3B39隔离式过程电流输出

3B39是单通道信号调理电流输出模块，可对0至+10 V或+10 V至+10 V输入信号进行接口、隔离和滤波，并在0至850 Ω负载两端提供隔离式过程电流输出。输出电流显示在3B系列背板输出螺丝端子板上。 它适合需要完整电流隔离和保护、避免因系统或隔离系统元件之间的瞬变和故障造成损坏的高精度过程控制和监控应用。 通过模块底部提供的编程跳线，两个输入电压范围均可转换为两个输出电流范围。 3B39型号具有±0.01%的非线性度和±0.1%的精度。 3B39提供基于±1500 V峰值电流变压器的输出-输入及电源隔离，以及50/60 Hz下90 dB的共模抑制(CMR)，以保持低电平信号在高噪声环境中的完整性。 3B39支持与其它3B系列模块之间的混搭使用和热插拔，可以在不中断系统电源的情况下将其插入或拔出同一背板中的任何插槽。

在3B39系列模块内

信号隔离通过变压器耦合提供，并利用专有调制技术来实现线性、稳定且可靠的性能。信号变压器的输出侧的解调器恢复初始信号，接着予以滤波并通过电流(V-I)转换器输出级将转换为精密电流输出。 输出保护使3B39可以承受高达220 V rms电源线路的意外连接而不受损坏，隔离计算机侧电路。与DAC至标准4-20 mA电流环路接口时，3B39提供全面接地隔离和瞬变保护，这是基于微电脑的控制系统的常见要求。

图1. 3B39功能框图

图2. 3B39输入现场连接

输入类型	双路输出
0 至 +10 V	4 mA 至 20 mA
-10 V 至 +10 V	0 至 20 mA

	Model	Input Range	Output  Ranges1
Order Now	3B39	0 V to +10 V or -10 V to +10 V	0 mA to 20 mA or 4 mA to 20 mA

¹ Output current range may be user programmed to 4 mA to 20 mA using jumper supplied.

(typical @ +25°C and ±15 V dc, and +24 V dc Power)

Description	Model 3B37
Input Range
Input Voltage Standard Ranges1	0 V to +10 V or -10 V to +10 V
Input, Without Damage	-20 V to +20 V, maximum
Input Resistance	10 kΩ
Output Range
Standard Ranges (RL = 0 to 850Ω)	4 mA to 20 mA or 0 mA to 20 mA
Custom Ranges	Not Available
Accuracy2
Initial @ +25°C	±0.1% Span + CJC Sensor Error
Nonlinearity	±0.01% Span
Stability vs. Temperature
Current Output
Zero	±25 ppm of Span/°C
Span	±25 ppm of Reading/°C
Zero and Span Adjustment Range	±5% of Span
Noise
Input, 0.1 Hz to 10 Hz Bandwidth	0.2 µV rms
Output, 100 kHz Bandwidth	50 µV rms
Bandwidth, -3 dB	3 Hz
Output Rise Time, 10% to 90% Span	2 ms
Common Mode Voltage (CMV)
Input-to-Output, Continuous	±1500 V peak, maximum
Transient	ANSI/IEEE C37.90.1-1989
Common Mode Rejection (CMR)
1 kΩ Source Imbalance, 50/60 Hz	90 dB
Output Protection
Continuous, Normal Mode	220 V rms, maximum
Transient	ANSI/IEEE C37.90.1-1989
Power Supply Voltages3
±15 V dc Supplies
Rated Operation	±(11.5 V dc to 16.5 V dc)
Current	±10 mA
Sensitivity	±0.01% span/V
+24 V dc Loop Supply
Rated Operation	+12 V dc to +30 V dc
Current	+27 mA @ lout = 20 mA
Sensitivity	±0.0002% span/V
Mechanical Dimensions	3.15" x 3.395" x 0.775" (80.0 mm x 86.2 mm x 19.7 mm)
Environmental
Temperature Range
Rated Performance	-25°C to +85°C
Storage	-55°C to +85°C
Relative Humidity, 24 hours	0 to 95% @ +60°C noncondensing
RFI Susceptibility	±0.5% Span error @ 400 MHz, 5 Watt, 3 ft

¹ Input and Output Range may be selected using jumpers supplied.
² Includes the combined effects of repeatability, hysteresis, and nonlinearity.
³ +24 V dc loop power is required for driving the current output at loads up to 850Ω. If a current output load of 400Ω or less is applied, +15 V dc is sufficient for loop power. If only voltage output is used, loop power is not required.