BQ24735_17 Datasheet, PDF (23/46 Pages) Texas Instruments – 1- to 4-Cell Li+ Battery SMBus Charge Controller for Supporting Turbo Boost Mode With N-Channel Power MOSFET Selector

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bq24735
SLUSAK9B – SEPTEMBER 2011 – REVISED APRIL 2015
Bit
[14:13]
[12:11]
[10]
[9]
[8]
[7]
[6]
[5]
[4]
[3]
[2]
[1]
Table 3. Charge Options Field Descriptions (continued)
Field
WATCHDOG Timer Adjust
Type
BAT Depletion Comparator
Threshold Adjust
EMI Switching Frequency Adjust
EMI Switching Frequency Enable
IFAULT_HI Comparator Threshold
Adjust
IFAULT_LOW Comparator
Threshold Adjust
LEARN Enable
IOUT Selection
AC Adapter Indication (Read Only)
BOOST Enable
Boost Mode Indication (Read Only)
ACOC Threshold Adjust
Reset Description
R/W Set maximum delay between consecutive SMBus Write charge
voltage or charge current command. The charge will be suspended if
IC does not receive write charge voltage or write charge current
command within the watchdog time period and watchdog timer is
enabled.
The charge will be resumed after receive write charge voltage or
write charge current command when watchdog timer expires and
charge suspends. During boost function, the timer is fixed to 175 s if
it is enabled.
00: Disable Watchdog Timer
01: Enabled, 44 sec
10: Enabled, 88 sec
11: Enable Watchdog Timer (175 s) <default at POR>
R/W This is used for LEARN function and boost mode function battery
over discharge protection. During LEARN cycle, when the IC detects
battery voltage is below depletion voltage threshold, the IC turns off
BATFET and turned on ACFET to power the system from AC
adapter instead of the battery. During boost mode function, when the
IC detects battery voltage is below depletion voltage threshold, IC
stops boost function. The rising edge hysteresis is 340 mV. Set
ChargeVoltage() register value to 0 V will disable this function.
00: Falling Threshold = 59.19% of voltage regulation limit
(approximately 2.486 V/cell)
01: Falling Threshold = 62.65% of voltage regulation limit
(approximately 2.631 V/cell)
10: Falling Threshold = 66.55% of voltage regulation limit
(approximately 2.795 V/cell)
11: Falling Threshold = 70.97% of voltage regulation limit
(approximately 2.981 V/cell) < default at POR>
R/W 0: Reduce PWM switching frequency by 18% <default at POR>
1: Increase PWM switching frequency by 18%
R/W 0: Disable adjust PWM switching frequency <default at POR>
1: Enable adjust PWM switching frequency
R/W Short circuit protection high-side MOSFET voltage drop comparator
threshold.
0: function is disabled
1: 750 mV <default at POR>
R/W Short circuit protection low-side MOSFET voltage drop comparator
threshold. This is also used for cycle-by-cycle current limit protection
threshold during boost function.
0: 135 mV <default at POR>
1: 230 mV
R/W Set this bit 1 start battery learn cycle. IC turns off ACFET and turns
on BATFET to discharge battery capacity. When battery voltage
reaches threshold defined in bit [12;11], the BATFET is turned off
and ACFET is turned on to finish battery learn cycle. After finished
learn cycle, this bit is automatically reset to 0. Set this bit 0 will stop
battery learn cycle. IC turns off BATFET and turns on ACFET.
0: Disable LEARN Cycle <default at POR>
1: Enable LEARN Cycle
R/W 0: IOUT is the 20x adapter current amplifier output <default at
POR>
1: IOUT is the 20x charge current amplifier output
R/W 0: AC adapter is not present (ACDET < 2.4 V) <default at POR>
1: AC adapter is present (ACDET > 2.4 V)
R/W 0: Disable Turbo Boost function <default at POR>
1: Enable Turbo Boost function
R/W 0: Charger is not in boost mode <default at POR>
1: Charger is in boost mode
R/W 0: function is disabled
1: 3.33x of input current regulation limit <default at POR>
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