ltc3445euf-pbf Linear Technology Corporation, ltc3445euf-pbf Datasheet
ltc3445euf-pbf
Related parts for ltc3445euf-pbf
ltc3445euf-pbf Summary of contents
Page 1
... U APPLICATIO S ■ Intel’s Microprocessor Supply (PXA27X) ■ Portable Instruments , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. PowerPath is a trademark of Linear Technology Corporation trademark of Philips Electronics N.V. Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131, Spread Spectrum patent pending ...
Page 2
... T JMAX EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB ORDER PART NUMBER LTC3445EUF 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 specified with wider operating temperature ranges. ...
Page 3
ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER I Additional Input DC Bias Current For Buck (Note 4) S Active Mode Sleep Mode f Nominal Oscillator Frequency OSC P-Channel FET PFET DS(ON ...
Page 4
... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3445EUF is guaranteed to meet performance specifica- tions from 0°C to 70°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls ...
Page 5
W U TYPICAL PERFOR A CE CHARACTERISTICS Buck Efficiency and Power Loss vs Load Current 2.5V CC1 100 90 EFFICIENCY 80 DAC MIN 70 DAC MAX 60 50 DAC MAX 40 POWER LOSS 30 20 DAC MIN 10 ...
Page 6
LTC3445 W U TYPICAL PERFOR A CE CHARACTERISTICS Slew Rates DAC Min to DAC Max 200mV/DIV 100µs/DIV 3445 G13 Buck Switching Frequency vs V CC1 1.60 1.56 1.52 1.48 1.44 1.40 2.5 3.5 4.5 V (V) CC1 3445 G16 V ...
Page 7
W U TYPICAL PERFOR A CE CHARACTERISTICS LDO Reference Voltage vs Temperature 0.604 0.602 0.600 0mA 0.598 0.596 0.594 0.592 0.590 0.498 – 100 125 –50 25 TEMPERATURE (°C) 3445 G22 LDO Output Voltage vs Load Current ...
Page 8
LTC3445 CTIO S V (Pin 1): Supply Sense that V TRACK above 3V. Must be ≤ CC1 V (Pin 2): Back-Up Battery Input. BACKUP V (Pins 3, 10): Power Supply (2.5V to 5.5V). ...
Page 9
CTIO AL DIAGRA S RUN PWR_EN 15 SDA SCL 8 ADD7 STRAPPABLE V OR GND 5 CC1 ADD6 V OR GND 9 STRAPPABLE CC1 V CC PGOOD POWER 4 GOOD V CC2 22 ...
Page 10
LTC3445 CTIO AL DIAGRA REF OSC 10 W PEAK CURRENT LEVEL REFERENCE EA I COMP LOGIC BURST I RCOMP Figure 2. Buck Regulator Detail V CC1 R S PFET ...
Page 11
DIAGRA SDA t LOW SCL t HD(STA START CONDITION Fast Mode Timing Specifications (for Reference) SYMBOL PARAMETER 2 f Maximum I C Operating Frequency I2C(MAX) t Bus Free Time ...
Page 12
LTC3445 U OPERATIO (refer to Figure 1) Burst Mode Operation The LTC3445 is capable of Burst Mode operation, in which the internal power MOSFETs operate intermittently based on load demand. In Burst Mode operation, the peak current of the inductor ...
Page 13
U OPERATIO (refer to Figure 1) SPR = 00 (Spread Spectrum OFF) NOISE 10dBm/DIV START FREQ: 100kHz, RBW: 10kHz, STOP FREQ: 30MHz SPR = 01 NOISE 10dBm/DIV START FREQ: 100kHz, RBW: 10kHz, STOP FREQ: 30MHz micro-steps. The table below shows ...
Page 14
LTC3445 U OPERATIO (refer to Figure 1) When V rises above 2.8V, the PowerPath’s LDO is CC1 enabled and set to the lesser higher, it controls the PowerPath’s LDO output (V BATT) voltage ...
Page 15
U OPERATIO (refer to Figure 1) be able to control the data line to acknowledge communi- cations from the master, and some devices will need to able to send data back to the master; they will be in control of ...
Page 16
LTC3445 U OPERATIO (refer to Figure 1) data line is also left high by the slave and master after a slave has transmitted a byte of data to the master in a read operation, but this is a not-acknowledge that ...
Page 17
U U APPLICATIO S I FOR ATIO BUCK REGULATOR The basic LTC3445 application circuit is shown on the first page of this data sheet. External component selection is driven by the load requirement and begins with the selec- tion of ...
Page 18
LTC3445 U U APPLICATIO S I FOR ATIO where f = operating frequency, C OUT and ∆I = ripple current in the inductor. For a fixed output L voltage, the output ripple is highest at maximum input voltage since ∆I ...
Page 19
U U APPLICATIO S I FOR ATIO 1000 100 10 DAC MAX DAC MIN 1 0.1 0 LOAD CURRENT (mA) Figure 8. Power Loss vs Load Current, V internal power MOSFET switches. Each time the gate is switched ...
Page 20
LTC3445 U U APPLICATIO S I FOR ATIO prevent oscillations. The LTC3445 LDOs are micropower devices and output transient response will be a function of output capacitance. Larger values of output capacitance decrease the peak deviations and provide improved tran- ...
Page 21
U U APPLICATIO S I FOR ATIO As an example, consider the LTC3445 in dropout at an input voltage of 2.7V, an ambient temperature of 70°C, a buck load current of 600mA, LDO1 set to 1.3V with a load of ...
Page 22
LTC3445 U U APPLICATIO S I FOR ATIO DESIGN EXAMPLE As a design example, assume the LTC3445 is used in a single lithium-ion battery-powered Intel PXA270 micro- processor application. The battery will be operating from a maximum of 4.2V down ...
Page 23
... SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights Package 24-Lead Plastic QFN (4mm × ...
Page 24
... Dual DC/DC Converter with USB Power Manager and Li-Ion Battery Charger LTC4055 USB Power Manager and Li-Ion Battery Charger LTC4411/LTC4412 PowerPath Controllers in ThinSOT ThinSOT and VLDO are trademarks of Linear Technology Corporation. Linear Technology Corporation 24 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● ...