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参数资料
| 型号： | MAX1536ETI+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 15/19页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 3.6A 28TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.7 V ~ 5.5 V |
| 输入电压： | 3 V ~ 5.5 V |
| PWM 型： | 电流模式，混合 |
| 频率 - 开关： | 1.4MHz |
| 电流 - 输出： | 3.6A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
3.6A, 1.4MHz, Low-Voltage, Internal-Switch Step-
Down Regulator with Dynamic Output Voltage Control
R TOFF = ( t OFF ? 0 . 07 μ s )
110k ?
1 . 00 μ s
The peak-inductor current at full load is 1.125 × I OUT if
the above equation is used; otherwise, the peak current
is calculated by:
V TOFF is typically 1.1V and the recommended values
for R TOFF range from 30.1k ? to 499k ? for off-times of
0.3μs to 4.5μs.
I PEAK = I OUT +
V OUT xt OFF
2 xL
Frequency Variation with Output Current
The operating frequency of the MAX1536 in PWM mode
is determined primarily by t OFF (set by R TOFF ), V IN , and
V OUT as shown in the following formula:
Choose an inductor with a saturation current at least as
high as the peak-inductor current. The inductor select-
ed should exhibit low losses at the chosen operating
frequency.
f PWM =
V IN - V OUT - V PMOS
t OFF ( V IN - V PMOS + V NMOS )
Capacitor Selection
The input-filter capacitor reduces peak currents and
noise at the voltage source. Use a low-ESR and low-
ESL capacitor located no further than 5mm from IN.
I RIPPLE = I LOAD
? f PWM = -
where:
V PMOS = the voltage drop across the internal PMOS
power switch, I OUT × R PMOS .
V NMOS = the voltage drop across the internal NMOS
synchronous-rectifier switch, I OUT × R NMOS .
As the output current increases, V NMOS and V PMOS
increase and the voltage across the inductor decreas-
es. This causes the frequency to drop. Approximate the
change in frequency with the following formula:
I OUT x R PMOS
V IN x t OFF
Select the input capacitor according to the RMS input
ripple-current requirements and voltage rating:
V OUT ( V IN - V OUT )
V IN
where I RIPPLE = input RMS current ripple.
The output-filter capacitor affects the output-voltage
ripple, output load-transient response, and feedback-
loop stability. For stable operation, the MAX1536
requires a minimum output ripple voltage of V RIPPLE ≥
1% × V OUT .
The minimum ESR of the output capacitor is calculated by:
where R PMOS is the resistance of the internal MOSFETs
(54m ? , typ).
Inductor Selection
ESR > 1% x
L
t OFF
The key inductor parameters must be specified: induc-
tor value (L) and peak current (I PEAK ). The following
equation includes a constant, denoted as LIR, which is
Stable operation requires the correct output-filter capaci-
tor. When choosing the output capacitor, ensure that:
the ratio of peak-to-peak inductor AC ripple current to
maximum DC load current. A higher value of LIR allows
smaller inductance but results in higher losses and rip-
C OUT ≥
t OFF
V OUT
x
79 μ F x 1 V
1 μ s
ple. A good compromise between size and losses is
found at approximately a 25% ripple-current to load-
current ratio (LIR = 0.25), which corresponds to a peak-
inductor current 1.125 times the DC load current:
Integrator Amplifier
An internal transconductance amplifier fine tunes the
output DC accuracy. A capacitor, C COMP , from COMP
to V CC compensates the transconductance amplifier.
L =
V OUT x t OFF
I OUT x LIR
For stability, choose C COMP = 470pF. A larger capaci-
tor value maintains a constant average output voltage,
but slows the loop response to changes in output volt-
where:
I OUT = maximum DC load current.
LIR = ratio of peak-to-peak AC inductor current to DC
load current, typically 0.25.
age. A smaller capacitor value speeds up the loop
response to changes in output voltage but decreases
stability.
______________________________________________________________________________________
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1536EVKIT | 功能描述:直流/直流开关调节器 Evaluation Kit for the MAX1536 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 |
| MAX1537AETX+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1537ETX | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1537ETX-T | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1537EVKIT | 制造商:Maxim Integrated Products 功能描述:MAIN POWER SUPPLY CONTROLLER FOR NOTEBOOK - Bulk |
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