LTC3401 Linear Technology, LTC3401 Datasheet
LTC3401
Available stocks
Related parts for LTC3401
LTC3401 Summary of contents
Page 1
... Other features include 1 A shutdown, antiringing control, open-drain power good output, thermal shutdown and current limit. The LTC3401 is available in the 10-lead thermally enhanced MSOP package. Higher current appli- cations should use the 2A rated LTC3402 synchronous boost converter. Applications that require V should use the LTC3423 ...
Page 2
... SHDN = 0V, Not Including Switch Leakage V = 0V, MODE/SYNC = 0V 300k (Note 15k 15k 5.5V MODE/SYNC I = – Referenced to Feedback Voltage U W ORDER PART NUMBER 10 SHDN LTC3401EMS OUT 6 PGOOD MS PART MARKING = 125 C LTPG = MIN TYP MAX 0.85 1.0 0.5 2.6 5.5 1.22 1.25 1 ...
Page 3
... Thermal Shutdown Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC3401 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 4
... LTC3401 W U TYPICAL PERFOR A CE CHARACTERISTICS Transient Response 50mA to 500mA V OUT 200mV/DIV 550mA I OUT 50mA 200 s/DIV OUT 3401 G04 1MHz OSC Converter Efficiency 1.2V to 3.3V 100 300kHz 90 Burst Mode 80 OPERATION 3MHz 70 60 1MHz 0 100 1000 OUTPUT CURRENT (mA) ...
Page 5
... TEMPERATURE ( C) Start-Up Voltage 1.1 1.0 0.9 0.8 0.7 0.6 125 –55 – TEMPERATURE ( C) Burst Mode Operation Current –15 25 –55 65 TEMPERATURE ( C) LTC3401 NMOS R DS(ON) 0. 3.3V OUT 0.25 0.20 0.15 0.10 0.05 105 125 –55 – TEMPERATURE ( C) 3401 G14 Shutdown Threshold 1.10 1.05 1.00 0.95 0.90 0.85 0.80 0.75 0.70 0.65 0.60 105 125 –55 –15 ...
Page 6
... LTC3401 CTIO S R (Pin 1): Timing Resistor to Program the Oscillator t Frequency • OSC R t MODE/SYNC (Pin 2): Burst Mode Select and Oscillator Synchronization. MODE/SYNC = High. Enable Burst Mode operation. The inductor peak inductor current will be 1/3 the current limit value and return to zero current on each cycle. ...
Page 7
... COND N + 10mV I SENSE AMP – + LIMIT – 1.6A TYP – CURRENT COMP + PWM LOGIC + – SLEEP Burst Mode CONTROL SLOPE COMP – + 1.25V – 9% LTC3401 P V OUT – I ZERO AMP + 1.25V ERROR R1 AMP FB – MODE/SYNC 0 = FIXED FREQ 1 = BURST MODE ...
Page 8
... A, high efficiency is achieved at light loads when Burst Mode operation is entered. Low Voltage Start-Up The LTC3401 is designed to start up at input voltages of typically 0.85V. The device can start up under some load, (see graph “Start-Up vs Input Voltage”). Once the output voltage exceeds a threshold of 2 ...
Page 9
... Burst Mode operation be entered after the part has started up. COMPONENT SELECTION Inductor Selection The high frequency operation of the LTC3401 allows the use of small surface mount inductors. The minimum inductance value is proportional to the operating fre- quency and is limited by the following constraints: V • ...
Page 10
... Specifically, a “load feed forward” signal coupled into the V current loop a head start in providing the change in output current. The transconductance of the LTC3401 converter at the V pin with respect to the inductor current is typically C ...
Page 11
... FF SIGNAL Figure 3 Closing the Feedback Loop The LTC3401 uses current mode control with internal adaptive slope compensation. Current mode control elimi- nates the 2nd order filter due to the inductor and output capacitor exhibited in voltage mode controllers, and sim- plifies single-pole filter response. The product of the modulator control to output DC gain plus the error amp open-loop gain equals the DC gain of the system ...
Page 12
... Single Cell Output Disconnect = 0.9V TO 1.5V LTC3401 SHDN V OUT 2 8 MODE/SYNC PGOOD GND t (V – V OUT INMIN * SET RB TO FORCE BETA OF 100 LTC3401 SHDN V OUT 2 8 MODE/SYNC PGOOD GND t ZETEX FMMT717 V OUT RB 3404 TA03 – ...
Page 13
... R5 39k 3404 TA05a R4 5. OUT 3V 200mA 4 R2 866k 470pF 619k 4.7pF R5 82k 3404 TA06a LTC3401 Efficiency 90 Burst Mode 80 OPERATION 70 FIXED 60 FREQUENCY 1. 0 100 1000 OUTPUT CURRENT (mA) 3401 TA05b Efficiency 100 90 Burst Mode ...
Page 14
... C2 470pF 5 R1 549k C4 4.7pF R5 82k 3404 TA07a C3 27pF 1kV 300 0. LTC3401 SHDN V OUT 2 8 MODE/SYNC PGOOD GND 0.1 F 150k L1: SUMIDA CD-54-330MC ...
Page 15
... BSC 4.88 0.10 DETAIL “A” (.192 .004) 0 – 6 TYP 0.53 0.01 (.021 .006) 1.10 (.043) DETAIL “A” MAX SEATING PLANE 0.17 – 0.27 (.007 – .011) LTC3401 0.497 0.076 (.0196 .003 REF 3.00 0.102 (.118 .004) NOTE 0.86 (.034) REF 0.13 0.05 (.005 .002) ...
Page 16
... Single Cell, High Current (2A) Micropower, Synchronous 3MHz Step-Up DC/DC Converter for V ThinSOT is a trademark of Linear Technology Corporation. Linear Technology Corporation 16 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 Triple Output Converter 0 L1, 4 LTC3401 SHDN V OUT 2 8 MODE/SYNC FB ...