Electronic Components Datasheet Search |
|
APL55375MCTI-TRG Datasheet(PDF) 10 Page - Anpec Electronics Coropration |
|
APL55375MCTI-TRG Datasheet(HTML) 10 Page - Anpec Electronics Coropration |
10 / 16 page Copyright © ANPEC Electronics Corp. Rev. A.7 - Oct., 2011 www.anpec.com.tw 10 APL5537 Input Capacitor Application Information The APL5537 requires proper input capacitors to supply surge current during stepping load transients to prevent the input rail from dropping. Because the parasitic induc- tor from the voltage sources or other bulk capacitors to the VIN limit the slew rate of the surge current, place the Input capacitors near VIN as close as possible. Input ca- pacitors should be larger than 1 µF and a minimum ce- ramic capacitor of 1 µF is necessary. Output Capacitor The APL5537 needs a proper output capacitor to main- tain circuit stability and improve transient response over temperature and current. In order to insure the circuit stability, the proper output capacitor value should be larger than 1 µF. With X5R and X7R dielectrics, 1µF is sufficient at all operating temperatures. Large output capacitor value can reduce noise and improve load-transient re- sponse and PSRR, Figure 1 shows the curves of allow- able ESR range as the function of load current for various output capacitor values. Figure1. Stable C OUT ESR Range Operation Region and Power Dissipation The APL5537 maximum power dissipation depends on the thermal resistance and temperature difference be- tween the die junction and ambient air. The TDFN1.6x 1.6-6 package power dissipation P D across the device is: P D = (TJ - TA) / θJA where (T J-TA) is the temperature difference between the junction and ambient air. θ JA is the thermal resistance between Junction and ambient air. Assuming the T A=25 oC and maximum T J=160 oC (typical thermal limit threshold), the maximum power dissipation is calculated as: P D(max)=(160-25)/165 = 0.82(W) For normal operation, do not exceed the maximum junc- tion temperature rating of T J = 125 oC. The calculated power dissipation should be less than: P D =(125-25)/165 = 0.61(W) The GND provides an electrical connection to the ground and channels heat away. Connect the GND to the ground by using a large pad or a ground plane. Layout Consideration Figure 2 illustrates the layout. Below is a checklist for your layout: 1. Please place the input capacitors close to the VIN. 2. Ceramic capacitors for load must be placed near the load as close as possible. 3. To place APL5537 and output capacitors near the load is good for performance. 4. Large current paths, the bold lines in figure 2, must have wide tracks. V IN V OUT1 C IN C OUT1 VIN VOUT1 GND APL5537 V OUT2 C OUT2 VOUT2 EN1 EN2 ON OFF Figure2. Large Current Paths Output Current (mA) Region of Stable C OUT ESR vs. Output Current APL5537-OC V IN=VEN=4.2V C IN=COUT=1µF/X7R Unstable Range Stable Range Stable by Simulation Verify 0 50 100 150 200 250 300 0.001 0.01 0.1 1 10 |
Similar Part No. - APL55375MCTI-TRG |
|
Similar Description - APL55375MCTI-TRG |
|
|
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 |