LTC3586EUFE-1#TRPBF Linear Technology, LTC3586EUFE-1#TRPBF Datasheet - Page 25

• Manufacturer Part Number: LTC3586EUFE-1#TRPBF
• Description: IC POWER MANAGER USB 38-QFN
• Manufacturer: Linear Technology

Specifications of LTC3586EUFE-1#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: 38-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Supply: -

applicaTions inForMaTion
PowerPath CONTROLLER APPLICATIONS SECTION
CLPROG Resistor and Capacitor
As described in the High Efficiency Switching PowerPath
Controller section, the resistor on the CLPROG pin deter-
mines the average input current limit when the switching
regulator is set to either the 1x mode (USB 100mA), the
5x mode (USB 500mA) or the 10x mode. The input cur-
rent will be comprised of two components, the current
that is used to drive V
switching regulator. To ensure that the USB specification is
strictly met, both components of input current should be
considered. The Electrical Characteristics table gives the
worst-case values for quiescent currents in either setting
as well as current limit programming accuracy. To get as
close to the 500mA or 100mA specifications as possible,
a 1% resistor should be used. Recall that I
+ V
An averaging capacitor is required in parallel with the
CLPROG resistor so that the switching regulator can
determine the average input current. This network also
provides the dominant pole for the feedback loop when
current limit is reached. To ensure stability, the capacitor
on CLPROG should be 0.1µF .
Choosing the PowerPath Inductor
Because the input voltage range and output voltage range
of the power path switching regulator are both fairly nar-
row, the LTC3586/LTC3586-1 are designed for a specific
inductance value of 3.3µH. Some inductors which may be
suitable for this application are listed in Table 4.
Table 4. Recommended Inductors for PowerPath Controller
INDUCTOR
TYPE
LPS4018
D53LC
DB318C
WE-TPC
Type M1
CDRH6D12
CDRH6D38
CLPROG
(µH)
/R
3.3
3.3
3.3
3.3 1.95 0.065 4.8 × 4.8 × 1.8 Wurth Elektronik
3.3
3.3
L
CLPPROG
MAX
2.26
1.55
2.2
2.2
3.5
I
(A)
DC
0.0625
0.034
0.070
0.020
MAX
DCR
0.08
OUT
(Ω)
• (h
CLPROG
and the quiescent current of the
3.9 × 3.9 × 1.7 Coilcraft
3.8 × 3.8 × 1.8
6.7 × 6.7 × 1.5
SIZE IN mm
(L × W × H)
5 × 5 × 3
7 × 7 × 4
+1).
MANUFACTURER
www.coilcraft.com
Toko
www.toko.com
www.we-online.com
Sumida
www.sumida.com
VBUS
= I
VBUSQ
V
The style and value of capacitors used with the LTC3586/
LTC3586-1 determine several important parameters
such as regulator control-loop stability and input volt-
age ripple. Because the LTC3586/LTC3586-1 use a buck
switching power supply from V
current waveform contains high frequency components.
It is strongly recommended that a low equivalent series
resistance (ESR) multilayer ceramic capacitor be used to
bypass V
recommended because of their high ESR. The value of the
capacitor on V
ripple for a given load current. Increasing the size of this
capacitor will reduce the input ripple.
To prevent large V
conditions, it is also recommended that a ceramic capaci-
tor be used to bypass V
in the compensation of the switching regulator. At least
4µF of actual capacitance with low ESR are required on
V
performance and stability.
Multilayer ceramic chip capacitors typically have excep-
tional ESR performance. MLCCs combined with a tight
board layout and an unbroken ground plane will yield very
good performance and low EMI emissions.
There are several types of ceramic capacitors available
each having considerably different characteristics. For
example, X7R ceramic capacitors have the best voltage and
temperature stability. X5R ceramic capacitors have appar-
ently higher packing density but poorer performance over
their rated voltage and temperature ranges. Y5V ceramic
capacitors have the highest packing density, but must be
used with caution, because of their extreme non-linear
characteristic of capacitance verse voltage. The actual
in-circuit capacitance of a ceramic capacitor should be
measured with a small AC signal as is expected in-circuit.
Many vendors specify the capacitance verse voltage with
a 1V RMS AC test signal and as a result overstate the ca-
pacitance 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.
BUS
OUT
. Additional capacitance will improve load transient
and V
BUS
OUT
. Tantalum and aluminum capacitors are not
BUS
Bypass Capacitors
LTC3586/LTC3586-1
OUT
directly controls the amount of input
voltage steps during transient load
OUT
. The output capacitor is used
BUS
to V
OUT
, its input

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