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参数资料
| 型号： | MAX8540EEE+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 9/16页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR PWM CM 16-QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 1MHz |
| 占空比： | 82% |
| 电源电压： | 7.6 V ~ 18 V |
| 降压： | 无 |
| 升压： | 无 |
| 回扫： | 是 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 是 |
| Cuk： | 无 |
| 隔离： | 是 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 16-SSOP（0.154"，3.90mm 宽） |
| 包装： | 带卷 (TR) |
Synchronizable, High-Frequency Current- and
Voltage-Mode PWM Controllers for Isolated Supplies
Detailed Description
Overvoltage Threshold
The MAX8540/MAX8541 include an overvoltage protec-
tion (OVP) feature that turns off the external MOSFET
Table 1. Typical Specifications of UV/OV
and the Actual On/Off Hysteresis of Input
Voltage
when the input voltage exceeds the user-set threshold.
Connect a resistor-divider from the system input to
GND with OV connected to the center to set the OVP
UV VOLTAGE
SPECIFICATIONS
(V)
V IN OFF
WINDOW (LTP)
(V)
V IN ON
WINDOW (UTP)
(V)
trip point. The threshold voltage for OV is 3.021V (typ):
MIN
1.083
29.76
V IN ( MAX ) = ? ? × V OV
? R1 + R2 ?
? R 2 ?
where V OV is the OV threshold, V IN(MAX) is the overvolt-
age trip point, R1 is the resistor from the system input
TYP
MAX
MIN
TYP
MAX
1.128
1.173
1.200
1.250
1.300
31.00
32.24
—
—
32.97
34.34
36.00
to OV, and R2 is the resistor from OV to GND.
Undervoltage Threshold
The MAX8540/MAX8541 also include an undervoltage
OV VOLTAGE
SPECIFICATIONS
(V)
V IN OFF
WINDOW (UTP)
(V)
V IN ON
WINDOW (LTP)
(V)
(UV) sensing input. The IC holds the external MOSFET
low until UV reaches its threshold (1.25V typ). Once the
threshold has been reached, the circuit enters soft-start
MIN
TYP
2.901
3.021
79.70
83.00
—
and brings the output into regulation. Connect a resistor-
divider from the system input to GND with UV at the cen-
MAX
MIN
3.142
2.778
86.32
76.32
ter to set the undervoltage protection (UVP) trip point.
TYP
2.894
—
79.50
V IN ( MIN ) = ? ? × V UV
? R3 + R4 ?
? R 4 ?
where V UV is the UV threshold, V IN(MIN) is the UV trip
MAX 3.010 82.68
Assume that 1.250V at UV/OV is scaled to 34.34V for a 48V bus.
Table 2. Switching Frequency Selection
point, R3 is the resistor from the system input to UV,
and R4 is the resistor from UV to GND.
An alternate method used in the application circuits for
setting the OV and UV trip points is demonstrated in
Figure 1. Use 36.5k ? for the bottom resistor (RC). RA
and RB are calculated as follows:
R FREQ/SYNC (k ? )
48.7
19.1
15.8
11.0
SWITCHING FREQUENCY (kHz)
200
500
600
800
? V OV × V IN(MIN)
RB = RC × ?
? V UV × V IN ( MAX )
?
?
1 ?
?
8.87 1000
Switching Frequency and Synchronization
The MAX8540/MAX8541 oscillator operates in two
RA =
RC × V IN(MIN)
V UV
?
RB
?
RC
modes: stand-alone or synchronized (sync). A single
input, FREQ/SYNC, doubles as the attachment point for
the frequency-programming resistor and as the syn-
chronization input. The mode recognition is automatic,
where V IN(MIN) is the UV trip point, V IN(MAX) is the OV
trip point, V UV is the UV threshold (1.25V typ), and V OV
is the OV threshold (3.021V typ). RA should consist of
two equal-value resistors in series to protect against
single-point failure.
based on the signal applied to FREQ/SYNC.
In stand-alone mode, an external resistor connected
from FREQ/SYNC to GND sets the operating frequency.
A 1.25V source is internally applied to FREQ/SYNC and
the oscillator frequency is proportional to the current
out of FREQ/SYNC through the programming resistor.
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX8541EEE | 功能描述:电压模式 PWM 控制器 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| MAX8541EEE+ | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX8541EEE-T | 功能描述:电压模式 PWM 控制器 RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel |
| MAX8543EEE | 功能描述:DC/DC 开关控制器 RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| MAX8543EEE+ | 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 |
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