- 您现在的位置：买卖IC网 > PDF目录17247 > IRDC3856W (International Rectifier)BOARD EVAL SUPIRBUCK IR3856W PDF资料下载
参数资料
| 型号： | IRDC3856W |
| 厂商： | International Rectifier |
| 文件页数： | 18/34页 |
| 文件大小： | 0K |
| 描述： | BOARD EVAL SUPIRBUCK IR3856W |
| 产品培训模块： | SupIRBuck? Family and POL Design Tools Overview |
| 标准包装： | 1 |
| 系列： | SupIRBuck™ |
| 主要目的： | DC/DC，步降 |
| 输出及类型： | 1，非隔离 |
| 输出电压： | 1.8V |
| 电流 - 输出： | 6A |
| 输入电压： | 12V |
| 稳压器拓扑结构： | 降压 |
| 频率 - 开关： | 600kHz |
| 板类型： | 完全填充 |
| 已供物品： | 板 |
| 已用 IC / 零件： | IR3856W |
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页当前第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页第29页第30页第31页第32页第33页第34页
PD-97506
IR3856WMPbF
Application Information
Design Example:
when an external resistor divider is connected to
the output as shown in figure 11.
Equation (7) can be rewritten as:
R 9 = R 8 ? ? ?
? .......... .......... .......... .... (8)
?
The following example is a typical application for
IR3856W. The application circuit is shown on
page 24.
? V ref
? V o ? V ref
?
?
V in = 12 V ( 13.2V max)
V o = 1.8 V
I o = 6 A
For the calculated values of R8
feedback compensation section.
V OU T
and R9 see
Δ V o ≤ 54mV
F s = 600 kHz
Enabling the IR3856W
As explained earlier, the precise threshold of
IR3624
IR3856W
Fb
R 8
R 9
the Enable lends itself well to implementation of
a UVLO for the Bus Voltage.
V in
Fig. 11. Typical application of the IR3856W for
programming the output voltage
Soft-Start Programming
The soft-start timing can be programmed by
IR3856W
Enable
R 1
R 2
selecting the soft-start capacitance value. From
(1), for a desired start-up time of the converter,
the soft start capacitor can be calculated by
using:
C SS ( μ F ) = T start ( ms ) × 0.02857 .......... (9)
= V EN = 1.2 .......... (5)
V in (min) *
R 2 = R 1
V EN
V o = V ref ? ? ? 1 + 8 ? ? .......... .......... .......... .....(7)
For a typical Enable threshold of V EN = 1.2 V
R 2
R 1 + R 2
.......... (6)
V in( min ) ? V EN
For a V in (min) =10.2V, R 1 =49.9K and R 2 =7.5K is a
good choice.
Programming the frequency
For F s = 600 kHz, select R t = 23.7 k ? , using
Table. 1.
Output Voltage Programming
Output voltage is programmed by reference
voltage and external voltage divider. The Fb pin
is the inverting input of the error amplifier, which
is internally referenced to 0.7V. The divider is
ratioed to provide 0.7V at the Fb pin when the
output is at its desired value. The output voltage
is defined by using the following equation:
? R ?
? R 9 ?
Rev 9.0
Where T start is the desired start-up time (ms).
For a start-up time of 3.5ms, the soft-start
capacitor will be 0.099 μ F. Choose a 0.1 μ F
ceramic capacitor.
Bootstrap Capacitor Selection
To drive the Control FET, it is necessary to
supply a gate voltage at least 4V greater than
the voltage at the SW pin, which is connected
the source of the Control FET . This is achieved
by using a bootstrap configuration, which
comprises the internal bootstrap diode and an
external bootstrap capacitor (C6), as shown in
Fig. 12. The operation of the circuit is as follows:
When the lower MOSFET is turned on, the
capacitor node connected to SW is pulled down
to ground. The capacitor charges towards V cc
through the internal bootstrap diode, which has a
forward voltage drop V D . The voltage V c across
the bootstrap capacitor C6 is approximately
given as
V c ? V cc ? V D .......... .......... ...... (10)
When the upper MOSFET turns on in the next
cycle, the capacitor node connected to SW rises
to the bus voltage V in . However, if the value of
C6 is appropriately chosen,
18
相关PDF资料 |
PDF描述 |
|---|---|
| HK160868NJ-T | INDUCTOR HI FREQ 68NH 5% 0603 |
| LM4040C25IDBZRG4 | IC VREF SHUNT PREC 2.5V SOT-23-3 |
| ASPI-0804T-102M-T | INDUCTOR POWER 1000UH 0804 SMD |
| RCC18DCSN-S288 | CONN EDGECARD 36POS .100 EXTEND |
| CGRB204-G | DIODE GEN PURP 2A 400V DO-214AA |
相关代理商/技术参数 |
参数描述 |
|---|---|
| IRDC3859 | 功能描述:电源管理IC开发工具 User Guide IR3859 Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| IRDC3859 - SUPIRBUCK | 制造商:International Rectifier 功能描述:INTERNATIONAL RECIFIER - GEN 2.1 SUPIRBUCK FAMILY - Bulk |
| IRDC3859 | 制造商:International Rectifier 功能描述:; MCU Supported Families:IR3859; Feature |
| IRDC3863 | 功能描述:电源管理IC开发工具 9999V 999A POL IC RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| IRDC3865 | 功能描述:电源管理IC开发工具 9999V 999A POL IC RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
发布紧急采购，3分钟左右您将得到回复。