Техническая Спецификация для Microchip Technology MCP7383XRD-PPM

 2005-2013 Microchip Technology Inc.

DS20001984F-page 13

The MCP73831/2 are highly advanced linear charge
management controllers. 

 depicts the

operational flow algorithm from charge initiation to
completion and automatic recharge.

An internal UVLO circuit monitors the input voltage and
keeps the charger in Shutdown mode until the input
supply rises above the UVLO threshold. The UVLO
circuitry has a built in hysteresis of 100 mV.
In the event a battery is present when the input power
is applied, the input supply must rise to a level 150 mV
above the battery voltage before the MCP73831/2
become operational. 

The UVLO circuit places the device in Shutdown mode
if the input supply falls to within +50 mV of the battery
voltage. Again, the input supply must rise to a level
150 mV above the battery voltage before the
MCP73831/2 become operational.
The UVLO circuit is always active. Whenever the input
supply is below the UVLO threshold or within +50 mV
of the voltage at the V

BAT

 pin, the MCP73831/2 are

placed in Shutdown mode.
During any UVLO condition, the battery reverse
discharge current is less than 2 µA.

A 6 µA (typical) current is sourced by the V

BAT

 pin to

determine if a battery is present or not. If the voltage at
V

BAT

 rises to V

REG

 + 100 mV (typical), the device

assumes that a battery is not present. If the voltage
stays below V

REG

 + 100 mV (typical), the device

assumes that a battery is detected. In order to correctly
detect a battery insertion, the impedance seen by the
V

BAT

 pin before the battery is connected must be

greater than 2 MΩ.

For a charge cycle to begin, all UVLO conditions must
be met and a battery or output load must be present. A
charge current programming resistor must be
connected from PROG to V

SS

. If the PROG pin is open

or floating, the MCP73831/2 are disabled and the
battery reverse discharge current is less than 2 µA. In
this manner, the PROG pin acts as a charge enable
and can be used as a manual shutdown.

If the voltage at the V

BAT

 pin is less than the

preconditioning threshold, the MCP73831/2 enter a
preconditioning or Trickle Charge mode. The
preconditioning threshold is factory set. Refer to

 for

preconditioning threshold options and the 

 for standard options.

In this mode, the MCP73831/2 supply a percentage of
the charge current (established with the value of the
resistor connected to the PROG pin) to the battery. The
percentage or ratio of the current is factory set. Refer to

 for

preconditioning current options and the 

 for standard options.

When the voltage at the V

BAT

 pin rises above the

preconditioning threshold, the MCP73831/2 enter the
Constant-Current or Fast Charge mode.

V

DD

 < V

UVLO

V

DD

 < V

BAT

or

PROG > 200 k

Ω 

STAT = Hi-Z

Charge Current = I

PREG

STAT = LOW

Charge Current = I

REG

STAT = LOW

Charge Voltage = V

REG

STAT = LOW

V

BAT

 < V

PTH

V

BAT

 > V

PTH

V

BAT

 = V

REG

V

BAT

 < V

RTH

V

BAT

 > V

PTH

I

BAT

 < I

TERM

No Charge Current

STAT = HIGH (MCP73831)

STAT = Hi-Z (MCP73832)