LT1513-2 Linear Technology, LT1513-2 Datasheet
LT1513-2
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LT1513-2 Summary of contents
Page 1
... Charges Any Number of Cells Up to 20V 1% Voltage Accuracy for Rechargeable Lithium Batteries 100mV Current Sense Voltage for High Efficiency (LT1513) 0mV Current Sense Voltage for Easy Current Programming (LT1513-2) Battery Can Be Directly Grounded 500kHz Switching Frequency Minimizes Inductor Size Charging Current Easily Programmable or Shut Down U ...
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... FB Reference Voltage Line Regulation V I Reference Voltage (LT1513) IREF FB I Input Current FB I Reference Voltage Line Regulation Voltage Offset (LT1513-2) (Note 3) FBVOS FB I Input Current FB V Source Current FB g Error Amplifier Transconductance m Error Amplifier Source Current Error Amplifier Sink Current ...
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... Duty Cycle = 80% (Note 1) 2.7V V 25V IN 2.7V V 25V, V 0.6V S/S T < 2.7V V 25V S/S Note 2: The I FB Note 3: Consult factory for grade selected parts. Note 4: The I FB LT1513/LT1513-2 MIN TYP MAX 1.70 1.95 2.30 0.25 0.40 0.52 500 0.8 1 1.25 450 500 550 430 500 580 400 580 85 95 ...
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... LT1513/LT1513 TYPICAL PERFORMANCE CHARACTERISTICS Switch Saturation Voltage vs Switch Current 1.0 150 C 0.9 100 0.8 0.7 0.6 0.5 –55 C 0.4 0.3 0.2 0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 SWITCH CURRENT (A) LT1513 • G01 Negative Feedback Input Current vs Temperature 0 –10 –20 –30 –40 –50 –50 – TEMPERATURE ( C) Minimum Peak-to-Peak Synchronization Voltage vs Temperature 3 ...
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... Figure 1) should be less than 50 . The 39 , 0.22 F filter shown in Figure 1 is used to convert the pulsating current in the sense resistor to a smooth DC current feedback signal. The LT1513-2 I pin regulates at 0mV to provide FB programmable current limit. The current through R5, Figure 5, is balanced by the current through R4, program- ming the maximum voltage across R3 ...
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... The current amplifier is set to a fixed gain of – 12.5 which provides a – 100mV current limit sense voltage. The LT1513-2 option removes the feedback resistors around the I signal. This provides a ground referenced current sense voltage suitable for external current programming and makes amplifier input and output available for external loop compensation ...
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... A typical value which gives about 0.5A peak-to-peak induc- = 8.2V), the error due tor current. Lower values will give higher ripple current, which reduces maximum charging current can be used if charging currents are at least 20% lower than the values LT1513/LT1513 L1A D2 V ...
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... LT1513/LT1513 APPLICATIONS INFORMATION shown in the maximum charging current graph. Higher inductance values give slightly higher maximum charging current, but are larger and more expensive. A low loss toroid ® core such as Kool M , Molypermalloy or Metglas recommended. Series resistance should be less than 0.04 for each winding. “Open core” inductors, such as rods or ...
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... P D(TOTAL) For V = 10V 4mA + 24mA = 28mA 0.64W (10)(0.028) + 0.64 = 0.92W D GROUND PLANE + C1 LT1513 TAB AND GROUND PIN SOLDERED TO GROUND PLANE 2 WINDING L1A INDUCTOR + LT1513/LT1513 024 ) BAT CHRG CHRG SW BAT IN BAT 2 ( ...
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... LT1513/LT1513 APPLICATIONS INFORMATION Programmed Charging Current LT1513-2 charging current can be programmed with a DC voltage source or equivalent PWM signal, as shown in Figure 5. In constant-current mode, I ground. The I voltage across R5 is balanced by the SET voltage across R4 in the ratio R4/R5. Charging current is given by: ...
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... AND AN INTERNAL OUTPUT SHUNT RESISTANCE OF 330k. AS SHOWN, THIS LOOP HAS A UNITY-GAIN FREQUENCY OF ABOUT 27kHz NOT USED IN ALL APPLICATIONS, BUT IT GIVES BETTER PHASE MARGIN IN CONSTANT VOLTAGE MODE. Figure 7. Constant-Current Small-Signal Model LT1513/LT1513-2 pin may create an un- C amplifier (gain of –12.5) has a FBA I ...
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... LT1513/LT1513 APPLICATIONS INFORMATION The suggested way to control unity loop frequency is to increase the filter time constant on the I Figures 1 and 7). The filter resistor cannot be arbitrarily increased because high values will affect charging current accuracy. Charging current will increase by 1% for each 40 increase in R4 ...
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... Figure 8 uses the LT1513-2 to provide switchable 1.35A and 0.13A constant-current modes. The circuit is based on a standard SEPIC battery charger circuit set to a single lithium-ion cell charge voltage of 4.1V. The LT1513-2 has I referenced to ground allowing a simple resistor network to set the charging current values. In constant-current mode, ...
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... Therefore, the LT1513 is connected to generate a negative current through L2 that allows the Royer to operate were connected to a constant higher voltage input 20V L1 ELECT S/S LT1513 GND 15V R4 20k C10 C9 10nF 4.7nF ...
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... LT1513/LT1513-2 0.165 – 0.180 0.045 – 0.055 (4.191 – 4.572) (1.143 – 1.397) 15 TYP +0.008 0.004 –0.004 ...
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... LT1513/LT1513-2 RELATED PARTS PART NUMBER DESCRIPTION LT1239 Backup Battery Management System ® LTC 1325 Microprocessor Controlled Battery Management System LT1510 1.5A Constant-Current/Constant-Voltage Battery Charger LT1511 3.0A Constant-Current/Constant-Voltage Battery Charger with Input Current Limiting LT1512 SEPIC Constant-Current/Constant-Voltage Battery Charger Step-Up/Step-Down Charger for Current ...