LTC3559 Linear Technology, LTC3559 Datasheet
LTC3559
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LTC3559 Summary of contents
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... A MODE pin provides the fl exibility to place both buck regulators in a power saving Burst Mode operation or a low noise pulse skip mode. The LTC3559 is offered in a low profi le thermally enhanced 16-lead (3mm × 3mm) QFN package. , LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation ...
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... BAT ORDER PART NUMBER LTC3559EUD Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. ● ...
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... 0.82V, MODE = 1 (One Buck Enabled) (Note 6) FB EN1 = EN2 = 2.0V IN MODE = 0V MODE, EN1, EN2 MODE, EN1, EN2 MODE = 0V or 3.8V MODE = 0V or 3.8V FB1, FB2 = 0.82V FB1, FB2 = 100mA –100mA SW LTC3559 MIN TYP 100 –85 –100 FLOAT 1.7 3.5 4 0.4 0.5 0.085 0.1 2.2 500 105 75 76.5 1.6 33.4 34 ...
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... °C/ Note 3: The LTC3559 is guaranteed to meet specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating temperature range TYPICAL PERFORMANCE CHARACTERISTICS Suspend State Supply and BAT Currents vs Temperature VCC ...
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... TEMPERATURE (°C) 3559 G10 ⎯ C ⎯ H ⎯ R ⎯ G Pin I-V Curve BAT = 3. CHRG (V) 3559 G13 LTC3559 PROG Voltage vs Battery Charge Current 1 HPWR = 5V 1 1.74k PROG EN1 = EN2 = 0V 0.8 0.6 0.4 0 100 150 200 250 ...
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... LTC3559 TYPICAL PERFORMANCE CHARACTERISTICS Timer Accuracy vs Temperature –1 –2 –55 –35 – TEMPERATURE (°C) Buck Regulator Input Current vs Temperature, Pulse Skip Mode 400 V = 0.82V FB 350 300 PV = 4.2V IN 250 PV = 2.7V IN 200 150 100 –55 –35 – ...
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... I LOAD LOAD PULSE SKIP MODE V = 2.5V OUT 100 1000 (mA) 3559 G25 3.9 4.2 3.6 PV (V) IN 3559 G27 MODE 100 1000 (mA) 3559 G29 LTC3559 Buck Regulator Load Regulation 2. 3. 2.5V OUT 2.58 2.56 2.54 Burst Mode OPERATION 2.52 2.50 PULSE SKIP MODE 2.48 2.46 2. 100 1000 I (mA) LOAD 3559 G26 Buck Regulator Effi ciency vs I ...
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... LTC3559 TYPICAL PERFORMANCE CHARACTERISTICS Buck Regulator Start-Up Transient V OUT 500mV/DIV INDUCTOR CURRENT I = 200mA/DIV L EN 2V/DIV PV = 3.8V IN PULSE SKIP MODE LOAD = 6 Buck Regulator Burst Mode Operation V OUT 20mV/DIV (AC) SW 2V/DIV INDUCTOR CURRENT I = 60mA/DIV 3.8V IN LOAD = 60mA 8 20mV/DIV (AC 3559 G33 ...
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... C ⎯ H ⎯ R ⎯ G requires a pull-up resistor and/or LED to provide indication. V (Pin 16): Battery Charger Input. A 1μF decoupling CC capacitor to GND is recommended. Exposed Pad (Pin 17): Ground. The Exposed Pad must be soldered to PCB ground to provide electrical contact and rated thermal performance. LTC3559 3559f 9 ...
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... LTC3559 BLOCK DIAGRAM CHRG 15 HPWR 12 SUSP 11 NTC 13 MODE 3 EN1 5 EN2 9 FB1 4 DIE TEMPERATURE BANDGAP OSCILLATOR 2.25MHz FB2 BAT IN BODY MAXER CA TA LOGIC T DIE NTCA NTC REF UNDERVOLTAGE LOCKOUT V FB – 0.8V T DIE V REF CLK V FB – ...
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... OPERATION The LTC3559 is a linear battery charger with dual monolithic synchronous buck regulators. The buck regulators are internally compensated and need no external compensa- tion components. The battery charger employs a constant- current constant- voltage charging algorithm and is capable of charging a single Li-Ion battery at charging currents up to 950mA. The user can program the maximum charging current available Figure 1 ...
