ds2710 Maxim Integrated Products, Inc., ds2710 Datasheet
ds2710
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ds2710 Summary of contents
Page 1
... Rev 0; 4/08 General Description The DS2710 is ideal for in-system charging of single-cell nickel metal hydride (NiMH) cells for low-current portable applications. Inputs to the DS2710 include USB voltage sources and 5V regulated adapters. Temperature, voltage, and charge time are monitored to provide proper fast-charging control algorithms for single-cell NiMH or nickel cadmium (NiCd) batteries ...
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Single-Cell NiMH Charger ABSOLUTE MAXIMUM RATINGS Voltage Range on All Pins Relative Continuous Source/Sink Current CS ...................................20mA Continuous Source Current STATUS ..................................10mA Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. ...
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DC ELECTRICAL CHARACTERISTICS (continued) (4.0V ≤ V ≤ 5.5V -20°C to +70°C, unless otherwise noted PARAMETER SYMBOL Cold Temperature Detect V THM-MIN Threshold Hot Temperature No-Start V THM-MAX Threshold Hot Temperature Safety V THM-STOP Shutdown Threshold ...
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... BIAS OSCILLATOR WATCHDOG UVLO ABORT STATE MACHINE PRESENSE TEST TEMPERATURE MEASUREMENT PRECHARGE FAST-CHARGE AND CELL TESTS TOP-OFF CHARGE MAINTENANCE CHARGE 0.125V SUSPEND Pin Description I PTST VP1 VOLTAGE AND VN1 THM VN0 DUTY- FACTOR V SS CONTROL CS DS2710 pin. DD ...
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... The watchdog-safety circuit and charge timer set by the TMR pin are derived from oscillators other than the main clock source. Figure 1 is the DS2710 block diagram and Figure 2 is the state diagram. POWER-ON RESET (POR) The UVLO circuit serves as a power-up and brownout ...
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Single-Cell NiMH Charger R > R TMR (ASYNCHRONOUSLY FROM ANYWHERE) V < UVLO UHYS (ASYNCHRONOUSLY FROM ANYWHERE) t < t PCHG AND V < 1.0V CELL V CELL T < +50°C t < FAST TIMEOUT t ...
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... CTEST pin. If the difference exceeds the thresh- old set by CTEST, the cell’s impedance is considered to be too high for charging and the DS2710 enters the FAULT state. The DS2710 also enters FAULT state if any voltage reading in CELL TEST exceeds the V threshold ...
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... VN1 and VN0 pins. VN1 and VN0 drive an internal comparator in the DS2710 to switch the CS output ON and OFF to drive a regulating pnp bipolar or a pMOS transistor. Hysteresis on the comparator input provides noise rejection. The ...
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... Single-Cell NiMH Charger the STATUS output and LED operation for each charge condition. The charge rate is determined by an external sense resistor connected between the VN1 and VN0 pins. The DS2710 regulates the charge current to maintain a volt- age drop of V resistor during FAST-CHARGE ...
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... Q1, L1, C2, and pro- and D2 form a switching buck-regulator circuit con- SS trolled by the CS pin of the DS2710. Current is regulat- ed through the current-sense resistor, R9, by switching Q1 on and off as the sense resistor voltage ramps up and down toward the preset sense voltage thresholds. ...
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... Proper Kelvin connection layout should IN be used to ensure the signal quality viewed by the sensing circuit inside the DS2710 is adequate. Figure 7 shows a recommended connection of the sense lines to the resistor footprint. For the latest package outline information and land patterns www.maxim-ic.com/packages. ...
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... CONTROL SENSE+ SENSE TRACES RUN CLOSE TOGETHER TO MINIMIZE LOOP INDUCTANCE CHARGE SOURCE registered trademark of Maxim Integrated Products, Inc. LOOP2 C BATTERY SIDE OUT BATTERY SIDE C O BACKSIDE GROUND PLANE SENSE- PROPER KELVIN CONNECTION AT SENSE RESISTOR R BATTERY- SNS ...