- 您现在的位置：买卖IC网 > PDF目录17413 > SP7650EB (Exar Corporation)EVAL BOARD FOR SP7650 PDF资料下载
参数资料
| 型号： | SP7650EB |
| 厂商： | Exar Corporation |
| 文件页数： | 6/16页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR SP7650 |
| 标准包装： | 1 |
| 系列： | * |
THEORY OF OPERATION
desired, then compensation can be as simple as
an RC circuit to Ground. If a more complex
compensation is required, then the amplifier has
enough bandwidth (45 ° at 4 MHz) and enough
gain (60dB) to run Type III compensation
schemes with adequate gain and phase margins
at crossover frequencies greater than 50kHz.
VBST
GH
Voltage
VSWN
V(VCC)
GL
Voltage
The common mode output of the error amplifier
is 0.9V to 2.2V. Therefore, the PWM voltage
ramp has been set between 1.1V and 2.2V to
ensure proper 0% to 100% duty cycle capability.
The voltage loop also includes two other very
important features. One is an asynchronous
startup mode. Basically, the synchronous recti-
fier cannot turn on unless the high side switch
has attempted to turn on or the SS pin has
exceeded 1.7V. This feature prevents the con-
troller from “dragging down” the output voltage
during startup or in fault modes. The second
feature is a 100% duty cycle timeout that en-
sures synchronized refreshing of the BST ca-
0V
V(VIN)
SWN
Voltage
-0V
-V(Diode) V
V(VIN)+V(VCC)
BST
Voltage
V(VCC)
TIME
pacitor at very high duty ratios. In the event that
the high side NFET is on for 20 continuous
clock cycles, a reset is given to the PWM flip-
flop half way through the 21st cycle. This forces
GL to rise for the cycle, in turn refreshing the
BST capacitor. The boost capacitor is used to
generate a high voltage drive supply for the high
side switch, which is 5V above V IN .
Power MOSFETs
The SP7650 contains a pair of integrated low
resistance N-channel switches designed to drive
up to 3A of output current. Care should be taken
to de-rate the output current based on the ther-
mal conditions in the system such as ambient
temperature, airflow and heat sinking. Maxi-
mum output current could be limited by thermal
limitations of a particular application by taking
advantage of the integrated-over-temperature
protective scheme employed in the SP7650.
The SP7650 incorporates a built-in over-tem-
perature protection to prevent internal overheat-
ing.
Setting Output Voltages
The SP7650 can be set to different output volt-
ages. The relationship in the following formula
is based on a voltage divider from the output to
the feedback pin VFB, which is set to an internal
reference voltage of 0.80V. Standard 1% metal
film resistors of surface mount size 0603 are
recommended.
Vout = 0.80V ( R1 / R2 + 1 ) =>
R2 = R1 / [ ( Vout / 0.80V ) – 1 ]
Where R1 = 68.1K and for Vout = 0.80V
setting, simply remove R2 from the board.
Furthermore, one could select the value of the
R1 and R2 combination to meet the exact
output voltage setting by restricting R1
resistance range such that 50K < R1 <
100K for overall system loop stability.
Date: 2/16/06
SP7650 Wide Input Voltage Range 3A, 300kHz, Buck Regulator
? Copyright 2006 Sipex Corporation
Date: / 5/06
SP7650 Wide Input Voltage Range 3A, 300kHz, Buck Regulator
6 6
? Copyright 2006 Sipex Corporation
相关PDF资料 |
PDF描述 |
|---|---|
| A9BAG-0806F | FLEX CABLE - AFF08G/AF08/AFE08T |
| LM2735SD3.3EVAL | BOARD EVALUATION FOR LM2735 |
| RB-0505D/P | CONV DC/DC 1W 5VIN +/-05VOUT |
| IPS1051LTRPBF | IC IPS SW LOW SIDE 1CH SOT-223 |
| A9CCA-0404E | FLEX CABLE - AFK04A/AE04/AFK04A |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SP7650ER | 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述: |
| SP7650ER/TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range 3A, 300kHz, Buck Regulator |
| SP7650ER-L | 功能描述:直流/直流开关调节器 Buck Regulator RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| SP7650ER-L/TR | 功能描述:直流/直流开关调节器 WIDE INPUT VOLTAGE RANGE, 3A 300k RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| SP7651 | 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。