Electronic Components Datasheet Search |
|
SY88307BLEY Datasheet(PDF) 7 Page - Micrel Semiconductor |
|
SY88307BLEY Datasheet(HTML) 7 Page - Micrel Semiconductor |
7 / 11 page Micrel, Inc. SY88307BL November 2007 7 M9999-111507-C hbwhelp@micrel.com or (408) 955-1690 Functional Block Diagram Detailed Description The SY88307BL low-power limiting post amplifiers operate from a single +3.3V power supply, over temperatures from –40 oC to +85oC. Signals with data rates up to 3.2Gbps and as small as 10mVpp can be amplified. Figure 1 shows the allowed input voltage swing. The SY88307BL generates a LOS output allowing feedback to EN/ for output stability. LOSLVL sets the sensitivity of the input amplitude detection. Input Amplifier Buffer Figure 2 shows a simplified schematic of the input stage. The high-sensitivity of the input amplifier allows signals as small as 10mVpp to be amplified. The input amplifier also allows input signals as large as 1800mVPP. Input signals below 12mVpp are linearly amplified with a typical 42dB differential voltage gain. Since it is a limiting amplifier, these devices output typically 1500mVPP voltage-limited waveforms for input signals greater than 12mVPP. Applications requiring the SY88307BL to operate with strong signals should have the upstream TIA placed as close as possible to the devices’ input pins. This ensures the best performance of the device. Output Buffer The SY88307BL PECL output buffers are designed to drive 50 Ω lines. The output buffer requires appropriate termination for proper operation. An external 50 Ω resistor to VCC-2V for each output pin provides this. Figure 3 shows a simplified schematic of the output stage. Loss-of-Signal The SY88307BL generates a chatter-free LOS open- collector TTL output, as shown in Figure 4. LOS is used to determine that the input amplitude is large enough to be considered a valid input. LOS asserts high if the input amplitude falls below the threshold sets by LOSLVL and de-asserts low otherwise. LOS can be fed back to the enable bar (EN/) input to maintain output stability under a loss-of-signal condition. EN/ de-asserts the true output signal without removing the input signals. Loss-of-Signal Level Set Programmable LOS level-set pin (LOSLVL) sets the threshold of the input amplitude detection. Connecting an external resistor between VCC and LOSLVL set the voltage at LOSLVL. This voltage ranges from VCC to VREF. The external resistor creates a voltage divider between VCC and VREF, as shown in Figure 5. Hysteresis The SY88307BL typically provide 3.5dB LOS electrical hysteresis. By definition, a power ratio measured in dB is 10log (power ratio). Power is calculated as V 2 IN / R for an electrical signal. Hence, the same ratio can be stated as 20log (voltage ratio). While in linear mode, the electrical voltage input changes linearly with the optical power and therefore, the ratios change linearly. Thus, the optical hysteresis in dB is half the electrical hysteresis in dB given in the data sheet. Since the SY88307BL is an electrical device, this data sheet refers to hysteresis in electrical terms. With 3.5dB LOS hysteresis, a voltage factor of 1.5 is required to assert or de-assert LOS. |
Similar Part No. - SY88307BLEY |
|
Similar Description - SY88307BLEY |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |