LDC-3724 is a 200/500mA Current Source, 32W TEC controller in the LDC-3700B series.
Model LDC-3700B Series Laser Diode Controllers conveniently offer both laser diode current and temperature control in the same instrument. Each unit is a dual-range current source offering 16 W TEC and either 50/100 mA, 200/500 mA, or 2/4 A output current. Each controller offers a low noise, highly stable current source operating in one of three modes: constant current, high bandwidth or constant optical power. Mode 1 is optimized for DC operation, supports external modulation and offers improved laser protection and noise performance. In Mode 2, the output stage supports higher frequency, external modulation with control circuitry optimized for high bandwidth operation of up to 1 MHz. Mode 3 supports constant optical power operation, using photodiode input current as the control setpoint.
Protection features like clamping current limits and braid-shielded cables suppress radiated noise and transients. Turn-on sequencing and output shorting circuits protect the laser from current transients. When output is turned on, the slow-start circuit allows current to be diverted to the laser slowly. The output shorting switch provides safe switching of output off/on during operation. In addition, the outputs are bound by fully independent hardware current limits, which cannot be exceeded, even under externally modulated conditions. In optical power mode, the output current also can be bound by a software optical power limit. In addition to these proven protection features, the LDC-3700B Series now offers adjustable compliance voltage and faster shut-off circuitry. This new level of protection reduces potentially dangerous reconnect current transients in the event of intermittent connections between the controller and the laser diode.
LDC-3700B Series controllers offer extended temperature control, from 99°C to 199°C, with a choice of temperature sensors. Temperature control is available in one of three modes: constant temperature, constant sensor value, constant TE module current. Mode 1 permits TE module operation anywhere over the temperature range, depending on parameter selection. Mode 2 supplies the flexibility to drive to a prescribed thermistor resistance value, or IC temperature sensor current or voltage. Mode 3 permits output to be driven to a predetermined TE-module current setting. As an added precaution, if the temperature sensor or TE module should open during operation, the laser diode output will shut down and the appropriate fault indicator lamp will flash. In addition, the LDC-3700B family now supports the measurement of TEC voltage via simple GPIB commands.
The standard GPIB/IEEE-488.2 interface allows remote programming and readout from most computers. All instrument functions accessible from the front panel are also accessible through the interface bus, and all commands are based on a set of easy-to-use mnemonics. LabVIEW® instrument drivers are also available. Routine maintenance is simplified since calibration can be performed via the front panel or the GPIB interface. The operating parameters, logically grouped together into TEC and LASER sections, offer a simultaneous dual display for laser current and temperature parameters. The units also offer bright green, five-digit LEDs, digital adjust knobs, informative error indicators and SAVE and RECALL features.
- Fast GPIB/IEEE-488.2 Interface
- 4-wire voltage sense and adjustable voltage limit
- Resistive heater adapters available for TEC modules