LTC4055 Linear Technology, LTC4055 Datasheet - Page 21

• Manufacturer Part Number: LTC4055
• Description: USB Power Controller and Li-Ion Linear Charger
• Manufacturer: Linear Technology

TYPICAL APPLICATIO S
LTC4055 Configured for USB Application with Wall
Adapter
Figure 5 shows an LTC4055 configured for USB applica-
tions with the optional wall adaptor input. The program-
ming resistor (R
nominal current limit of 467mA in high power mode
(92mA in low power). This is done to prevent the various
tolerances in the part and programming resistors from
ADAPTER INPUT
CABLE V
FROM USB
5V (NOM)
5V WALL
CLPROG
BUS
) is set to 105k which sets up a
R3
1
10 F
Figure 5. USB Power Control Application with Wall Adapter Input
R1
34.8k
R2
10k
U
R
100k
NTC
100k
NTCBIAS
C
TIMER
0.1 F
IN1
IN2
CHRG
ACPR
WALL
V
NTC
TIMER PROG
NTC
R
61.9k
LTC4055
PROG
CLPROG
allowing the input current supplied by V
500mA/100mA limits.
The programming resistor (R
sets up a nominal charge current of approximately 800mA.
Note that this is the charge current when the wall adapter
is present. When the wall adapter is absent, the current
limit supersedes the charge current programming and
charge current is limited to 467mA.
R
105k
CLPROG
HPWR
SHDN
SUSP
GND
OUT
BAT
4055 F05
+
Li-Ion
CELL
SUSPEND USB POWER
500mA/100mA SELECT
SHUTDOWN
10 F
TO LDOs,
REGs, ETC
PROG
) with a value of 61.9k
BUS
LTC4055
to exceed the
21
4055p