AVALANCHE PHOTODIODE BIAS SUPPLY 1 Provides an output voltage of 0V to +80V for reverse biasing an avalanche photodiode to control its gain. This circuit can also be reconfigured to supply a 0V to –80V output. LINEAR TEC DRIVER–1 This is a bridge-tied load (BTL) linear amplifier for driving a thermoelectric cooler (TEC). It operates on a single +5V supply and can drive ±2A into a common TEC. LINEAR TEC DRIVER–2 This is very similar to DRIVER–1 but its power output stage was modified to operate from a single +3.3V supply in order to increase its efficiency. Driving this amplifier from a standard +2.5V referenced signal causes the output transistors to have unequal power dissipation. LINEAR TEC DRIVER–3 This BTL TEC driver power output stage achieves very high efficiency by swinging very close to its supply rails, ±2.5V. This driver can also drive ±2A into a common TEC. Operation is shown with the power output stage operating on ±1.5V supplies. Under these conditions, this linear amplifier can achieve very high efficiency.