LTC4160EUDC-1#PBF Linear Technology, LTC4160EUDC-1#PBF Datasheet - Page 22

• Manufacturer Part Number: LTC4160EUDC-1#PBF
• Description: IC, BATT CHRG, Li-Ion, Li-Polymer, 1.2A, QFN20
• Manufacturer: Linear Technology

Specifications of LTC4160EUDC-1#PBF

• Battery Type: Li-Ion, Li-Polymer
• Input Voltage: 5.5V
• Battery Charge Voltage: 4.1V
• Charge Current Max: 1.2A
• Battery Ic Case Style: QFN
• No. Of Pins: 20
• No. Of Series Cells: 1
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LTC4160/LTC4160-1
APPLICATIONS INFORMATION
There are MLCCs available with several types of dielectrics
each having considerably different characteristics. For
example, X7R MLCCs have the best voltage and tempera-
ture stability. X5R MLCCs have apparently higher packing
density but poorer performance over their rated voltage
and temperature ranges. Y5V MLCCs have the highest
packing density, but must be used with caution, because
of their extreme nonlinear characteristic of capacitance
versus voltage. The actual in-circuit capacitance of a
ceramic capacitor should be measured with a small AC
signal and DC bias as is expected in-circuit. Many vendors
specify the capacitance versus voltage with a 1V
test signal and, as a result, over state the capacitance that
the capacitor will present in the application. Using similar
operating conditions as the application, the user must
measure or request from the vendor the actual capacitance
to determine if the selected capacitor meets the minimum
capacitance that the application requires.
Overvoltage Protection
V
additional components, a resistor R1 and an N-channel
MOSFET MN1, as shown in Figure 5. Suitable choices for
MN1 are listed in Table 4.
Table 4. Recommended N-Channel MOSFETs for the Overvoltage
Protection Circuit
22
BUS
NTLJS4114N
IRLML2502
Si2302ADS
Si2306BDS
Si1472DH
Si2316DS
FDN372S
PART #
can be protected from overvoltage damage with two
USB/WALL
ADAPTER
Figure 5. Overvoltage Protection
BVDSS
30V
20V
30V
30V
20V
30V
30V
R1
MN1
57mΩ
60mΩ
47mΩ
50mΩ
50mΩ
50mΩ
35mΩ
R
ON
C1
V
OVGATE
OVSENS
LTC4160-1
LTC4160/
BUS
41601 F05
PACKAGE
WDFN6
SC70-6
SOT-23
SOT-23
SOT-23
SOT-23
SOT-23
RMS
AC
R1 is a 6.2k resistor and must be rated for the power dis-
sipated during maximum overvoltage. In an overvoltage
condition the OVSENS pin will be clamped at 6V. R1 must
be sized appropriately to dissipate the resultant power.
For example, a 1/10W 6.2k resistor can have at most
√(PMAX • 6.2kΩ) = 25V applied across its terminals. With
the 6V at OVSENS, the maximum overvoltage magnitude
that this resistor can withstand is 31V. A 1/4W 6.2k resis-
tor raises this value to 45V. OVSENS’s absolute maximum
current rating of 10mA imposes an upper limit of 68V
protection.
Reverse Voltage Protection
The LTC4160/LTC4160-1 can also be easily protected
against the application of reverse voltages, as shown in
Figure 6. D1 and R1 are necessary to limit the maximum
V
breakdown voltage must be safely below MP1’s BVGS. The
circuit shown in Figure 6 offers forward voltage protection
up to MN1’s BVDSS and reverse voltage protection up to
MP1’s BVDSS.
Battery Charger Over Programming
The USB high power specification allows for up to 2.5W
to be drawn from the USB port. The LTC4160/LTC4160-1’s
bidirectional switching regulator in step-down mode con-
verts the voltage at V
V
grammed at CLPROG. The charger should be programmed
(with the PROG pin) to deliver the maximum safe charging
current without regard to the USB specifications. If there
is insufficient current available to charge the battery at the
programmed rate, the charge current will be reduced until
the system load on V
rent limit is satisfied. Programming the charger for more
GS
OUT
USB/WALL
seen by MP1 during positive overvoltage events. D1’s
ADAPTER
, while limiting power to less than the amount pro-
V
V
BUS
BUS
POSITIVE PROTECTION UP TO BVDSS OF MN1
NEGATIVE PROTECTION UP TO BVDSS OF MP1
Figure 6. Dual Polarity Voltage Protection
MP1
R1
BUS
OUT
D1
to a voltage just above BAT on
is satisfied and the V
R2
MN1
C1
V
LTC4160-1
OVGATE
OVSENS
LTC4160/
BUS
41601 F06
BUS
41601fa
cur-