参数资料
型号: DC1379A
厂商: Linear Technology
文件页数: 12/22页
文件大小: 0K
描述: BOARD EVAL LTM8025
软件下载: LTM8025 Spice Model
设计资源: DC1379A Design Files
DC1379A Schematic
标准包装: 1
系列: µModule®
主要目的: DC/DC,步降
输出及类型: 1,非隔离
输出电压: 3.3V
电流 - 输出: 3A
输入电压: 5.5 ~ 36 V
稳压器拓扑结构: 降压
频率 - 开关: 250kHz ~ 2MHz
板类型: 完全填充
已供物品:
已用 IC / 零件: LTM8025
相关产品: LTM8025IV#PBF-ND - IC CONVERTER BUCK 3A ADJ 70LGA
LTM8025MPV#PBF-ND - IC CONVERTER BUCK 3A ADJ 70LGA
LTM8025EV#PBF-ND - IC CONVERTER BUCK 3A ADJ 70LGA
LTM8025
APPLICATIONS INFORMATION
Table 2. Switching Frequency vs R T Value
SWITCHING FREQUENCY
0.2MHz
0.3MHz
0.4MHz
0.5MHz
0.6MHz
0.7MHz
0.8MHz
0.9MHz
1MHz
1.2MHz
1.4MHz
1.6MHz
1.8MHz
2MHz
2.2MHz
2.4MHz
R T VALUE
215kΩ
137kΩ
100kΩ
76.8kΩ
63.4kΩ
52.3kΩ
44.2kΩ
38.3kΩ
34.0kΩ
26.7kΩ
21.5kΩ
17.8kΩ
14.7kΩ
12.1kΩ
9.76kΩ
8.25kΩ
voltage, output voltage and switching frequency, but 4V to
5V works well in many applications. In all cases, ensure
that the maximum voltage at the BIAS pin is less than 25V
and that the sum of V IN and BIAS is less than 56V. If BIAS
power is applied from a remote or noisy voltage source, it
may be necessary to apply a decoupling capacitor locally
to the pin.
Load Sharing
Two or more LTM8025’s may be paralleled to produce higher
currents. To do this, tie the V IN , ADJ, V OUT and SHARE
pins of all the paralleled LTM8025’s together. To ensure
that paralleled modules start up together, the RUN/SS pins
may be tied together, as well. If the RUN/SS pins are not
tied together, make sure that the same valued soft-start
capacitors are used for each module. Current sharing can
be improved by synchronizing the LTM8025s. An example
of two LTM8025s configured for load sharing is given in
the Typical Applications section.
Operating Frequency Tradeoffs
It is recommended that the user apply the optimal R T
value given in Table 1 for the input and output operating
condition. System level or other considerations, however,
may necessitate another operating frequency. While the
LTM8025 is flexible enough to accommodate a wide range
of operating frequencies, a haphazardly chosen one may
result in undesirable operation under certain operating or
fault conditions. A frequency that is too high can reduce
efficiency, generate excessive heat or even damage the
LTM8025 if the output is overloaded or short circuited. A
frequency that is too low can result in a final design that has
too much output ripple or too large of an output capacitor.
BIAS Pin Considerations
The BIAS pin is used to provide drive power for the in-
ternal power switching stage and operate other internal
circuitry. For proper operation, it must be powered by at
least 2.8V. If the output voltage is programmed to 2.8V
or higher, BIAS may be simply tied to AUX. If V OUT is less
than 2.8V, BIAS can be tied to V IN or some other voltage
source. If the BIAS pin voltage is too high, the efficiency
of the LTM8025 may suffer. The optimum BIAS voltage is
dependent upon many factors, such as load current, input
Burst Mode Operation
To enhance efficiency at light loads, the LTM8025 auto-
matically switches to Burst Mode operation which keeps
the output capacitor charged to the proper voltage while
minimizing the input quiescent current. During Burst Mode
operation, the LTM8025 delivers single cycle bursts of
current to the output capacitor followed by sleep periods
where the output power is delivered to the load by the output
capacitor. In addition, V IN and BIAS quiescent currents are
each reduced to microamps during the sleep time. As the
load current decreases towards a no load condition, the
percentage of time that the LTM8025 operates in sleep
mode increases and the average input current is greatly
reduced, resulting in higher efficiency.
Burst Mode operation is enabled by tying SYNC to GND.
To disable Burst Mode operation, tie SYNC to a stable
voltage above 0.7V. Do not leave the SYNC pin floating .
Minimum Input Voltage
The LTM8025 is a step-down converter, so a minimum
amount of headroom is required to keep the output in
regulation. In addition, the input voltage required to turn
on is higher than that required to run, and depends upon
8025fc
12
For more information www.linear.com/LTM8025
相关PDF资料
PDF描述
BAV199T-7 DIODE SWITCH 85V 150MW SOT-523
NR8040T101M INDUCTOR 100UH 1A 20% SMD
VE-J3P-CW-F2 CONVERTER MOD DC/DC 13.8V 100W
R1DA-051212/P CONV DC/DC 1W 5V IN 12/12V OUT
F720J157MRC CAP TANT 150UF 6.3V 20% 2824
相关代理商/技术参数
参数描述
DC1379B 制造商:Linear Technology 功能描述:BOARD EVAL LTM8025 制造商:Linear Technology 功能描述:EVAL BOARD, LTM8025 BUCK REGULATOR, Silicon Manufacturer:Linear Technology, Silicon Core Number:LTM8025, Kit Application Type:Power Management - Voltage Regulator, Application Sub Type:Synchronous Buck Regulator , RoHS Compliant: NA
DC1381B01XC_D4X WAF 制造商:Fairchild Semiconductor Corporation 功能描述:
DC1383A-A 功能描述:BOARD DELTA SIGMA ADC LTC2451 RoHS:是 类别:编程器,开发系统 >> 评估板 - 模数转换器 (ADC) 系列:QuikEval™ 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率(每秒):94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源(标准):- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板,软件
DC1384A-A 功能描述:BOARD DELTA SIGMA ADC LTC2452 RoHS:是 类别:编程器,开发系统 >> 评估板 - 模数转换器 (ADC) 系列:QuikEval™ 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:- ADC 的数量:1 位数:12 采样率(每秒):94.4k 数据接口:USB 输入范围:±VREF/2 在以下条件下的电源(标准):- 工作温度:-40°C ~ 85°C 已用 IC / 零件:MAX11645 已供物品:板,软件
DC1385A 功能描述:BOARD EVAL LTM4614 RoHS:否 类别:编程器,开发系统 >> 评估板 - DC/DC 与 AC/DC(离线)SMPS 系列:µModule® 标准包装:1 系列:- 主要目的:DC/DC,步降 输出及类型:1,非隔离 功率 - 输出:- 输出电压:3.3V 电流 - 输出:3A 输入电压:4.5 V ~ 28 V 稳压器拓扑结构:降压 频率 - 开关:250kHz 板类型:完全填充 已供物品:板 已用 IC / 零件:L7981 其它名称:497-12113STEVAL-ISA094V1-ND