- 您现在的位置：买卖IC网 > PDF目录20516 > 750106 (Wurth Electronics Inc)BOARD EVAL FOR LT3575 PDF资料下载
参数资料
| 型号： | 750106 |
| 厂商： | Wurth Electronics Inc |
| 文件页数： | 7/24页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL FOR LT3575 |
| 标准包装： | 1 |
| 主要目的： | DC/DC，步降 |
| 输出及类型： | 1，隔离 |
| 功率 - 输出： | 10W |
| 输出电压： | 5V |
| 电流 - 输出： | 2A（最小值） |
| 输入电压： | 10 ~ 28 VDC |
| 稳压器拓扑结构： | 回扫 |
| 板类型： | 完全填充 |
| 已供物品： | 板 |
| 已用 IC / 零件： | LT3575 |
| 相关产品： | LT3575IFE#TRPBF-ND - IC REG FLYBACK ISO ADJ 16TSSOP LT3575IFE#PBF-ND - IC REG FLYBACK ISO ADJ 16TSSOP LT3575EFE#TRPBF-ND - IC REG FLYBACK ISO ADJ 16TSSOP LT3575EFE#PBF-ND - IC REG FLYBACK ISO ADJ 16TSSOP |
| 其它名称： | 732-3306 |
LT3575
OPERATION
The LT3575 is a current mode switching regulator IC
designed speci?cally for the isolated ?yback topology. The
special problem normally encountered in such circuits is
that information relating to the output voltage on the isolated
secondary side of the transformer must be communicated to
the primary side in order to maintain regulation. Historically,
this has been done with optoisolators or extra transformer
windings. Optoisolator circuits waste output power and
the extra components increase the cost and physical size
of the power supply. Optoisolators can also exhibit trouble
due to limited dynamic response, nonlinearity, unit-to-unit
variation and aging over life. Circuits employing extra
transformer windings also exhibit de?ciencies. Using an
extra winding adds to the transformer’s physical size and
cost, and dynamic response is often mediocre.
The LT3575 derives its information about the isolated
output voltage by examining the primary side ?yback
pulse waveform. In this manner, no optoisolator nor extra
transformer winding is required for regulation. The output
voltage is easily programmed with two resistors. Since this
IC operates in boundary control mode, the output voltage is
calculated from the switch pin when the secondary current
is almost zero. This method improves load regulation
without external resistors and capacitors.
The Block Diagram shows an overall view of the system.
Many of the blocks are similar to those found in traditional
switching regulators including: internal bias regulator,
oscillator, logic, current ampli?er and comparator, driver,
and output switch. The novel sections include a special
?yback error ampli?er and a temperature compensation
circuit. In addition, the logic system contains additional
logic for boundary mode operation, and the sampling
error ampli?er.
The LT3575 features a boundary mode control method,
where the part operates at the boundary between continuous
conduction mode and discontinuous conduction mode. The
V C pin controls the current level just as it does in normal
current mode operation, but instead of turning the switch
on at the start of the oscillator period, the part detects
when the secondary side winding current is zero.
Boundary Mode Operation
Boundary mode is a variable frequency, current-mode
switching scheme. The switch turns on and the inductor
current increases until a V C pin controlled current limit. The
voltage on the SW pin rises to the output voltage divided
by the secondary-to-primary transformer turns ratio plus
the input voltage. When the secondary current through
the diode falls to zero, the SW pin voltage falls below V IN .
A discontinuous conduction mode (DCM) comparator
detects this event and turns the switch back on.
Boundary mode returns the secondary current to zero
every cycle, so the parasitic resistive voltage drops do not
cause load regulation errors. Boundary mode also allows
the use of a smaller transformer compared to continuous
conduction mode and no subharmonic oscillation.
At low output currents the LT3575 delays turning on the
switch, and thus operates in discontinuous mode. Unlike
a traditional ?yback converter, the switch has to turn on
to update the output voltage information. Below 0.6V on
the V C pin, the current comparator level decreases to
its minimum value, and the internal oscillator frequency
decreases in frequency. With the decrease of the internal
oscillator, the part starts to operate in DCM. The output
current is able to decrease while still allowing a minimum
switch off-time for the error amp sampling circuitry. The
typical minimum internal oscillator frequency with V C
equal to 0V is 40kHz.
3575f
7
相关PDF资料 |
PDF描述 |
|---|---|
| MBR1545CT | DIODE SCHOTTKY 45V 7.5A TO220AB |
| IR2233JTR | IC DRIVER 3-PHASE BRIDGE 44-PLCC |
| 356-015-525-101 | CARDEDGE 15POS .156 BLACK |
| IR2153D | IC HALF BRIDGE DRIVER W/DIO 8DIP |
| 356-015-521-104 | CARDEDGE 15POS .156 BLACK |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 750-106 | 制造商:GLENAIR 制造商全称:Glenair, Inc. 功能描述:Pre-Terminated Assemblies |
| 750107 | 功能描述:BOARD EVAL FOR LT3748 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 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 |
| 7501078 | 制造商:ARK-LES CONNECTORS 功能描述:.240 SQUARED RING TERMINAL 16-14 AWG 6 STUD SIZE |
| 750108 | 功能描述:BOARD EVAL FOR LT3748 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 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 |
| 750109 | 制造商:Pilz International 功能描述:CONTACT MODULE 3NO/1NC 24V 制造商:PILZ 功能描述:CONTACT MODULE, 3NO/1NC, 24V, 30OHM 制造商:PILZ 功能描述:CONTACT MODULE, 3NO/1NC, 24V, 30OHM; Coil Voltage VDC Nom:24V; Contact Current Max:6A; Contact Voltage AC Nom:240V; Contact Voltage DC Max:24V; Coil Resistance:30ohm; Contact Configuration:3PST-NO, SPST-NC; Average Power ;RoHS Compliant: Yes |
发布紧急采购，3分钟左右您将得到回复。