- 您现在的位置：买卖IC网 > PDF目录15309 > LTC3824HMSE#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 10-MSOP PDF资料下载
参数资料
| 型号： | LTC3824HMSE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/14页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 10-MSOP |
| 标准包装： | 2,500 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 600kHz |
| 占空比： | 100% |
| 电源电压： | 4 V ~ 60 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 150°C |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 |
| 包装： | 带卷 (TR) |
LTC3824
APPLICATIONS INFORMATION
I RMS = I OUT(MAX)
V OUT V IN
ontheP-channelswitchdutycycle.Athighinputvoltages
the diode conducts most of the time. As V IN approaches
V OUT the diode conducts only a small fraction of the time.
The worst condition for the diode is when the output is
shorted to ground. Under this condition the diode must
safely handle the maximum current at close to 100% of
the time. Therefore, the diode must be carefully chosen
to meet the worst case voltage and current requirements.
Under normal conditions, the average current conducted
by the diode is:
I D = I OUT ? (1 – D)
A fast switching Schottky diode must be used to optimize
efficiency.
C IN and C OUT Selection
A low ESR input capacitor, C IN , sized for the maximum
RMS P-channel switch current is required to prevent large
input voltage transients. The maximum RMS capacitor
current is given by:
–1
V IN V OUT
This formula has a maximum at V IN = 2V OUT , where I RMS =
I OUT /2. This simple worst-case condition is commonly used
for design because even significant deviations do not offer
much relief. Note that ripple current ratings from capacitor
manufacturers are often based on only 2000 hours of life
which makes it advisable to further derate the capacitor,
or choose a capacitor rated at a higher temperature than
required. Several capacitors may also be paralleled to meet
size or height requirements in the design.
The selection of C OUT is determined by the effective series
resistance (ESR) that is required to minimize voltage ripple
and load step transients as well as the amount of bulk
capacitance that is necessary to ensure that the control
loop is stable.
The output ripple, ? V OUT , is determined by:
The output ripple is highest at maximum input voltage
since ? I L increases with input voltage. Multiple capacitors
placed in parallel may be needed to meet the ESR and
RMS current handling requirements. Dry tantalum, special
polymer, aluminum electrolytic and ceramic capacitors are
all available in surface mount packages. Special polymer
capacitors offer very low ESR but have lower capacitance
density than other types. Tantalum capacitors have the
highest capacitance density but it is important to only
use types that have been surge tested for use in switching
power supplies. Aluminum electrolytic capacitors have
significantly higher ESR, but can be used in cost-sensitive
applications provided that consideration is given to ripple
current ratings and long-term reliability. Ceramic capaci-
tors have excellent low ESR characteristics but can have
a high voltage coefficient and audible noise.
Efficiency Considerations
The efficiency of a switching regulator is equal to the output
power divided by the input power. Percentage efficiency
can be expressed as:
% Efficiency = 100%–(L1 + L2 + L3 +......)
where L1, L2, L3...are the individual loss components as a
percentage of the input power. It is often useful to analyze
individual losses to determine what is limiting the efficiency
and which change would produce the most improvement.
Although all dissipative elements in the circuit produce
losses, the following are the main sources:
1. The supply current into V CC . The V CC current is the sum
of the DC supply current and the MOSFET driver and
control currents. The DC supply current into the V CC pin
is typically about 1mA. The driver current results from
switching the gate capacitance of the power MOSFET;
this current is typically much larger than the DC current.
Each time the MOSFET is switched on and off, a packet
of gate charge Q G is transferred from the CAP pin to
V CC throughout the external bypass capacitor, C CAP .
The resulting dQ/dt is a current that must be supplied
to the capacitor by the internal regulator.
1
8fC OUT ?
?
Δ V OUT ≤ Δ I L ? ESR +
?
?
?
