MCP73830_V01 datasheet(11/24 Pages) MICROCHIP

11 / 24 page

 2011-2019 Microchip Technology Inc.

DS20005049E-page 11

MCP73830/L

5.4

Constant-Current Mode – Fast

Charge

During Constant-Current mode, the programmed

charge current is supplied to the battery or load.

The charge current is established using a single resistor

from PROG to VSS. The program resistor and the charge

current are calculated using the following equation:

EQUATION 5-1:

MCP73830L

EQUATION 5-2:

MCP73830

Constant-Current mode is maintained until the voltage

at the VBAT pin reaches the regulation voltage, VREG.

When Constant-Current mode is invoked, the internal

timer is reset.

5.4.1

TIMER EXPIRED DURING

CONSTANT-CURRENT/FAST

CHARGE MODE

If the internal 4-hour timer expires before the recharge

voltage threshold is reached, a timer Fault is indicated

and the charge cycle terminates. The MCP73830/L

devices remain in this condition until the battery is

reinserted, or the input power or CE is cycled.

5.5

Constant Voltage Mode

When voltage at the VBAT pin reaches the regulation

voltage, VREG, the constant voltage regulation begins.

The regulation voltage is factory set to 4.2V with a

tolerance of ±0.75%.

5.6

Charge Termination

The charge cycle is terminated when, during Constant

Voltage mode, the average charge current diminishes

below a threshold established with the value of 7.5%,

10% of fast charge current or the internal timer has

expired. A 1 ms filter time on the termination com-

parator ensures that transient load conditions do not

result in premature charge cycle termination. The timer

period is factory set. Refer to Section 1.0 “Electrical

Characteristics” for the timer period value.

5.7

Automatic Recharge

MCP73830/L devices with automatic recharge options

continuously monitor the voltage at the VBAT pin during

the Charge Complete mode. If the voltage drops below

the recharge threshold, another charge cycle begins

and current is once again supplied to the battery or

load. The recharge threshold is factory set. Refer to

Section 1.0 “Electrical Characteristics” for recharge

threshold options.

For the MCP73830/L with no recharge option, the

devices will go into Standby mode when a termination

condition is met. The charge will not restart until the

battery voltage is below the automatic recharge

threshold and one of the following conditions is met:

• Battery is removed from the system and inserted

again.

•VDD is removed and plugged in again.

•CE is cycled.

The automatic recharge voltage threshold is always

active, regardless of whether the automatic recharge

option is selected or not.

5.8

Thermal Regulation

The MCP73830/L should limit the charge currents

based on the die temperature. The thermal regulation

optimizes the charge cycle time while maintaining

device reliability. Figure 5-1 depicts the thermal reg-

ulation for the MCP73830/L devices. Refer to

Section 1.0 “Electrical Characteristics” for thermal

package resistances and Section 6.1.1.3 “Thermal

Considerations” for calculating power dissipation.

FIGURE 5-1:

Thermal Regulation.

IREG

200

RPROG

--------------------

Where:

RPROG =kilohms (k)

IREG = milliampere (mA)

IREG

1000

RPROG

--------------------

Where:

RPROG = kilohms (k)

IREG = milliampere (mA)

Note:

The MCP73830/L also offer options with

no automatic recharge.

MCP73830 bảng dữ liệu(PDF) 11 Page - Microchip Technology

MCP73830 bảng dữ liệu(HTML) 11 Page - Microchip Technology

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

bảng dữ liệu tải về

Link URL