JAJSMU3C August 2021 – November 2022 LMH32404
PRODUCTION DATA
Figure 8-3 and Figure 8-4 shows the LMH32404 test circuit used to measure its bandwidth, noise and transient response. The voltage source is DC biased close to the input bias voltage of the LMH32404. The LMH32404 internal design is optimized to only source current out of the input pin (INx). When testing the LMH32404 with a network analyzer or sinusoidal source, set the DC bias such that sum of the input AC and DC component does not result in a sourcing current into the amplifier input. Only use the LMH32404 with avalanche photodiodes (APDs) that sink current. An anode-biased APD satisfies this requirement.
Figure 8-5 shows the measured results for bandwidth of LMH32404 for all four channels.
Figure 8-6 shows the output noise spectral density of the LMH32404 with CAPD = 1 pF and no photodiode capacitance.
Figure 8-7 shows the turn-on time of the LMH32404 channel when the Mx pin is toggled from logic low to high. When the amplifier is off, the output is in a high-impedance state. When the amplifier turns on, the output settles and starts tracking the input within a few nanoseconds.
Figure 8-8 shows the turn-off time of the LMH32404 channel when the Mx pin is toggled from logic high to low. When the amplifier is off, the output is in a high-impedance state.