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... LTC3559 APPLICATIONS INFORMATION Suspend Mode The battery charger can also be disabled by pulling the SUSP pin above 1.2V. In suspend mode, the battery drain current is reduced to 1.5μA and the input current is reduced to 8.5μA. Charge Cycle Overview When a battery charge cycle begins, the battery charger fi ...
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... LTC3559 or external components. The benefi the LTC3559 battery charger thermal regulation loop is that charge current can be set ...
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... LTC3559 APPLICATIONS INFORMATION NTC Thermistor The battery temperature is measured by placing a nega- tive temperature coeffi cient (NTC) thermistor close to the battery pack. The NTC circuitry is shown in Figure 3. To use this feature, connect the NTC thermistor, R between the NTC pin and ground, and a bias resistor, R from V to NTC ...
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... NTC COLD NOM 105k TOO_COLD NTC 13 R1 12.7k R NTC 100k TOO_HOT NTC_ENABLE 3559 F03 Figure 4. NTC Thermistor Circuit with Additional Bias Resistor LTC3559 to R25 NTC|COLD to R25 NTC|HOT for the CC for the cold threshold 349 • • 765 • ...
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... LTC3559 APPLICATIONS INFORMATION Solving these equations for R results in the following 0.536 • R NTC|HOT NOM and R = 3.25 • R NTC|COLD NOM By setting R equal to R25, the above equations result NOM 0.536 and r = 3.25. Referencing these ratios HOT COLD to the Vishay Resistance-Temperature Curve 1 chart gives a hot trip point of about 40° ...
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... C – • ° The LTC3559 can be used above 70°C, but the charge cur- rent will be reduced from 500mA. The approximate current at a given ambient temperature can be calculated: ° 105 C T – BAT • θ V – ...
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... USB voltage. To prevent excessive voltage from damag- ing the LTC3559 during a hot insertion, the soft connect circuit in Figure 7 can be employed. In the circuit of Figure 7, capacitor C1 holds MP1 off when the cable is fi ...
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... MODE pin low. R1 Buck Switching Regulator in Shutdown The buck switching regulators are in shutdown when R2 not enabled for operation. In shutdown, all circuitry in the buck switching regulator is disconnected from the 3559 F08 regulator input supply, leaving only a few nanoamps of LTC3559 > OUT 3559f 19 ...
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... Lower inductor values will cause Burst Mode switching frequency to increase. Table 2 shows several inductors that work well with the LTC3559. These inductors offer a good compromise in current rating, DCR and physical size. Consult each manufacturer for detailed information on their entire shuts IN selection of inductors ...
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... LTC3559 as possible and on the same side as the LTC3559. All connections must be made on that same layer. Place a local unbroken ground plane below these components that is tied to the Exposed Pad (Pin 17) of the LTC3559. The Exposed Pad must also be soldered to system ground for proper operation. ...
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... An LED at ⎯ C ⎯ H ⎯ R ⎯ G Gives a Visual Indication of the Battery Charger State. A LOAD UP TO 950mA V BAT CC 1μF 510Ω 110k PV IN NTC 28.7k 100k NTC LTC3559 NTH50603N01 CHRG SW1 887Ω PROG FB1 SUSP HPWR SW2 MODE DIGITALLY CONTROLLED EN1 FB2 EN2 ...
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... EN2 GND EXPOSED PAD UD Package 16-Lead Plastic QFN (3mm × 3mm) (Reference LTC DWG # 05-08-1691) 3.00 ± 0.10 (4 SIDES) 0.70 ±0.05 PIN 1 TOP MARK (NOTE 6) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC LTC3559 Approximately OUT1 UP TO 950mA SINGLE + Li-lon CELL 2.7V TO 4.2V 2.2μF 4.7μH 2.5V AT 400mA 655k 22pF 10μF 309k 4.7μ ...
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... LTC3559 RELATED PARTS PART NUMBER DESCRIPTION LTC3550 Dual Input USB/AC Adapter Li-Ion Battery Charger with Adjustable Output 600mA Buck Converter LTC3552 Standalone Linear Li-Ion Battery Charger with Adjustable Output Dual Synchronous Buck Converter LTC3552-1 Standalone Linear Li-Ion Battery Charger with Dual ...