Ultra-Low Dropout Voltage Regulator Product Specification Revisio

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

Ultra-Low Dropout Voltage Regulator Product Specification Revisio

Datasheet Thumbnail

Top Searches for this datasheet

AQ112
Ultra-Low Dropout Voltage Regulator
Product Specification Revision September 2006
AQ112 ultra-low dropout three terminal voltage regulator, offered popular fixed options adjustable version that precise voltage from 1.22V with external resistors. drops into footprint popular LM1117 SOT-223 provides true separated from output which allows separate bias connection from pass transistor order achieve enable ultra dropout from VOUT. enable provides remote turn-off power consumption. draws virtually zero current shutdown mode implements Sequential, Ratiometric, Simultaneous sequencing schemes. assure accuracy within heart AQ112 self-correcting AcuRefbandgap reference. On-chip current limit thermal shutdown with hysteresis protects against combination overload ambient temperature that might cause junction temperature exceed safe limits.
Applications Graphic cards motherboards Switching power supply post-regulation Telecom equipment video player Features Ultra Dropout (400mV Enable implements sequencing Vout tolerance less than 1.5% over
temperature Stable with cost capacitor Thermal protection with hysteresis Short circuit protection Adjustable output AQ112 featured SOT223 4-lead TetraPackpackage. RoHS compliant available
Typical Application
www.acutechnology.com
AQ112
Acutechnology Semiconductor Inc.
AQ112
Configuration
Descriptions
Name ENABLE Ground/Adjust VOUT Function Unregulated Input Voltage, Collector Pass Transistor Active high, ENABLE (0.95V VOUT), Chip bias circuit supply low, ENABLE 0.25V Ground Adjust (Connect resistive feed back divider) Regulated Output
Functional Block Diagram
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Ordering Information
Device AQ112 AQ112 AQ112 AQ112 AQ112 AQ112 AQ112 AQ112
Note:
Operating 125C° 125C° 125C° 125C° 125C° 125C° 125C° 125C°
%Tol
Type SOT-223-4 SOT-223-4 SOT-223-4 SOT-223-4 SOT-223-4 SOT-223-4 SOT-223-4 SOT-223-4
VOUT 1.8V 1.8V 2.5V 2.5V 3.3V 3.3V
Wrap
Ordering Number AQ112CY-S4-18-TR AQ112CY-S4-18-TRL AQ112CY-S4-25-TR AQ112CY-S4-25-TRL AQ112CY-S4-33-TR AQ112CY-S4-33-TRL AQ112CY-S4-AJ-TR AQ112CY-S4-AJ-TRL
parts Lead Free RoHS compliant.
Absolute Maximum Ratings
Stress greater than those listed under "Absolute Maximum Ratings" cause permanent damage device. These stress ratings only, functional operation device these conditions beyond those indicated under recommended Operating Conditions implied. Exposure "Absolute Maximum Rating" extended periods affect device reliability. standard handling precautions required. Parameter Maximum Maximum VENABLE Power Dissipation (Internally limited) Maximum Junction Temperature Operating Junction Temperature Range Storage Temperature Range Lead Temperature (Soldering, 4sec.) SOT- package Value Units Volts Volts
Thermal Management
Thermal Resistance (Junction TAB) SOT-223 Thermal Resistance (Junction Ambient) SOT-223 (tab soldered copper PCB) Typical Value Typical Value Units °C/W Units °C/W
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Electrical Specifications
Electrical characteristics guaranteed over full temperature range <Tj< Ambient temperature must de-rated based upon power dissipation package thermal characteristics. Unless otherwise specified: (VOUT 1.5V), IOUT 25C. values bold over full temperature range. Symbol VOUT LNREG LDREG Parameter Output Voltage Line Regulation Load Regulation Conditions 125°C VOUT (1.5V 10V) IOUT (10mA Amp) IOUT Drop Voltage IOUT IOUT IENON Current Limit Quiescent Current Enable Voltage (OFF) Enable Voltage (ON) Enable Current VEN-VOUT 125°C With respect With respect VOUT IOUT IOUT IOUT VADJ IADJ IADJ IQMIN PSRR TSDHYST Reference Voltage Adjust Current Adjust Current Change Minimum Load Current Temperature Coefficient Temperature Stability Output Noise Ripple Rejection Ratio Thermal Shutdown Hysteresis Junction Temperature 10mA IOUT 1Amp Maintain regulation Note 125°C 1.208 1.202 0.005 0.003 0.25 0.45 0.92 1.220 0.95 10.0 1.232 1.238 -1.5 VOUT VOUT 0.035 10.0 +1.5 Units %/°C %/°C VOUT
Notes: duty cycle pulse testing with Kelvin connections required. Measure (VIN VOUT) when VOUT, VREF Bandwidth 10Hz 10kHz 120Hz input ripple Adjustable version only
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Typical Response Curves
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Application Notes
Typical Application
Notes: Output voltage 1.22V +R1)/R1 Input output capacitors should located close device. AQ112 will remain stable with Overall transient performance improved with increased capacitance addition output fully enabled when Enable above expected VOUT. driven either digital analog signal control either turn-on time give full control risetime. Enable, tied separate source >0.95V VOUT, will insure Ultra-low drop voltage (400mV@ from VOUT. Enable, tied will support drop voltage (0.95V).
Stability
Enable capacitor recommended. capacitor suitable input bypass almost applications. larger capacitor also suitable. adjustable version "adjust" terminal bypassed ground with bypass capacitor (CADJ) improve ripple rejection. This bypass capacitor prevents ripple from being amplified output voltage increased. ripple frequency, impedance CADJ should less than (being resistor between output adjust pin) prevent ripple from being amplified: 1/(2*fRIPPLE* CADJ) normally range output capacitor critical maintaining regular stability. AQ1541 stable with output capacitor greater than course increase output capacitor will merely improve loop stability load transient response. case adjustable regulator, when CADJ used, larger output capacitance required. capacitor also necessary large ripple present line. Tantalum Capacitors exhibit best stability over wide range loads recommended.
