Texas Instruments TPS65820 Evaluation Module TPS65820EVM TPS65820EVM データシート
製品コード
TPS65820EVM
FUNCTIONALITY GUIDE — SYSTEM POWER AND CHARGE MANAGEMENT
AC
BAT
OUT
USB
TMR
ISET1
TS
BAT
OUT
DPPM
POWER PATH
CONTROL
LINEAR
CHARGER
Battery
GND
+
-
AC _DC Adapter
Output
USB Power
AC SWITCH
USB SWITCH
BATTERY
SWITCH
SYSTEM POWER BUS
TPS 65820
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
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
System Power
Selection
Input Current Limit
Selection
Charge Voltage
Fast Charge
Current Scaling
Charge Suspend
I2
C REGISTERS
R
37.4 k
DPPM
W
A1
C26
22 F
22 F
m
C25
10 F
10 F
m
50 k
NTC
W
R
49.9 k
TMR
W
C2
10 F
m
C23
47 nF
47 nF
A1
R
1 k
SET
W
A1
C24
0.22 F
0.22 F
m
A1
C1
10 F
m
POWER PATH AND CHARGE MANAGEMENT
Overview
SLVS663B – MAY 2006 – REVISED APRIL 2008
..............................................................................................................................................................
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CHARGE MANAGEMENT
Fast Charge
(1)
Precharge
Termination
Charge
Precharge
SafetyTimer
Power Up
Current
Voltage
Voltage
Timeout
Default
Charge
Charge Current
Current
Current Scaling
Current Value
Scaling
I
O(BAT)
,
25%, 50%, 75%,
10% of
I(TERM), 10% of
25%, 50%, 75%,
4.2 V or
3 V
Programmable
Charger ON
Programmable,
100% of I
O(BAT)
I
O(BAT)
I
O(BAT)
100% of I
(TERM)
4.36 V
1.5A max
value
Set via external
Fixed ratio
Fixed ratio
Fixed
Set via external
Set via I
2
C
Set via I
2
C
Set via I
2
C
resistor
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 is lower than the fast charge current value programmed.
POWER PATH MANAGEMENT
INPUT CURRENT LIMIT
INPUT CONNECTED TO OUT PIN
POWER UP DEFAULT
AC PIN
USB PIN
INPUT POWER TO SYSTEM
BATTERY TO SYSTEM
2.5 A typ
100 mA max or
#1 – AC
Battery connected to system,
Input power to system,
500 mA max or
#2 – USB
independently of battery
USB mode selected,
2.5 A typ
#3 – Battery (when AC pin power and USB pin power are
voltage
100 mA max
not detected )
Internal fixed
Automatic internal algorithm
Set via I
2
C
Set via I
2
C, overrides
current limit
internal algorithm
Figure 30. Required External Components, Recommended Values, External Connections
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).
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).
42
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