TPS65820 Datasheet, PDF (43/94 Pages) Texas Instruments – SINGLE-CELL Li-ION BATTERY- AND POWER-MANAGEMENT IC

TPS65820
www.ti.com
SLVS663 – MAY 2006
FUNCTIONALITY GUIDE — SYSTEM POWER AND CHARGE MANAGEMENT
Fast Charge⁽¹⁾
Charge
Charge Current
Current Value
Scaling
I_O(BAT) ,
Programmable,
1.5A max
25%, 50%, 75%,
100% of I_O(BAT)
Set via external
resistor
Set via I2C
Precharge
Current
CHARGE MANAGEMENT
Termination
Current
Current Scaling
Charge
Voltage
10% of
I_O(BAT)
Fixed ratio
I(TERM), 10% of 25%, 50%, 75%,
I_O(BAT)
100% of I_(TERM)
value
Fixed ratio
Set via I2C
4.2 V or
4.36 V
Set via I2C
Precharge
Voltage
SafetyTimer
Timeout
Power Up
Default
3.0 V
Programmable Charger ON
Fixed
Set via external
resistor
(1) The input current limit (see system power management below ) regulates the input current , effectively limiting the charge current if the
input current limit is lower than the fast charge current value programmed.
INPUT CURRENT LIMIT
AC PIN
USB PIN
2.5 A typ
100 mA max or
500 mA max or
2.5 A typ
Internal fixed
current limit
Set via I2C
POWER PATH MANAGEMENT
INPUT CONNECTED TO OUT PIN
INPUT POWER TO SYSTEM
BATTERY TO SYSTEM
#1 – AC
#2 – USB
#3 – Battery (when AC pin power and USB pin power are
not detected )
Battery connected to
system, independently of
battery voltage
Automatic internal algorithm
Set via I2C, overrides
internal algorithm
POWER UP DEFAULT
Input Power to System,
USB mode selected,
100 mA max
AC _DC Adapter
Output
USB Power
C1 C2
10 mF 10 mF
TPS 65820
AC
AC SWITCH
USB
USB SWITCH
A1 A1
POWER PATH
CONTROL
LINEAR
CHARGER
System Power
Selection
Input Current Limit
Selection
Charge Voltage
Fast Charge
Current Scaling
Charge Suspend
I2C REGISTERS
OUT
OUT
BATTERY
SWITCH
BAT
BAT
TS
DPPM
TMR
ISET1
SYSTEM POWER BUS
C26
22 mF
A1
Battery
C24
0.22 mF
+
C25 _{50 kW}
10 mF NTC
R_SET
1 kW
A1
R_TMR
49.9 kW
R_DPPM
37.4 kW
C23
47 nF
-
GND
With the above components the following system
parameters are set :
Fast Charge Current = 1A (100% scaling, input limit=2. 5A)
Safety Timer = 5hours, 30 min pre-charge
DPPM threshold = 4. 3V
Temp hot: 65C
Temp Cold : 5C
Figure 30. Required External Components, Recommended Values, External Connections
POWER PATH AND CHARGE MANAGEMENT
Overview
The TPS65820 has an integrated charger with power path integrated MOSFETs. This topology, shown in the
simplified block diagram below, enables using an external input power to run the system and charge the battery
simultaneously. The power path has dual inputs that can be used to select either an external AC_DC adapter
(AC pin) or an USB port power (USB pin) to power the end equipment main power rail (OUT pin, also referred to
as the system power bus) and charge the battery pack (connected to BAT pin).
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