G04
520
90
–50 –25
12
VCC (V)
TEMPERATURE (°C)
IBAT (mA)
100
2.46
2.45
470
480
9
10
11
460
–50 –25
12
VCC (V)
0
25
50
75
100
2.44
9
10
11
12
VCC (V)
TEMPERATURE (°C)
1732-8.4 G08
1732-8.4 G07
Program Pin Voltage vs
Temperature
1732-8.4 G09
Recharge Threshold Voltage vs
Temperature
8.25
2.470
VCC = 9V
RPROG = 19.6k
VCC = 9V
8.15
VRECHRG (V)
2.465
VPROG (V)
125
2.460
7.95
2.455
2.450
–50 –25
8.05
0
25
50
75
100
125
7.85
–50 –25
0
25
50
75
100
125
TEMPERATURE (°C)
TEMPERATURE (°C)
1732-8.4 G10
1732-8.4 G11
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LTC1732-8.4
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PIN FUNCTIONS
BAT (Pin 1): Battery Sense Input. A bypass capacitor of
10µF or more is required to keep the loop stable when the
battery is not connected. A precision internal resistor
divider sets the final float voltage. The resistor divider is
disconnected in sleep mode to reduce the current drain on
the battery.
SEL (Pin 2): This pin must be connected to VCC.
CHRG (Pin 3): Open-Drain Charge Status Output. When
the battery is charging, the CHRG pin is pulled low by an
internal N-channel MOSFET. When the charge current
drops to 10% of the full-scale current for more than 15ms,
the N-channel MOSFET turns off and a 35µA current
source is connected from the CHRG pin to GND. When the
timer runs out or the input supply is removed, the current
source is disconnected and the CHRG pin is forced into a
high impedance state.
TIMER (Pin 4): Timer Capacitor and Constant-Voltage
Mode Disable Input Pin. The timer period is set by placing
a capacitor, CTIMER, to GND. The timer period is tTIMER =
(CTIMER • 3 hours)/(0.1µF). When the TIMER pin is
connected to VCC, the timer is disabled, thus the constantvoltage mode is turned off and the IC will operate in
constant-current mode only. Shorting the TIMER pin to
GND will disable the internal timer function and the C/10
function.
PROG (Pin 6): Charge Current Program and Shutdown
Input Pin. The charge current is programmed by connecting a resistor, RPROG to ground. The charge current is IBAT
= (VPROG • 800Ω)/(RPROG • RSENSE). The IC can be forced
into shutdown by floating the PROG pin and allowing the
internal 2.5µA current source to pull the pin above the
2.457V shutdown threshold voltage.
DRV (Pin 7): Drive Output Pin for the P-Channel MOSFET
or PNP Transistor. If a PNP transistor is used, it must have
high gain (see Applications Information section).
VCC (Pin 8): Input Supply Voltage. VCC can range from
8.8V to 12V. If VCC drops below VBAT + 54mV, for example
when the input supply is disconnected, then the IC enters
sleep mode with ICC < 30µA. Bypass this pin with a 1µF
capacitor.
SENSE (Pin 9): Current Sense Input. A sense resistor,
RSENSE, must be connected from VCC to the SENSE pin.
This resistor is chosen using the following equation:
RSENSE = (VPROG • 800Ω)/(RPROG • IBAT)
ACPR (Pin 10): Wall Adapter Present Output. When the
input voltage (wall adapter) is applied to the LTC1732-8.4,
this pin is pulled to ground by an internal N-channel
MOSFET which is capable of sinking 5mA to drive an
external LED (See Applications Information Section).
GND (Pin 5): Ground.
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LTC1732-8.4
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BLOCK DIAGRA
VCC
8
+
UNDERVOLTAGE
LOCKOUT
VCC = 8.2V
8.05V
C5
–
RSENSE
SENSE
+
3
+
–
800Ω
80Ω
C1
–
CHRG
9
54mV
+
C4
–
–
C/10 STOP RECHRG C/10
+
TIMER
DRV
CA
SLP
OSCILLATOR
BAT
LBO
COUNTER
1
4.9V
SEL*
VREF
2
–
ACPR
+
+
C3
A1
–
VA
VCC
–
+
10
7
C2
+
SHDN
4
720Ω
UVLO
ACPR
–
35µA
VREF
2.457V
2.5µA
CHARGE
6
BATTERY CURRENT IBAT = (2.457V • 800Ω)/(RPROG • RSENSE)
PROG
GND
5
1732-8.4 BD
RPROG
*THE LTC1732-8.4 IS OPTIMIZED FOR 2-CELL (8.4V) Li-Ion BATTERIES.
