- 您现在的位置：买卖IC网 > PDF目录14819 > LT3685EMSE#PBF (Linear Technology)IC REG BUCK ADJ 2A 10MSOP PDF资料下载
参数资料
| 型号： | LT3685EMSE#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 13/24页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK ADJ 2A 10MSOP |
| 标准包装： | 50 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.79 V ~ 20 V |
| 输入电压： | 3.6 V ~ 36 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 200kHz ~ 2.4MHz |
| 电流 - 输出： | 2A |
| 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： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽）裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 10-MSOP |
| 产品目录页面： | 1332 (CN2011-ZH PDF) |
LT3685
APPLICATIONS INFORMATION
forms a high quality (under damped) tank circuit. If the
LT3685 circuit is plugged into a live supply, the input volt-
age can ring to twice its nominal value, possibly exceeding
the LT3685’s rating. This situation is easily avoided (see
the Hot Plugging Safely section).
Frequency Compensation
The LT3685 uses current mode control to regulate the
output. This simpli?es loop compensation. In particular, the
LT3685 does not require the ESR of the output capacitor
most cases a zero is required and comes from either the
output capacitor ESR or from a resistor R C in series with
C C . This simple model works well as long as the value
of the inductor is not too high and the loop crossover
frequency is much lower than the switching frequency.
A phase lead capacitor (C PL ) across the feedback divider
may improve the transient response. Figure 3 shows the
transient response when the load current is stepped from
500mA to 1500mA and back to 500mA.
for stability, so you are free to use ceramic capacitors to
achieve low output ripple and small circuit size. Frequency
compensation is provided by the components tied to the
V C pin, as shown in Figure 2. Generally a capacitor (C C )
LT3685
CURRENT MODE
POWER STAGE
g m = 3.5mho
ERROR
AMPLIFIER
SW
R1
C PL
OUTPUT
and a resistor (R C ) in series to ground are used. In addi-
tion, there may be lower value capacitor in parallel. This
capacitor (C F ) is not part of the loop compensation but
is used to ?lter noise at the switching frequency, and is
3M
g m =
420μmho
FB
0.8V
ESR
+
C1
C1
required only if a phase-lead capacitor is used or if the
POLYMER
CERAMIC
output capacitor has high ESR.
V C
GND
OR
TANTALUM
Loop compensation determines the stability and transient
performance. Designing the compensation network is a
bit complicated and the best values depend on the ap-
plication and in particular the type of output capacitor. A
practical approach is to start with one of the circuits in
C F
R C
C C
R2
Figure 2. Model for Loop Response
3685 F02
this data sheet that is similar to your application and tune
the compensation network to optimize the performance.
Stability should then be checked across all operating
conditions, including load current, input voltage and
temperature. The LT1375 data sheet contains a more
thorough discussion of loop compensation and describes
how to test the stability using a transient load. Figure 2
shows an equivalent circuit for the LT3685 control loop.
The error ampli?er is a transconductance ampli?er with
?nite output impedance. The power section, consisting of
the modulator, power switch and inductor, is modeled as
a transconductance ampli?er generating an output cur-
V OUT
100mV/DIV
I L
0.5A/DIV
V IN = 12V; FRONT PAGE APPLICATION
rent proportional to the voltage at the V C pin. Note that
10μs/DIV
3685 F03
the output capacitor integrates this current, and that the
capacitor on the V C pin (C C ) integrates the error ampli-
?er output current, resulting in two poles in the loop. In
Figure 3. Transient Load Response of the LT3685 Front Page
Application as the Load Current is Stepped from 500mA to
1500mA. V OUT = 3.3V
3685fb
13
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3388EMSE-1#PBF | IC REG BUCK SYNC 50MA 10MSOP |
| LTC3523EUD#PBF | IC REG BUCK BOOST SYNC ADJ 16QFN |
| LT3991EMSE-5#PBF | IC REG BUCK 5V 1.2A 10-MSOP |
| VI-JVN-EY-F3 | CONVERTER MOD DC/DC 18.5V 50W |
| LT3511EMS#PBF | IC REG FLYBACK ISOLATD 16-MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3685EMSE-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.4MHz Step-Down Switching Regulator |
| LT3685IDD#PBF | 功能描述:IC REG BUCK ADJ 2A 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 |
| LT3685IDD#TRPBF | 功能描述:IC REG BUCK ADJ 2A 10DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 设计资源:Design Support Tool 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:3V 输入电压:0.75 V ~ 2 V PWM 型:- 频率 - 开关:- 电流 - 输出:100mA 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:SOT-23-5 细型，TSOT-23-5 包装:剪切带 (CT) 供应商设备封装:TSOT-23-5 其它名称:AS1323-BTTT-30CT |
| LT3685IDD-PBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.4MHz Step-Down Switching Regulator |
| LT3685IDD-TRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:36V, 2A, 2.4MHz Step-Down Switching Regulator |
发布紧急采购，3分钟左右您将得到回复。