Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF HTML

LT8697 Datasheet(PDF) 13 Page - Linear Dimensions Semiconductor

Part No. LT8697
Description  USB 5V 2.5A Output, 42V Input Synchronous Buck with Cable Drop Compensation
Download  28 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  LINEAR_DIMENSIONS [Linear Dimensions Semiconductor]
Homepage  http://www.lineardimensions.com
Logo 

LT8697 Datasheet(HTML) 13 Page - Linear Dimensions Semiconductor

Zoom Inzoom in Zoom Outzoom out
 13 / 28 page
background image
LT8697
13
8697p
For more information www.linear.com/LT8697
applicaTions inForMaTion
Cable Drop Compensation Over a Wide Temperature
Range
Cable drop compensation with zero temperature variation
may be used in many applications. However, matching
the cable drop compensation temperature variation to the
cable resistance temperature variation may result in bet-
ter overall output voltage accuracy over a wide operating
temperature range. For example, in an application with
0.26Ω of wire resistance and a maximum output current
of 2.1A, cable drop compensation adds 0.55V at 25°C to
the output at max load for a fully compensated wire re-
sistance. If the wire in this example is copper, the copper
resistance temperature coefficient of about 4000ppm/°C
results in an output voltage error of –130mV at 85°C and
55mV at 0°C. Figure 2a shows this behavior.
See Table 1 for a list of copper wire resistances vs gauge.
Table 1. Copper Wire Resistance vs Wire Gauge
AWG
RESISTANCE OF Cu WIRE AT 20°C (mΩ/m)
15
10.4
16
13.2
17
16.6
18
21.0
19
26.4
20
33.3
21
42.0
22
53.0
23
66.8
24
84.2
25
106
26
134
27
169
28
213
29
268
30
339
31
427
32
538
33
679
34
856
35
1080
36
1360
37
1720
38
2160
39
2730
40
3440
Cable drop compensation can be made to vary positively
versus temperature with the addition of a negative tem-
perature coefficient (NTC) resistor as a part of the RCBL
resistance. This circuit idea assumes the NTC resistor is
at the same temperature as the cable. Figure 2b shows
an example resistor network for RCBL that matches cop-
per resistance variation over a wide –40°C to 125°C
temperature range. Figure 2c shows the resultant cable
drop compensation output at several temperatures using
RCBL with negative temperature variation.
Figure 2b. RCBL Resistor Network for Matching
Copper Wire Temperature Coefficient
Figure 2a. Cable Drop Compensation Through 4m of AWG 20
Twisted-Pair Cable (260mΩ) without Temperature Compensation
TEMPERATURE (°C)
–20
4.8
5.0
5.2
5.4
5.6
5.8
VLOAD
VOUT
0
20
40
60
8697 F02a
80
100
ILOAD = 2.1A
CABLE = 4 METERS AWG
20 TWISTED-PAIR COPPER
10k
1%
RCBL
8697 F02b
10k
1%
MURATA
NCP21XV103J03RA
10k THERMISTOR


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 


Datasheet Download




Link URL




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

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   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