- 您现在的位置：买卖IC网 > PDF目录17380 > SP6125EB (Exar Corporation)EVAL BOARD FOR SP6125 PDF资料下载
参数资料
| 型号： | SP6125EB |
| 厂商： | Exar Corporation |
| 文件页数： | 6/12页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR SP6125 |
| 标准包装： | 1 |
| 系列： | * |
General Overview
Overcurrent protection
SP6125
Vin
Using the ON/OFF Function
The Feedback pin serves a dual role of
ON/OFF control. The MOSFET driver is
Gate
Q1
disabled when a voltage greater than 1V is
applied at the FB pin. Maximum voltage rating
of this pin is 5.5V. The controlling signal should
Ov er-Current Comparator
LX
Rs
be applied through a small signal diode as
shown on page 1. Please note that an optional
10k
bleeding resistor across the output helps
keep the output capacitor discharged under no
30uA
Ds
load condition.
Vin - 0.3V
Programming the Output Voltage
To program the output voltage, calculate R2
Figure 3- Overcurrent protection circuit
using the following equation:
? ?
? 1 ? ?
The overcurrent protection circuit functions by
monitoring the voltage across the high-side FET
Q1. When this voltage exceeds 0.3V, the
R 2 =
R 1
? Vout
? Vref
?
?
0 . 3 ? ( 1 . 15 × Iout × Rds ( on ) )
overcurrent comparator triggers and the
controller enters hiccup mode. For example if
Q1 has Rds(on)=0.1 , then the overcurrent will
trigger at I = 0.3V/0.1 =3A. To program a lower
overcurrent use a resistor Rs as shown in figure
1. Calculate Rs from:
Rs = ……… (5)
30 uA
The overcurrent circuit triggers at peak current
through Q1 which is usually about 15% higher
than average output current. Hence the
multiplier 1.15 is used in (5).
Example: A switching MOSFET used with
SP6125 has Rds(on) of 0.1 . Program the over-
current circuit so that maximum output is 2A.
Where:
Vref=0.6 is the reference voltage of the SP6125
R1=200k is a fixed-value resistor that, in
addition to being a voltage divider, it is part of
the compensation network. In order to simplify
compensation calculations, R1 is fixed at
200k .
Soft Start
Soft Start is preset internally to 5ms (nominal).
Internal Soft Start eliminates the need for the
external capacitor CSS that is commonly used
to program this function.
MOSFET Gate Drive
Rs =
0 . 3 ? ( 1 . 15 × 2 A × 0 . 1 Ohm )
30 uA
P-channel drive is derived through an internal
regulator that generates V IN -5V. This pin (VDR)
has to be connected to V IN with a 0.1uF
Rs = 2333
Using the above equation there is good
agreement between calculated and test results
decoupling capacitor. The gate drive circuit
swings between V IN and V IN -5 and employs
powerful drivers for efficient switching of the P-
channel MOSFET.
for Rs in the range of 0.5k
to 3k . For Rs
larger than 3k
test results are lower than those
predicted by (5), due to circuit parasitics.
Therefore maximum value of Rs should be
limited to 3k .
Jan28-08 RevG
SP6125: TSOT-6 PFET Buck Controller
6
? 2007 Exar Corporation
相关PDF资料 |
PDF描述 |
|---|---|
| R1S8-1509/P-R | CONV DC/DC 1W 15VIN 09VOUT |
| SP6123EB | EVAL BOARD FOR SP6123 |
| MAX4825ETP+T | IC RELAY DRIVER 8CHAN 20-TQFN |
| MAX4822ETP+T | IC RELAY DRIVER 8CHAN 20-TQFN |
| R1S8-1505/P-R | CONV DC/DC 1W 15VIN 05VOUT |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SP6125EK1L | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High-Voltage, Step Down Controller in TSOT6 |
| SP6125EK1-L | 功能描述:DC/DC 开关控制器 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| SP6125EK1-L/TR | 功能描述:电源管理IC开发工具 High-Voltage Step Down Controller 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 |
| SP6125EK1L/TR1 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:High-Voltage, Step Down Controller in TSOT6 |
| SP6126 | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
发布紧急采购，3分钟左右您将得到回复。