Texas Instruments TPS65820 Evaluation Module TPS65820EVM TPS65820EVM データシート
製品コード
TPS65820EVM
System Voltage Regulation
Input Overvoltage Detection
Output Short-Circuit Detection
Battery Short-Circuit Detection
Boot-Up Algorithm
No-Battery Detection Circuit
BAT
OUT
V
- V
(OUT)
(NOBATID)
+
_
ANLG 1
Battery
I C
2
TPS65820
PACK ID
Resistor
Resistor
SLVS663B – MAY 2006 – REVISED APRIL 2008
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The system voltage is regulated to a fixed voltage when one of the input power supplies is connected to the
system. The system voltage regulation is implemented by a control loop that modulates the selected switch
Rds(on).
system. The system voltage regulation is implemented by a control loop that modulates the selected switch
Rds(on).
The typical system regulation voltage is 4.6 V.
The AC and USB input voltages are monitored by voltage comparators that identify an overvoltage condition. If
an overvoltage condition is detected a status register bit is set, indicating a potential fault condition.
an overvoltage condition is detected a status register bit is set, indicating a potential fault condition.
When an overvoltage condition is detected the AC or USB switches state is not modified. If any of those switches
was ON, it is kept in the ON state. During overvoltage conditions the system voltage is still regulated, and no
major safety issues are observed when not modifying the input switch state.
was ON, it is kept in the ON state. During overvoltage conditions the system voltage is still regulated, and no
major safety issues are observed when not modifying the input switch state.
If the input overvoltage condition results in excessive power dissipation, the thermal shutdown circuit is activated,
the AC and USB switches are turned OFF and the BAT switch is turned ON.
the AC and USB switches are turned OFF and the BAT switch is turned ON.
If the OUT pin voltage falls below an internal threshold V
INOUTSH
the AC and USB switches are turned off and
internal pullup resistors are connected from AC pin to OUT pin and USB pin to OUT pin. When the short circuit is
removed those resistors enable the OUT pin voltage to rise above the V
removed those resistors enable the OUT pin voltage to rise above the V
INOUTSH
threshold, returning the system to
normal operation.
If the OUT pin voltage falls below the BAT pin voltage by more than an internal threshold V
BATOUTSH
the battery
switch is turned off and internal pullup resistor is connected between the OUT pin and the BAT pin. This resistor
enables detection of the short removal, returning the system to normal operation.
enables detection of the short removal, returning the system to normal operation.
During the initial TPS65820 power-up the contents of the ISET2, CE and SUSPEND bits on the control register
are ignored for a time period t
are ignored for a time period t
BOOT
. During that time the charger is enabled, and the selected input current limit is
set internally to 100 mA max. At the end of t
BOOT
period the control register settings are implemented.
The ANLG1 pin may be used to detect the connection of an external resistor that is embedded in a battery pack
and is used as a pack ID function. The ANLG1 pin has an internal current source connected between OUT and
ANLG1, which is automatically enabled when the TPS65820 is not in SLEEP mode. The current levels for
ANLG1 pin can be programmed via I
and is used as a pack ID function. The ANLG1 pin has an internal current source connected between OUT and
ANLG1, which is automatically enabled when the TPS65820 is not in SLEEP mode. The current levels for
ANLG1 pin can be programmed via I
2
C register ADC_WAIT, bits BATID_n, as shown below:
Figure 33. Battery Removal Detection, ANLG1 Pin
46
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