AQ120 LDO Regulator Controller SOT23-5 Package Preliminary Specification Revision 1.2 General Description The AQ120 is a low cost LDO controller. The AQ120 flexibility allows the setting of the output voltage and controls up to 2 Amps of output current with a minimum number of external components. April 1, 2006 Applications • Graphic cards • PC motherboards • Switching power supply post-regulation • Telecom equipment • DVD video player The open collector output is capable of driving an external PNP transistor. A temperature stable bandgap reference (1.25 V) controls the output voltage and is programmable through two external resistors. The AQ120 if offered in the very small SOT23-5 package. Features • 1.25V reference with 1.5% accuracy • Low current consumption • Offered in small SOT23-5 package • Wide Vin range: 2.5V to 18V • 20mA drive current sink • RoHS compliant available Block Diagram Pin Configuration www.acutechnology.com AQ120 AQ120 Acutechnology Semiconductor Inc. Typical Application Note: The values of R1and R2 set the output voltage. The typical Vref is 1.25V Pin Descriptions Pin Pin Name Function 1 DRIVE 2 GND 3 GND BIAS 4 VCC Positive supply 5 VREF Voltage programming pin; has a threshold of 1.25V. Output of error amplifier. 20 mA sink capability to drive PNP pass element Ground Must connect to GND for proper operation as an LDO Controller Ordering Information Device Operating Tj %Tol Pkg Type VOUT Wrap Order Number AQ120 -40C˚ ≤ 85C˚ 1.5 SOT-23-5 1.25V T&R AQ120EX-M5-AJ-TR AQ120 -40C˚ ≤ 85C˚ 1.5 SOT-23-5 1.25V T&R AQ120EX-M5-AJ-TRL Note: The TRL parts are Lead Free and RoHS compliant. www.acutechnology.com 2 Rev. 1.2 April 1, 2006 AQ120 Acutechnology Semiconductor Inc. Absolute Maximum Ratings Parameter Value Units VCC Voltage 18 V DRIVE Voltage 18 V REF Voltage 18 V VCC, DRIVE, REF Current 50 mA Operating Junction Temperature 150 ºC Lead Temperature (soldering 10 seconds) 300 ºC -80 to +150 ºC Storage Temperature Range Electrical Specifications Electrical characteristics are guaranteed over the full temperature range –40ºC <Tj< 85ºC. Ambient temperature must be de-rated based upon power dissipation and package thermal characteristics. Unless otherwise stated, test conditions are VCC = 5V, VDRIVE = 4.3V, VGND BIAS = GND. Symbol Parameter Conditions Vcc Supply Voltage Range Icc Vcc Quiescent Supply Current VREF= VCC= VDRIVE= 5V Reference Voltage Ta=25ºC VREF Min Typ Max Units 2.5 5 18 V 150 300 µA 1.250 1.268 V 1.231 Reference Temperature Deviation Output variation with Supply Voltage Vref variation with Drive Current -40ºC <Tj<85ºC 0.5 1 % VCC=2.5V to 18V IDRIVE = 500 µA 0.3 1.0 mV/V IDRIVE = 0.1mA to 10 mA 0.15 0.20 %/mA Reference input current VREF = 0V Output Saturation Voltage IDRIVE = 10 mA, VREF = 0V I DRIVE Drive Current V DRIVE = 5V, VREF = VGND BIAS = GND I LEAK Output Leakage Current VDRIVE = VREF = VCC = 18V TC REF LnREG LdREG I REF VDRVlow www.acutechnology.com -50 3 -20 1.8 20 nA 2.2 25 200 Rev. 1.2 V mA 400 nA April 1, 2006 AQ120 Acutechnology Semiconductor Inc. APPLICATION (Figure 1) GENERAL DESCRIPTION The AQ120 is a linear LDO voltage regulator controller. It drives a discrete PNP transistor while comparing the output to a 1.25V reference. The output voltage is programmable through an external resistor divider. VOUT can be set to any value above 1.25 Volts. The collector of the external PNP transistor provides the output current to the load. Vin range is 2.5V to 18V. The Maximum Load current is Beta of the PNP times IDRIVE. IDRIVE range is 0.1 mA to 20 mA (max). SETTING THE OUTPUT VOLTAGE The AQ120 VREF pin is the input to an amplifier comparing to a precision 1.25V reference. With VREF tied back to the output, it will drive the base of the external PNP to maintain output voltage with changing load current and VCC. The regulated output voltage can be set by selecting the proper ratio of R1 and R2. The Output Voltage is set by: Vout = VREF ∗ www.acutechnology.com ( R1 + R 2 = 1.25V ∗ 1 + R1 R2 R2 4 ) Rev. 1.2 April 1, 2006 AQ120 Acutechnology Semiconductor Inc. SELECTION OF PNP PASS DEVICE In the application of (figure 1) above, an FMMT549 SOT223 package was used. However, selection of the PNP pass device is based on Vin max, Iout max, and Power dissipation for your particular application. VIN max BVCEO and BVCBO minimum rating of the PNP transistor must exceed the maximum Vin of the application. The AQ120 will stand off 18V max. Therefore the maximum voltage the PNP will experience is 18V. Iout max Beta of the PNP transistor will dictate the maximum output current as per the equation: Iout max = Idrive max(20mA) ∗ BetaExt.PNP Higher beta of the PNP will improve the Vout variation due to change in load (load reg.) Minimizing the Idrive required will also minimize the Load reg. as Vout will decrease by .15% per mA of Idrive. Therefore, delta 10mA of Idrive will cause a delta 1.5% of Vout. Power dissipation Selection of the external PNP package is based on size requirements and power dissipation. Consult the transistor data sheet for power considerations. Contact Information Acutechnology Semiconductor Inc. 3487 McKee Rd. Suite 52 San Jose CA , USA 95127 TEL: FAX: website: (408) 259-2300 (408) 259-9160 www.acutechnology.com Disclaimer The information furnished by Acutechnology in this data sheet is believed to be accurate and reliable. However, Acutechnology assumes no responsibility for its use. Acutechnology reserves the right to change circuitry and specifications at any time without notification to the customer. Life Support Policy Acutechnology Products are not designed or authorized for use as components in life support devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. www.acutechnology.com 5 Rev. 1.2 April 1, 2006 AQ120 Acutechnology Semiconductor Inc. Package Dimensions SOT23-3, SOT23-4, SOT23-5, SOT23-6 www.acutechnology.com 6 Rev. 1.2 April 1, 2006