LTC3566EUF#TRPBF Linear Technology, LTC3566EUF#TRPBF Datasheet - Page 13

• Manufacturer Part Number: LTC3566EUF#TRPBF
• Description: IC USB POWER MANAGER 24-QFN
• Manufacturer: Linear Technology

Specifications of LTC3566EUF#TRPBF

• Applications: Handheld/Mobile Devices
• Voltage - Supply: 4.35 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -

OPERATION
the programmed limit, CLPROG reaches V
and power out is held constant.
The input current is programmed by the ILIM0 and ILIM1
pins. It can be confi gured to limit average input current to
one of several possible settings as well as be deactivated
(USB Suspend). The input current limit will be set by the
V
cording to the following expression:
Figure 1 shows the range of possible voltages at V
a function of battery voltage.
The LTC3566 Versus the LTC3566-2
For very low battery voltages, the battery charger acts
like a load and, due to limited input power, its current
can cause V
operating under input current limit conditions. To prevent
V
undervoltage circuit that automatically detects that V
is falling and reduces the battery charge current as V
falls from 3.5V to 3.3V. This reduction prevents V
collapsing suddenly towards the battery voltage when input
current limit is reached and ensures that load current and
output voltage are always prioritized while delivering as
much battery charge current as possible. The standard
LTC3566 does not include this circuit and thus favors
maximum charge current at all times over output voltage
preservation. See graph titled Output Current vs Output
CLPROG
OUT
I
VBUS
from falling to this level, the LTC3566-2 includes an
=I
servo voltage and the resistor on CLPROG ac-
4.5
4.2
3.9
3.6
3.3
3.0
2.7
2.4
BUSQ
2.4
OUT
+
to approach the battery voltage when
2.7
NO LOAD
R
V
Figure 1. V
CLPROG
CLPROG
3.0
BAT (V)
3.3
•(h
OUT
CLPROG
vs BAT
3.6
300mV
3.9
+ 1)
3566 F01
CLPROG
4.2
OUT
, 1.188V
OUT
from
OUT
OUT
as
Voltage (Battery Charger Enabled) 5x Mode in the Typical
Performance Characteristics section.
If instant-on operation under low battery and input current
limited conditions is a requirement, then the LTC3566-2
should be used. If maximum charge effi ciency at low
battery voltages is preferred, and instant-on operation is
not a requirement, then the standard LTC3566 should be
selected. All versions of the LTC3566 family will start up
with a removed battery.
Ideal Diode from BAT to V
The LTC3566 family has an internal ideal diode as well as
a controller for an optional external ideal diode. The ideal
diode controller is always on and will respond quickly
whenever V
If the load current increases beyond the power allowed
from the switching regulator, additional power will be
pulled from the battery via the ideal diode. Furthermore,
if power to V
of the application power will be provided by the battery via
the ideal diode. The transition from input power to battery
power at V
capacitor to keep V
consists of a precision amplifi er that enables a large on-
chip P-channel MOSFET transistor whenever the voltage at
V
BAT. The resistance of the internal ideal diode is approxi-
mately 180mΩ. If this is suffi cient for the application, then
no external components are necessary. However, if more
OUT
is approximately 15mV (V
1000
2200
2000
1800
1600
1400
1200
800
600
400
200
OUT
OUT
0
BUS
0
Figure 2. Ideal Diode Operation
will be quick enough to allow only a 10μF
drops below BAT.
FORWARD VOLTAGE (mV) (BAT – V
LTC3566/LTC3566-2
(USB or wall power) is removed, then all
60
VISHAY Si2333
OPTIONAL EXTERNAL
IDEAL DIODE
OUT
120
IDEAL DIODE
SEMICONDUCTOR
180
MBRM120LT3
LTC3566
from drooping. The ideal diode
OUT
240 300
ON
FWD
360
) below the voltage at
OUT
420
3566 F02
)
480
13
3566fb