- 您现在的位置：买卖IC网 > PDF目录14819 > LTC3631EDD#PBF (Linear Technology)IC REG BUCK SYNC ADJ 0.1A 8DFN PDF资料下载
参数资料
| 型号： | LTC3631EDD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/22页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 0.1A 8DFN |
| 标准包装： | 121 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.8 V ~ 45 V |
| 输入电压： | 4.5 V ~ 45 V |
| PWM 型： | Burst Mode? |
| 电流 - 输出： | 100mA |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-WFDFN 裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 8-DFN-EP（3x3） |
| 产品目录页面： | 1335 (CN2011-ZH PDF) |
LTC3631
APPLICATIONS INFORMATION
? ? ? 1 – OUT ?
L = ?
L MIN =
The basic LTC3631 application circuit is shown on the front
page of this data sheet. External component selection is
determined by the maximum load current requirement and
begins with the selection of the peak current programming
resistor, R ISET . The inductor value L can then be determined,
followed by capacitors C IN and C OUT .
Peak Current Resistor Selection
The peak current comparator has a maximum current limit
of 225mA nominally, which results in a maximum aver-
age current of 112mA. For applications that demand less
current, the peak current threshold can be reduced to as
little as 50mA. This lower peak current allows the use of
lower value, smaller components (input capacitor, output
capacitor and inductor), resulting in lower input supply
ripple and a smaller overall DC/DC converter.
The threshold can be easily programmed with an ap-
propriately chosen resistor (R ISET ) between the I SET pin
and ground. The value of resistor for a particular peak
current can be computed by using Figure 1 or the follow-
ing equation:
R ISET = I PEAK ? 4.5 ? 10 6
where 50mA < I PEAK < 225mA.
The peak current is internally limited to be within the
range of 50mA to 225mA. Shorting the I SET pin to ground
programs the current limit to 50mA, and leaving it floating
sets the current limit to the maximum value of 225mA.
When selecting this resistor value, be aware that the
maximum average output current for this architecture is
limited to half of the peak current. Therefore, be sure to
select a value that sets the peak current with enough mar-
gin to provide adequate load current under all foreseeable
operating conditions.
Inductor Selection
The inductor, input voltage, output voltage and peak cur-
rent determine the switching frequency of the LTC3631.
For a given input voltage, output voltage and peak current,
the inductor value sets the switching frequency when the
output is in regulation. A good first choice for the inductor
value can be determined by the following equation:
? V OUT ? ? V ?
? f ? I PEAK ? ? V IN ?
The variation in switching frequency with input voltage
and inductance is shown in the following two figures for
typical values of V OUT . For lower values of I PEAK , multiply
the frequency in Figure 2 and Figure 3 by 225mA/I PEAK .
An additional constraint on the inductor value is the
LTC3631’s 100ns minimum on-time of the high side switch.
Therefore, in order to keep the current in the inductor well
controlled, the inductor value must be chosen so that it
is larger than L MIN , which can be computed as follows:
V IN(MAX) ? t ON(MIN)
I PEAK(MAX)
1100
1000
900
800
700
600
500
400
300
200
100
0
20
MAXIMUM LOAD CURRENT (mA)
Figure 1. R ISET Selection
30 40 50 60 70 80 90 100
3631 F01
where V IN(MAX) is the maximum input supply voltage for
the application, t ON(MIN) is 100ns, and I PEAK(MAX) is the
maximum allowed peak inductor current. Although the
above equation provides the minimum inductor value,
higher efficiency is generally achieved with a larger inductor
value, which produces a lower switching frequency. For a
given inductor type, however, as inductance is increased
DC resistance (DCR) also increases. Higher DCR trans-
lates into higher copper losses and lower current rating,
both of which place an upper limit on the inductance. The
recommended range of inductor values for small surface
mount inductors as a function of peak current is shown in
Figure 4. The values in this range are a good compromise
between the trade-offs discussed above. For applications
3631fe
10
For more information www.linear.com/LTC3631
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3631EDD-5#PBF | IC REG BUCK SYNC 5V 0.1A 8DFN |
| VI-J52-EY-F2 | CONVERTER MOD DC/DC 15V 50W |
| LTC3388EDD-3#PBF | IC REG BUCK SYNC 50MA 10DFN |
| LT3682EDD#PBF | IC REG BUCK ADJ 1A 12DFN |
| LTC3388EMSE-3#PBF | IC REG BUCK SYNC 50MA 10MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3631EMS8E#PBF | 功能描述:IC REG BUCK SYNC ADJ 0.1A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| LTC3631EMS8E#TRPBF | 功能描述:IC REG BUCK SYNC ADJ 0.1A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC3631EMS8E-3.3#PBF | 功能描述:IC REG BUCK SYNC 3.3V 0.1A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
| LTC3631EMS8E-3.3#TRPBF | 功能描述:IC REG BUCK SYNC 3.3V 0.1A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V，1.5V，1.8V，2.5V 输入电压:2.7 V ~ 20 V PWM 型:- 频率 - 开关:- 电流 - 输出:50mA 同步整流器:是 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 包装:带卷 (TR) 供应商设备封装:10-MSOP 裸露焊盘 |
| LTC3631EMS8E-5#PBF | 功能描述:IC REG BUCK SYNC 5V 0.1A 8MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:250 系列:- 类型:降压（降压） 输出类型:固定 输出数:1 输出电压:1.2V 输入电压:2.05 V ~ 6 V PWM 型:电压模式 频率 - 开关:2MHz 电流 - 输出:500mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:6-UFDFN 包装:带卷 (TR) 供应商设备封装:6-SON（1.45x1） 产品目录页面:1032 (CN2011-ZH PDF) 其它名称:296-25628-2 |
发布紧急采购，3分钟左右您将得到回复。