Item# |
LD1100 |
LD1101 |
EK1101a |
EK1102b |
Output Current |
0 - 250 mA |
Supported Laser Pin Configurations |
A, B, D, & F |
C, D, & F |
A |
B |
Recommended for LEDsb |
No |
No |
Yes |
Yes |
Output Control |
12-Turn Power Adjustment (On-Board) |
Output Stability |
1.5% |
Output Noise |
5 μA RMS |
Feedback Gain |
Adjustable |
Monitor Current Range |
5 μA to 5 mA |
Operating Voltage |
8 to 12 VDC |
Quiescent Current |
9 mA |
Dimensions |
1" x 1.5" 12-Pin SIP Package |
See Drawing |
ESD Protection |
100 ms Slow Start |
Max Output Voltage |
~6.5 V (with a 12 V Power Supply) |
Laser Diode Drivers
The LD1100 and LD1101 Laser Diode Drivers are constant-power laser driver modules that support common laser anode and common laser cathode pin configurations. They feature an on-board 12-turn trim pot for continuous laser power output adjustment, pin-programmable feedback gain, ON/OFF control input, and a current monitor output for observing the laser drive current. With dimensions of only 1" x 1.5", they are compact and can be embedded into custom designs. The compliance voltage, which is the maximum output voltage, is ~6.5 V for the LD1100 and LD1101 when using a 12 V power supply. All input and output signals are provided on a 12-pin SIP connector, which allows simple integration into a printed circuit design.
The LD1100 and LD1101 can drive lasers up to 250 mA in a constant-power mode. Either uses the internal monitor photodiode for a feedback signal into a proportional-integral feedback loop to stabilize the output power to within 1.5%. To accommodate a wide range of laser diodes, the feedback gain can be set by using jumpers between any combination of the five gain setting resistor pins to the power supply common. This allows lasers with monitor currents over a range from 5 μA to 5 mA to be used with a single driver.
Evaluation Kits
The EK1100 Series Evaluation Kit is an LD1100 Laser Driver soldered to a PCB that features an on/off switch and a dip switch bank for controlling the gain on the feedback signal. A 3-pin laser socket cable (S8060) is also soldered onto the PCB board (this determines the pin configuration supported by the kit). In addition to driving lasers, the EK1101 and EK1102 are also suggested for operating LEDs that contain a monitor photodiode with an A or B style pin configuration, respectively.
Power Supply Options
A power supply cable for 9 V batteries is included but not attached. Alternatively, our LDS9 power supply can be used if the phono connector is removed and the bare wires are exposed.
Supported Pin Configurations

LD1100 Pin Configurations
Pin | Signal | Description |
1 |
+V |
Circuit Power, 8 to 12 VDC, 9 mA + Laser Drive Current NOTE: Internally tied to Laser Diode Anode, the laser anode must be isolated from the power supply COM |
2 |
COM |
Circuit Ground |
3 |
VREF |
Internal 2.5 V reference |
4 |
PDA |
Photodiode Anode |
5 |
LDA |
Laser Diode Anode (Internally Tied to +V (Pin 1)) |
6 |
LDC |
Laser Diode Cathode |
7 |
RA |
When Tied to Common, Puts 100 kΩ in Parallel with 249 kΩ Internal Gain Resistor |
8 |
RB |
When Tied to Common, Puts 33.2 kΩ in Parallel with 249 kΩ Internal Gain Resistor |
9 |
RC |
When Tied to Common, Puts 10 kΩ in Parallel with 249 kΩ Internal Gain Resistor |
10 |
RD |
When Tied to Common, Puts 3.32 kΩ in parallel with 249 kΩ Internal Gain Resistor |
11 |
RE |
When Tied to Common, Puts 1 kΩ in Parallel with 249 kΩ Internal Gain Resistor |
12 |
ILD |
Laser Diode Current Monitor (10 mV/mA) |
LD1101 Pin Configurations
Pin | Signal | Description |
1 |
+V |
Circuit Power, 8 to 12 VDC, 9 mA + Laser Drive Current NOTE: Internally tied to Laser Diode Anode. The laser anode must be isolated from the power supply COM. |
2 |
COM |
Circuit Ground |
3 |
VREF |
Internal 2.5 V reference |
4 |
PDC |
Photodiode Cathode |
5 |
LDA |
Laser Diode Anode (Internally Tied to +V (Pin 1)) |
6 |
LDC |
Laser Diode Cathode |
7 |
RA |
When Tied to Pin 6, Puts 5 kΩ in parallel with 12.4 kΩ Internal Gain Resistor |
8 |
RB |
When Tied to Pin 6, Puts 1.5 kΩ in parallel with 12.4 kΩ Internal Gain Resistor |
9 |
RC |
When Tied to Pin 6, Puts 499 Ω in parallel with 12.4 kΩ Internal Gain Resistor |
10 |
RD |
When Tied to Pin 6, Puts 160 Ω in parallel with 12.4 kΩ Internal Gain Resistor |
11 |
RE |
When Tied to Pin 6, Puts 33 Ω in parallel with 12.4 kΩ Internal Gain Resistor |
12 |
ILD |
Laser Diode Current Monitor (10 mV/mA) |
EK1101
Laser Anode - Photodiode Cathode Common

Laser Pin | J1 Pin (on Evaluation Board) | Wire Color |
PDA |
PD_A |
Green |
LDA/PDC |
LD_A |
Red |
LDC |
LD_C |
Yellow |
EK1102
Laser Cathode - Photodiode Cathode Common

Laser Pin | J1 Pin (on Evaluation Board) | Wire Color |
PDA |
PD_A |
Green |
LDA |
LD_A |
Yellow |
LDC/PDC |
LD_C |
Red |
EK110x Laser Socket Wire Harness


Item # | % Weight Reduction | CO2-Equivalent Reductiona |
EK1101 |
19.70% |
3.79 kg |
EK1102 |
19.70% |
0.28 kg |
Smart Pack
- Reduce Weight of Packaging Materials
- Increase Usage of Recyclable Packing Materials
- Improve Packing Integrity
- Decrease Shipping Costs
Thorlabs' Smart Pack Initiative is aimed at waste minimization while still maintaining adequate protection for our products. By eliminating any unnecessary packaging, implementing packaging design changes, and utilizing eco-friendly packaging materials for our customers when possible, this initiative seeks to improve the environmental impact of our product packaging. Products listed above are now shipped in re-engineered packaging that minimizes the weight and the use of non-recyclable materials.b As we move through our product line, we will indicate re-engineered packages with our Smart Pack logo.