LTC2941 Linear Technology, LTC2941 Datasheet
LTC2941
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LTC2941 Summary of contents
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... SMBus alert protocol or by setting a fl the internal status register. The LTC2941 requires only a single low value external sense resistor to set the current range. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation ...
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... SCL, SDA, AL/CC ......................................... –0. – SENSE .................................. –0. Operating Ambient Temperature Range LTC2941C ................................................ 0°C to 70°C LTC2941I.............................................. –40°C to 85°C Storage Temperature Range ..................... –65°C to 150° ORDER INFORMATION Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL ...
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... C and the setting of the B Note 7: Guaranteed by design, not subject to test SU, STA HD, DATO HD, STA HD, DATI REPEATED START CONDITION 2 Figure 1. Defi nition of Timing on I www.DataSheet4U.com LTC2941 MIN TYP MAX l 0.3 • 0.7 • SENSE + SENSE + l 0 ...
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... LTC2941 TYPICAL PERFORMANCE CHARACTERISTICS Total Charge Error vs Differential Sense Voltage –1 – 2.7V SENSE + V = 4.2V SENSE + –3 0 (mV) SENSE 2941 G01 Supply Current vs Supply Voltage 100 2.5 3.0 3.5 4.0 4 SENSE 4 Total Charge Error vs Supply Voltage 1.00 0.75 0.50 0.25 0 –0.25 –0.50 –0.75 V SENSE V SENSE – ...
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... A high level at CC sets the value of the accumulated charge (registers FFFFh. – SENSE (Pin 6): Negative Current Sense Input. Connect – SENSE to the positive battery terminal side of the sense resistor. The voltage between SENSE remain within ±50mV in normal operation. www.DataSheet4U.com LTC2941 – + and SENSE must 2941f 5 ...
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... LTC2941 BLOCK DIAGRAM V SUPPLY + SENSE 1 – SENSE 6 GND 2 6 ACCUMULATED BIDIRECTIONAL PRESCALER INTEGRATOR M REF CLK INTERNAL INTERNAL REFERENCE OSCILLATOR GENERATOR Figure 2. Block Diagram of the LTC2941 www.DataSheet4U.com CC CHARGE AL AL/CC REGISTER 5 2 SCL SMBus SDA STATUS/ 4 CONTROL REGISTER 2941 F02 2941f ...
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... OPERATION Overview The LTC2941 is a battery gas gauge device designed for use with single Li-Ion cells and other battery types with a terminal voltage between 2.7V and 5.5V. A precision coulomb counter integrates current through a sense resistor between the battery’s positive terminal and the load or charger ...
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... I C and SMBus. The 7-bit 2 hard-coded I C address of LTC2941 is 1100100. The LTC2941 is a slave-only device. Therefore the serial clock line (SCL) is input only while the data line (SDA) is bidirectional. For more details refer to the I section. Internal Registers ...
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... SUPPLY Power Down B[0] Programming the last bit B[0] of the control register to 1 sets the analog parts of the LTC2941 in power down and the current consumption drops typically below 1μA. All analog circuits are disabled while the values in the registers are retained. Note that any charge fl owing while B[ not measured and the charge information below 1 LSB of the accumulated charge register is lost ...
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... The battery capacity then corresponds to only 1176 q and less than 2% of the accumulated charge register is is not sufficient in utilized. To preserve digital resolution in this case, the LTC2941 includes a programmable prescaler. Lowering the prescaler factor M allows reducing q lated charge registers C and D to the capacity of the battery. ...
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... The coulomb counter of the LTC2941 integrates current through the sense resistor. The 16-bit result of this charge integration is stored in the accumulated charge registers C and D. As the LTC2941 does not know the actual battery status after initial power-up, the accumulated charge is set to mid-scale (7FFFh). If the host knows the status of ...
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... Read Protocol The master begins a read operation with a START condition followed by the seven bit slave address 1100100 and the R/W bit set to zero, as shown in Figure 7. The LTC2941 acknowledges and then the master sends a command byte which indicates which internal register the master is to read ...
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... The master initiates the ARA procedure with a START con- dition and the special 7-bit ARA bus address (0001100) followed by the read bit ( the LTC2941 is asserting the AL/CC pin in alert mode, it acknowledges and responds by sending its 7-bit bus address (1100100) and a 1. While ...
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... PC Board Layout Recommendations Keep all traces as short as possible to minimize noise and inaccuracy. Use a 4-wire Kelvin sense connection for the sense resistor, locating the LTC2941 close to the resis- tor with short sense traces to SENSE wider traces from the resistor to the battery, load and/or charger (see Figure 10) ...
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... DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE www.DataSheet4U.com LTC2941 0.40 0.10 TYP 4 6 PIN 1 NOTCH R0 ...
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... GND COMMENTS Pin Compatible with LTC2942-1 14-Bit ∑Δ-ADC, Pin Compatible with LTC2941 14-Bit ∑Δ-ADC, Pin Compatible with LTC2941-1 2.7V to 8.5V Operation, 10-Pin MSOP Package Simple ThinSOT Charger, No Blocking Diode, No Sense Resistor Needed Standalone, 4.7V ≤ Blocking Diode or External Power FET Required, ≤1.5A Charge Current Standalone Charger with Programmable Timer ...