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参数资料
| 型号： | MAX038CWP+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 17/17页 |
| 文件大小： | 0K |
| 描述： | IC GEN WAVEFORM HI-FREQ 20-SOIC |
| 标准包装： | 36 |
| 频率： | 0.1Hz ~ 20MHz |
| 电源电压： | 4.75 V ~ 5.25 V |
| 电流 - 电源： | 45mA |
| 工作温度： | 0°C ~ 70°C |
| 封装/外壳： | 20-SOIC（0.295"，7.50mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 20-SOIC W |
| 安装类型： | 表面贴装 |
A stable 2.5V reference voltage, REF, allows simple
determination of IIN, FADJ, or DADJ with fixed resistors,
and permits adjustable operation when potentiometers
are connected from each of these inputs to REF. FADJ
and/or DADJ can be grounded, producing the nominal
frequency with a 50% duty cycle.
The output frequency is inversely proportional to
capacitor CF. CF values can be selected to produce
frequencies above 20MHz.
A sine-shaping circuit converts the oscillator triangle
wave into a low-distortion sine wave with constant
amplitude. The triangle, square, and sine waves are
input to a multiplexer. Two address lines, A0 and A1,
control which of the three waveforms is selected. The
output amplifier produces a constant 2VP-P amplitude
(±1V), regardless of wave shape or frequency.
The triangle wave is also sent to a comparator that pro-
duces a high-speed square-wave SYNC waveform that
can be used to synchronize other oscillators. The SYNC
circuit has separate power-supply leads and can be
disabled.
Two other phase-quadrature square waves are gener-
ated in the basic oscillator and sent to one side of an
"exclusive-OR" phase detector. The other side of the
phase-detector input (PDI) can be connected to an
external oscillator. The phase-detector output (PDO) is
a current source that can be connected directly to
FADJ to synchronize the MAX038 with the external
oscillator.
Waveform Selection
The MAX038 can produce either sine, square, or trian-
gle waveforms. The TTL/CMOS-logic address pins (A0
and A1) set the waveform, as shown below:
X = Don’t care.
Waveform switching can be done at any time, without
regard to the phase of the output. Switching occurs
within 0.3s, but there may be a small transient in the
output waveform that lasts 0.5s.
Waveform Timing
Output Frequency
The output frequency is determined by the current
injected into the IIN pin, the COSC capacitance (to
ground), and the voltage on the FADJ pin. When
VFADJ = 0V, the fundamental output frequency (Fo) is
given by the formula:
Fo (MHz) = IIN (A) ÷ CF (pF)
[1]
The period (to) is:
to (s) = CF (pF) ÷ IIN (A)
[2]
where:
IIN = current injected into IIN (between 2A and
750A)
CF = capacitance connected to COSC and GND
(20pF to >100F).
For example:
0.5MHz = 100A ÷ 200pF
and
2s = 200pF ÷ 100A
Optimum performance is achieved with IIN between
10A and 400A, although linearity is good with IIN
between 2A and 750A. Current levels outside of this
range are not recommended. For fixed-frequency oper-
ation, set IIN to approximately 100A and select a suit-
able capacitor value. This current produces the lowest
temperature coefficient, and produces the lowest fre-
quency shift when varying the duty cycle.
The capacitance can range from 20pF to more than
100F, but stray circuit capacitance must be minimized
by using short traces. Surround the COSC pin and the
trace leading to it with a ground plane to minimize cou-
pling of extraneous signals to this node. Oscillation
above 20MHz is possible, but waveform distortion
increases under these conditions. The low frequency
limit is set by the leakage of the COSC capacitor and
by the required accuracy of the output frequency.
Lowest frequency operation with good accuracy is usu-
ally achieved with 10F or greater non-polarized
capacitors.
An internal closed-loop amplifier forces IIN to virtual
ground, with an input offset voltage less than ±2mV. IIN
may be driven with either a current source (IIN), or a
voltage (VIN) in series with a resistor (RIN). (A resistor
between REF and IIN provides a convenient method of
generating IIN: IIN = VREF/RIN.) When using a voltage in
series with a resistor, the formula for the oscillator fre-
quency is:
Fo (MHz) = VIN ÷ [RIN x CF (pF)]
[3]
and:
to (s) = CF(pF) x RIN ÷VIN
[4]
High-Frequency Waveform Generator
A0
A1
WAVEFORM
X
1
Sine wave
0
Square wave
1
0
Triangle wave
MAX038
Maxim Integrated
9
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相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX038CWP+ | 功能描述:时钟发生器及支持产品 RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56 |
| MAX038CWP+T | 功能描述:时钟发生器及支持产品 RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56 |
| MAX038CWP-T | 功能描述:时钟发生器及支持产品 RoHS:否 制造商:Silicon Labs 类型:Clock Generators 最大输入频率:14.318 MHz 最大输出频率:166 MHz 输出端数量:16 占空比 - 最大:55 % 工作电源电压:3.3 V 工作电源电流:1 mA 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:QFN-56 |
| MAX038EPP | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:High-Frequency Waveform Generator |
| MAX038EVKIT | 制造商:MAXIM 制造商全称:Maxim Integrated Products 功能描述:Evaluation Kit for the MAX038 |
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