LTC3586EUFE
DEMO CIRCUIT 1306
QUICK START GUIDE
LTC3586EUFE
High Efficiency USB Power Manager + Dual Buck +
Boost + Buck-Boost DC/DC
DESCRIPTION
Demonstration Circuit 1306 is a High Efficiency USB
Power Manager plus Dual Buck plus Multi-Output
Power Supply featuring the LTC
®
3586.
The LTC3586
integrates a high efficiency USB Li-Ion battery
charger with PowerPath control and four general
purpose switching regulators, all in one chip. The
PowerPath manager includes a synchronous
switching low voltage input regulator, a full-featured
battery charger and an ideal diode. Designed
specifically for USB applications, the LTC3586’s low
voltage switching regulator automatically limits its
input current to a maximum of either 1x (for USB
100mA), 5x (for USB 500mA) or 10x for wall-
powered applications (1A). The switching input stage
provides power to VOUT where power sharing
between the application circuit and the battery
charger is managed.
Unlike linear PowerPath controllers, the LTC3586’s
switching input stage can use nearly all of the 0.5W
or 2.5W available from the USB port with minimal
power dissipation. This feature allows the LTC3586
to provide more power to the application and eases
thermal issues in constrained applications. An ideal
diode ensures that system power is available from
the battery when the input current limit is reached or
if the USB or wall supply is removed. The LTC3586
includes two 400mA buck regulators, one 1A buck-
boost regulator and one 800mA boost regulator for a
variety of handheld applications.
Design files for this circuit board are available. Call
the LTC factory.
L
, LTC, LTM, LT, Burst Mode, are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TABLE 1. Typical Specifications (25°C)
Input Voltage Range: V
CC
VOUT
LDO3V3
VOUT1
VOUT2
VOUT3
VOUT4
4.35V to 5.5V
3.4V to 4.7V, 1.5A (Max)
3.1V to 3.5V, 25mA (Max) Buck
1.16V to 1.26V, 400mA (Max) Buck
1.69V to 1.90V, 400mA (Max) Buck
3.13V to 3.51, 1.0A (Max) Buck-Boost
4.74V to 5.26V 800mA (Max) Boost
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LTC3586EUFE
OPERATING PRINCIPLES
The LTC3586 is a highly integrated power manage-
ment IC which includes a high efficiency switch
mode PowerPath controller, a battery charger, an
ideal diode, an always-on LDO, two 400mA buck
switching regulators, a 1A buck-boost switching
regulator, and an 800mA boost switching regulator.
All of the regulators can be independently controlled
via ENABLE pins.
Designed specifically for USB applications, the Po-
werPath controller incorporates a precision average
input current buck switching regulator to make max-
imum use of the allowable USB power. Because
power is conserved, the LTC3586 allows the load
current on V
OUT
to exceed the current drawn by the
USB port without exceeding the USB load specifica-
tions.
The PowerPath switching regulator and battery
charger communicate to ensure that the input cur-
rent never violates the USB specifications.
The ideal diode from BAT to V
OUT
guarantees that
ample power is always available to V
OUT
even if there
is insufficient or absent power at V
BUS
.
An “always on” LDO provides a regulated 3.3V from
available power at V
OUT
. Drawing very little quiescent
current, this LDO will be on at all times and can be
used to supply up to 20mA.
Along with constant frequency PWM mode, the buck
and the buck-boost switching regulators have a low
power burst mode setting for significantly reduced
quiescent current under light load conditions.
QUICK START PROCEDURE
Using short twisted pair leads for any power connec-
tions and with all loads and power supplies off, refer
to Figure 1 for the proper measurement and equip-
ment setup. The Battery should not be connected to
the circuit until told to do so in the procedure below.
When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscillo-
scope probe. Measure the input or output voltage ripple
by touching the probe tip directly across the VCC or
VOUT and GND terminals. See Figure 2 for proper scope
probe technique.
1. Jumper, PS and LOAD Settings to start:
JP1 (NTC) = INT
PS1 = OFF
JP2 (ILIM0) = 0
PS2 = NC
JP3 (ILIM1) = 0
LOAD1 = OFF
JP4 (MODE) = 0
LOAD2 = OFF
JP5 (EN1) = OFF
LOAD3 = OFF
JP6 (EN2) = OFF
LOAD4 = OFF
JP7 (EN3) = OFF
LOAD5 = OFF
JP8 (EN4) = OFF
LOAD6 = OFF
NC: Not Connected
2. Turn on PS1 and slowly increase voltage until
the voltage at VBUS is 4.35V while monitoring
input current. If input current exceeds 200mA
turn off PS1 and look for shorts.
3. Turn on LOAD1 and LOAD2. Set LOAD1 on
LDO3V3 to 5mA and LOAD2 on VOUT to
50mA in constant current mode.
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LTC3586EUFE
4. Verify the DC voltage levels on LDO3V3 as
~3.3V, VOUT as ~4.5V and BAT as ~4.3V.
5. Continue to increase PS1 until the voltage at
VBUS is 5.0V and verify the DC voltages on
LDO3V3 as ~3.3V, VOUT as ~4.5V and BAT as
~4.3V.
