- 您现在的位置：买卖IC网 > PDF目录14102 > LT3470EDDB#TRMPBF (Linear Technology)IC REG BUCK ADJ 0.2A 8DFN PDF资料下载
参数资料
| 型号： | LT3470EDDB#TRMPBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 0.2A 8DFN |
| 标准包装： | 500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1.25 V ~ 16 V |
| 输入电压： | 4 V ~ 40 V |
| PWM 型： | Burst Mode? |
| 电流 - 输出： | 200mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 8-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 8-DFN（3x2） |
LT3470
APPLICATIONS INFORMATION
Table 2. Inductor Vendors
VENDOR
Coilcraft
Sumida
Toko
Würth Elektronik
Coiltronics
Murata
URL
www.coilcraft.com
www.sumida.com
www.tokoam.com
www.we-online.com
www.cooperet.com
www.murata.com
PART SERIES
DO1605
ME3220
DO3314
CR32
CDRH3D16/HP
CDRH3D28
CDRH2D18/HP
DB320C
D52LC
WE-PD2 Typ S
WE-TPC Typ S
SD10
LQH43C
LQH32C
INDUCTANCE RANGE (μH)
10 to 47
10 to 47
10 to 47
10 to 47
10 to 33
10 to 47
10 to 15
10 to 27
10 to 47
10 to 47
10 to 22
10 to 47
10 to 47
10 to 15
SIZE (mm)
1.8 × 5.4 × 4.2
2.0 × 3.2 × 2.5
1.4 × 3.3 × 3.3
3.0 × 3.8 × 4.1
1.8 × 4.0 × 4.0
3.0 × 4.0 × 4.0
2.0 × 3.2 × 3.2
2.0 × 3.8 × 3.8
2.0 × 5.0 × 5.0
3.2 × 4.0 × 4.5
1.6 × 3.8 × 3.8
1.0 × 5.0 × 5.0
2.6 × 3.2 × 4.5
1.6 × 2.5 × 3.2
? I
?
C OUT > 50 ? L ? ? LIM ?
be used. It is important to note that inductor saturation
current is reduced at high temperatures—see inductor
vendors for more information.
Input Capacitor
Step-down regulators draw current from the input sup-
ply in pulses with very fast rise and fall times. The input
capacitor is required to reduce the resulting voltage ripple
at the V IN pin of the LT3470 and to force this switching
current into a tight local loop, minimizing EMI. The input
capacitor must have low impedance at the switching
frequency to do this effectively. A 1μF to 2.2μF ceramic
capacitor satisfies these requirements.
If the input source impedance is high, a larger value ca-
pacitor may be required to keep input ripple low. In this
case, an electrolytic of 10μF or more in parallel with a 1μF
ceramic is a good combination. Be aware that the input
capacitor is subject to large surge currents if the LT3470
circuit is connected to a low impedance supply, and that
some electrolytic capacitors (in particular tantalum) must
be specified for such use.
Output Capacitor and Output Ripple
The output capacitor filters the inductor’s ripple current
and stores energy to satisfy the load current when the
LT3470 is quiescent. In order to keep output voltage ripple
low, the impedance of the capacitor must be low at the
LT3470’s switching frequency. The capacitor’s equivalent
series resistance (ESR) determines this impedance. Choose
one with low ESR intended for use in switching regulators.
The contribution to ripple voltage due to the ESR is ap-
proximately I LIM ? ESR. ESR should be less than ~150mΩ.
The value of the output capacitor must be large enough to
accept the energy stored in the inductor without a large
change in output voltage. Setting this voltage step equal
to 1% of the output voltage, the output capacitor must be:
2
? V OUT ?
where I LIM is the top current limit with V FB = 0V (see Elec-
trical Characteristics). For example, an LT3470 producing
3.3V with L = 33μH requires 22μF. The calculated value
can be relaxed if small circuit size is more important than
low output ripple.
Sanyo’s POSCAP series in B-case and provides very good
performance in a small package for the LT3470. Similar
performance in traditional tantalum capacitors requires
a larger package (C-case). With a high quality capacitor
filtering the ripple current from the inductor, the output
voltage ripple is determined by the delay in the LT3470’s
feedback comparator. This ripple can be reduced further
by adding a small (typically 22pF) phase lead capacitor
between the output and the feedback pin.
3470fd
10
相关PDF资料 |
PDF描述 |
|---|---|
| LNK2W682MSEJ | CAP ALUM 6800UF 450V 20% SCREW |
| EBA44DRSD-S288 | CONN EDGECARD 88POS .125 EXTEND |
| CGH602T350X4L | CAP ALUM 6000UF 350V SCREW |
| ECA30DRMT-S288 | CONN EDGECARD 60POS .125 EXTEND |
| RCM15DRMN-S273 | CONN EDGECARD 30POS .156 SQ WW |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3470ETS8 | 制造商:Linear Technology 功能描述:Conv DC-DC Single Step Down 4V to 40V 8-Pin TSOT-23 |
| LT3470ETS8#PBF | 制造商:Linear Technology 功能描述:DC-DC CONVERTER BUCK ADJ 20 制造商:Linear Technology 功能描述:DC-DC CONVERTER, BUCK, ADJ, 200mA, TSOT-23-8; Primary Input Voltage:40V; No. of Outputs:1; Output Current:200mA; No. of Pins:8; Operating Temperature Min:-40C; Operating Temperature Max:85C; Package / Case:8-TSOT-23 ;RoHS Compliant: Yes |
| LT3470ETS8#TR | 制造商:Linear Technology 功能描述:Conv DC-DC Single Step Down 4V to 40V 8-Pin TSOT-23 T/R |
| LT3470ETS8#TRM | 制造商:Linear Technology 功能描述:Conv DC-DC Single Step Down 4V to 40V 8-Pin TSOT-23 T/R |
| LT3470ETS8#TRMPBF | 功能描述:IC REG BUCK ADJ 0.2A TSOT23-8 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。