- 您现在的位置：买卖IC网 > PDF目录17413 > SP7655EB (Exar Corporation)EVAL BOARD FOR SP7655 PDF资料下载
参数资料
| 型号： | SP7655EB |
| 厂商： | Exar Corporation |
| 文件页数： | 6/16页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR SP7655 |
| 标准包装： | 1 |
| 系列： | * |
THEORY OF OPERATION
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 compen-
sation 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 non-s ynchronous
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
[ ( Vout / 0.80V ) – 1 ]
pacitoratveryhighdutyratios.Intheeventthat
the high side NFET is on for 20 continuous
clock cycles, a reset is given to the PWM flip-
flop half way through the 21 st 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 SP7655 contains a pair of integrated low
resistance N-channel switches designed to drive
up to 10 Amps of output current. Care should be
taken to de-rate the output current based on the
thermal conditions in the system such as ambi-
ent 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 SP7655.
The SP7655 incorporates a built-in over-tem-
perature protection to prevent internal overheat-
ing.
Setting Output Voltages
The SP7655 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 / R SET + 1 ) =>
R1 .
R set =
Where R1 = 68.1K and for V OUT = 0.80V
setting, simply remove R SET from the board. Fur-
thermore, one could select the value of the R1
and R SET combination to meet the exact output
voltage setting by restricting R1 resistance range
such that 50K < R1 < 100K for overall
system loop stability.
Rev E: 3/2 /07
SP7655 Wide Input Voltage Range 8A, 300kHz, Buck Regulator
6
? 2007 Sipex Corporation
相关PDF资料 |
PDF描述 |
|---|---|
| SP7653EB | EVAL BOARD FOR SP7653 |
| A9CAA-0804F | FLEX CABLE - AFG08A/AF08/AFG08T |
| LM2735YSDEVAL | BOARD EVAL LM2735 520KHZ 6LLP |
| A9AAT-1606F | FLEX CABLE - AFE16T/AF16/AFE16T |
| A9BAA-0905F | FLEX CABLE - AFF09A/AF09/AFE09T |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SP7655ER | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Evaluation Board Manual |
| SP7655ER/TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range, 8Amp 300kHz, Buck Regulator |
| SP7655ERL | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range, 8Amp 300kHz, Buck Regulator |
| SP7655ER-L | 功能描述:线性稳压器 - 标准 Buck Regulator RoHS:否 制造商:STMicroelectronics 输出类型: 极性: 输出电压:1.8 V 输出电流:150 mA 负载调节: 最大输入电压:5.5 V 线路调整率: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SOT-323-5L |
| SP7655ERL/TR | 制造商:SIPEX 制造商全称:Sipex Corporation 功能描述:Wide Input Voltage Range, 8Amp 300kHz, Buck Regulator |
发布紧急采购，3分钟左右您将得到回复。