- 您现在的位置：买卖IC网 > PDF目录14459 > LTC3546EUFD#PBF (Linear Technology)IC REG BUCK SYNC ADJ 1A/2A 28QFN PDF资料下载
参数资料
| 型号： | LTC3546EUFD#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 19/30页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 1A/2A 28QFN |
| 标准包装： | 73 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 2 |
| 输出电压： | 0.6 V ~ 5 V |
| 输入电压： | 2.25 V ~ 5.5 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 2.25MHz，750kHz ~ 4MHz |
| 电流 - 输出： | 1A，2A |
| 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： | 28-WFQFN 裸露焊盘 |
| 包装： | 管件 |
| 供应商设备封装： | 28-QFN（4x5） |
| 产品目录页面： | 1335 (CN2011-ZH PDF) |
第1页第2页第3页第4页第5页第6页第7页第8页第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页当前第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页第29页第30页
LTC3546
APPLICATIONS INFORMATION
The LTC3546 can also track an external voltage during
startup by using an external voltage divider to the TRACK/SS
pin, and also insuring that the ramp rate on the TRACK/SS
pin is slower than the internal 1.2ms ramp rate.
As indicated in Figure 3, a resistor divider from an external
voltage can be connected to the TRACK/SS pin to allow
the start-up of V OUT to ratiometrically track an external
voltage V X .
V X
V OUT
V OUT = V X ?
For V TRACKSS < 0.6V
R2X
R1X + R2X
V X
?
R1 + R2
R2
V OUT
TIME
3546 F04
Figure 4. Coincident Tracking
V X
R1X
LTC3546
R1
R2X
V TRACK/SS
V FB
3546 F03
R2
V OUT
Figure 3. Tracking External Voltages
Coincident tracking is where V OUT = V X during startup. To
implement coincident tracking R1X in Figure 3 is set to the
same value as R1 and R2X to the value of R2. Coincident
tracking is illustrated in Figure 4. The voltage at TRACK/SS
when V X is at its final value should be ≥0.8V (sufficient
margin above the 0.6V reference voltage).
Ratiometric tracking is where V OUT ≠ V X during startup
but rather, it is set to some fractional value of V X . To
implement ratiometric tracking (as illustrated in Figure
5), set R1X in Figure 3 to the same value as R1 and R2X
to the value of R2 + ΔR. The ΔR added to R2 should be
sufficient so that the TRACK/SS voltage is ≥ 0.8V when
V X is at its final value.
The internal 1.15μA pull up current on TRACK/SS can cause
a tracking error at V OUT when using a resistor divider on
TRACK/SS. For example, if a 59k resistor is chosen for
R2X, the R2X current will be about 10μA (0.6V/59k). In this
case, the 1.15μA internal current source will cause about
11% (1.15μA/10μA) tracking error, which is about 66mV
referred to V FB . This is acceptable for most applications.
If a better tracking accuracy is required, the value of R2X
can be reduced or the 1.15μA current can be taken into
account in the equations.
TIME
3546 F05
Figure 5. Ratiometric Tracking
Table 2 summarizes the different states in which the
TRACK/SS can be used.
Table 2. The States of the TRACK/SS Pin
TRACK/SS PIN RESULT
Capacitor to Ground External Soft-Start
Floating Internal Soft-Start
Resistor Divider V OUT Tracking an External Voltage V X
Regardless of the mode implemented, the TRACK/SS pin
should never be pulled high externally as this will result
in excessive current during shutdown.
The LTC3546 can smoothly handle starting up into a pre-
biased output. The tracking function will pick up from the
pre-biased voltage and ramp the output up from there.
Mode Selection
The SYNC/MODE pin is a multipurpose pin which provides
mode selection and frequency synchronization. Connecting
this pin to V IN enables Burst Mode operation for both reg-
19
For more information www.linear.com/3546
3546fc
相关PDF资料 |
PDF描述 |
|---|---|
| LTC1514IS8-5#PBF | IC REG MULTI CONFIG 5V 8SOIC |
| LT3510IFE#PBF | IC REG BUCK ADJ 2A DL 20TSSOP |
| VE-J2H-EX-B1 | CONVERTER MOD DC/DC 52V 75W |
| VE-J23-EX-B1 | CONVERTER MOD DC/DC 24V 75W |
| VE-J22-EX-B1 | CONVERTER MOD DC/DC 15V 75W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3546EUFDTRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
| LTC3546IFE#PBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP 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 |
| LTC3546IFE#TRPBF | 功能描述:IC REG BUCK SYNC ADJ DL 28TSSOP 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 |
| LTC3546IFEPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
| LTC3546IFETRPBF | 制造商:LINER 制造商全称:Linear Technology 功能描述:Dual Synchronous, 3A/1A or 2A/2A Confi gurable Step-Down DC/DC Regulator |
发布紧急采购，3分钟左右您将得到回复。