参数资料
| 型号： | LT1934IDCB-1#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 10/20页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 60MA 6DFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1.25 V ~ 28 V |
| 输入电压： | 3.2 V ~ 34 V |
| PWM 型： | Burst Mode? |
| 电流 - 输出： | 60mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 6-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 6-DFN-EP（2x3） |
LT1934/LT1934-1
APPLICATIONS INFORMATION
capacitor is subject to large surge currents if the LT1934
circuit is connected to a low impedance supply, and that
some electrolytic capacitors (in particular tantalum) must
be speci?ed for such use.
Output Capacitor and Output Ripple
The output capacitor ?lters the inductor’s ripple current and
stores energy to satisfy the load current when the LT1934
is quiescent. In order to keep output voltage ripple low, the
impedance of the capacitor must be low at the LT1934’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 approxi-
mately I LIM ? ESR. ESR should be less than ~150mΩ for
the LT1934 and less than ~500mΩ for the LT1934-1.
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:
C OUT > 50 ? L ? (I LIM /V OUT ) 2
For example, an LT1934 producing 3.3V with L = 47μH
requires 33μF. This value can be relaxed if small circuit
size is more important than low output ripple.
Sanyo’s POSCAP series in B-case and C-case sizes
provides very good performance in a small package for
the LT1934. Similar performance in traditional tantalum
capacitors requires a larger package (C- or D-case).
Table 3. Capacitor Vendors
The LT1934-1, with its lower switch current, can use a
B-case tantalum capacitor.
With a high quality capacitor ?ltering the ripple current
from the inductor, the output voltage ripple is determined
by the hysteresis and delay in the LT1934’s feedback
comparator. This ripple can be reduced further by adding
a small (typically 10pF) phase lead capacitor between the
output and the feedback pin.
Ceramic Capacitors
Ceramic capacitors are small, robust and have very low
ESR. However, ceramic capacitors can cause problems
when used with the LT1934.
Not all ceramic capacitors are suitable. X5R and X7R
types are stable over temperature and applied voltage
and give dependable service. Other types (Y5V and Z5U)
have very large temperature and voltage coef?cients of
capacitance. In the application circuit they may have only
a small fraction of their nominal capacitance and voltage
ripple may be much larger than expected.
Ceramic capacitors are piezoelectric. The LT1934’s switch-
ing frequency depends on the load current, and at light
loads the LT1934 can excite the ceramic capacitor at audio
frequencies, generating audible noise. If this is unaccept-
able, use a high performance electrolytic capacitor at the
output. The input capacitor can be a parallel combination
of a 2.2μF ceramic capacitor and a low cost electrolytic
capacitor. The level of noise produced by the LT1934-1
VENDOR
Panasonic
PHONE
(714) 373-7366
URL
www.panasonic.com
PART SERIES
Ceramic,
COMMENTS
Polymer,
Tantalum
EEF Series
Kemet
Sanyo
(864) 963-6300
(408) 749-9714
www.kemet.com
www.sanyovideo.com
Ceramic,
Tantalum
Ceramic,
Polymer,
T494, T495
POSCAP
Tantalum
Murata
AVX
(404) 436-1300
www.murata.com
www.avxcorp.com
Ceramic,
Ceramic,
Tantalum
TPS Series
Taiyo Yuden
(864) 963-6300
www.taiyo-yuden.com Ceramic
1934fe
10
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1934IS6 | 制造商:LINER 制造商全称:Linear Technology 功能描述:Micropower Step-Down Switching Regulators in ThinSOT |
| LT1934IS6#PBF | 制造商:Linear Technology 功能描述:Conv DC-DC Single Step Down 3.2V to 34V 6-Pin TSOT-23 制造商:Linear Technology 功能描述:SP-SWREG/Monolithic, Cut Tape 300mA (Iout), Micropower Step-Down |
| LT1934IS6#TR | 功能描述:IC REG BUCK ADJ 0.3A SOT23-6 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:2,500 系列:- 类型:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 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-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
| LT1934IS6#TRM | 功能描述:IC REG BUCK ADJ 0.3A SOT23-6 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: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 |
| LT1934IS6#TRMPBF | 功能描述:IC REG BUCK ADJ 0.3A SOT23-6 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:升压（升压） 输出类型:可调式 输出数:1 输出电压:1.24 V ~ 30 V 输入电压:1.5 V ~ 12 V PWM 型:电流模式，混合 频率 - 开关:600kHz 电流 - 输出:500mA 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-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:8-SOIC |
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