LTC4055 Linear Technology, LTC4055 Datasheet
LTC4055
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LTC4055 Summary of contents
Page 1
... When the battery drops 100mV below the float voltage, automatic recharging of the battery occurs. Also featured is an NTC thermistor input used to monitor battery temperature while charging. The LTC4055 is available in a 16-pin low profile (4mm 4mm) QFN package. TO LDOs, OUT REGs, ETC ...
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... Rising – V Falling – Rising IN OUT IN (V – Falling IN OUT INFORMATION ORDER PART TOP VIEW NUMBER LTC4055EUF 12 TIMER 11 PROG 17 10 GND 9 CLPROG UF PART MARKING 4055 UF PACKAGE = 125 C 3.5V, HPWR = 5V, WALL = 0V, MIN TYP MAX 4 ...
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... SUSP, SHDN, HPWR Pin High to Low SUSP, SHDN, HPWR TIMER Falling TIMER V Rising Threshold WALL V Rising – V Falling Threshold WALL WALL WALL LTC4055 = 3.5V, HPWR = 5V, WALL = 0V, MIN TYP MAX 4.165 4.200 4.235 4.158 4.200 4.242 445 485 525 55 80 105 ...
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... Hysteresis Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 6: The LTC4055EUF is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls. ...
Page 5
... TEMPERATURE ( C) Battery Regulated Output (Float) Voltage vs Supply Voltage 4.220 4.215 4.210 4.205 4.200 4.195 4.190 4.185 4.180 100 4.5 4.75 5 5.25 5.5 5.75 V (V) IN LTC4055 R vs Temperature ON 250 I = 400mA LOAD 225 200 V = 4.5V IN 175 V = 5.5V IN 150 125 100 –50 – ...
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... LTC4055 W U TYPICAL PERFOR A CE CHARACTERISTICS Charging from USB BAT BAT 600 LOAD OUT 500 R = 100k PROG R = 100k CLPROG HPWR = 1 400 300 200 100 0 0 0.5 1 1.5 2.5 3 (V) BAT 4055 G13 Charge Current vs Temperature (Thermal Regulation) 1 50k PROG ...
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... WALL Connect Waveforms WALL 5V/DIV I IN 0.5A/DIV I WALL 0.5A/DIV I BAT 0.5A/DIV 1ms/DIV V = 3.5V BAT 4055 G26 I = 100mA OUT R = 57.6k PROG LTC4055 WALL Connect Waveforms WALL 5V/DIV OUT 5V/DIV I WALL 0.5A/DIV I BAT 0.5A/DIV V = 3.5V 1ms/DIV BAT 4055 G24 I = 100mA OUT R = 57.6k PROG WALL Disconnect Waveforms ...
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... LTC4055 CTIO S BAT (Pin 2): Connect to a single cell Li-Ion battery. Used as an output when charging the battery and as an input when supplying power to OUT. When the OUT pin potential drops below the BAT pin potential, an ideal diode function connects BAT to OUT and prevents V more than 100mV below V ...
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... There is approximately temperature hysteresis associated with each of the input comparators. If the NTC function is not to be used, connect the NTC to ground. This will disable all of the LTC4055 NTC functions. Exposed Pad (Pin 17): Ground. The Exposed Pad must be soldered to a good thermally conductive PCB ground. ...
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... LTC4055 W BLOCK DIAGRA DIE TEMP 105 C – – CLPROG CURRENT CONTROL 9 100k + 1V – PROG 11 100k 500mA/100mA HPWR 8 2u ACPR 13 WALL + 5 – NTC 15 100k – 2COLD NTC + 16 NTC 100k – 2HOT + + NTC ENABLE – 0. BUS 4 IN1 0.2 IN1 OUT V REF ...
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... Wall adapter power can be connected to the output (load side) of the LTC4055 through an external device such as a power Schottky or FET, as shown in Figure 1. The LTC4055 has the unique ability to use the output, which is powered by the wall adapter alternate path to charge the battery while providing power to the load ...
