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| 型号： | MAX1845EEI+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 12/27页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 540kHz |
| 电源电压： | 4.5 V ~ 5.5 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（0.154"，3.90mm 宽） |
| 包装： | 管件 |
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Dual, High-Efficiency, Step-Down
Controller with Accurate Current Limit
Table 1. Component Selection for
Table 2. Component Suppliers
Standard Applications
COMPONENT
Input Range
Q1 High-Side MOSFET
Q2 Low-Side MOSFET
Q3, Q4 High/Low-Side
MOSFETs
SIDE 1: 1.8V AT 8A/
SIDE 2: 2.5V AT 4A
4.5V to 28V
Fairchild Semiconductor
FDS6612A or
International Rectifier
IRF7807
Fairchild Semiconductor
FDS6670A or
International Rectifier
IRF7805
Fairchild Semiconductor
FDS6982A
MANUFACTURER
Central Semiconductor
Dale/Vishay
Fairchild Semiconductor
International Rectifier
IRC
Kemet
NIEC (Nihon)
Sanyo
Siliconix
Sumida
Taiyo Yuden
TDK
USA PHONE
516-435-1110
203-452-5664
408-822-2181
310-322-3331
800-752-8708
408-986-0424
805-867-2555*
619-661-6835
408-988-8000
800-554-5565
847-956-0666
408-573-4150
847-390-4461
FACTORY FAX
[Country Code]
[1] 516-435-1824
[1] 203-452-5670
[1] 408-721-1635
[1] 310-322-3332
[1] 828-264-7204
[1] 408-986-1442
[81] 3-3494-7414
[81] 7-2070-1174
[1] 408-970-3950
[81] 3-3607-5144
[1] 408-573-4159
[1] 847-390-4405
D1, D2 Rectifier
D3 Rectifier
L1 Inductor
L2 Inductor
Nihon EP10QY03
Central Semiconductor
CMPSH-3A
2.2μH
Panasonic ETQP6F2R2SFA
or
Sumida CDRH127-2R4
4.7μH
Sumida CDRH124-4R7MC
*Distributor
both dead times. It occurs only in PWM mode ( SKIP =
high) when the inductor current reverses at light or neg-
ative load currents. With reversed inductor current, the
inductor’s EMF causes LX to go high earlier than nor-
mal, extending the on-time by a period equal to the
low-to-high dead time.
For loads above the critical conduction point, the actual
switching frequency is:
C1 (3), C2 (2) Input
10μF, 25V
Taiyo Yuden
f =
V OUT + V DROP 1
t ON ( V IN + V DROP 2 )
Capacitor
C3 (3), C4 Output Capacitor
R SENSE1
R SENSE2
TMK432BJ106KM or
TDK C4532X5R1E106M
470μF, 6V
Kemet T510X477M006AS or
Sanyo 6TPB330M
5m Ω , ±1%, 1W
IRC LR2512-01-R005-F or
D ALE WSL-2512-R005F
10m Ω , ±1%, 0.5W
IRC LR2010-01-R010-F or
D ALE WSL-2010-R010F
where V DROP1 is the sum of the parasitic voltage drops
in the inductor discharge path, including synchronous
rectifier, inductor, and PC board resistances; V DROP2 is
the sum of the resistances in the charging path; and
t ON is the on-time calculated by the MAX1845.
Automatic Pulse-Skipping Switchover
In skip mode ( SKIP = GND), an inherent automatic
switchover to PFM takes place at light loads. This
switchover is effected by a comparator that truncates
the low-side switch on-time at the inductor current’s
zero crossing. This mechanism causes the threshold
between pulse-skipping PFM and nonskipping PWM
operation to coincide with the boundary between con-
Two external factors that influence switching-frequency
accuracy are resistive drops in the two conduction
loops (including inductor and PC board resistance) and
the dead-time effect. These effects are the largest con-
tinuous and discontinuous inductor-current operation
(also known as the critical conduction point). For a 7V
to 24V battery range, of this threshold is relatively con-
stant, with only a minor dependence on battery voltage:
?
?
? ?
tributors to the change of frequency with changing load
current. The dead-time effect increases the effective
on-time, reducing the switching frequency as one or
I LOAD(SKIP) ≈
K × V OUT_ ? V IN -V OUT_ ?
2L V IN
12
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1845EEI+ | 功能描述:电流型 PWM 控制器 Step-Down Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1845EEI+T | 功能描述:电流型 PWM 控制器 Step-Down Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1845EEI-T | 功能描述:电流型 PWM 控制器 RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX1845EEI-TG05 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX1845EEI-TG068 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
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