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参数资料
| 型号： | MAX1964TEEE+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 21/30页 |
| 文件大小： | 0K |
| 描述： | IC POWER CTRLR/SEQUENCER 16QSOP |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 100 |
| 应用： | 电源控制器，序列发生器 |
| 输入电压： | 4.5 V ~ 28 V |
| 电流 - 电源： | 1.25mA |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-SSOP（0.154"，3.90mm 宽） |
| 供应商设备封装： | 16-QSOP |
| 包装： | 管件 |
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Tracking/Sequencing Triple/Quintuple
Power-Supply Controllers
?
?
?
With the output pole ’ s frequency and series com-
pensation capacitor values, the required series
resistance can be determined. Based on the above
equation, select R COMP = 5.1M ? .
Now we must determine if the selected output
capacitor ’ s ESR generates a second zero before
crossover — the circuit shown in Figure 1 uses a
1000μF 10V Sanyo CZ-series electrolytic capacitor
with an ESR rating of 0.2 ? , so the zero occurs at
800Hz. Since crossover occurs at 40kHz, add the
second parallel compensation capacitor.
Finally, the second compensation capacitor value
can source at least 25mA. Typically, the OUT pin is
connected to the step-down converter ’ s output.
However, if the step-down converter ’ s output voltage is
set higher than 5V, OUT must be connected to one of
the positive linear regulators with an output voltage
between 2V and 5V.
Transistor Selection
The pass transistors must meet specifications for cur-
rent gain (h FE ), input capacitance, collector-emitter sat-
uration voltage, and power dissipation. The transistor ’ s
current gain limits the guaranteed maximum output cur-
rent to:
I LOAD ( MAX ) = ? I DRV - ? BE ? ? h FE ( MIN )
R 3 = R 4 ? ? OUT ? - 1 ?
R 5 = R 6 ? OUT ?
must be approximately 43pF. Select the closest
standard capacitor value of 47pF.
Boost-Supply Diode
A signal diode, such as the 1N4148, works well in most
applications. If the input voltage goes below 6V, use a
small 20mA Schottky diode for slightly improved effi-
ciency and dropout characteristics. Do not use large
power diodes, such as the 1N5817 or 1N4001, since
high junction capacitance can charge up VL to exces-
sive voltages.
Linear Regulator Controllers
Positive Output Voltage Selection
The MAX1964/MAX1965 ’ s positive linear regulator out-
put voltages are set by connecting a voltage divider
from the output to FB_ to GND (Figure 6). Select R4 in
the 1k ? to 50k ? range. Calculate R3 with the following
equation:
? ? V ? ?
? ?
? ? V FB ? ?
where V FB = 1.24V and V OUT may range from 1.24V to
30V.
Negative Output Voltage Selection (MAX1965)
The MAX1965 ’ s negative output voltage is set by con-
necting a voltage divider from the output to FB5 to a
positive voltage reference (Figure 6). Select R6 in the
1k ? to 50k ? range. Calculate R5 with the following
equation:
? V ?
? V REF ?
where V REF is the positive reference voltage used and
V OUT may be set between 0 and -20V.
If the negative regulator is used, the OUT pin must be
connected to a voltage supply between 2V and 5V that
? ? V ? ?
? ?
? ? R BE ? ?
where I DRV is the minimum 10mA base drive current
and R BE (220 ? ) is the pullup resistor connected
between the transistor ’ s base and emitter. Furthermore,
the transistor ’ s current gain increases the linear regula-
tor ’ s DC loop gain (see Stability Requirements ), so
excessive gain will destabilize the output. Therefore,
transistors with current gain over 100 at the maximum
output current, such as Darlington transistors, are not
recommended. The transistor ’ s input capacitance and
input resistance also create a second pole, which
could be low enough to destabilize the output when
heavily loaded.
The transistor ’ s saturation voltage at the maximum out-
put current determines the minimum input-to-output
voltage differential that the linear regulator will support.
Alternatively, the package ’ s power dissipation could
limit the useable maximum input-to-output voltage dif-
ferential. The maximum power dissipation capability of
the transistor ’ s package and mounting must exceed the
actual power dissipation in the device. The power dissi-
pated equals the maximum load current times the maxi-
mum input-to-output voltage differential:
P = I LOAD(MAX) (V LDOIN - V OUT ) = I LOAD(MAX) V CE
Stability Requirements
The MAX1964/MAX1965 linear regulators use an inter-
nal transconductance amplifier to drive an external
pass transistor. The transconductance amplifier, pass
transistor ’ s specifications, the base-emitter resistor,
and the output capacitor determine the loop stability. If
the output capacitor and pass transistor are not proper-
ly selected, the linear regulator will be unstable.
The transconductance amplifier regulates the output
voltage by controlling the pass transistor ’ s base cur-
rent. Since the output voltage is a function of the load
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1964TEEE+ | 功能描述:电流和电力监控器、调节器 Track/Seq Trpl/Wuint Power-Supply Ctlr RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1964TEEE+T | 功能描述:电流和电力监控器、调节器 Track/Seq Trpl/Wuint Power-Supply Ctlr RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1964TEEE-T | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1965TEEP | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
| MAX1965TEEP-T | 功能描述:电流和电力监控器、调节器 RoHS:否 制造商:STMicroelectronics 产品:Current Regulators 电源电压-最大:48 V 电源电压-最小:5.5 V 工作温度范围:- 40 C to + 150 C 安装风格:SMD/SMT 封装 / 箱体:HPSO-8 封装:Reel |
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