CONNECT THE SEL PIN TO VCC. FOR CHARGING 8.2V BATTERIES USING
THE LTC1732, PLEASE CONTACT THE FACTORY
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LTC1732-8.4
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OPERATIO
The LTC1732-8.4 is a linear battery charger controller. The
charge current is programmed by the combination of a
program resistor (RPROG) from the PROG pin to ground
and a sense resistor (RSENSE) between the VCC and SENSE
pins. RPROG sets a program current through an internal
trimmed 800Ω resistor setting up a voltage drop from VCC
to the input of the current amplifier (CA). The current
amplifier servos the gate of the external P-channel MOSFET
to force the same voltage drop across RSENSE which sets
the charge current. When the voltage at the BAT pin
approaches the preset float voltage, the voltage amplifier
(VA) will start sinking current which shrinks the voltage
drop across RSENSE, thus reducing the charge current.
A charge cycle begins when the potential at VCC pin rises
above the UVLO level and a program resistor is connected
from the PROG pin to ground. At the beginning of the
charge cycle, if the battery voltage is below 4.9V, the
charger goes into trickle charge mode. The trickle charge
current is 10% of the full-scale current. If the battery
voltage stays low for one quarter of the total charge time,
the charge sequence will terminate.
The charger goes into the fast charge constant-current
mode after the voltage on the BAT pin rises above 4.9V. In
constant-current mode, the charge current is set by the
combination of RSENSE and RPROG.
When the battery approaches the final float voltage, the
charge current will begin to decrease. When the current
drops to 10% of the full-scale charge current, an internal
comparator will turn off the pull-down N-channel MOSFET
at the CHRG pin and connect a weak current source to
ground to indicate an end-of-charge (C/10) condition.
An external capacitor on the TIMER pin sets the total
charge time. After a time-out occurs, the charge cycle is
terminated and the CHRG pin is forced to a high impedance state. To restart the charge cycle, remove the input
voltage and reapply it, or float the PROG pin momentarily.
Replacing the battery while in the charge mode will cause
the timer to be reset if the voltage of the new battery is
below 8.05V. If the voltage is above 8.05V, the timer will
continue for the remaining charge time. In the case when
a time out has occurred, a new battery with a voltage of
less than 8.05V can be inserted and charged automatically
with the full programmed charge time.
For batteries like lithium-ion that require accurate final
float voltage, the internal 2.457V reference, voltage amplifier and the resistor divider provide regulation with ±1%
(max) accuracy. For NiMH and NiCd batteries, the
LTC1732-8.4 can be used as a current source by pulling
the TIMER pin to VCC. When in the constant-current only
mode, the voltage amplifier, timer, C/10 comparator and
the trickle charge function are all disabled.
The charger can be shut down by floating the PROG
pin(ICC ≈ 1mA). An internal current source will pull this pin
high and clamp it at 3.5V.
When the input voltage is not present, the charger goes
into a sleep mode, dropping ICC to 10µA. This greatly
reduces the current drain on the battery and increases the
standby time.
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LTC1732-8.4
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APPLICATIONS INFORMATION
Charger Conditions
The charger is off when any of the following conditions exist:
the VCC pin is less than 8.2V, the dropout voltage (VCC –
VBAT) is less than 54mV, or the PROG pin is floating. The
DRV pin will be pulled to VCC and the internal resistor divider is disconnected to reduce the current drain on the
battery.
Undervoltage Lockout (UVLO)
An internal undervoltage lockout circuit monitors the
input voltage and keeps the charger in shutdown mode
until VCC rises above 8.2V. To prevent oscillation around
VCC = 8.2V, the UVLO circuit has built-in hysteresis.
Trickle Charge and Defective Battery Detection
At the beginning of the charging sequence, if the battery
voltage is below 4.9V, the charger goes into trickle mode.
The charge current drops to 10% of the full-scale current.
If the low voltage persists for one quarter of the total
charge time, the battery is considered defective, the charge
cycle is terminated and the CHRG pin output is forced to
a high impedance state.
Shutdown
The LTC1732-8.4 can be forced into shutdown by floating
the PROG pin and allowing the internal 2.5µA current
source to pull the pin above the 2.457V shutdown threshold voltage. The DRV pin is pulled up to VCC turning off the
external P-channel MOSFET. The internal timer is reset in
the shutdown mode.
