MAX1773A Maxim Integrated Products, MAX1773A Datasheet
MAX1773A
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MAX1773A Summary of contents
Page 1
... The MAX1773/MAX1773A are designed for use with a buck topology charger. They provide a simple and easily controlled solution to a difficult analog power control prob- lem ...
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Power Source Selector for Dual-Battery Systems ABSOLUTE MAXIMUM RATINGS GND ............................................-0.3V to +20V BATA BATB V to GND........................................-0. COMA V to GND........................................-0. COMB GND ...
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ELECTRICAL CHARACTERISTICS (continued 16.8V 3.3µF, V BATA BATB VDD BATSEL COMA COMB DISA PARAMETER TCOMP Input Leakage Current THM_ to TCOMP Trip Threshold THM_ to TCOMP ...
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Power Source Selector for Dual-Battery Systems ELECTRICAL CHARACTERISTICS (continued 16.8V 3.3µF, V BATA BATB VDD BATSEL COMA COMB DISA PARAMETER DIS_ Turn-On Clamp Voltage ...
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ELECTRICAL CHARACTERISTICS (continued 16.8V 3.3µF, V BATA BATB VDD BATSEL COMA COMB DISA PARAMETER THM_ Input Voltage Range THM_ Input Leakage Current TCOMP Input Voltage Range ...
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... Battery Switchover Delay Battery Action Delay Thermistor Action Delay AC to Battery Switchover Delay Battery to AC Switchover Delay CHG_ Turn-On Delay Note 2: TCOMP undervoltage lockout sets the MAX1773/MAX1773A’s internal status bits for the batteries to be designated as “absent” (V > THM_ TCOMP Note 3: V must remain above 2 ...
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A V ERROR vs. INPUT VOLTAGE DD 0. BAT_ = OPEN IN ACDET 0 -0.04 -0. 3.3V IN BAT ACDET -0. ...
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Power Source Selector for Dual-Battery Systems (T = +25°C, unless otherwise noted.) A TRANSITION FROM BATTERY A TO BATTERY B (TCOMP 4A 66µF) EXTLD EXTLD MAX1773-07 12V 11V V EXTLD THMA 10µs/div V ...
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PIN NAME 1 BATA Battery A Connection 2 THMA Thermistor A Input 3 CHGA Open-Drain Gate Driver for Charge Path MOSFET to Battery A 4 DISA Gate Driver for Discharge Path MOSFET to Battery A. Switches from V 5 COMA ...
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Power Source Selector for Dual-Battery Systems (V = COM_ turn-on clamp voltage, V COM_GS MAX1773-Fig-01 V BATA V COMA V DISA V COMB V DISB BATTERY ACTION DELAY BATTERY SWITCHOVER V < V THMA TCOMP DELAY V < V THMB ...
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COM_ turn-on clamp voltage, V COM_GS MAX1773-Fig-05 V ACDET V _ DIS AC TO BATTERY SWITCHOVER DELAY ✕ > BAT MINV V _ < V THM TCOMP Figure Battery Switchover Delay ...
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... Battery States mode requires an external supply with an output voltage between 2.2V and 4.5V for ACDET, as shown in Figure 10. The external power supply must be powered from EXTLD. The MAX1773/MAX1773A check for the presence adapter by sensing the voltage at ACDET. When V exceeds the batteries’ voltage and 4.75V, then ...
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... X No connections. , Absent: V > V THM_ TCOMP To prevent the MAX1773/MAX1773A from switching to a discharged battery, the Low-Battery Latch suspends the state table when the unconnected battery’s voltage is below 5 drops below 5 unconnected battery, the MAX1773/MAX1773A continue to power from the discharging battery. This latch is ...
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... R12 R14 P1 8kΩ 8kΩ SYSTEM LOAD When V ACDET MAX1773A use Startup States. See Table 3 for a detailed listing of the MAX1773/MAX1773A states in this mode. Note that once ACDET rises above 2.2V, the MAX1773/MAX1773A are no longer in the Startup V DD 28.7kΩ 0.33µF 3 ...
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... When both batteries are absent in the AC Adapter States mode and BATSEL changes states, BATSTAT is imme- diately updated. However, changes to the connection states are delayed (see Table 1 for connection states MAX1773 MAX1773A COMB COMA DISA DISB PDS CHGA CHGB ...
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... To accomplish this, the MAX1773/ MAX1773A do not connect the second battery to EXTLD until it senses that the first battery is disconnect- ed from EXTLD. See Notes 4 and 5 of Electrical Characteristics ...
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... Smaller resistances and less output capacitance reduce the transient duration. Figure 12 shows a typical discharge and charge cycle for a system utilizing the MAX1773/MAX1773A, two 3-cell lithium-ion (Li+) batteries, and a 20V AC adapter power supply. The diagram starts with the AC adapter applied, no batteries present, and battery A selected (see AC Adapter States). BATSTAT = BATSEL = 1 indi- cates that battery A is not present and battery A’ ...
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... Configuration, then BATSTAT would return BATSEL (0) to indicate that battery B is not present battery A is inserted and the MAX1773/ 1 MAX1773A connect battery A’s charge path. Note that BATSTAT changes to BATSEL (0) to indicate that bat- tery A is present battery B is inserted. BATSTAT does not change 2 and still indicates that battery A is present ...
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... When the adapter is removed, the MAX1773 PDS FET Switching does not switch to the nonselected battery, which is the issue. In the MAX1773A, when the AC adapter is removed in the scenario detailed, three separate conditions are possible charger is present but does not charge the selected battery. This can happen if the input cur- rent-limit feature in the charger has been activated, reducing the charger current to zero ...
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... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products ...