Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

LTC1174CN8-5 Datasheet(PDF) 7 Page - Linear Technology

Part # LTC1174CN8-5
Description  High Efficiency Step-Down and Inverting DC/DC Converter
Download  20 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  LINER [Linear Technology]
Direct Link  http://www.linear.com
Logo LINER - Linear Technology

LTC1174CN8-5 Datasheet(HTML) 7 Page - Linear Technology

Back Button LTC1174CN8-5 Datasheet HTML 3Page - Linear Technology LTC1174CN8-5 Datasheet HTML 4Page - Linear Technology LTC1174CN8-5 Datasheet HTML 5Page - Linear Technology LTC1174CN8-5 Datasheet HTML 6Page - Linear Technology LTC1174CN8-5 Datasheet HTML 7Page - Linear Technology LTC1174CN8-5 Datasheet HTML 8Page - Linear Technology LTC1174CN8-5 Datasheet HTML 9Page - Linear Technology LTC1174CN8-5 Datasheet HTML 10Page - Linear Technology LTC1174CN8-5 Datasheet HTML 11Page - Linear Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 7 / 20 page
background image
7
LTC1174
LTC1174-3.3/LTC1174-5
1174fe
(Refer to Functional Diagram)
The LTC1174 uses a constant off-time architecture to
switch its internal P-channel power MOSFET. The off-time
is set by an internal timing capacitor and the operating
frequency is a function of VIN.
The output voltage is set by an internal resistive divider
(LTC1174-3.3 and LTC1174-5) or an external divider re-
turned to VFB Pin 1 (LTC1174). A voltage comparator A1
compares the divided output voltage to a reference voltage
of 1.25V.
To optimize efficiency, the LTC1174 automatically switches
between continuous and Burst Mode
® operation. The volt-
age comparator is the primary control element when the
device is in Burst Mode operation, while the current com-
parator controls the output voltage in continuous mode.
During the switch“ON” time, switch current flows through
the 0.1
Ω sense resistor. When this current reaches the
threshold of the current comparator A2, its output signal will
change state, setting the flip-flop and turning the switch off.
The timing capacitor, CT, begins to discharge until its
voltage goes below VTH1. Comparator A4 will then trip,
which resets the flip-flop and causes the switch to turn on
again. Also, the timing capacitor is recharged. The inductor
current will again ramp up until the current comparator A2
trips. The cycle then repeats.
When the load is relatively light, the LTC1174 automatically
goes into Burst Mode operation. The current mode loop is
interrupted when the output voltage reaches the desired
regulated value. The hysteretic voltage comparator A1 trips
when VOUT is above the desired output voltage, shutting off
the switch and causing the timing capacitor to discharge.
This capacitor discharges past VTH1 until its voltage drops
below VTH2. Comparator A5 then trips and a sleep signal is
generated.
In sleep mode, the LTC1174 is in standby and the load
current is supplied by the output capacitor. All unused
circuitry is shut off, reducing quiescent current from
0.45mA to 0.13mA. When the output capacitor discharges
by the amount of the hysteresis of the comparator A1, the
P-channel switch turns on again and the process repeats
itself.
Operating Frequency and Inductor
Since the LTC1174 utilizes a constant off-time architecture,
its operating frequency is dependent on the value of VIN. The
frequency of operation can be expressed as:
f
t
VV
VV
Hz
OFF
IN
OUT
IN
D
=
+
⎝⎜
⎠⎟ ()
1
where tOFF =4µsandVDisthevoltagedropacrossthediode.
Note that the operating frequency is a function of the input
and ouput voltage.
Although the size of the inductor does not affect the fre-
quency, it does affect the ripple current. The peak-to-peak
ripple current is given by:
I
VV
L
A
RIPPLE
OUT
D
PP
=
+
⎝⎜
⎠⎟ ()
410 6
By choosing a smaller inductor, a low ESR output filter
capacitor has to be used (see CIN and COUT). Moreover, core
loss will also increase (see Inductor Core Selection section)
due to higher ripple current.
OPERATIO
Burst Mode is a registered trademark of Linear Technology Corporation.


Similar Part No. - LTC1174CN8-5

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC1174CN8-5 LINER-LTC1174CN8-5 Datasheet
353Kb / 16P
   High Efficiency Step-Down and Inverting DC/DC Converter
More results

Similar Description - LTC1174CN8-5

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC1174 LINER-LTC1174_15 Datasheet
262Kb / 20P
   High Efficiency Step-Down and Inverting DC/DC Converter
LTC1174-3.3 LINER-LTC1174-3.3_15 Datasheet
262Kb / 20P
   High Efficiency Step-Down and Inverting DC/DC Converter
LTC1174 LINER-LTC1174 Datasheet
353Kb / 16P
   High Efficiency Step-Down and Inverting DC/DC Converter
LTC1174-5 LINER-LTC1174-5_15 Datasheet
262Kb / 20P
   High Efficiency Step-Down and Inverting DC/DC Converter
logo
Semtech Corporation
SC1578 SEMTECH-SC1578 Datasheet
130Kb / 5P
   HIGH-EFFICIENCY STEP-DOWN DC-DC CONVERTER
logo
Fairchild Semiconductor
FAN5307 FAIRCHILD-FAN5307 Datasheet
623Kb / 13P
   High-Efficiency Step-Down DC-DC Converter
logo
Analog Intergrations Co...
AIC1578 AIC-AIC1578 Datasheet
266Kb / 7P
   High-Efficiency, Step-Down DC/DC Converter
logo
Shindengen Electric Mfg...
MD1422N SHINDENGEN-MD1422N Datasheet
41Kb / 2P
   high-efficiency step down DC-DC converter
logo
HTC Korea TAEJIN Techno...
MC34063C HTC-MC34063C_11 Datasheet
436Kb / 10P
   Step Down / Step Up / Inverting DC-DC Converter
logo
Texas Instruments
TPS62205 TI-TPS62205 Datasheet
264Kb / 19P
[Old version datasheet]   HIGH-EFFICIENCY, SOT23 STEP-DOWN, DC-DC CONVERTER
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   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