您的位置：维库电子市场网 > Datasheet > LTC1624CS

LTC1624CS Datasheet

  • LTC1624CS

  • Linear Technology [High Efficiency SO-8 N-Channel Switching...

  • 492.67KB

  • LINER

阅览下载 纠错 0

扫码查看芯片数据手册

上传产品规格书

PDF预览

LTC1624
APPLICATIONS INFORMATION
100鈩?resistor in series with the SENSE
鈥?/div>
pin. This offset
cancels the internal offset in current comparator I
2
(refer
to Functional Diagram). This comparator in conjunction
with the voltage on the I
TH
/RUN pin determines when to
enter into Burst Mode operation (refer to Low Current
Operation in Operation section). With the additional exter-
nal offset present, the drive to the topside MOSFET is
always enabled every cycle and constant frequency opera-
tion occurs for I
OUT
> I
OUT(MIN)
.
Step-Down Converter: Design Example
As a design example, assume V
IN
= 12V(nominal),
V
IN
= 22V(max), V
OUT
= 3.3V and I
MAX
= 2A. R
SENSE
can
immediately be calculated:
R
SENSE
= 100mV/2A = 0.05鈩?/div>
Assume a 10碌H inductor. To check the actual value of the
ripple current the following equation is used:
With the 0.05鈩?sense resistor I
SC(AVG)
= 2A will result,
increasing the 0.5V Schottky diode dissipation to 0.98W.
C
IN
is chosen for an RMS current rating of at least 1.0A at
temperature. C
OUT
is chosen with an ESR of 0.03鈩?for low
output ripple. The output ripple in continuous mode will be
highest at the maximum input voltage. The output voltage
ripple due to ESR is approximately:
V
ORIPPLE
= R
ESR
(鈭咺
L
) = 0.03鈩?(1.58A
P-P
) = 47mV
P-P
Step-Down Converter: Duty Cycle Limitations
At high input to output differential voltages the on-time
gets very small. Due to internal gate delays and response
times of the internal circuitry the minimum recommended
on-time is 450ns. Since the LTC1624鈥檚 frequency is inter-
nally set to 200kHz a potential duty cycle limitation exists.
When the duty cycle is less than 9%, cycle skipping may
occur which increases the inductor ripple current but does
not cause V
OUT
to lose regulation. Avoiding cycle skipping
imposes a limit on the input voltage for a given output
voltage only when V
OUT
< 2.2V using 30V MOSFETs.
(Remember not to exceed the absolute maximum voltage
of 36V.)
V
IN(MAX)
= 11.1V
OUT
+ 5V
For DC > 9%
V
IN
鈭?/div>
V
OUT
铮?/div>
V
OUT
+
V
D
铮?/div>
鈭咺
L
=
铮?/div>
铮?/div>
f L
铮?/div>
V
IN
+
V
D
铮?/div>
( )( )
The highest value of the ripple current occurs at the
maximum input voltage:
鈭咺
L
=
22V
鈭?/div>
3
.
3V
铮?/div>
3
.
3V
+
0
.
5V
铮?/div>
铮?/div>
22V
+
0
.
5V
铮?=
1
.
58A
P-P
铮?/div>
200kHz 10
碌
H
铮?/div>
(
)
The power dissipation on the topside MOSFET can be
easily estimated. Choosing a Siliconix Si4412DY results
in: R
DS(ON)
= 0.042鈩? C
RSS
= 100pF. At maximum input
voltage with T(estimated) = 50掳C:
P
MAIN
=
2
3
.
3V
+
0
.
5V
2A 1
+
0
.
005 50
掳
C
鈭?/div>
25
掳
C 0
.
042
鈩?/div>
22V
+
0
.
5V
( )
[
( )(
)
]
(
1
.
85
+
2
.
5
(
22V
) (
2A
)(
100pF
)(
200kHz
)
=
62mW
铮?/div>
V
IN
铮?/div>
P
D
=
I
SC AVG
V
D
铮?/div>
铮?/div>
铮?/div>
V
IN
+
V
D
铮?/div>
The most stringent requirement for the Schottky diode
occurs when V
OUT
= 0V (i.e. short circuit) at maximum V
IN
.
In this case the worst-case dissipation rises to:
( )
(
)
U
W
U
U
Boost Converter Applications
The LTC1624 is also well-suited to boost converter appli-
cations. A boost converter steps up the input voltage to a
higher voltage as shown in Figure 6.
V
IN
R
SENSE
+
C
IN
)
V
IN
SENSE
鈥?/div>
L1
BOOST
LTC1624
TG
C
B
GND
SW
V
FB
R1
M1
R2
D1
V
OUT
+
C
OUT
1624 F06
Figure 6. Boost Converter
13

