Junction temperature may be measured indirectly using the device's inherent voltage/temperature dependency characteristic. Combined with a Joint Electron Device Engineering Council (JEDEC) technique such as JESD 51-1 and JESD 51-51, this method will produce accurate Tj measurements. However, this measurement technique is difficult to implement in multi-LED series circuits due to high common mode voltages and the need for fast, high duty cycle current pulses. This difficulty can be overcome by combining high-speed sampling digital multimeters and fast high-compliance pulsed current sources.