Overview
The LM234Z-3 is a 3-terminal adjustable current source produced by National Semiconductor. It is part of the LM134/LM234/LM334 family, known for their adjustable current sources and true temperature sensing capabilities. The LM234Z-3 operates over a wide dynamic voltage range of 1V to 40V and is programmable from 1µA to 10mA. This device is ideal for various applications requiring precise current control and temperature sensing.
Key Specifications
| Parameter | Units | Min | Typ | Max |
|---|---|---|---|---|
| V+ to V- Forward Voltage | V | 30 | 30 | |
| V+ to V- Reverse Voltage | V | 20 | ||
| R Pin to V- Voltage | V | 5 | ||
| Set Current | mA | 10 | ||
| Power Dissipation | mW | 400 | ||
| Operating Temperature Range | °C | -25 | 100 | |
| Set Current Error (V+=2.5V) | % | 1 | 2 | |
| Minimum Operating Voltage | V | 0.9 | 0.9 |
Key Features
- Operates from 1V to 40V
- 0.02%/V current regulation
- Programmable from 1µA to 10mA
- True 2-terminal operation
- Available as fully specified temperature sensor
- ±3% initial accuracy
- True floating current source with no separate power supply connections
- Reverse applied voltages of up to 20V draw only a few dozen microamperes of current, allowing operation as both a rectifier and current source in AC applications
- Sense voltage directly proportional to absolute temperature (°K)
- Zero drift operation achievable with additional resistor and diode
Applications
- Bias networks
- Surge protection
- Low power reference
- Ramp generation
- LED driver
- Temperature sensing
- Remote sense applications due to immunity to series resistance in long wire runs
Q & A
- What is the operating voltage range of the LM234Z-3?
The LM234Z-3 operates from 1V to 40V.
- What is the programmable current range of the LM234Z-3?
The current is programmable from 1µA to 10mA.
- What is the initial accuracy of the LM234Z-3?
The initial accuracy is ±3%.
- How does the LM234Z-3 handle reverse voltages?
Reverse applied voltages of up to 20V will only draw a few dozen microamperes of current.
- What is the temperature dependence of the set current?
The set current increases at approximately 0.33%/°C.
- Can the LM234Z-3 be used as a temperature sensor?
- What are the package options for the LM234Z-3?
The device is available in TO-92 and SO-8 plastic packages.
- What is the operating temperature range of the LM234Z-3?
The operating temperature range is from -25°C to +100°C.
- How does the LM234Z-3 handle ESD susceptibility?
The device has an ESD susceptibility of 2000V.
- What are some common applications of the LM234Z-3?
Common applications include bias networks, surge protection, low power reference, ramp generation, LED driver, and temperature sensing.
