DEMO CIRCUIT 1463A
QUICK START GUIDE
LTC4160EPDC / LTC4160EPDC-1
Switching Power Manager with USB
On-the-Go and Overvoltage Protection
DESCRIPTION
Demonstration Circuit DC1463A is a Switching Power Manager with USB On-the-Go and Overvoltage Protection
featuring the LTC
®
4160.
PERFORMANCE SUMMARY
Specifications are at T
A
= 25°C
SYMBOL PARAMETER
VBUS
Bus Input Voltage Range
V(LDO3V3) 3.3V LDO Output
V(BAT)
I(BAT)
VOUT
V
OTG
Battery Float Voltage
Battery Charge Current
Output Voltage
VBUS voltage in OTG mode
CONDITIONS
VOUT > 3.5V
LTC4160 Constant Voltage Mode
LTC4160-1 Constant Voltage Mode
Constant Current Mode, R
PROG
= 2.00k
ILIM[1..0] = 01b, I(VOUT) ≤ 1.25A, V(BAT) > 3.6V
I(VOUT) ≤ 1.25A, V(BAT) < 3.6V
I(VBUS) ≤ -500mA
MIN
4.35
3.1
4.15
4.05
485
V(BAT)
3.6V
4.5
TYP
MAX
UNITS
6
V
3.4
V
4.23
V
4.13
515
mA
VBAT + 0.45V
V
V
5.5
V
5
QUICK START PROCEDURE
Refer to Figure 1 for the proper measurement
equipment setup and jumper settings and follow the
procedure below.
NOTE.
When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscilloscope
probe. Measure the input or output voltage ripple by touching the
probe tip directly across the VBUS or VOUT(x) and GND terminals.
See Figure 2 for proper scope probe technique.
1. Set all jumpers as shown in Figure 1 and LD1 =
0A, PS1 = 5V, LD2 = 0A, LD3 = 0A, PS2 = 3.6V.
Observe VOUT (VM4), LDO3V3 (VM3), and
V(NTC) (VM2). The LTC4160 is operating as
USB power manager. The current from PS1 will
try to be the charging current * (3.6V/5V), or ap-
proximately 400mA, but will be limited by the in-
put current limiter to ~ 100mA.
2. Increase LD3 to 80mA, and LD2 to 25mA. Ob-
serve VOUT(VM4), I(VUSB) (AM1) and LDO3V3
(VM3). Set LD2 to 0A. The loads on VOUT and
LDO3V3 are now reducing the charge current
further.
3. Increase LD3 to 250mA. Observe VOUT(VM4),
I(VUSB) (AM1). The load on VOUT will engage
the input current limit, and VOUT will drop until
the ideal diode engages to provide the difference
current.
1
LTC4160EPDC/LTC4160EPDC-1
4. Change JP1 & JP2 to ‘1’. Observe VOUT(VM4)
and I(VUSB) (AM1). The input current limit is
now 500mA, and the load on VOUT is 250mA, so
the battery charge current will be approximately
250mA.
5. Increase LD3 to 750mA. Observe VOUT(VM4)
and I(VUSB)(AM1). The load on VOUT again ex-
ceeds the input current limit and the VOUT volt-
age will drop until the ideal diode turns on and
supplies current from the battery.
6. Change JP1 to ‘0’. Observe VOUT(VM4) and
I(VUSB) (AM1). The input current limit is now
1A, and the battery is charging at 250mA. VOUT
is loaded at 750mA, so only the remaining cur-
rent is available to charge the battery.
7. Increase LD3 to 1.25A. Observe VOUT(VM4)
and I(VUSB) (AM1). Set LD3 to 0A. Observe
I(BAT) (AM4).The input current limit is activated
and VOUT will drop until the ideal diode turns on.
8. Increase PS2 until I(BAT) is less than 25mA.
Observe V(BAT) (VM5). Set PS2 to 3.6V.
9. Disconnect PS1. Change JP3 (ENOTG) to ‘ON’.
Observe VUSB (VM1) and V(CLPROG)(VM6).
Although PS1 is disconnected, the USB On-The-
Go mode is enabled, and the LTC4160 is provid-
ing VUSB from the battery.
10. Increase LD1 to 500mA. Observe VUSB(VM1)
and V(CLPROG)(VM6). In On-The-Go mode the
LTC4160 can provide 500mA of output current
on the USB.
11. Reset the Jumpers to their default position.
2
LTC4160EPDC/LTC4160EPDC-1
Figure 1. Proper Measurement Equipment Setup for DC1463A
Figure 2. Measuring Input or Output Ripple
VIN
GND
3
LTC4160EPDC/LTC4160EPDC-1
Figure 3. Circuit Schematic
4
LTC4160EPDC/LTC4160EPDC-1
Figure 4. Bill of Materials
5
PCB设计
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