- 您现在的位置：买卖IC网 > PDF目录5148 > MAX881REUB+T (Maxim Integrated Products)IC SUPPLY BIAS LN 10-UMAX PDF资料下载
参数资料
| 型号： | MAX881REUB+T |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 7/8页 |
| 文件大小： | 0K |
| 描述： | IC SUPPLY BIAS LN 10-UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 2,500 |
| 应用： | 充电泵，无线设备 |
| 输入电压： | 2.5 V ~ 5.5 V |
| 输出数： | 1 |
| 输出电压： | -2V，-2.5 V ~ 6.1 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 供应商设备封装： | 10-µMAX |
| 包装： | 带卷 (TR) |
Low-Noise Bias Supply in μMAX
with Power-OK for GaAsFET PA
regulating, the output resistance of the circuit is simply
V IN
the linear-regulator load regulation (2mV/mA).
ON
C1
0.22 μ F
OFF
C1+
C1-
SHDN
IN
MAX881R
OUT
FB
C3
0.22 μ F
R2
C4
4.7 μ F
C1, C2, and C3 should be 0.22μF capacitors with less
than 0.4 ? ESR. C4 should be a 4.7μF capacitor with
less than 0.1 ? ESR. Larger capacitor values can be
used (C1 = C2 = C3 = 1μF, C4 = 10μF) to reduce out-
put noise and ripple (1mVp-p), at the expense of cost
and board space. All capacitors should be either
ceramic or surface-mount chip tantalum (Figures 3a
and 3b).
C2
0.22 μ F
NEGOUT
GND
POK
R1
Layout and Grounding
Good layout is important for good noise performance.
To optimize the layout:
1) Mount all components as close together as possible.
Figure 4. Adjustable Output Configuration
Capacitors
Use capacitors with a low effective series resistance
(ESR) to maintain a low dropout voltage (V IN - |V OUT |).
The overall dropout voltage is a function of the output
resistance of the charge pump and the voltage drop
across the linear regulator (N-channel pass transistor).
At the 100kHz charge-pump switching frequency, out-
put resistance is a function of the value of C1 and the
ESR of C1 and C2. Therefore, increasing C1 and mini-
mizing the ESR of the charge-pump capacitors mini-
mizes dropout voltage.
The output resistance of the entire circuit (in dropout) is
approximately:
R OUT = R O + 4 x ESR C1 + ESR C2 + 1 / (f S x C1)
+ R (linear regulator)
2) Keep traces short to minimize parasitic inductance
and capacitance, especially connections to FB.
3) Use a ground plane.
Noise and Ripple Measurement
Accurately measuring the output noise and ripple is a
challenge. Slight momentary differences in ground
potential between the circuit and the oscilloscope
(which result from the charge pump’s switching action)
cause ground currents in the probes’ wires, inducing
sharp voltage spikes. For best results, measure directly
across the output capacitor (C4). Do not use the
ground lead of the probe; instead, remove the probe’s
tip cover and touch the ground ring on the probe
directly to C4’s ground terminal. This direct connection
gives the most accurate noise and ripple measurement.
Where R (linear regulator) (the output impedance of the
linear regulator) is approximately 2 ? and R O (the resis-
tance of the internal switches) is typically 10 ? . When
TRANSISTOR COUNT: 413
Chip Information
_______________________________________________________________________________________
7
相关PDF资料 |
PDF描述 |
|---|---|
| GBM43DTKT | CONN EDGECARD 86POS DIP .156 SLD |
| X40411V8-B | IC VOLTAGE MON DUAL W/SUP 8TSSOP |
| MAX845EUA+T | IC DRVR TRANSF ISO 8-UMAX |
| UUP1V3R3MCL1GS | CAP ALUM 3.3UF 35V 20% SMD |
| MAX8805WEWEEE+TC8E | IC PWM STEP-DN CONV 650MA 16-WLP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX881REUB-TG069 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX881REUB-TG074 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX881REUB-TG075 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
| MAX8821ETI+ | 功能描述:LED照明驱动器 White LED Charge Pump RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N |
| MAX8821ETI+T | 功能描述:LED照明驱动器 White LED Charge Pump RoHS:否 制造商:STMicroelectronics 输入电压:11.5 V to 23 V 工作频率: 最大电源电流:1.7 mA 输出电流: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:SO-16N |
发布紧急采购，3分钟左右您将得到回复。