SY88923V

The SY88923V limiting post amplifier with its high gain and wide bandwidth is ideal for use as a post amplifier in fiber-optic receivers with data rates up to 2.5Gbps. Signals as small as 5mVp-p can be amplified to drive devices with PECL inputs. The SY88923V generates a chatter-free Loss of Signal (LOS) open collector TTL output.

The SY88923V incorporates a programmable level detect function to identify when the input signal has been lost. The LOS output will change from logic "LOW" to logic "HIGH" when input signal is smaller than the swing set by LOS_LVL. This information can be fed back to the EN input of the device to maintain stability under loss of signal condition. Using LOS_LVL pin, the sensitivity of the level detection can be adjusted. The LOS_LVL voltage can be set by connecting a resistor divider between V_CC and VREF show in Figure 3. Figure 4, 5, 6, and 7 show the relationship between input level sensitivity and the voltage set on LOS_LVL.The LOS output is a TTL open collector output that requires a pull-up resistor for proper operation, Figure 1.