- 您现在的位置：买卖IC网 > PDF目录1830 > LTC3538EDCB#TRPBF (Linear Technology)IC REG BUCK BOOST SYNC ADJ 8DFN PDF资料下载
参数资料
| 型号： | LTC3538EDCB#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 8/16页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK BOOST SYNC ADJ 8DFN |
| 标准包装： | 2,500 |
| 类型： | 降压（降压），升压（升压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 1.8 V ~ 5.25 V |
| 输入电压： | 2.4 V ~ 5.5 V |
| 频率 - 开关： | 1MHz |
| 电流 - 输出： | 800mA |
| 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： | 8-WFDFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 8-DFN（3x2） |
LTC3538
OPERATION
The LTC3538 provides high ef?ciency, low noise power
for a wide variety of handheld electronic devices. The LTC
proprietary topology allows input voltages above, below
and equal to the output voltage through proper phasing
of the four on-chip MOSFET switches. The error ampli?er
output voltage on V C determines the output duty cycle of the
switches. Since V C is a ?ltered signal, it provides rejection
of frequencies from well below the switching frequency.
The low R DS(ON) , low gate charge synchronous switches
provide high frequency pulse width modulation control at
high ef?ciency. High ef?ciency is achieved at light loads
when Burst Mode operation is selected.
LOW NOISE FIXED FREQUENCY OPERATION
Operating Frequency
The operating frequency is internally ?xed to 1MHz to
maximize overall converter ef?ciency while minimizing
external component size.
Error Ampli?er
The error ampli?er controls the duty cycle of the internal
switches. The loop compensation components are con-
?gured around the ampli?er to provide converter loop
stability. Pulling down the output of the error ampli?er
Internal Current Limit
There are two current limit circuits in the LTC3538. The ?rst
is a high speed peak current limit ampli?er that will shut
off switch A once the input current exceeds ~ 3.5A typical.
The delay to output of this ampli?er is typically 50ns.
The second current limit sources current out of the FB pin
to drop the output voltage once the input average current
exceeds 2A typical. This method provides a closed loop
means of clamping the input current. During conditions
when V OUT is near ground, such as during a short circuit
or during start-up, this threshold is cut to 1A typical,
providing a foldback feature to limit power dissipation. For
this current limit feature to be most effective, the Thevenin
resistance (typically the parallel combination of R1 and
R2) from FB to ground should be greater than 100k.
Reverse Current Limit
During ?xed frequency operation, the LTC3538 operates in
forced continuous conduction mode. The reverse current
limit comparator monitors the inductor current from the
output through switch D. Should this negative inductor
current exceed 500mA typical, the LTC3538 shuts off
switch D.
Four-Switch Control
(V C ) below 0.25V will disable the LTC3538. In shutdown
the LTC3538 will draw only 1.5μA typical from the input
supply. During normal operation the V C pin should be
allowed to ?oat.
V IN
8
PMOS A
V OUT
5
PMOS D
Soft-Start
The converter has an internal voltage mode soft-start
circuit with a nominal duration of 1.5ms. The converter
SW1
7
NMOS B
L1
SW2
6
NMOS C
remains in regulation during soft-start and will therefore
respond to output load transients that occur during this
time. In addition, the output voltage risetime has minimal
dependency on the size of the output capacitor or load.
During soft-start, the converter is forced into PWM
operation regardless of the state of the BURST pin.
3538 FO1
Figure 1. Simpli?ed Diagram of Output Switches
Figure 1 shows a simpli?ed diagram of how the four internal
switches are connected to the inductor, V IN , V OUT and GND.
Figure 2 shows the regions of operation for the LTC3538
as a function of the internal control voltage.
3538fb
8
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3539EDCB-2#TRPBF | IC REG BOOST SYNC ADJ 2A 8DFN |
| LTC3542IDC#TRMPBF | IC REG BUCK SYNC ADJ 0.5A 6DFN |
| LTC3543EDCB#TRPBF | IC REG BUCK SYNC ADJ 0.6A 8DFN |
| LTC3544BEUD#TRPBF | IC REG BUCK SYNC ADJ QUAD 16QFN |
| LTC3545IUD-1#TRPBF | IC REG BUCK SYNC ADJ 0.8A 16QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3539 | 制造商:LINER 制造商全称:Linear Technology 功能描述:400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up |
| LTC3539-2 | 制造商:LINER 制造商全称:Linear Technology 功能描述:400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up |
| LTC3539EDCB#PBF | 制造商:Linear Technology 功能描述: 制造商:Linear Technology 功能描述:DP-SWREG/Monolithic, Cut Tape 2A, 1MHz Synchronous Step-Up DC/DC Converter in 2m |
| LTC3539EDCB#TRMPBF | 功能描述:IC REG BOOST SYNC ADJ 2A 8DFN 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 |
| LTC3539EDCB#TRPBF | 功能描述:IC REG BOOST SYNC ADJ 2A 8DFN 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 |
发布紧急采购，3分钟左右您将得到回复。