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参数资料
| 型号： | MAX5038EAI33+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 24/26页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-SSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,000 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 占空比： | 90% |
| 电源电压： | 4.75 V ~ 28 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 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： | 28-SSOP（0.209"，5.30mm 宽） |
| 包装： | 带卷 (TR) |
Dual-Phase, Parallelable, Average Current-Mode
Controllers
The allowable deviation of the output voltage during the
fast transient load dictates the output capacitance and
ESR. The output capacitors supply the load step until
the controller responds with a greater duty cycle. The
response time (t RESPONSE ) depends on the closed-loop
bandwidth of the converter. The resistive drop across
the capacitor ESR and capacitor discharge causes a
voltage drop during a step load. Use a combination of
SP polymer and ceramic capacitors for better transient
load and ripple/noise performance.
Keep the maximum output voltage deviation less than
or equal to the adaptive voltage-positioning window
( ? V OUT ). Assume 50% contribution each from the out-
put capacitance discharge and the ESR drop. Use the
following equations to calculate the required ESR and
Compensation
The main control loop consists of an inner current loop
and an outer voltage loop. The MAX5038/MAX5041 use
an average current-mode control scheme to regulate
the output voltage (Figures 3a and 3b). I PHASE1 and
I PHASE2 are the inner average current loops. The VEA
output provides the controlling voltage for these current
sources. The inner current loop absorbs the inductor
pole reducing the order of the outer voltage loop to that
of a single-pole system.
A resistive feedback around the VEA provides the best
possible response, since there are no capacitors to
charge and discharge during large-signal excursions, R F
and R IN determine the VEA gain. Use the following equa-
tion to calculate the value for R F :
capacitance value:
ESR OUT =
? V ESR
I STEP
(23)
R F =
I OUT × R IN
N × G C × ? V OUT
(27)
C OUT = STEP RESPONSE
G C =
I × t
? V Q
(24)
0.05
(28)
R S
where G C is the current-loop gain and N is number of
R SENSE =
I OUT
2 × f SW × L × 10 2
R CF ≤
where I STEP is the load step and t RESPONSE is the
response time of the controller. Controller response
time depends on the control-loop bandwidth.
Current Limit
The average current-mode control technique of the
MAX5038/MAX5041 accurately limits the maximum out-
put current per phase. The MAX5038/MAX5041 sense
the voltage across the sense resistor and limit the peak
inductor current (I L-PK ) accordingly. The ON cycle ter-
minates when the current-sense voltage reaches 45mV
(min). Use the following equation to calculate maximum
current-sense resistor value:
0.045
(25)
N
phases.
When designing the current-control loop ensure that the
inductor downslope (when it becomes an upslope at the
CEA output) does not exceed the ramp slope. This is a
necessary condition to avoid sub-harmonic oscillations
similar to those in peak current-mode control with insuffi-
cient slope compensation. Use the following equation to
calculate the resistor R CF :
(29)
V OUT × R SENSE
For example, the maximum R CF is 12k ? for R SENSE =
1.35m ? .
C CF provides a low-frequency pole while R CF provides a
midband zero. Place a zero at f Z to obtain a phase bump
PD R =
2 . 5 × 10 ? 3
R SENSE
(26)
at the crossover frequency. Place a high-frequency pole
(f P ) at least a decade away from the crossover frequency
to achieve maximum phase margin.
where PD R is the power dissipation in sense resistors.
Select 5% lower value of R SENSE to compensate for any
parasitics associated with the PC board. Also, select a
non-inductive resistor with the appropriate wattage rating.
24
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| MAX5039 | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Voltage-Tracking Controllers for PowerPC.DSPs.and ASICs |
| MAX5039EUA | 功能描述:其他电源管理 V-Track Ctlr for PowerPC DSPs & ASICs RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
| MAX5039EUA+ | 功能描述:其他电源管理 V-Track Ctlr for PowerPC DSPs & ASICs RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
| MAX5039EUA+T | 功能描述:其他电源管理 V-Track Ctlr for PowerPC DSPs & ASICs RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
| MAX5039EUA-T | 功能描述:其他电源管理 V-Track Ctlr for PowerPC DSPs & ASICs RoHS:否 制造商:Texas Instruments 输出电压范围: 输出电流:4 mA 输入电压范围:3 V to 3.6 V 输入电流: 功率耗散: 工作温度范围:- 40 C to + 110 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-48 封装:Reel |
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