Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.COM

X  

LTC3826 Datasheet(PDF) 17 Page - Linear Technology

Part # LTC3826
Description  30A IQ, Dual, 2-Phase Synchronous Step-Down Controller
Download  36 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  LINER [Linear Technology]
Direct Link  http://www.linear.com
Logo LINER - Linear Technology

LTC3826 Datasheet(HTML) 17 Page - Linear Technology

Back Button LTC3826_15 Datasheet HTML 13Page - Linear Technology LTC3826_15 Datasheet HTML 14Page - Linear Technology LTC3826_15 Datasheet HTML 15Page - Linear Technology LTC3826_15 Datasheet HTML 16Page - Linear Technology LTC3826_15 Datasheet HTML 17Page - Linear Technology LTC3826_15 Datasheet HTML 18Page - Linear Technology LTC3826_15 Datasheet HTML 19Page - Linear Technology LTC3826_15 Datasheet HTML 20Page - Linear Technology LTC3826_15 Datasheet HTML 21Page - Linear Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 17 / 36 page
background image
LTC3826
17
3826fc
APPLICATIONS INFORMATION
selected. As inductance increases, core losses go down.
Unfortunately, increased inductance requires more turns
of wire and therefore copper losses will increase.
Ferrite designs have very low core loss and are preferred
at high switching frequencies, so design goals can con-
centrate on copper loss and preventing saturation. Ferrite
core material saturates “hard,” which means that induc-
tance collapses abruptly when the peak design current is
exceeded. This results in an abrupt increase in inductor
ripple current and consequent output voltage ripple. Do
not allow the core to saturate!
Power MOSFET and Schottky Diode (Optional)
Selection
Two external power MOSFETs must be selected for each
controller in the LTC3826: one N-channel MOSFET for the
top (main) switch, and one N-channel MOSFET for the
bottom (synchronous) switch.
The peak-to-peak drive levels are set by the INTVCC voltage.
This voltage is typically 5V during start-up (see EXTVCC Pin
Connection). Consequently, logic-level threshold MOSFETs
must be used in most applications. The only exception
is if low input voltage is expected (VIN < 5V); then, sub-
logic level threshold MOSFETs (VGS(TH) < 3V) should be
used. Pay close attention to the BVDSS specification for
the MOSFETs as well; most of the logic level MOSFETs are
limited to 30V or less.
Selection criteria for the power MOSFETs include the “ON”
resistance RDS(ON), Miller capacitance CMILLER, input
voltage and maximum output current. Miller capacitance,
CMILLER, can be approximated from the gate charge curve
usually provided on the MOSFET manufacturers’ data
sheet. CMILLER is equal to the increase in gate charge
along the horizontal axis while the curve is approximately
flat divided by the specified change in VDS. This result is
then multiplied by the ratio of the application applied VDS
to the Gate charge curve specified VDS. When the IC is
operating in continuous mode the duty cycles for the top
and bottom MOSFETs are given by:
Main Switch Duty Cycle
V
V
OUT
IN
=
Synchronous Switch Duty Cycle
VV
V
IN
OUT
IN
=
The MOSFET power dissipations at maximum output
current are given by:
PMAIN =
VOUT
VIN
IMAX
()
2
1+
()RDS(ON) +
VIN
()
2
IMAX
2
RDR
() CMILLER
()
1
VINTVCC –VTHMIN
+
1
VTHMIN
f
()
PSYNC =
VIN –VOUT
VIN
IMAX
()
2
1+
()RDS(ON)
where δ is the temperature dependency of RDS(ON) and
RDR (approximately 2Ω) is the effective driver resistance
at the MOSFET’s Miller threshold voltage. VTHMIN is the
typical MOSFET minimum threshold voltage.
Both MOSFETs have I2R losses while the topside N-channel
equation includes an additional term for transition losses,
which are highest at high input voltages. For VIN < 20V
the high current efficiency generally improves with larger
MOSFETs, while for VIN > 20V the transition losses rapidly
increase to the point that the use of a higher RDS(ON) device
with lower CMILLER actually provides higher efficiency. The
synchronous MOSFET losses are greatest at high input
voltage when the top switch duty factor is low or during
a short-circuit when the synchronous switch is on close
to 100% of the period.


Similar Part No. - LTC3826_15

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC3826-1 LINER-LTC3826-1 Datasheet
424Kb / 32P
   30關A IQ, Dual, 2-Phase Synchronous Step-Down Controller
LTC3826-1 LINER-LTC3826-1 Datasheet
312Kb / 26P
   Dual, 2-Phase Step-Down Switching Controller Programmable Soft-Start
LTC3826-1 LINER-LTC3826-1 Datasheet
598Kb / 44P
   Triple Output, Buck/Buck/Boost Synchronous Controller with 28關A Burst Mode IQ
LTC3826-1 LINER-LTC3826-1 Datasheet
541Kb / 36P
   60V Low IQ Inverting DC/DC Controller Wide Operating VIN Range: 3.5V to 60V
LTC3826-1 LINER-LTC3826-1_15 Datasheet
433Kb / 32P
   30A IQ, Dual, 2-Phase Synchronous Step-Down Controller
More results

Similar Description - LTC3826_15

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC3826-1 LINER-LTC3826-1_15 Datasheet
433Kb / 32P
   30A IQ, Dual, 2-Phase Synchronous Step-Down Controller
LTC3834 LINER-LTC3834_15 Datasheet
780Kb / 30P
   30A IQ Synchronous Step-Down Controller
LTC3834-1 LINER-LTC3834-1_15 Datasheet
298Kb / 28P
   30A IQ Synchronous Step-Down Controller
LTC3827-1 LINER-LTC3827-1_15 Datasheet
452Kb / 32P
   Low IQ, Dual, 2-Phase Synchronous Step-Down Controller
LTC3858-1 LINER-LTC3858-1_15 Datasheet
434Kb / 38P
   Low IQ, Dual 2-Phase Synchronous Step-Down Controller
LTC3868 LINER-LTC3868_15 Datasheet
402Kb / 38P
   Low IQ, Dual 2-Phase Synchronous Step-Down Controller
LTC3857 LINER-LTC3857 Datasheet
531Kb / 38P
   Low IQ, Dual, 2-Phase Synchronous Step-Down Controller
LTC3858-1 LINER-LTC3858-1 Datasheet
591Kb / 38P
   Low IQ, Dual 2-Phase Synchronous Step-Down Controller
LTC3868-1 LINER-LTC3868-1 Datasheet
595Kb / 38P
   Low IQ, Dual 2-Phase Synchronous Step-Down Controller
LTC3827 LINER-LTC3827 Datasheet
446Kb / 36P
   Low IQ, Dual, 2-Phase Synchronous Step-Down Controller
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com