参数资料
型号: MAX1631EAI+
厂商: Maxim Integrated Products
文件页数: 17/29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: 46
PWM 型: 电流模式,混合
输出数: 2
频率 - 最大: 330kHz
占空比: 99%
电源电压: 4.2 V ~ 30 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 28-SSOP(0.209",5.30mm 宽)
包装: 管件
Multi-Output, Low-Noise Power-Supply
Controllers for Notebook Computers
Remote output-voltage sensing, while not possible in
fixed-output mode due to the combined nature of the
voltage-sense and current-sense inputs (CSL3 and
CSL5), is easy to do in adjustable mode by using the top
of the external resistor divider as the remote sense point.
When using adjustable mode, it is a good idea to
1-SHOT
TRIG
SECFB
R2
R1
always set the “3.3V output” to a lower voltage than the
“5V output.” The 3.3V output must always be less than
VL, so that the voltage on CSH3 and CSL3 is within the
common-mode range of the current-sense inputs. While
2.5V REF
DH_
V+
POSITIVE
SECONDARY
OUTPUT
VL is nominally 5V, it can be as low as 4.7V when lin-
early regulating, and as low as 4.2V when automatically
bootstrapped to CSH5.
Secondary Feedback Regulation Loop
(SECFB or V DD )
A flyback-winding control loop regulates a secondary
MAX1631
MAX1634
DL_
MAIN
OUTPUT
(
)
winding output, improving cross-regulation when the
primary output is lightly loaded or when there is a low
input-output differential voltage. If V DD or SECFB falls
R1
+V TRIP = V REF 1 + –––
R2
WHERE V REF (NOMINAL) = 2.5V
below its regulation threshold, the low-side switch is
turned on for an extra 1μs. This reverses the inductor
Figure 5. Adjusting the Secondary Output Voltage with SECFB
(primary) current, pulling current from the output filter
capacitor and causing the flyback transformer to oper-
12OUT
+12V OUTPUT
200mA
ate in forward mode. The low impedance presented by
the transformer secondary in forward mode dumps cur-
rent into the secondary output, charging up the sec-
ondary capacitor and bringing V DD or SECFB back into
regulation. The secondary feedback loop does not
V DD
0.1 μ F
0.1 μ F
10 Ω
2N3906
10 μ F
improve secondary output accuracy in normal flyback
mode, where the main (primary) output is heavily
loaded. In this condition, secondary output accuracy is
determined by the secondary rectifier drop, transformer
turns ratio, and accuracy of the main output voltage. A
linear post-regulator may still be needed to meet strict
output-accuracy specifications.
Devices with a 12OUT linear regulator have a V DD pin
that regulates at a fixed 13.5V, set by an internal resis-
tor divider. The MAX1631/MAX1634 have an adjustable
secondary output voltage set by an external resistor
MAX1630
MAX1632
MAX1633
MAX1635 DH_
DL_
V+
0.1 μ F
V DD OUTPUT
2.2 μ F
MAIN
OUTPUT
divider on SECFB (Figure 5). Ordinarily, the secondary
regulation point is set 5% to 10% below the voltage nor-
mally produced by the flyback effect. For example, if
the output voltage as determined by turns ratio is 15V,
set the feedback resistor ratio to produce 13.5V.
Otherwise, the SECFB one-shot might be triggered
unintentionally, unnecessarily increasing supply current
and output noise.
Figure 6. Increased 12V Linear Regulator Output Current
12V Linear Regulator Output
(MAX1630/MAX1632/MAX1633/MAX1635)
The MAX1630/MAX1632/MAX1633/MAX1635 include a
12V linear regulator output capable of delivering 120mA
of output current. Typically, greater current is available
at the expense of output accuracy. If an accurate output
of more than 120mA is needed, an external pass tran-
______________________________________________________________________________________
17
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MAX1631EAI+ 功能描述:DC/DC 开关控制器 Multi-Out Low-Noise Power-Supply Ctlr 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
MAX1631EAI+T 功能描述:DC/DC 开关控制器 Multi-Out Low-Noise Power-Supply Ctlr 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
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MAX1631EAI-TG074 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX1631EVKIT-SO 功能描述:DC/DC 开关控制器 Evaluation Kit for the MAX1630 MAX1631 MAX1632 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