Motore di ricerca datesheet componenti elettronici |
|
ISL58327 Scheda tecnica(PDF) 9 Page - Intersil Corporation |
|
ISL58327 Scheda tecnica(HTML) 9 Page - Intersil Corporation |
9 / 15 page ISL58327 9 FN6577.2 July 29, 2013 from the reference voltage. When using an external reference voltage, the user needs to adjust the gain registers to set proper channel gain to prevent output saturation. To use ISL58327 as a single-ended output, the user can take either OUTP or OUTN signal and load the unused output with the equivalent resistor and capacitor load to keep both outputs with the same loading condition. However, it is acceptable to leave the unused output floating. It is not recommended to use VREF as a reference source to drive other devices. To obtain the best signal quality at the input of the AFE, it is recommended to keep OUTP and OUTN traces in parallel and to keep them with same length, width, and routing. If output signals from ISL58327 need to travel through a flex cable to the AFE, matching with the impedance of flex cable is necessary. The best value should be determined according to the actual application. Slow Tail Compensation Photons at longer wavelengths will penetrate deeper into the photo detector structure than photons at shorter wavelengths. It takes more time for electron-hole pairs to become photo current and results in longer response of pulse outputs, called slow tail. Longer wavelength light such as 638nm or IR has more visible slow tail effect than blue light. To minimize the slow tail effect, ISL58327 has incorporated Intersil’s proprietary slow tail compensation technology. There are three registers for slow tail compensation adjustment for each wavelength (638nm, 532nm, and 445nm). Slow tail compensation function is not limited to the specific wavelength listed previously; it is in conjunction with the selected fine gain registers. The user can disable slow tail compensation by setting Bit 7 (MSB) of the register to “0”. This function can also be used to improve the quality of the pulse output waveforms due to impedance mismatch from the OEIC outputs to the flex. One example is to improve Tr/Tf or to minimize overshoot. Layout Consideration When using differential output, layout the OUTP and OUTN traces next to each other. The ground trace should be placed to another side of the OUTP and OUTN traces. When using single-ended, the reference trace needs to be laid out next to the output signal trace. The ground trace should be laid out on the other side of the output. For best results, a dual layer flex with signal on one side and the ground plane on another side is a must. Reference Voltage The ISL58327 has a built-in reference voltage generator to generate 2.1V reference voltage for all circuit blocks. Output is biased at the internal reference voltage automatically when the VREF pin is left floating. When a DC voltage is applied to the VREF pin, OUTP and OUTN will be biased at the external reference voltage. External reference should be within the range of 1.5V to 2.5V. Outside of this range may yield distorted outputs. When using external reference voltage, good decoupling is very important to prevent noise coupling into VREF. A 0.1µF ceramic capacitor placed as close to the VREF pin as possible is recommended to decouple VREF to ground. Power Supply Decoupling Due to the current being switched rapidly at OUTP and OUTN, it is important to ensure that the power supply is well decoupled to ground. During output switching, the VDD undergoes severe current transients, thus every effort should be made to decouple the VDD as close to the package as possible. Without proper power supply decoupling, the result could be poor rise/fall times, overshoot, and poor settling response. Sensitivity Curves FIGURE 2. NORMALIZED SPECTRAL RESPONSE vs WAVELENGTH FIGURE 3. INTENSITY vs OUTPUT (RED LED 620nm; GREEN LED 532nm; BLUE LED 460nm) 0 0.2 0.4 0.6 0.8 1.0 1.2 300 400 500 600 700 800 900 1000 WAVELENGTH (nm) 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 0 100 200 300 400 500 600 700 800 INPUT (µW) 450nm P 530nm P 640nm P 450nm N 530nm N 640nm N |
Codice articolo simile - ISL58327 |
|
Descrizione simile - ISL58327 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEETIT.COM |
Lei ha avuto il aiuto da alldatasheet? [ DONATE ] |
Di alldatasheet | Richest di pubblicita | contatti | Privacy Policy | scambio Link | Ricerca produttore 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 |