LTC3900ES8 Linear Technology, LTC3900ES8 Datasheet
LTC3900ES8
Specifications of LTC3900ES8
Available stocks
Related parts for LTC3900ES8
LTC3900ES8 Summary of contents
Page 1
... MOSFET, shutting off the MOSFET if the inductor current reverses. The LTC3900 also shuts off the drivers if the supply voltage is too low. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. L0 ...
Page 2
... LTC3900IS8#PBF LTC3900IS8#TRPBF LEAD BASED FINISH TAPE AND REEL LTC3900ES8 LTC3900ES8#TR LTC3900IS8 LTC3900IS8#TR Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. For more information on lead free part marking, go to: For more information on tape and reel specifi ...
Page 3
ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER Current Sense + Input Current CS – I – CS Input Current Pin Clamp Voltage CSMAX V Current Sense Threshold Voltage ...
Page 4
LTC3900 TYPICAL PERFORMANCE CHARACTERISTICS Timeout 5. 25° 51k TMR C = 470pF TMR 5.15 5.10 5.05 5.00 4.95 4.90 4.85 4.80 4. ...
Page 5
TYPICAL PERFORMANCE CHARACTERISTICS Propagation Delay vs C LOAD 120 T = 25° 110 CC 100 SYNC SYNC ...
Page 6
LTC3900 PIN FUNCTIONS + – (Pin 1, 2): Current Sense Differential Input. + Connect CS through a series resistor to the drain of the external catch MOSFET, Q4. Connect CS The LTC3900 monitors the CS inputs 250ns ...
Page 7
... C the inductor current is negative, the inductor current will produce high voltage across Q4, resulting in a MOSFET avalanche. Depending on the amount of energy stored in the inductor, this avalanche energy may damage Q4. Burst Mode is a registered trademark of Linear Technology Corporation. GATE (OUT ...
Page 8
LTC3900 APPLICATIONS INFORMATION The timer circuit and current sense comparator in LTC3900 are used to prevent reverse current buildup in the output inductor. Timer Figure 3 shows the LTC3900 timer internal and external circuits. The timer operates by using an ...
Page 9
APPLICATIONS INFORMATION time. The current sinking capability of the circuit is around 1mA. The timeout function can be disabled by connecting the timer pin to GND. Current Sense The differential input current sense comparator is used for sensing the voltage ...
Page 10
LTC3900 APPLICATIONS INFORMATION The value of the resistors CS1 be calculated using the following formulas to meet both the threshold and clamp voltage requirements • I • R –1 RIPPLE DS(ON {200 ...
Page 11
APPLICATIONS INFORMATION An alternative method of generating the SYNC pulse is shown in Figure 8. This circuit produces square SYNC pulses with amplitude dependent on the logic supply voltage. The SYNC pulse width can be adjusted with R1 and C1 ...
Page 12
LTC3900 APPLICATIONS INFORMATION the driver dissipation, the total gate charge Q This parameter is found on the MOSFET manufacturers data sheet. The power dissipated in each LTC3900 MOSFET driver is • V • f DRIVER G CC ...
Page 13
TYPICAL APPLICATIONS 36V to 72V, 3.3V at 40A Synchronous Forward Converter +V IN 36V TO 72V 370k 13.2k 7 SD_V SEC 115k 3 R OSC 27k 9 BLANK 5 0.22μF SS_MAXDC 59k 10k LT1952 6 0.1μ 2.5V R ...
Page 14
LTC3900 TYPICAL APPLICATIONS 36V to 72V Input to 12V and 24V (or ± 12V), 2A Output Converter in 1/8th Brick Footprint V IN 36V TO 72V 82k 2.2μ LT1952-1 22k 33k 1 COMP S OUT BC857BF 2 FB ...
Page 15
TYPICAL APPLICATIONS 18V to 40V Input to 14V at 14A Output Converter in 1/4 Brick Footprint V IN 18V TO 40V 6.8μF ×4 LTC4441 1 10 PGND OUT 332k 2 9 220pF BL DRV ...
Page 16
LTC3900 TYPICAL APPLICATIONS 36V to 72V Input to 12V, 14A Output Converter in 1/8th Brick Footprint PZTA42 V IN 36V TO 72V 370k LT1952-1 13.3k 7 SD/V OUT SEC 133k OSC 82k 9 BLANK I SENSE 1μF ...
Page 17
TYPICAL APPLICATIONS 18V to 72V Input to 12V at 13A Active Reset Converter Fits in 1/8th Brick Size V IN 18V TO 72V 2.2μF × BAS516 3 5 LTC4440 2, 4 57Ω 220pF V FB LT1952-1 ...
Page 18
LTC3900 TYPICAL APPLICATIONS PZTA42 V IN 36V TO 72V 82k 2.2μ LT1952-1 22k 33k 1 16 COMP S OUT BC857 1.23V V IN 115k OUT OSC 4 13 SYNC PGND 0.47μF ...
Page 19
... SHALL NOT EXCEED .006" (0.15mm) 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. S8 Package 8-Lead Plastic Small Outline (Narrow ...
Page 20
... LTC3900 10k GND CS 10k 4 2 – SYNC TIMER 1nF 15k 8V BIAS 560Ω L1: PULSE PA1494.242 ALL CAPACITORS ARE TDK, X5R CERAMIC 3900 TA07a Range: 4.5V to 12V CC LT 1008 REV A • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2003 3900fa ...