- 您现在的位置：买卖IC网 > PDF目录20624 > LT3694IUFD#PBF (Linear Technology)IC REG TRPL BUCK/LINEAR 28QFN PDF资料下载
参数资料
| 型号： | LT3694IUFD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 9/28页 |
| 文件大小： | 338K |
| 描述： | IC REG TRPL BUCK/LINEAR 28QFN |
| 标准包装： | 73 |
| 拓扑： | 降压（降压）（1），线性（LDO）（2） |
| 功能： | 任何功能 |
| 输出数： | 3 |
| 频率 - 开关： | 250kHz ~ 2.5MHz |
| 电压/电流 - 输出 1： | 0.75 V ~ 16 V，2.6A |
| 电压/电流 - 输出 2： | 控制器 |
| 电压/电流 - 输出 3： | 控制器 |
| 带 LED 驱动器： | 无 |
| 带监控器： | 无 |
| 带序列发生器： | 是 |
| 电源电压： | 4 V ~ 36 V |
| 工作温度： | -40°C ~ 125°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-QFN（4x5） |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页当前第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LT3694/LT3694-1
9
36941fb
OPERATION
Unless specifically noted, this data sheet refers to both the
LT3694 and the LT3694-1 generically as the LT3694.
The LT3694 is a constant-frequency, current mode, buck
regulator with an internal power switch plus two low
dropout linear regulator controllers. The three regulators
share common circuitry including input source, voltage
reference, undervoltage lockout, and enable, but are oth-
erwise independent. Operation can be best understood by
referring to the Block Diagram (Figure 1).
If the EN/UVLO pin is below 0.35V (min), the LT3694 is
shut down and draws <2礎 from the input source tied to
V
IN1
. If the EN/UVLO pin is driven above 0.5V (typ), the
internal bias circuits turn on, including the internal regulator,
reference and master oscillator. The switching regulator
will only begin to operate when the EN/UVLO pin reaches
>1.20V (typ). The EN/UVLO pin can be driven from a logic
gate or can be used as an undervoltage lockout by using
a resistor divider to V
IN
.
The switcher is a current mode regulator. Instead of directly
modulating the duty cycle of the power switch, the feedback
loop controls the peak current in the switch during each
cycle. Compared to voltage mode control, current mode
control improves loop dynamics and provides cycle-by-
cycle current limit.
A pulse from the oscillator sets the RS flip-flop and turns
on the internal NPN bipolar power switch. Current in the
switch and the external inductor begins to increase. When
this current exceeds a level determined by the voltage
at V
C1
, the current comparator resets the RS flip-flop,
turning off the switch. The current in the inductor flows
through the external, Schottky, catch diode, and begins to
decrease. The cycle begins again at the next pulse from the
oscillator. In this way, the voltage on the V
C1
pin controls
the current through the inductor to the output. The internal
error amplifier regulates the output voltage by continually
adjusting the V
C1
pin voltage. The threshold for switching
on the V
C1
pin is 0.75V and an active clamp of 2V limits
the output current.
Overcurrent protection is provided by the DA comparator.
The DA comparator senses the catch diode current and
will delay the switch-on cycle if the diode current is too
high at the beginning of a cycle.
The TRK/SS pins override the 0.75V reference for the FB
pins when the TRK/SS pins are below 0.75V. This allows
either coincident or ratiometric supply tracking on start-up
as well as a soft-start capability.
The switch driver operates either from V
IN
or from the BST
pin. An external capacitor is used to generate a voltage at
the BST pin that is higher than the input supply. This al-
lows the driver to saturate the internal bipolar NPN power
switch for efficient operation.
The BIAS pin allows the internal circuitry to draw its cur-
rent from a voltage supply lower than V
IN
, reducing power
dissipation and increasing efficiency. If the voltage on the
BIAS pin falls below 2.7V, then its quiescent current will
flow from V
IN
.
The LDO regulator uses an external NPN pass transistor to
form a linear regulator. The loop is internally compensated
to be stable with a minimum load capacitance of 2.2 礔. The
LDO also has a foldback current limiter available to protect
the external transistor under overload conditions
The overvoltage detection shuts down the LT3694 if the
input voltage goes above 38V. This will prevent the switch
from turning on under high voltage conditions and allows
the LT3694 to survive transient input voltages up to 70V.
相关PDF资料 |
PDF描述 |
|---|---|
| GBM06DCMI-S288 | CONN EDGECARD 12POS .156 EXTEND |
| ECC36DJWN | CONN EDGECARD 72POS .100X.200 |
| GMA50DTBZ-S664 | CONN EDGECARD 100PS R/A .125 SLD |
| CS5460A-BSZR | IC ENERGY METERING 1PHASE 24SSOP |
| EEM08DCMI-S288 | CONN EDGECARD 16POS .156 EXTEND |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LT3695 | 制造商:LINER 制造商全称:Linear Technology 功能描述:1A Fault Tolerant Micropower Step-Down Regulator |
| LT3695EMSE#PBF | 功能描述:IC REG BUCK ADJ 1A 16MSOP 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 |
| LT3695EMSE#TRPBF | 功能描述:IC REG BUCK ADJ 1A 16MSOP 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 |
| LT3695EMSE-3.3#PBF | 功能描述:IC REG BUCK 3.3V 1A 16MSOP 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 |
| LT3695EMSE-3.3#PBF | 制造商:Linear Technology 功能描述:IC STEP-DOWN REGULATOR MSOP-16 |
发布紧急采购，3分钟左右您将得到回复。