Electronic Components Datasheet Search |
|
SP6205EM5-2.5 Datasheet(PDF) 8 Page - Sipex Corporation |
|
SP6205EM5-2.5 Datasheet(HTML) 8 Page - Sipex Corporation |
8 / 14 page 8 Date: 05/25/04 SP6203/6205 Low Noise, 300 and 500mA CMOS LDO Regulators © Copyright 2004 Sipex Corporation General Overview The SP6203/6205 is intended for applications where very low dropout voltage, low supply current and low output noise are critical, even with high load conditions (500mA maximum). Unlike bipolar regulators, the SP6203/6205 (CMOS LDO) supply current increases only slightly with load current. The SP6203/6205 contains an internal bandgap reference which is fed into the inverting input of the LDO-amplifier. The output voltage is then set by means of a resistor divider and compared to the bandgap reference voltage. The error LDO-amplifier drives the gate of a P-channel MOSFET pass device that has a RDS(ON) of 0.6Ω at 500mA producing a 300mV drop at the out- put. Furthermore, the SP6203/6205 has its own cur- rent limit circuitry (500mA/850mA) to ensure that the output current will not damage the device during output short, overload or start-up. Also, the SP6203/6205 includes thermal shut- down circuitry to turn off the device when the junction temperature exceeds 170 °C and it re- mains off until the temperature drops by 12 °C. Enable/Shutdown Operation The SP6203/6205 is turned off by pulling the VEN pin below 0.4V and turned on by pulling it above 1.6V. If this enable/shutdown feature is not required, it should be tied directly to the input supply voltage to keep the regulator output on at all time. While in shutdown, VOUT quickly falls to zero (turn-off time is dependent on load conditions and output capacitance on VOUT) and power consumption drops nearly to zero. Input Capacitor A small capacitor of 2.2 µF is required from VIN to GND if a battery is used as the power source. Any good quality electrolytic, ceramic or tantalum capacitor may be used at the input. Output Capacitor An output capacitor is required between VOUT and GND to prevent oscillation. A 2.2 µF output capacitor is recommended. Larger values make the chip more stable which means an improvement of the regulator’s tran- sient response. Also, when operating from other sources than batteries, supply-noise rejection can be improved by increasing the value of the input and output capacitors and using passive filtering techniques. For a lower output current, a smaller output capacitance can be chosen. Finally, the output capacitor should have an effective series resistance (ESR) of 0.5 Ω or less. Therefore, the use of good quality ceramic or tantalum capacitors is advised. Bypass Capacitor A bypass pin (BYP) is provided to decouple the bandgap reference. A 10nF external capacitor connected from BYP to GND reduces noise present on the internal reference, which in turn significantly reduces output noise and also im- proves power supply rejection. Note that the minimum value of COUT must be increased to maintain stability when the bypass capacitor is used because CBYP reduces the regulator phase margin. If output noise is not a concern, this input may be left unconnected. Larger capacitor values may be used to further improve power supply rejection, but result in a longer time period (slower turn on) to settle output voltage when power is initially applied. No Load Stability The SP6203/6205 will remain stable and in regulation with no external load (other than the internal voltage driver) unlike many other volt- age regulators. This is especially important in CMOS RAM battery back-up applications. THEORY OF OPERATION |
Similar Part No. - SP6205EM5-2.5 |
|
Similar Description - SP6205EM5-2.5 |
|
|
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 |