Other op amps can be used in this circuit if lower output 1 voltages are desired. An OPA551 or OPA552 can be used 1 10 100 1k 10k 100k 1M for a 0V to +50V bias supply if its positive supply voltage Frequency (Hz) is reduced to +55V. FIGURE 3.APD Bias Supply Small Signal Bandwidth. Bandwidth of this