6. Set LOAD1 to 25mA and increase LOAD2
while monitoring the input current. Verify the
input limit current of ~100mA when VOUT
drops below 3.4V.
7. A. Repeat with JP3 (ILIM1) and JP2 (ILIM0) in
the 1 position . Verify the input limit current of
~500mA
B. Repeat with JP3 (ILIM1) in the 0 position
and JP2 (ILIM0) in the 1 position. Verify the
input limit current of ~900mA
8. Set LOAD1 to 1mA and LOAD2 to 0mA then
set JP3 (ILIM1) to the 1 position and JP2
(ILIM0) to the 0 position. Verify the DC
voltage levels on LDO3V3 as <0.5V, VOUT as
< 1.0Vand BAT as <VOUT.
9. Set JP3 (ILIM1) in the 0 position and JP2
(ILIM0) in the 1 position.
10. Set LOAD1 to 25mA and LOAD2 to 750mA
while monitoring the input current. Verify the
DC output voltage on LDO3V3 as 3.3V, VOUT
as 4.3V and BAT as VOUT- ~0.3V.
11. Adjust LOAD2 until Iin is 500mA. Verify the
DC voltage levels at NTC as ~2.5V, CLPROG
as ~0.7V and PROG of <10mV. Verify that the
FAULT and CHRG LEDs are off.
12. Adjust LOAD1 to 5mA and LOAD2 to 50mA.
Set jumper JP5 (EN1) to ON position and
adjust LOAD3 to 50mA. Verify the DC voltage
level on VOUT1 as ~1.2V .
13. Increase LOAD3 to 400mA and verify the DC
voltage level as 1.2V. Adjust LOAD3 to 50mA.
14. Set jumpers JP5 (EN1) to the OFF position,
JP6 (EN2) to the ON position and adjust
LOAD4 to 50mA. Verify the DC voltage on
VOUT2 of ~1.8V.
15. Increase LOAD4 to 400mA and verify the DC
voltage level on VOUT2 as ~1.8V. Adjust
LOAD4 to 50mA.
16. Set jumpers JP6 (EN2) to the OFF position,
JP7 (EN3) to the ON position and adjust
LOAD5 to 50mA. Verify the DC voltage level
VOUT3 as ~3.3V.
17. Increase LOAD5 to 750mA and verify the DC
voltage level on VOUT3 as ~3.3V. Adjust
LOAD5 to 50mA.
18. Set jumpers JP7 (EN3) to the OFF position,
JP8 (EN4) to the ON position and adjust
LOAD6 to 50mA. Verify the DC voltage level
on VOUT4 as ~5.0V.
19. Increase LOAD6 to 600mA and verify the input
current, the DC voltage level on VOUT4 as
~5.0V. Adjust LOAD6 to 50mA.
20. Set jumper JP8 (EN4) to the OFF
position.
21. Turn on PS2 and adjust until the voltage at
BAT is 3.6V. Verify the Iin from PS1 is ~
450mA and the charging current going into
PS2 is ~500mA. Verify that the CHRG LED is
ON. Verify the DC voltage on VOUT is ~ 3.9V
and VPROG is ~ 1.0V.
22. Adjust PS2 until the voltage at BAT is 4.3V.
Verify the Iin from PS1 is ~ 65mA and
charging current going into PS2 is < 10mA.
Verify that the CHRG LED is OFF. Verify the DC
voltage on VOUT is ~4.6V and VPROG is <
10mV.
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LTC3586EUFE
23. Set Jumpers
JP5 (EN1) = ON
JP6 (EN2) = ON
JP7 (EN3) = ON
JP8 (EN4) = ON
Verify LOAD1 is set to 5mA and LOAD2 – LOAD5
are set to 50mA. Verify that LDO3V3, VOUT,
VOUT1, VOUT2, VOUT3 and VOUT4 are enabled.
24. Using a jumper wire short the FAULT turret to
a GND turret. Verify that LDO3V3 and VOUT
are enabled and that VOUT1, VOUT2, VOUT3
and VOUT4 outputs are disabled. Remove the
short.
25. Turn PS1 and PS2 off, wait 15 seconds and
turn PS2 on and then turn PS1 on. Verify that
LDO3V3, VOUT, VOUT1, VOUT2, VOUT3 and
VOUT4 are enabled.
26. Verify PS2 is set at 4.3V. Adjust PS1 to 4.2V.
Verify DC voltage levels on LDO3V3, VOUT,
VOUT1, VOUT2, VOUT3 and VOUT4 are
enabled. Verify the current is sourced from
PS2. Set PS2 to 3.8V.
27. Set jumper JP1 (NTC) to EXT. Connect a 51K
resistor between the NTC turret and a GND
turret. The CHRG LED will blink slowly at a 1.5
Hz rate and verify that the charging current
going into PS2 is ~0mA.
28. Set jumper JP1 (NTC) to EXT. Connect a
330K resistor between the NTC turret and a
GND turret. The CHRG LED will blink slowly at
a 1.5 Hz rate and verify that the charging
current going into PS2 is ~0mA.
29. Set jumper JP1 to INT.
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LTC3586EUFE
Figure 1. Proper Measurement Equipment Setup
Figure 2. Measuring Input or Output Ripple
VIN
GND
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