Programming Charge Current
The formula for the battery charge current (see Block
Diagram) is:
IBAT
= (IPROG)(800Ω/RSENSE)
= (2.457V/RPROG)(800Ω/RSENSE) or
RPROG = (2.457V/IBAT)(800Ω/RSENSE)
For example, if 0.5A charge current is needed, select a
value for RSENSE that will drop 100mV at the maximum
charge current. RSENSE = 0.1V/0.5A = 0.2Ω, then calculate:
RPROG = (2.457V/500mA)(800Ω/0.2Ω) = 19.656k
For best stability over temperature and time, 1% resistors
are recommended. The closest 1% resistor value is 19.6k.
Programming the Timer
The programmable timer terminates the charge cycle.
Typically, when charging at a 1C rate, a discharged Li-Ion
battery will become fully charged in 3 hours. For lower
charge current rates, extend the timer accordingly.The
length of the timer is programmed by an external capacitor at the TIMER pin. The total charge time is:
Time (Hours) = (3 Hours) • (CTIMER/0.1µF) or
CTIMER = 0.1µF • Time (Hours)/3 (Hours)
The timer starts when an input voltage greater than 8.2V
is applied and the program resistor is connected to ground.
After a time-out occurs, the CHRG output will go into a
high impedance state to indicate that charging has stopped.
Connecting the TIMER pin to VCC disables the timer and
also puts the charger into a constant-current mode. To
only disable the timer function, short the TIMER pin to
GND.
CHRG Status Output Pin
When a charge cycle starts, the CHRG pin is pulled to
ground by an internal N-channel MOSFET that can drive an
LED. When the battery current drops to 10% of the fullscale current (C/10), the N-channel MOSFET is turned off
and a weak 35µA current source to ground is connected to
the CHRG pin. After a time-out occurs, the pin will go into
a high impedance state. By using two different value pullup resistors, a microprocessor can detect three states
from this pin (charging, C/10 and stop charging). See
Figure 1 and Table 1.
where RPROG is the total resistance from the PROG pin to
ground.
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APPLICATIONS INFORMATION
V+
VDD
8
VCC
400k
CHRG
3
µPROCESSOR
2k
LTC1732-8.4
OUT
IN
1732-8.4 F01
Figure 1. Microprocessor Interface
Table 1. Microprocessor Interface
IN
OUT
CHARGE STATUS
LOW
HIGH
Charge
LOW
Hi-Z
C/10
HIGH
Hi-Z
Stop Charging
When the LTC1732-8.4 is in charge mode, the CHRG pin
is pulled low by an internal N-channel MOSFET. To detect
this mode, force the digital output pin, OUT, high and
measure the voltage at the CHRG pin. The N-channel
MOSFET will pull the pin low even with a 2k pull-up
resistor. Once the charge current drops to 10% of the fullscale current (C/10), the N-channel MOSFET is turned off
and a 35µA current source is connected to the CHRG pin.
The IN pin is then pulled high by the 2k pull-up. By forcing
the OUT pin into a high impedance state, the current
source pulls the pin low through the 400k resistor. When
the internal timer has expired, the CHRG pin changes to
high impedance and the 400k resistor pulls the pin high to
indicate that charging has stopped.
ACPR Output Pin
The LTC1732-8.4 has an ACPR output pin to indicate that
the input supply (wall adapter) is higher than 8.2V and
55mV above the voltage at the BAT pin. When both
conditions are met, the ACPR pin is pulled to ground by an
N-channel MOSFET that is capable of driving an LED.
Otherwise, this pin is high impedance.
CHRG Status Output Pin (C/10)
The LTC1732-8.4 includes a comparator to monitor the
charge current to detect a near end-of-charge condition.
This comparator does not terminate the charge cycle, but
provides an output signal to indicate a near full charge
condition. The timer is used to terminate the charge cycle.
When the battery current falls below 10% of full scale, the
comparator trips and turns off the N-channel MOSFET at
the CHRG pin and switches in a 35µA current source to
ground. After an internal time delay of 15ms, this state is
latched. This delay helps prevent false triggering due to
transient currents. The end-of-charge comparator is disabled in trickle charge mode.