LTC1624CS相关型号PDF文件下载

  • 型号
    版本
    描述
    厂商
    下载
  • LTC1040
    英文版
    Dual Micropower Comparator
    LINER
    LTC1040
  • LTC1040
    英文版
    DUAL MICROPOWER COMPARATOR
    LINER [Lin...
    LTC1040
  • LTC1040
    英文版
    Dual Micropower Comparator
    LINER [Lin...
    LTC1040
  • LTC1041
    英文版
    BANG-BANG Controller
    LINER
    LTC1041
  • LTC1041
    英文版
    BANG-BANG Controller
    LINER [Lin...
    LTC1041
  • LTC1042
    英文版
    Window Comparator
    LINER
    LTC1042
  • LTC1042
    英文版
    Window Comparator
    LINER [Lin...
    LTC1042
  • LTC1042
    英文版
    Window Comparator
    LINER [Lin...
    LTC1042
  • LTC1043
    英文版
    2-Channel Differential Input 16-Bit No Latency DS ADC
    LINER
    LTC1043
  • LTC1043
    英文版
    2-Channel Differential Input 24-Bit No Latency DS ADC
    LINER [Lin...
    LTC1043
  • LTC1043
    英文版
    2-Channel Differential Input 16-Bit No Latency DS ADC
    LINER [Lin...
    LTC1043
  • LTC1043
    英文版
    Dual Precision Intrumentation Switched-Capacitor Building Bl...
    LINER [Lin...
    LTC1043
  • LTC1044
    英文版
    Switched Capacitor Voltage Converter
    LINER
    LTC1044
  • LTC1044
    英文版
    Switched Capacitor Voltage Converter
    LINER [Lin...
    LTC1044
  • LTC1045
    英文版
    Programmable Micropower Hex Translator/ Receiver/Driver
    LINER
    LTC1045
  • LTC1045
    英文版
    Programmable Micropower Hex Translator/ Receiver/Driver
    LINER [Lin...
    LTC1045
  • LTC1046
    英文版
    “Inductorless” 5V to + 5V Converter
    LINER
    LTC1046
  • LTC1046
    英文版
    “Inductorless” 5V to + 5V Converter
    LINER [Lin...
    LTC1046
  • LTC1047
    英文版
    Dual Micropower Chopper Stabilized Operational Amplifier wit...
    LINER
    LTC1047
  • LTC1047
    英文版
    Dual Micropower Zero-Drift Operational Amplifier with Intern...
    LINER [Lin...
    LTC1047

您可能感兴趣的PDF文件资料

热门IC型号推荐

©2025 维库电子市场网（www.dzsc.com）　备案号：浙B2-20050339-1 经营许可证：浙B2-20210386版权声明
买家服务热线：0571-85317607 | 买家服务部QQ： QQ:1609526468
卖家服务热线：0571-85317607 | 卖家服务部QQ： QQ:331652727

扫码下载APP，
一键连接广大的电子世界。

在线人工客服

买家服务：
卖家服务：
技术客服：

0571-85317607

网站技术支持

13606545031

客服在线时间周一至周五
9:00-17:30

关注官方微信号，
第一时间获取资讯。

建议反馈
返回顶部

建议反馈

联系人：

联系方式：

按住滑块，拖拽到最右边
>>
感谢您向阿库提出的宝贵意见，您的参与是维库提升服务的动力！意见一经采纳，将有感恩红包奉上哦！

PDF纠错X

投诉电话：0571-85317607 投诉QQ：

如选匿名将无法为您反馈投诉结果，建议实名投诉！