Moteur de recherche de fiches techniques de composants électroniques |
|
TPS712 Fiches technique(PDF) 9 Page - Texas Instruments |
|
|
TPS712 Fiches technique(HTML) 9 Page - Texas Instruments |
9 / 21 page TPS712xx GND EN2 NR IN OUT1 EN1 OUT2 V IN V OUT1 V OUT2 0.1 µF 2.2 µF 2.2 µF 0.01 µF TPS71202, TPS71219 TPS71229, TPS71247 TPS71256, TPS71257 www.ti.com SBVS049D – MAY 2004 – REVISED AUGUST 2010 APPLICATION INFORMATION 1.8 V or less is chosen, the minimum recommended The TPS712xx family of dual low-dropout (LDO) output capacitor is 4.7 mF. Any ceramic capacitor that regulators has been optimized for use in meets the minimum output capacitor requirements is noise-sensitive battery-operated equipment. The suitable. Capacitors with higher ESR may be used, device features extremely low dropout, high PSRR, provided the ESR is less than 1 Ω. ultralow output noise, and low quiescent current (190 mA typical per channel). When both outputs are OUTPUT NOISE disabled, the supply currents are reduced to less than 2 mA. A typical application circuit is shown in The internal voltage reference is a key source of Figure 24. noise in an LDO regulator. The TPS712xx has an NR pin that is connected to the voltage reference through a 250 k Ω internal resistor. The 250 kΩ internal resistor, in conjunction with an external ceramic bypass capacitor connected to the NR pin, creates a low-pass filter to reduce the voltage reference noise and, therefore, the noise at the regulator output. To achieve a fast startup, the 250 k Ω internal resistor is shorted for 400 ms after the device is enabled. Because the primary noise source is the internal voltage reference, the output noise will be greater for higher output voltage versions. For the case where no noise reduction capacitor is used, the typical noise Figure 24. Typical Application Circuit (mVrms) over 10 Hz to 100 kHz is 80 times the output (fixed-voltage versions) voltage. If a 0.01 mF capacitor is used from the NR pin to ground, the noise (mVrms) drops to 11.8 times INPUT AND OUTPUT CAPACITOR the output voltage. For example, the TPS71256 REQUIREMENTS exhibits only 33 mVrms of output voltage noise using a 0.01 mF ceramic bypass capacitor and a 2.2 mF A 0.1 mF or larger ceramic input bypass capacitor, ceramic output capacitor. connected between IN and GND and located close to the TPS712xx, is required for stability. It improves STARTUP CHARACTERISITCS transient response, noise rejection, and ripple rejection. A higher-value input capacitor may be To minimize startup overshoot, the TPS712xx will necessary if large, fast-rise-time load transients are initially target an output voltage that is approximately anticipated and the device is located several inches 80% of the final value. To avoid a delayed startup from the power source. time, noise reduction capacitors of 0.01 mF or less are recommended. Larger noise reduction capacitors The TPS712xx requires an output capacitor will cause the output to hold at 80% until the voltage connected between the outputs and GND to stabilize on the noise reduction capacitor exceeds 80% of the the internal control loops. The minimum bandgap voltage. The typical startup time with a recommended output capacitor is 2.2 mF. If an output 0.001 mF noise reduction capacitor is 60 ms. Once voltage of one of the output voltages is present, the startup time of the other output will not be affected by the noise reduction capacitor. Copyright © 2004–2010, Texas Instruments Incorporated Submit Documentation Feedback 9 Product Folder Link(s): TPS71202 TPS71219 TPS71229 TPS71247 TPS71256 TPS71257 |
Numéro de pièce similaire - TPS712 |
|
Description similaire - TPS712 |
|
|
Lien URL |
Politique de confidentialité |
ALLDATASHEET.FR |
ALLDATASHEET vous a-t-il été utile ? [ DONATE ] |
À propos de Alldatasheet | Publicité | Contactez-nous | Politique de confidentialité | Echange de liens | Fabricants 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 |