Does an analog-to-digital converter cost you a lot if you need many bits of accuracy and dynamic range? Absolute accuracy better than 0.1% is likely to be expensive. But a capability for wide dynamic range can be quite inexpensive. Voltage-to-frequency (V-to-F) converters are becoming popular as a low-cost form of A-to-D conversion because they can handle a wide dynamic range of signals with good accuracy. source

This current to voltage converter rely on the very high input impedance of the operational amplifier. The input current (I) is forced through feedback resistor (Rf), and generates an output voltage equal to (-I x Rf). This output voltage is valid for output voltages from rail to rail, namely from -5 to +5 volts in this example.This output voltage is valid for output voltages from rail to rail, namely from -5 to +5 volts in this example. source

Here are some ways to use high-speed Current Feedback and Voltage Feedback op amps to do the job.It’s more difficult to design a good current-to-voltage converter using a Voltage Feedback Amplifier (VFA). As discussed above, phase shift caused by photo-diode capacitance is often a source of instability. Furthermore, wide bandwidth usually comes at the expense of supply currents and higher supply voltage. However, the new LMH6642 high-speed low-voltage VFA op amp has excellent performance
in a transimpedance gain block.This device can operate down to 2.7V single supply and its −3dB BW (AV = +1) is more than 100MHz (with a supply current of only 2.7mA)source

This current to voltage converter rely on the very high input impedance of the operational amplifier. The input current (I) is forced through feedback resistor (Rf), and generates an output voltage equal to (-I x Rf).This output voltage is valid for output voltages from rail to rail, namely from -1 to +1 volts in this example.source

This power supply build based on the application note of the LM317 of National Semiconductor .
Some features:

• Adjustable from 1.2V – 25 V
• Current output 1.5 Amp
• Short circuit proof
• Thermally protected

Other features as adjustable current limit, starting a 0 Volt, higher output voltage and higher output current are possible too: see the LM317 specification.source