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Output Voltage
AQ112 adjustable version develops 1.22V reference voltage between output adjust terminal. This voltage applied across resistor generate constant current (I1). current from adjust terminal could introduce error output, since very small 20µA) compared with current very constant with line load changes, error ignored. constant current then flows through resistor sets output voltage desired level. fixed voltages resistor integrated inside devices. AQ112 regulates voltage that appears between output ground pins between output adjust pins. some cases, line resistances introduce errors voltage across load. obtain best load regulation precautions needed. example important minimize line resistances load, load itself should tied directly output terminal positive side directly ground terminal negative side. When adjustable regulator used, best performance obtained with positive side resistor tied directly output terminal regulator rather than near load. This will eliminate line drops from appearing effectively series with reference degrading regulation. addition ground side resistor returned near ground load provide remote ground sensing improve load regulation. capacitor (470pF) between system ground will enhance stability.
Enable/Sequencing
AQ112 provides enable function. least higher than output voltage device fully turned When voltage device shutdown mode will draw current from terminal.
ENABLE
FIG.2 ENABLE 0-5V, Output follows 3.3V (1V/div vertical, 200us/div horizontal) addition enable function includes sequencing feature, because when enable ramps voltage output voltage follows will around less than enable voltage until reaches regulation voltage) shown Fig. above. www.acutechnology.com Rev. September 2006
Acutechnology Semiconductor Inc.
AQ112
applications where multiple regulated supply rails required, often required that relationship between various supply voltages controlled during start-up shutdown. this end, AQ112 allows analog control output voltage ENABLE pin. This allows sequential, ratio-metric simultaneous sequencing schemes.
Protection Diodes
Unlike older regulators, AQ112 family does need protection diodes between adjustment output from output input prevent over-stressing die. Internal resistors limiting internal current paths adjustment pin. Therefore, even with capacitors adjustment pin, protection diode needed ensure device safety under short circuit conditions. External diodes between input output usually needed. Only high value output capacitors used 1000uF) input instantaneously shorted ground, damage occur.
Thermal Considerations
When integrated circuit operates with appreciable current, junction temperature elevated. important quantify thermal limits order achieve acceptable performance reliability. This limit determined summing individual parts consisting series temperature rises from semiconductor junction operating environment. heat generated device junction flows through attach pad, through lead frame surrounding case material, printed circuit board, eventually ambient environment. AQ112 regulators have internal thermal shutdown protect device from overheating. Under possible operating conditions, junction temperature AQ112 must lower than 125°C. heatsink required depending maximum power dissipation maximum ambient temperature application. determine heatsink needed, power dissipated regulator, must calculated: (VC-VOUT) where load current. next parameter which must calculated maximum allowable temperature rise, T(max): T(max)=TJ(max)-TA(max) where TJ(max) maximum allowable junction temperature (125°C), TA(max) maximum ambient temperature which will encountered application. Using calculated values T(max) maximum allowable value junction ambient thermal resistance (JA) calculated: JA=T(max)/ maximum allowable value found greater than junction ambient thermal resistance package used, heatsink needed since package alone will dissipate enough heat satisfy these requirements.
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Ultra Dropout Operation
AQ112 allows ultra dropout operation connecting ENABLE >0.95V Vout. This results dropout load current, between VOUT. This feature important when supply voltage dropping near output regulated voltage. Furthermore voltage dropout low, internal power dissipation also reduced thermal requirements device less stringent.
www.acutechnology.com
Rev.
September 2006
Acutechnology Semiconductor Inc.
AQ112
Package Dimensions SOT223-4 TetraPack
Contact Information
Acutechnology Semiconductor Inc. 3487 McKee Suite Jose 95127
Disclaimer
information furnished Acutechnology this data sheet believed accurate reliable. However, Acutechnology assumes responsibility use. Acutechnology reserves right change circuitry specifications time without notification customer.
TEL: FAX: website:
(408) 259-2300 (408) 259-9160 www.acutechnology.com
Life Support Policy
Acutechnology Products designed authorized components life support devices systems where malfunction product reasonably expected result personal injury. Life support devices systems devices systems that intended surgical implant into body support sustain life, whose failure perform reasonably expected result significant injury user.
TetraPack AcuRef trademarks Acutechnology Semiconductor www.acutechnology.com Rev. September 2006

Ultra-Low Dropout Voltage Regulator Product Specification Revisio

Top Searches for this datasheet

Other recent searches