Gate Drive
Typically the LTC1732-8.4 controls an external P-channel
MOSFET to supply current to the battery. An external PNP
transistor can also be used as the pass transistor instead
of the P-channel MOSFET. Due to the low current gain of
the current amplifier (CA), a high gain Darlington PNP
transistor is required to avoid excessive charge current
error. The gain of the current amplifier is around 0.6µA/
mV. For every 1µA of base current, a 1.6mV of gain error
shows up at the inputs of CA. With RPROG = 19.6k (100mV
across RSENSE), it represents 1.67% of error in charging
current.
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APPLICATIONS INFORMATION
Constant-Current Only Mode
VCC Bypass Capacitor
The LTC1732-8.4 can be used as a programmable current
source by connecting the TIMER pin to VCC. This is
particularly useful for charging NiMH or NiCd batteries. In
the constant-current only mode, the timer and voltage
amplifier are both disabled. An external termination method
is required to properly terminate the charge.
Many types of capacitors can be used for input bypassing.
However, caution must be exercised when using multilayer ceramic capacitors. Because of the self resonant and
high Q characteristics of some types of ceramic capacitors, high voltage transients can be generated under some
start-up conditions, such as connecting the charger input
to a hot power source. To minimize these transients, only
ceramic capacitors with X5R or X7R dielectric are recommended. Also, adding 1Ω or 2Ω in series with the ceramic
capacitor will further reduce these start-up transients. For
more information refer to Application Note 88.
Battery Detection
The LTC1732-8.4 can detect the insertion of a new battery.
When a battery with voltage of less than 8.05V is inserted,
the LTC1732-8.4 resets the timer and a new charge cycle
begins. If the voltage of the new battery is above 8.05V, the
charging will not start if the TIMER has already timed out.
If a new battery (with a voltage above 8.05V) is inserted
while in the charging process, the timer will not be reset
and charging will continue until the timer runs out.
After a time out has occurred and the battery remains
connected, a new charge cycle will begin if the battery
voltage drops below 8.05V due to self-discharge or external loading.
Stability
The charger is stable without any compensation when a
P-channel MOSFET is used as the pass transistor.
However, a 10µF capacitor is recommended at the BAT
pin to keep the ripple voltage low when the battery is
disconnected.
If a PNP transistor is used for the pass transistor, a 1000pF
capacitor is required from the DRV pin to VCC. This
capacitor is needed to help stablize the voltage loop. A
10µF capacitor at the BAT pin is also recommended when
a battery is not present.
17328f
10
LTC1732-8.4
U
PACKAGE DESCRIPTIO
MS Package
10-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1661)
0.889 ± 0.127
(.035 ± .005)
5.23
(.206)
MIN
3.2 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.50
3.05 ± 0.38
(.0197)
(.0120 ± .0015)
BSC
TYP
RECOMMENDED SOLDER PAD LAYOUT
WITHOUT EXPOSED PAD OPTION
0.254
(.010)
10 9 8 7 6
3.00 ± 0.102
(.118 ± .004)
NOTE 4
4.88 ± 0.10
(.192 ± .004)
DETAIL “A”
0.497 ± 0.076
(.0196 ± .003)
REF
0° – 6° TYP
GAUGE PLANE
1 2 3 4 5
0.53 ± 0.01
(.021 ± .006)
DETAIL “A”
0.86
(.034)
REF
1.10
(.043)
MAX
0.18
(.007)
SEATING
PLANE
0.17 – 0.27
(.007 – .011)
0.50
(.0197)
TYP
0.13 ± 0.05
(.005 ± .002)
MSOP (MS) 1001
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
17328f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC1732-8.4
U
TYPICAL APPLICATIO
2-Cell 8.4V Linear Charger Using a PNP Pass Transistor
VIN = 10V
MBRM120T3
R2
2k
CHARGE
STATUS
2k
2
3
10
SEL
VCC
9
CHRG
SENSE
LTC1732-8.4
7
DRV
R1
10k
RSENSE
0.25Ω
TIMER
CTIMER*
0.1µF
PROG
C3
1µF
Q2
ZTX749
Q1
2N5087
ACPR
BAT
4
C1
1nF
8
IBAT = 400mA
1
6
GND
RPROG
19.6k
5
*AVX 0603ZC104KAT1A
+
2-CELL
Li-ION
C2
10µF
1732 TA02
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ThinSot and PowerPath are trademarks of Linear Technology Corporation.
17328f
12
Linear Technology Corporation
LT/TP 0203 2K • PRINTED IN THE USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
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