Overview
The XTR117, produced by Texas Instruments, is a precision current output converter designed to transmit analog 4-mA to 20-mA signals over an industry-standard current loop. This device is a fundamental building block of smart sensors and is used in various industrial and test applications. It features a low quiescent current, a built-in 5-V regulator for powering external circuitry, and high accuracy in current scaling and output current limit functions. The XTR117 operates over a wide temperature range of –40°C to +125°C and is available in VSON-8 and VSSOP-8 packages.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Quiescent Current | 130 | µA |
| Regulator Voltage | 5 | V |
| Span Error | 0.05% | |
| Nonlinearity Error | 0.003% | |
| Loop Supply Range | 7.5 V to 36 V | V |
| Temperature Range | –40°C to +125°C | °C |
| Current Gain | 100 | |
| Maximum Output Current | 25 mA (limited to 32 mA internally) | mA |
| Small-signal Bandwidth | 380 kHz | kHz |
| Slew Rate | 3.2 mA/µs | mA/µs |
Key Features
- Low quiescent current: 130 µA
- 5-V regulator for external circuits
- Low span error: 0.05%
- Low nonlinearity error: 0.003%
- Wide-loop supply range: 7.5 V to 36 V
- Temperature range: –40°C to +125°C
- Reverse-voltage protection and overvoltage surge protection capabilities
- Available in VSON-8 and VSSOP-8 packages
- High accuracy in current scaling and output current limit functions
- Current return pin (IRET) for accurate control of output current
Applications
- Two-wire, 4-20mA current-loop transmitter
- Smart transmitter
- Industrial process control
- Test systems
- Current amplifier
- Voltage-to-current amplifier
Q & A
- What is the primary function of the XTR117?
The XTR117 is a precision current output converter designed to transmit analog 4-mA to 20-mA signals over an industry-standard current loop.
- What is the quiescent current of the XTR117?
The quiescent current of the XTR117 is typically 130 µA.
- What is the voltage range of the built-in regulator?
The built-in regulator provides a 5-V output.
- What are the package options for the XTR117?
The XTR117 is available in VSON-8 and VSSOP-8 packages.
- What is the temperature range for the XTR117?
The XTR117 operates over a temperature range of –40°C to +125°C.
- How does the XTR117 protect against reverse voltage and overvoltage surges?
The XTR117 features reverse-voltage protection using diode bridges and overvoltage surge protection using Zener diodes.
- What is the maximum output current of the XTR117?
The XTR117 provides accurate, linear output up to 25 mA, with an internal limit of approximately 32 mA.
- How does the XTR117 handle radio-frequency interference (RFI)?
RFI can be mitigated by using decoupling capacitors and ensuring proper wiring and shielding of the current-loop connections.
- Can the XTR117 be used without an external transistor?
While the XTR117 can be used without an external transistor, this configuration is not always practical at higher loop voltages and currents due to self-heating concerns.
- What is the recommended bypass capacitance for HART applications?
For HART applications, a bypass capacitance of 2 nF to 3 nF is recommended.
