ILC7280 FAIRCHILD | Alldatasheet

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 9

Technical content

Features

  • Low Power Consumption
  • 150mV Dropout at 150mA
  • 1% Output Voltage Accuracy
  • Requires only 0.47µF Output Capacitor
  • Only 135µA Ground Current at 150mA load
  • 50µV RMS Noise at BW = 300Hz to 50kHz
  • Excellent Line and Load Transient Response
  • Over Current/Over Temperature Protection
  • 8-pin MSOP package available upon request.
  • Minimum External Components

Applications

  • Cellular Phones, pagers and wireless headsets
  • Palmtops, organizers, PDAs and portable electronics
  • Battery powered portable appliances and equipment
  • Remote data accumulation and instrumentation General Description The ILC7280 is two independent 150mA low dropout (LDO)voltage regulators in an 8-pin MSOP package. Each regulator output is independently short circuit protected and has independent enable lines. The device offers a unique combination of low dropout voltage and low quiescent current offered by CMOS technology as well as the low noise and good ripple rejection characteristics of bipolar LDO regulators. The ILC7280 is available in a space saving MSOP-8 package. Block Diagram Current Limit Thermal Shutdown VINA VOUTA Bandgap Reference Current Limit Thermal Shutdown ENA *CNOISE *Optional GND ENB VINB VOUTB ILC7280 Micropower Dual 150mA CMOS RF LDO™ Regulators

REV. 1.0.5 6/3/02 Pin Configuration Pin Definitions *If maximum current is required from each regulator, then connect both pin 6 and 8 to power supply. Absolute Maximum Ratings Absolute maximum ratings are the values beyond which the device may be damaged or have its useful life impaired. Functional operation under these conditions is not implied. Recommended Operating Conditions Pin Number Pin Name Pin Function Description V OUTA Output A.Regulated voltage GND Ground of the IC V OUTB Output B.Regulated voltage C NOISE Optional bypass for noise reduction. EN A Digital Input Enable for regulator A V INB Supply input B.Internally connected to pin 8* EN B Digital Input Enable for regulator B V INA Supply input B.Internally connected to pin 6* Parameter Min. Max. Units Supply Voltage: V INA or V INB to GND V Voltage on all other pin to GND –0.3 V IN + 0.3 V Junction Temperature 150 Storage Temperature 150 Lead Soldering Temperature, 10 seconds 300 Power Dissipation at 85°C 315 mW Parameter Conditions Min. Typ. Max. Units Supply Voltage V DD V INA or V INB to GND V OUT + V DO V OUT + 1V V Output Current I OUT 150 mA Ambient Operating Temperature -40 C MSOP-8 VOUTA

8 VINA

7 ENA

6 VINB

(Optional)

5 ENB

Figure 1. Test Circuit

REV. 1.0.5 6/3/02 Typical Applications Diagrams Power Spectral Density and Output Noise Voltage Thermal Protection Under Short Circuit Conditions ON/OFF Response, One Regulator ON ON/OFF Response, Both Regulators ON Ripple Rejection, Low Frequencies Ripple Rejection, High Frequencies VEN Isc(0.5A/div) VEN VOUT@ 100mA load COUT=2.2µF CN=0 VOUT@ 10mA load, COUT=2.2µF, CN=1nF COUT=4.7µF Load=10mA COUT=4.7µF Load=10mA COUT=2.2µF CNOISE=1nF Load=10mA BW=300Hz to 50kHz

REV. 1.0.5 6/3/02 100 150 200 250 300 350 no load 150mA load VOUTnom Input Voltage (V) Ground Current (µA) Ripple Rejection, Low Frequencies, 150mA Load Ripple Rejection, High Frequencies, 150mA Load VOUT(AC) VIN Line Transient Response, 10mA Load Load Transient Response VOUT(AC) ILOAD (0.1A/div) Ground Pin Current, Both Regulators ON

REV. 1.0.5 6/3/02 -40 -30 -20 -10 10 20 60 70 100 150 Temperature, °C Output Current, mA Reference Voltage,V Dropout Voltage, mV Reference Voltage vs. Temperature Dropout Voltage vs. IOUT 1.206 1.204 1.202 1.200 1.198 1.196 200 180 160 140 120 100 1.194 1.192 1.190 85°C 25°C -40°C