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... LTC4055 U OPERATIO Table 1. Operating Modes—PowerPath States Current Limited Input Power (IN1/IN2 to OUT) WALL PRESENT SHUTDOWN SUSPEND Input Powered Charger (IN1/IN2 to BAT) WALL PRESENT SHUTDOWN SUSPEND ...
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... U OPERATIO LTC4055 4055p 13 ...
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... LTC4055 U OPERATIO USB CURRENT LIMIT AND CHARGE CURRENT CONTROL The current limit and charger control circuits of the LTC4055 are designed to limit input current as well as control battery charge current as a function of I grammed current limit defined as 000 , 50 000 I • ...
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... No blocking diode or sense resistor is required when charging through IN1/IN2. The CHRG open-drain status output provides information regarding the charging status of the LTC4055 at all times. An NTC input provides the option of charge qualification using battery temperature. An internal thermal limit reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 105 C ...
Page 16
... This change in charge time is inversely propor- tional to the change in charge current. As the LTC4055 approaches constant-voltage mode the charge current begins to drop. This change in charge current is part of the normal charging operation of the part and should not affect the timer duration ...
Page 17
... THERMISTORS The LTC4055 NTC trip points were designed to work with thermistors whose resistance-temperature characteristics follow Vishay Dale’s “R-T Curve 2.” The Vishay NTHS0603N02N1002J is an example of such a thermistor. However, Vishay Dale has many thermistor products that follow the “R-T Curve 2” characteristic in a variety of sizes. ...
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... All power paths are – . put in a Hi-Z state. – . SUSPEND The LTC4055 can be put in suspend mode by forcing the – . – 3602 SUSP pin greater than 1V. In suspend mode the ideal diode function from BAT to OUT and the output charger are kept alive ...
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... IC is 105 C – 105 C – (Adapter set Example: An LTC4055 operating from a wall adapter with OUT ambient temperature above, which the LTC4055 will begin to reduce the 0.8A charge current, is approximately 105 C – (5V – 3V) • 0.8A • 105 C – ...
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... MAX I FWD Figure 4. LTC4055 vs Schottky Diode Forward Voltage Drop 20 LTC4055 can deliver over battery from a 5V supply at room temperature. Without a backside thermal connec- tion, this number could drop to less than 500mA. STABILITY The constant-voltage mode feedback loop is stable with- out any compensation when a battery is connected. How- ...
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... U TYPICAL APPLICATIO S LTC4055 Configured for USB Application with Wall Adapter Figure 5 shows an LTC4055 configured for USB applica- tions with the optional wall adaptor input. The program- ming resistor ( set to 105k which sets up a CLPROG nominal current limit of 467mA in high power mode (92mA in low power) ...
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... LTC4055 U TYPICAL APPLICATIO S USB Hosting Application: The LTC4055’s IN1 and IN2 are Set Hi-Z by Pulling the SUSP Pin Above 1.2V In applications where the power is required to go back out on to the USB V the LTC4055 can be configured to turn BUS off its input power path, IN1 and IN2. Forcing the SUSP input pin above 1 ...
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... U UF Package 16-Lead Plastic QFN (4mm 4mm) (Reference LTC DWG # 05-08-1692) 0.72 0.05 PACKAGE OUTLINE 0.30 0.05 0.65 BSC 0.75 0.05 4.00 0.10 (4 SIDES) 2.15 0.10 (4-SIDES) 0.200 REF 0.00 – 0.05 LTC4055 BOTTOM VIEW—EXPOSED PAD R = 0.115 0.55 0.20 TYP (UF) QFN 0503 0.30 0.05 0.65 BSC 4055p 23 ...
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... LTC4055 RELATED PARTS PART NUMBER DESCRIPTION Battery Chargers LTC1733 Monolithic Lithium-Ion Linear Battery Charger LTC1734 Lithium-Ion Linear Battery Charger in ThinSOT LTC1734L Lithium-Ion Linear Battery Charger in ThinSOT LTC4002 Switch Mode Lithium-Ion Battery Charger LTC4050 Lithium-Ion Linear Battery Charger Controller LTC4052 Monolithic Lithium-Ion Battery Pulse Charger ...