- 您现在的位置：买卖IC网 > PDF目录14190 > LT1617ES5#TRM (Linear Technology)IC REG INV ADJ 0.35A TSOT23-5 PDF资料下载
参数资料
| 型号： | LT1617ES5#TRM |
| 厂商： | Linear Technology |
| 文件页数： | 5/8页 |
| 文件大小： | 0K |
| 描述： | IC REG INV ADJ 0.35A TSOT23-5 |
| 标准包装： | 500 |
| 类型： | 反相 |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 可调至 -34V |
| 输入电压： | 1.2 V ~ 15 V |
| 电流 - 输出： | 350mA |
| 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： | SOT-23-5 细型，TSOT-23-5 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | TSOT-23-5 |
| 其它名称： | LT1617ES5 LT1617ES5-ND |
LT1617/LT1617-1
APPLICATIO S I FOR ATIO
Choosing an Inductor
Several recommended inductors that work well with the
LT1617 and LT1617-1 are listed in Table 1, although there
are many other manufacturers and devices that can be
used. Consult each manufacturer for more detailed infor-
mation and for their entire selection of related parts. Many
different sizes and shapes are available. Use the equations
and recommendations in the next few sections to find the
correct inductance value for your design.
For higher output voltages, the formula above will give
large inductance values. For a 2V to 20V converter (typical
LCD bias application), a 47 μ H inductor is called for with
the above equation, but a 10 μ H or 22 μ H inductor could be
used without excessive reduction in maximum output
current.
Inductor Selection—Inverting Charge Pump Regulator
For the inverting regulator, the voltage seen by the internal
Table 1. Recommended Inductors
PART VALUE ( μ H) MAX DCR ( ? )
LQH3C4R7 4.7 0.26
LQH3C100 10 0.30
LQH3C220 22 0.92
VENDOR
Murata
(714) 852-2001
www.murata.com
power switch is equal to the sum of the absolute value of
the input and output voltages, so that generating high
output voltages from a high input voltage source will often
exceed the 36V maximum switch rating. For instance, a
12V to – 30V converter using the inverting topology would
CD43-4R7
CD43-100
CDRH4D18-4R7
CDRH4D18-100
DO1608-472
DO1608-103
D01608-223
4.7
10
4.7
10
4.7
10
22
0.11
0.18
0.16
0.20
0.09
0.16
Sumida
(847) 956-0666
www.sumida.com
Coilcraft
(847) 639-6400
www.coilcraft.com
generate 42V on the SW pin, exceeding its maximum
rating. For such a system, an inverting charge pump is the
best topology.
The formula below calculates the approximate inductor
value to be used for an inverting charge pump regulator
using the LT1617. As for the boost inductor selection, a
Inductor Selection—Inverting Regulator
The formula below calculates the appropriate inductor
larger or smaller value can be used. For designs with
varying V IN such as battery powered applications, use the
minimum V IN value in the equation below.
V OUT ? V IN ( ) + V D
value to be used for an inverting regulator using the
LT1617 or LT1617-1 (or at least provides a good starting
point). This value provides a good tradeoff in inductor size
and system performance. Pick a standard inductor close
L =
MIN
I LIM
t OFF
to this value (both inductors should be the same value). A
larger value can be used to slightly increase the available
output current, but limit it to around twice the value
calculated below, as too large of an inductance will in-
crease the output voltage ripple without providing much
additional output current. A smaller value can be used
(especially for systems with output voltages greater than
12V) to give a smaller physical size. Inductance can be
calculated as:
Current Limit Overshoot
For the constant off-time control scheme of the LT1617,
the power switch is turned off only after the 350mA (or
100mA) current limit is reached. There is a 100ns delay
between the time when the current limit is reached and
when the switch actually turns off. During this delay, the
inductor current exceeds the current limit by a small
amount. The peak inductor current can be calculated by:
L = 2 ?
?
? t OFF
?
I PEAK LIM + ?
? V IN ( MAX ) ? V SAT ?
? 100 ns
? V OUT + V D
? I LIM
?
?
= I
? L ?
where V D = 0.4V (Schottky diode voltage), I LIM = 350mA or
100mA, and t OFF = 400ns.
Where V SAT = 0.25V (switch saturation voltage). The
current overshoot will be most evident for systems with
high input voltages and for systems where smaller induc-
5
相关PDF资料 |
PDF描述 |
|---|---|
| MAX6865UK44D3L+T | IC MPU SUPERVISOR SOT23-5 |
| VI-J5H-CZ-F2 | CONVERTER MOD DC/DC 52V 25W |
| MAX6865UK44D2L+T | IC MPU SUPERVISOR SOT23-5 |
| MAX6865UK42D3L+T | IC MPU SUPERVISOR SOT23-5 |
| ESC26DRTH-S13 | CONN EDGECARD 52POS .100 EXTEND |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1617ES5TRMPBF | 制造商:Linear Technology 功能描述:DC-DC Conv.Micropower Inverting TSOT23-5 |
| LT1618 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Constant-Current/Constant-Voltage 1.4MHz Step-Up DC/DC Converter |
| LT1618_1 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Constant-Current/Constant-Voltage 1.4MHz Step-Up DC/DC Converter |
| LT1618EDD | 功能描述:IC REG BOOST ADJ 1.5A 10DFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:500 系列:- 类型:切换式电容器（充电泵），反相 输出类型:固定 输出数:1 输出电压:-3V 输入电压:2.3 V ~ 5.5 V PWM 型:Burst Mode? 频率 - 开关:900kHz 电流 - 输出:100mA 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:SOT-23-6 细型，TSOT-23-6 包装:带卷 (TR) 供应商设备封装:TSOT-23-6 其它名称:LTC1983ES6-3#TRMTR |
| LT1618EDD#PBF | 功能描述:IC REG BOOST ADJ 1.5A 10DFN 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。