- 您现在的位置：买卖IC网 > PDF目录15155 > MAX1524EUT+T (Maxim Integrated Products)IC REG CTRLR BST FLYBK SOT23-6 PDF资料下载
参数资料
| 型号： | MAX1524EUT+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 9/14页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BST FLYBK SOT23-6 |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| PWM 型： | 电压模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 占空比： | 90% |
| 电源电压： | 1.5 V ~ 5.5 V |
| 降压： | 无 |
| 升压： | 是 |
| 回扫： | 是 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | SOT-6 |
| 包装： | 带卷 (TR) |
Simple SOT23 Boost Controllers
( V IN ( MIN ) ) 2 × t ON ( MIN )
3 × ( V OUT + V D ) × I LOAD ( MAX )
×
C OUT ( MIN ) =
×
( V OUT + V D ? V IN )
tance value two or three times larger than C OUT(MIN) is
typically needed. Output ripple due to ESR is:
V RIPPLE ( ESR ) ? 0 . 3 × I PEAK × ESR COUT
at light and medium loads, and three times as great at
peak load.
Continue the CCM design procedure by going to the
Optional Feed-Forward Capacitor Selection section.
Design Procedure for DCM
On-Time Selection
The MAX1522/MAX1523/MAX1524 may operate in
DCM at any duty cycle as required by the application’s
input and output voltages. However, best performance
is achieved when the maximum duty cycle of the appli-
cation is similar to the MAX1522/MAX1523/MAX1524s’
maximum duty factor as set using the SET input.
Connect SET to GND for applications with maximum
duty cycles less than 67%. Connect SET to V CC for
applications with maximum duty cycles between 67%
and 99%.
Inductor Selection
For DCM, the ideal inductor value is given by:
L IDEAL =
If L IDEAL is not a standard value, choose the next lower
Due to the MAX1522/MAX1523/MAX1524s’ high switch-
ing frequencies, inductors with a ferrite core or equiva-
lent are recommended. Powdered iron cores are not
recommended due to their high losses at frequencies
over 50kHz.
Switching Frequency
In DCM, the switching frequency is proportional to the
load current and is approximately given by:
? SWITCHING ≈ 0 . 7 I OUT × ( V OUT + V D ? V IN ) × 2 L
t ON 2 × V IN 2
Note that f SWITCHING is a function of load and input
voltage.
Output Capacitor Selection
In DCM, the MAX1522/MAX1523/MAX1524 may use
either a ceramic output capacitor (with very low ESR) or
other capacitors, such as tantalum or organic, with
higher ESR. For less than 2% output ripple, the mini-
mum value for ceramic output capacitors should be
greater than:
1 t ON 2 × V IN 2 1
2 L 0 . 02 V OUT
To control inductor current during soft-start, the maxi-
mum value for any type of output capacitors should be
less than:
nominal value. The above formula already includes a
factor for ±30% inductor tolerance. Values higher than
ideal may not supply the maximum load when the input
voltage is low, while values much lower than ideal will
C OUT ( MAX ) =
I LOAD(MAX ) × t SS
V OUT
V IN ( MAX ) × t ON ( MAX )
I PEAK =
? 1 t ON IN 2 ?
× V
1
( V OUT + V D ? V IN ) C OUT ? ?
+ ? IN
× ESR COUT ?
? ?
have poorer efficiency.
Calculate the Peak Inductor Current
For DCM, the peak inductor current is given by:
L
The saturation rating of the selected inductor should
meet or exceed the calculated value for I PEAK ,
although most coil types can be operated up to 20%
over their saturation rating without difficulty. In addition
to the saturation criteria, the inductor should have as
low a series resistance as possible. The power loss in
the inductor resistance is approximately given by:
where t SS = 3.2ms.
The capacitor should be chosen to provide an output
ripple between 25mV minimum and 2% of V OUT maxi-
mum. The output ripple due to capacitance ripple and
ESR ripple can be approximated by:
2
V RIPPLE ( COUT + ESR ) ? ? × × ?
? ? 2 L
? V × t ON ?
L
For output ripple close to 2% of V OUT , the optional
feed-forward capacitor may not be required. For lower
? I PEAK × I OUT × ? ? ? RL
P LR ?
2 ? ? V OUT + V D ? ?
3 ? ? V IN ? ?
output ripple, a feed-forward capacitor is necessary for
stability and to control inductor current during soft-start.
_______________________________________________________________________________________
9
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1522EUT+T | IC REG CTRLR BST FLYBK SOT23-6 |
| MAX1954CEUB+T | IC REG CTRLR BUCK PWM CM 10-UMAX |
| CAT1162WI45 | IC SUPERVSR CPU 16K EEPROM 8SOIC |
| MAX1954BEUB+T | IC REG CTRLR BUCK PWM CM 10-UMAX |
| ISL88003IE46Z-T7A | IC VOLT SUPERVISOR 4.64V SC70-3 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1526ETM | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1526ETM+ | 制造商:Maxim Integrated Products 功能描述:HIGHLY INTEGRATED LINEAR BATTERY CHARGER - Rail/Tube |
| MAX1526ETM+G104 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1526ETM+T | 制造商:Maxim Integrated Products 功能描述:HIGHLY INTEGRATED LINEAR BATTERY CHARGER - Tape and Reel |
| MAX1526ETM-G104 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
发布紧急采购，3分钟左右您将得到回复。