 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
MIC5335-PPYMT Datasheet(PDF) 8 Page - Micrel Semiconductor |
|
||||||||||||||||||||||||||||||
MIC5335-PPYMT Datasheet(HTML) 8 Page - Micrel Semiconductor |
|
|
8 / 10 page  Micrel, Inc. MIC5335 May 2008 8 M9999-051508 Applications Information Enable/Shutdown The MIC5335 comes with dual active-high enable pins that allow each regulator to be enabled independently. Forcing the enable pin low disables the regulator and sends it into a “zero” off-mode-current state. In this state, current consumed by the regulator goes nearly to zero. Forcing the enable pin high enables the output voltage. The active-high enable pin uses CMOS technology and the enable pin cannot be left floating; a floating enable pin may cause an indeterminate state on the output. Input Capacitor The MIC5335 is a high-performance, high bandwidth device. Therefore, it requires a well-bypassed input supply for optimal performance. A 1µF capacitor is required from the input-to-ground to provide stability. Low-ESR ceramic capacitors provide optimal performance at a minimum of space. Additional high- frequency capacitors, such as small-valued NPO dielectric-type capacitors, help filter out high- frequency noise and are good practice in any RF- based circuit. Output Capacitor The MIC5335 requires an output capacitor of 1µF or greater to maintain stability. The design is optimized for use with low-ESR ceramic chip capacitors. High ESR capacitors may cause high frequency oscillation. The output capacitor can be increased, but performance has been optimized for a 1µF ceramic output capacitor and does not improve significantly with larger capacitance. X7R/X5R dielectric-type ceramic capacitors are recommended because of their temperature performance. X7R-type capacitors change capacitance by 15% over their operating temperature range and are the most stable type of ceramic capacitors on the market. Z5U and Y5V dielectric capacitors change value by as much as 50% and 60%, respectively, over their operating temperature ranges. To use a ceramic chip capacitor with Y5V dielectric, the value must be much higher than an X7R ceramic capacitor to ensure the same minimum capacitance over the equivalent operating temperature range. No-Load Stability Unlike many other voltage regulators, the MIC5335 will remain stable and in regulation with no load. This is especially important in CMOS RAM keep-alive applications. Thermal Considerations The MIC5335 is designed to provide 300mA of continuous current for both outputs in a very small package. Maximum ambient operating temperature can be calculated based upon the output current and the voltage drop across the part. Given that the input voltage is 3.3V, the output voltage is 2.8V for VOUT1, 2.5V for VOUT2 and the output current = 300mA. The actual power dissipation of the regulator circuit can be determined using the equation: PD = (VIN – VOUT1) IOUT1 + (VIN – VOUT2) IOUT2+ VIN IGND Because this device is CMOS and the ground current is typically <100µA over the load range, the power dissipation contributed by the ground current is < 1% and can be ignored for this calculation. PD = (3.3V – 2.8V) × 300mA + (3.3V – 2.5V) × 300mA PD = 0.39W To determine the maximum ambient operating temperature of the package, use the junction-to- ambient thermal resistance of the device and the following basic equation: ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ − = JA A J(max) D(max) θ T T P TJ(max) = 125°C, the maximum junction temperature of the die θJA thermal resistance = 100°C/W. The table that follows shows junction-to-ambient thermal resistance for the MIC5335 in the Thin MLF ® package. Package θ JA Recommended Minimum Footprint θ JC 6-Pin 1.6 X1.6 Thin MLF™ 100°C/W 2°C/W Thermal Resistance Substituting PD for PD(max) and solving for the ambient operating temperature will give the maximum operating conditions for the regulator circuit. The junction-to-ambient thermal resistance for the minimum footprint is 100°C/W. The maximum power dissipation must not be exceeded for proper operation. For example, when operating the MIC5335-MFYML at an input voltage of 3.3V and 300mA loads on each output with a minimum footprint layout, the maximum ambient operating temperature TA can be determined as follows: 0.39W = (125°C – TA)/(100°C/W) |
Similar Part No. - MIC5335-PPYMT |
|
Similar Description - MIC5335-PPYMT |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
