LTC4160EPDC-PBF View Datasheet(PDF) - Linear Technology

Part Name

Description

MFG CO.

LTC4160EPDC-PBF

Switching Power Manager with USB On-The-Go And Overvoltage Protection

Linear Technology 

LTC4160/LTC4160-1

OPERATION

the programmed limit, CLPROG reaches 1.18V and power

delivered by the switching regulator is held constant.

The input current limit is programmed by the ILIM0 and

ILIM1 pins. The input current limit has four possible set-

tings ranging from the USB suspend limit of 500μA up

to 1A for wall adapter applications. Two of these settings

are specifically intended for use in the 100mA and 500mA

USB application. Refer to Table 1 for current limit settings

using ILIM0 and ILIM1.

Table 1. USB Current Limit Settings Using ILIM0 and ILIM1

ILIM1

ILIM0 USB SETTING

0

0

1x Mode (USB 100mA Limit)

0

1

10x Mode (Wall 1A Limit)

1

0

Low Power Suspend (USB 500μA Limit)

1

1

5x Mode (USB 500mA Limit)

When the switching regulator is activated, the average

input current will be limited by the CLPROG programming

resistor according to the following expression:

( ) IVBUS

=

IVBUSQ

+

VCLPROG

RCLPROG

•

hCLPROG + 1

where IVBUSQ is the quiescent current of the LTC4160/

LTC4160-1, VCLPROG is the CLPROG servo voltage in

current limit, RCLPROG is the value of the programming

resistor and hCLPROG is the ratio of the measured cur-

rent at VBUS to the sample current delivered to CLPROG.

Refer to the Electrical Characteristics table for values of

hCLPROG, VCLPROG and IVBUSQ. Given worst-case circuit

tolerances, the USB specification for the average input

current in 100mA or 500mA mode will not be violated,

provided that RCLPROG is 3.01k or greater.

While not in current limit, the switching regulator’s

Bat-Track feature will set VOUT to approximately 300mV

above the voltage at BAT. However, if the voltage at BAT

is below 3.3V, and the load requirement does not cause

the switching regulator to exceed its current limit, VOUT

will regulate at a fixed 3.6V, as shown in Figure 2. This

instant-on operation will allow a portable product to run

immediately when power is applied without waiting for the

battery to charge. If the load does exceed the current limit

at VBUS, VOUT will range between the no-load voltage and

slightly below the battery voltage, indicated by the shaded

region of Figure 2.

TO USB

OR WALL

ADAPTER

14

13

VBUS

ISWITCH/N

VBUS

VOLTAGE

CONTROLLER

–

+

5V

PWM AND

GATE DRIVE

CLPROG

17

1.18V

AVERAGE VBUS INPUT

– CURRENT LIMIT

CONTROLLER

+

1

OVGATE

2

OVSENS

+–

s2

6V

OVERVOLTAGE PROTECTION

0.3V

+–

3.6V

VOUT VOLTAGE

CONTROLLER

BATTERY CHARGER

1V

VFLOAT

IBAT/1000

14

SW

VOUT

12

IDEAL

DIODE

+

OmV

–

15mV +–

10

IDGATE

11

BAT

8

PROG

USB INPUT

BATTERY POWER

Figure 1. Power Path Block Diagram – Power Available from USB/Wall Adapter

3.5V TO

(BAT + 0.3V)

TO SYSTEM LOAD

+ SINGLE CELL

Li-Ion

41601 F01

41601f

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