- 您现在的位置：买卖IC网 > PDF目录67759 > LTC4069EDC-4.4#TRPBF (LINEAR TECHNOLOGY CORP) 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 PDF资料下载
参数资料
| 型号： | LTC4069EDC-4.4#TRPBF |
| 厂商： | LINEAR TECHNOLOGY CORP |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| 封装： | 2 X 2 MM, LEAD FREE, PLASTIC, MO-229WCCD-2, DFN-6 |
| 文件页数： | 6/16页 |
| 文件大小： | 197K |
| 代理商： | LTC4069EDC-4.4#TRPBF |
LTC4069-4.4
14
406944fa
Thermistors
The LTC4069-4.4 NTC trip points are designed to
work with thermistors whose resistance-temperature
characteristics follow Vishay Dale’s “R-T Curve 1.” The
Vishay NTHS0603N01N1003J is an example of such a
thermistor. However, Vishay Dale has many thermistor
products that follow the “R-T Curve 1” characteristic in a
variety of sizes. Furthermore, any thermistor whose ratio
of RCOLD to RHOT is about 6 will also work (Vishay Dale R-T
Curve 1 shows a ratio of RCOLD to RHOT of 3.266/0.5325
= 6.13).
Designers may want to use thermistors whose room
temperature value is different than 100k. Vishay Dale has
a number of values of thermistor from 32k to 100k that
follow the “R-T Curve 1.” Using different R-T curves, such
as Vishay Dale “R-T Curve 2”, is also possible. This curve,
combined with LTC4069-4.4 internal thresholds, gives
temperature trip points of approximately –3°C (falling) and
42°C (rising), a delta of 45°C. This delta in temperature
can be moved in either direction by changing the value of
RNOM with respect to RNTC. Increasing RNOM will move
both trip points to higher temperatures.
To calculate RNOM for a shift to lower temperature for
example, use the following equation:
R
Rat
C
NOM
COLD
NTC
=°
3 266
25
.
where RCOLD is the resistance ratio of RNTC at the desired
cold temperature trip point. If you want to shift the trip points
to higher temperatures use the following equation:
R
Rat
C
NOM
HOT
NTC
=°
0 5325
25
.
where RHOT is the resistance ratio of RNTC at the desired
hot temperature trip point.
Here is an example using a 10k R-T Curve 2 thermistor
from Vishay Dale. The difference between the trip points
is 45°C, from before, and we want the cold trip point to
be 0°C, which would put the hot trip point at 45°C. The
RNOM needed is calculated as follows:
R
Rat
C
NOM
COLD
NTC
=°
=
3 266
25
2 816
3
.
.
..
.
266
10
8 62
kk
=
The nearest 1% value for RNOM is 8.66k. This is the value
used to bias the NTC thermistor to get cold and hot trip
points of approximately 0°C and 45°C respectively. To
extend the delta between the cold and hot trip points, a
resistor, R1, can be added in series with RNTC (see Figure
6). The values of the resistors are calculated as follows:
R
RR
R
NOM
COLD
HOT
=
=
3 266 0 5325
0 5325
3 266
1
..
.
()
0 5325
.
R
COLD
HOT
where RNOM is the value of the bias resistor and RHOT and
RCOLD are the values of RNTC at the desired temperature
trip points. Continuing the example from before with a
desired trip point of 50°C:
4069 F06
RNOM
8.87k
RNTC
10k
VCC
–
+
–
+
–
+
TOO COLD
TOO HOT
NTC_ENABLE
R1
604Ω
0.76 VCC
0.35 VCC
0.016 VCC
6
NTC
Figure 6. NTC Circuits
APPLICATIONS INFORMATION
相关PDF资料 |
PDF描述 |
|---|---|
| LTC4069EDC-4.4#PBF | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| LTC4098EUDC-3.6#PBF | BATTERY CHARGE CONTROLLER, PQCC20 |
| LTC4210-4IS6 | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| LTC4210-3IS6 | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
| LTC4210-4CS6 | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO6 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4069EDC-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Standalone 750mA Li-Ion Battery Charger in 2 × 2 DFN with NTC Thermistor Input |
| LTC4069EDC-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Standalone 750mA Li-Ion Battery Charger in 2 × 2 DFN with NTC Thermistor Input |
| LTC4070 | 制造商:LINEAR 制造商全称:LINEAR 功能描述:Ultralow Voltage Step-Up Converter and Power Manager |
| LTC4070EDDB | 制造商:LINER 制造商全称:Linear Technology 功能描述:Li-Ion/Polymer Shunt Battery Charger System |
| LTC4070EDDB#PBF | 制造商:Linear Technology 功能描述:Battery Charger Li-Ion/Li-Pol 50mA 4.2V 10-Pin DFN EP Bulk 制造商:Linear Technology 功能描述:IC BATTERY CHARGER 50mA DFN-8 制造商:Linear Technology 功能描述:IC, BATTERY CHARGER, 50mA, DFN-8 制造商:Linear Technology 功能描述:IC, BATTERY CHARGER, 50mA, DFN-8; Battery Type:Li-Ion, Li-Polymer; Battery Charge Voltage:4.2V; Charge Current Max:50mA; Battery IC Case Style:DFN; No. of Pins:8; No. of Series Cells:1; Operating Temperature Min:-40C ;RoHS Compliant: Yes |
发布紧急采购，3分钟左右您将得到回复。