REV. 1.0.5 6/3/02

Application Information

V IN A and B These pins are connected internally through a galvanic connection. For maximum power from each regulator, both V INA and V INB must be connected externally to V+. Enable/Shutdown Forcing EN A and/or EN B to a voltage greater than 2V, enables the regulator(s). These inputs are CMOS logic compatible gates. If this feature is not required, connect EN A and/or EN B to V IN . Note that V INA and V INB are connected internally. To minimize the effect of imbalanced current sharing and possible noise, both V INA and V INB should also be connected externally. Input Capacitor A 1µF capacitor should be placed from VINA/B to GND if there is more than 10 inches of wire between the input and the ac filter capacitor or if a battery is used as the input. Reference Bypass Capacitor CNOISE (the reference voltage bypass capacitor) may be connected to the internal VREF which is common to regula- tor’s A and B. For low noise applications use of 1nF CNOISE is recom- mended. Value higher than 1nF will lead to minimum improvement of output noise, but it will substantially increase the start-up time. Lower value of CNOISE results in faster start –up. If a slow or delayed start up time is desired, a larger value of CNOISE is used. Conversely, faster start up times or instant-on applications will require smaller values of CNOISE or its omission with the pin left open. The trade- off of noise to response time should be considered. Output Capacitor An output capacitor is required from VOUTA and VOUTB to GND to prevent oscillation and minimize the effect of load transient currents. The minimum size of the output capaci- tor(s) is dependent on the usage of CNOISE and its value. Without CNOISE, a minimum of 0.47µF is recommended. For CNOISE = 1nF, a minimum of 2.2µF is recommended. Larger values of output capacitance will slightly slow the regulator’s response during power up. The ILC7280 remains stable even with ESR values as low as 10mΩ. If the system design calls for smaller load currents, lower capacitance may be used. Below 10mA the capacitance may be reduced to 0.33µF. No-load Stability The ILC7280 will remain stable and in regulation with no load current. These are desirable performance features for applications such as keep-alive modes in CMOS systems. Split-Supply Operation When using the ILC7280 in a system requiring that the load be returned to the negative voltage source, the output(s) must be diode clamped to inhibit significant voltage excursions below ground. A simple external diode clamp to ground will protect the device from damage. Thermal Considerations In order to minimize thermal resistance (θJA), the device mounted on conventional FR4 PCB material should be surrounded as much ground copper ground plane as possible. In a worst case application with minimum trace widths and no ground plane, the MSOP-8 package exhibits a thermal resistance of 200 °C/W. The maximum allowable power dissipation is calculated in the following examples. Thermal Evaluation Examples The maximum allowed package power dissipation is: PD(max) =(TJmax–TA) / θJA, where TJmax is the maximum junction temperature and TA is the ambient temperature. For an ambient temperature of 50°C PD(max) = (150°C - 50°C) / 200°C/W PD(max) = 500mW If the intent is to operate from a 4V power source with a 150mA load current from both outputs at a 50°C ambient temperature, the expected power dissipation is found in the following calculation: PD (each regulator) = (VIN – VOUT) * IOUT + (VIN * IGND) PD (each regulator) = (4V – 3V) * 150mA + (4V * 0.12mA) PD (each regulator) = 150mW PD (both regulators) = 2 * 150mW PD (both regulators) = 300mW In this example the total power dissipated is 300mW which is below the 500mW maximum package consideration and therefore safe to operate. It should be noted that it is not always possible to operate both regulators at the maximum output current.

REV. 1.0.5 6/3/02 Mechanical Dimensions MSOP-8 0.118 - 0.004 [3 ± 0.1] 0.193 ± 0.004 [4.9 ± 0.1] 0.118 ± 0.004 [3 ± 0.1] (0.189) [4.8] (0.040) [1.02] SYMM C LAND PATTERN RECOMMENDATION 0.030 - 0.037 [0.78 - 0.94] 0.021 ± 0.005 [0.53 ± 0.12] 0.007 ± 0.002 [0.18 ± 0.05] 0.002 - 0.006 [0.06 - 0.15] 0.012 ± 0.002 [0.3 ± 0.05] (0.033) [0.84] 0.0375 [0.953] PIN 1 IDENT TYP TYP TYP (0.016) [0.41] TYP 0.005 [0.13] TYP TYP GAGE PLANE R 0.005 [0.13] TYP TYP R (0.0256) [0.65] TYP 0°–6° TYP SEATING PLANE (0.0256) [0.65] –A– –B– –C– 0.002 [0.05] 0.002 [0.05] M S A C S B (0.010) [0.23]

6/3/02 0.0m 002 Stock#DS30007280  2002 Fairchild Semiconductor Corporation LIFE SUPPORT POLICY FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.

Ordering Information

Temperature Range (°C) Package ILC7280AR2530X 2.5V and 3.0V -40 to +85 MSOP-8 ILC7280AR2830X 3.0V and 2.8V -40 to +85 MSOP-8 ILC7280AR2828X 2.8V and 2.8V -40 to +85 MSOP-8 ILC7280AR8585X 2.85V and 2.85V -40 to +85 MSOP-8 ILC7280AR3030X 3.0V and 3.0V -40 to +85 MSOP-8 ILC7280AR3333X 3.3V and 3.3V -40 to +85 MSOP-8