I Q = 1mA + f ? Q G
P IC = V IN ? I Q
3824fg
10
相关PDF资料 |
PDF描述 |
|---|---|
| ADM695SQ | IC SUPERVISOR MPU 4.65V 16CDIP |
| VI-2WH-EW-F1 | CONVERTER MOD DC/DC 52V 100W |
| SRP1235-R82M | INDUCTOR 820NH 25A SMD |
| LTC1735CF#TRPBF | IC REG CTRLR BUCK PWM CM 20TSSOP |
| VI-2WF-EY-B1 | CONVERTER MOD DC/DC 72V 50W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 74AUP1G0832GW-G | 功能描述:逻辑门 1.8V LOW-POW 3-INPUT AND-OR RoHS:否 制造商:Texas Instruments 产品:OR 逻辑系列:LVC 栅极数量:2 线路数量（输入/输出）:2 / 1 高电平输出电流:- 16 mA 低电平输出电流:16 mA 传播延迟时间:3.8 ns 电源电压-最大:5.5 V 电源电压-最小:1.65 V 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:DCU-8 封装:Reel |
| 74AUP1G08FS3-7 | 功能描述:AND Gate IC 1 Channel 4-X2DFN (0.80x0.80) 制造商:diodes incorporated 系列:74AUP 包装:剪切带（CT） 零件状态:有效 逻辑类型:与门 电路数:1 输入数:2 特性:- 电压 - 电源:0.8 V ~ 3.6 V 电流 - 静态（最大值）:0.5μA 电流 - 输出高，低:4mA，4mA 逻辑电平 - 低:0.7 V ~ 0.9 V 逻辑电平 - 高:1.6 V ~ 2 V 不同 V，最大 CL 时的最大传播延迟:6.2ns @ 3.3V，30pF 工作温度:-40°C ~ 125°C 安装类型:表面贴装 供应商器件封装:4-X2DFN（0.80x0.80） 封装/外壳:4-XFDFN 裸露焊盘 标准包装:1 |
| 74AUP1G08FW4-7 | 功能描述:逻辑门 AUP CMOS 2-Input AND 6.3pF 0.8 to 3.6 RoHS:否 制造商:Texas Instruments 产品:OR 逻辑系列:LVC 栅极数量:2 线路数量（输入/输出）:2 / 1 高电平输出电流:- 16 mA 低电平输出电流:16 mA 传播延迟时间:3.8 ns 电源电压-最大:5.5 V 电源电压-最小:1.65 V 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:DCU-8 封装:Reel |
| 74AUP1G08FW5-7 | 功能描述:AND Gate IC 1 Channel X1-DFN1010-6 制造商:diodes incorporated 系列:74AUP 包装:剪切带（CT） 零件状态:有效 逻辑类型:与门 电路数:1 输入数:2 特性:- 电压 - 电源:0.8 V ~ 3.6 V 电流 - 静态（最大值）:0.5μA 电流 - 输出高，低:4mA，4mA 逻辑电平 - 低:0.7 V ~ 0.9 V 逻辑电平 - 高:1.6 V ~ 2 V 不同 V，最大 CL 时的最大传播延迟:6.2ns @ 3.3V，30pF 工作温度:-40°C ~ 125°C 安装类型:表面贴装 供应商器件封装:X1-DFN1010-6 封装/外壳:6-XDFN 标准包装:1 |
| 74AUP1G08FX4-7 | 功能描述:AND Gate IC 1 Channel X2-DFN1409-6 制造商:diodes incorporated 系列:74AUP 包装:剪切带（CT） 零件状态:有效 逻辑类型:与门 电路数:1 输入数:2 特性:- 电压 - 电源:0.8 V ~ 3.6 V 电流 - 静态（最大值）:0.5μA 电流 - 输出高，低:4mA，4mA 逻辑电平 - 低:0.7 V ~ 0.9 V 逻辑电平 - 高:1.6 V ~ 2 V 不同 V，最大 CL 时的最大传播延迟:6.2ns @ 3.3V，30pF 工作温度:-40°C ~ 125°C 安装类型:表面贴装 供应商器件封装:X2-DFN1409-6 封装/外壳:6-XFDFN 标准包装:1 |
发布紧急采购，3分钟左右您将得到回复。