參數(shù)資料
型號(hào): MAX5038EAI33
廠商: MAXIM INTEGRATED PRODUCTS INC
元件分類: 穩(wěn)壓器
英文描述: JT 18C 18#20 SKT WALL RECP
中文描述: SWITCHING CONTROLLER, 525 kHz SWITCHING FREQ-MAX, PDSO28
封裝: 5.30 MM, MO150, SSOP-28
文件頁(yè)數(shù): 23/26頁(yè)
文件大?。?/td> 406K
代理商: MAX5038EAI33
M
Dual-Phase, Parallelable, Average Current-Mode
Controllers
______________________________________________________________________________________
23
For example, from the typical specifications in the
Applications Information
section with V
OUT
= +1.8V, the
high-side and low-side MOSFET RMS currents are 9.9A
and 24.1A, respectively. Ensure that the thermal imped-
ance of the MOSFET package keeps the junction tem-
perature at least 25°C below the absolute maximum
rating. Use the following equation to calculate maxi-
mum junction temperature:
T
J
= PD
MOS
x
θ
J -A
+ T
A
Input Capac itors
The discontinuous input-current waveform of the buck
converter causes large ripple currents in the input
capacitor. The switching frequency, peak inductor cur-
rent, and the allowable peak-to-peak voltage ripple
reflected back to the source dictate the capacitance
requirement. Increasing the number of phases increas-
es the effective switching frequency and lowers the
peak-to-average current ratio, yielding lower input
capacitance requirement.
The input ripple is comprised of
V
Q
(caused by the
capacitor discharge) and
V
ESR
(caused by the ESR of
the capacitor). Use low-ESR ceramic capacitors with
high ripple-current capability at the input. Assume the
contributions from the ESR and capacitor discharge are
equal to 30% and 70%, respectively. Calculate the
input capacitance and ESR required for a specified rip-
ple using the following equation:
where I
OUT
is the total output current of the multiphase
converter and N is the number of phases.
For example, at V
OUT
= +1.8V, the ESR and input
capacitance are calculated for the input peak-to-peak
ripple of 100mV or less yielding an ESR and capaci-
tance value of 1m
and 200μF.
Output Capac itors
The worst-case peak-to-peak and capacitor RMS ripple
current, the allowable peak-to-peak output ripple volt-
age, and the maximum deviation of the output voltage
during step loads determine the capacitance and the
ESR requirements for the output capacitors.
In multiphase converter design, the ripple currents from
the individual phases cancel each other and lower the
ripple current. The degree of ripple cancellation
depends on the operating duty cycle and the number of
phases. Choose the right equation from Table 3 to calcu-
late the peak-to-peak output ripple for a given duty
cycle of two-, four-, and six-phase converters. The max-
imum ripple cancellation occurs when N
PH
= K / D.
C
I
N
D
D
V
f
IN
OUT
Q
SW
=
×
(
)
×
1
ESR
V
I
N
I
IN
ESR
OUT
L
=
(
)
+
2
I
I
I
I
I
D
RMS LO
DC
PK
DC
PK
=
+
+
×
(
)
×
3
(
)
2
2
1
PD
Q
(
V
f
C
V
f
R
I
MOS LO
G
DD
SW
OSS
IN
SW
DS ON
(
RMS LO
=
×
×
)
+
×
×
×
+
×
2
3
1 4
.
2
2
)
Table 3. Peak-to-Peak Output Ripple
Current Calculations
NUMBER OF
PHASES (N)
DUTY
CYCLE (D)
EQUATION FOR
I
P-P
2
< 50%
2
> 50%
4
0 to 25%
4
25% to 50%
4
> 50%
6
< 17%
I
V
D
L
f
O
SW
=
×
(
)
1 2
I
V
V
×
D
L
f
IN
O
SW
=
(
)
(
)
2
1
I
V
D
L
f
O
SW
=
×
(
)
1 4
I
V
D
D
f
SW
D L
O
2
=
×
(
)(
)
1 2
4
1
I
V
D
D
D L
f
O
SW
=
(
)(
)
2
1 3 4
I
V
D
L
f
O
SW
=
×
(
)
1 6
(18)
(19)
(20)
(21)
(22)
相關(guān)PDF資料
PDF描述
MAX5038EAI15 Dual-Phase, Parallelable, Average Current-Mode Controllers
MAX5038EAI18 Dual-Phase, Parallelable, Average Current-Mode Controllers
MAX5038 Dual-Phase, Parallelable, Average Current-Mode Controllers
MAX503 Low Power 5V RS232 Dual Driver/Receiver with 0.1?μF Capacitors; Package: SO; No of Pins: 16; Temperature Range: -40?°C to 85?°C
MAX503EWG 5V, Low-Power, Parallel-Input, Voltage-Output, 10-Bit DAC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX5038EAI33+ 功能描述:電流型 PWM 控制器 Dual-Phase Parallelable Average RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
MAX5038EAI33+T 功能描述:電流型 PWM 控制器 Dual-Phase Parallelable Average RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
MAX5038EAI33-T 功能描述:電流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
MAX5039 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:Voltage-Tracking Controllers for PowerPC.DSPs.and ASICs
MAX5039EUA 功能描述:其他電源管理 V-Track Ctlr for PowerPC DSPs & ASICs RoHS:否 制造商:Texas Instruments 輸出電壓范圍: 輸出電流:4 mA 輸入電壓范圍:3 V to 3.6 V 輸入電流: 功率耗散: 工作溫度范圍:- 40 C to + 110 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-48 封裝:Reel