MP2661 datasheet(19/35 Pages) MPS

19 / 35 page

MP2661 – 0.5A, 1-CELL CHARGER W/ I2C CONTROL AND POWER PATH

MP2661 Rev. 1.03

www.MonolithicPower.com

4/9/2018

MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.

The following actions restart the safety timer:

 A new charge cycle is kicked in

 Reg01 bit [3] is written from 0 to 1 (charge

enable)

 Reg05 bit [3] is written from 0 to 1 (safety

timer enable)

 Reg01 bit [7] is written from 0 to 1 (software

reset)

Host Mode and Default Mode

The IC is a host-controlled device. After the

power-on reset, the IC starts in the watchdog

timer expiration state or default mode. All

registers are in the default settings.

Any write to the IC changes it to host mode. All

charge parameters are programmable. If the

watchdog timer (Reg05 bit [5:4]) is not disabled,

the host must reset the watchdog timer

regularly by writing 1 to the Reg01 bit [6] before

the watchdog timer expires to keep the device

in host mode. Once the watchdog timer expires,

the IC returns to default mode. The watchdog

timer limit can also be programmed or disabled

by the host control. When there is no VIN, the

watchdog timer is suspended. (Figure 9)

The operation can also be changed to default

mode when one of the following conditions

occur:

 Refresh input without battery

 Re-insert battery with no VIN

 Register reset Reg01 bit [7] is reset

Battery Discharge Function

If battery is connected and the input source is

missing, the battery MOSFET is fully on when

VBATT is above the VUV_BATT threshold. The

100mΩ battery MOSFET minimizes conduction

loss during discharge. The quiescent current of

the IC is as low as 11μA in this mode. The low

on resistance and low quiescent current help

extend the running time of the battery.

Over-Discharge Current Protection

The IC has an over-discharge current protection

in discharge mode and supplement mode.

Once

IBATT

exceeds

the

programmable

discharge current limit (default 1.785A), the

battery MOSFET is turned off after a 60µs delay,

and the MP2661enters hiccup mode in over-

current protection. The discharge current can

be programmed high to 3.2A through the

I2C.Ifthe discharge current goes high to reach

the internal fixed current limit (about 3.7A), the

battery MOSFET is turned off and starts hiccup

mode immediately.

Similarly, when the battery voltage falls below

the programmable VUV_BATT threshold (default

2.8V), the battery MOSFET is turned off to

prevent over-discharge.

System Short-Circuit Protection (SCP)

The MP2661 features SYS node short-circuit

protection (SCP) for the IN to SYS path and the

BATT to SYS path.

The system voltage is continuously monitored.

If VSYS is lower than 1.5V, the system (SCP) for

the IN to SYS path and the BATT to SYS path

are active. IBATTOC is decreased to half of the

original value.

1) IN to SYS path: Once IIN is over the

protection

threshold, both

the

LDO

MOSFET and the BATT MOSFET are

turned off immediately, and the IC enters

hiccup mode. Otherwise, the max current

limit and the setting input current limit are

not reached, and IIN is regulated at IINLMT.

Hiccup mode also starts after a 60µs delay.

The interval of the hiccup mode is 800µs.

2) BATT to SYS path: Once IBATT is over the

3.7A protection threshold, both the LDO

MOSFET and the BATT MOSFET are

turned off immediately, and the IC enters

hiccup mode. When the battery discharge

current limit threshold is reached, hiccup

mode starts after a 60µs delay. The interval

of the hiccup mode is 800µs.

If a system short-circuit occurs when both the

input and battery are present, the protection

mechanism of both paths work, with the faster

one dominating the hiccup operation. (Figure 12)

Interrupt to Host (INT)

The IC has an alert mechanism which can

output an interrupt signal via INT to notify the

system of the operation by outputting a 256μs

low-state INT pulse. All of the below events can

trigger the INT output:

MP2661 Datasheet(PDF) 19 Page - Monolithic Power Systems

MP2661 Datasheet(HTML) 19 Page - Monolithic Power Systems

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Datasheet Download

Link URL