AP2008 PWM BUCK CONTROLLER General Description Features • • • • • • • • • • The AP2008 integrates Pulse-Width-Modulation (PWM) control circuit into a single chip, mainly designs for power-supply regulator. All the functions include an on-chip 0.77V reference output, an error amplifier, an adjustable oscillator, a soft-start, UVLO, SCP circuitry, and a push-pull output circuit. Switching frequency is adjustable by trimming CT. During low VCC situation, the UVLO makes sure that the outputs are off until the internal circuit is operational normally. PWM Buck Control Circuitry Operating voltage can be up to 20V Under voltage Lockout (UVLO) Protection Short Circuit Protection (SCP) Soft-start circuit Variable Oscillator Frequency -- 300Khz Max 0.77V voltage reference Output 8-pin SOP package SOP-8L: Available in “Green” Molding Compound (No Br, Sb) Lead Free Finish/ RoHS Compliant (Note 1) Applications • • • • Backlight inverter LCD Monitor XDROM, XDSL Product DC/DC converters in computers, etc. Ordering Information AP 2008 S X - 13 Device Lead-free AP2008SL-13 AP2008SG-13 Notes: Package Lead Free Packing S : SOP-8L L : Lead Free G : Green 13 : Tape & Reel Package Code S S Packaging (Note 2) SOP-8L SOP-8L 13” Tape and Reel Quantity Part Number Suffix 2500/Tape & Reel -13 2500/Tape & Reel -13 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied. Please visit our website at http://www.diodes.com/products/lead_free.html. 2. Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at http://www.diodes.com/datasheets/ap02001.pdf. AP2008 Rev. 2 1 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Pin Assignments ( Top View ) OUT 1 8 GND VCC 2 7 CT COMP 3 6 SS 4 5 SCP FB SOP-8L Pin Descriptions Pin Name Description OUT PWM Output VCC Supply Voltage COMP FB SCP Feedback Loop Compensation Voltage Feedback Short Circuit Protection SS Soft-Start. CT Timing Capacitor GND AP2008 Rev. 2 Ground 2 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Block Diagram VCC CT SS 10K-300KHz / CT value 0.77V Bandgap Reference 2.5V Internal use Oscillator UVLO VCC Iss PWM Amplifier FB + + - OUT Error Amplifier COMP 1.5V 0.7V + + SCP GND Absolute Maximum Ratings Symbol VCC Parameter Supply voltage VI Amplifier input voltage VO Collector output voltage Rating Unit 22 V 20 V VCC-1.0V V Source current 200 mA ISINK Sink current 200 mA TOP Operating temperature range ISOURCE TST Storage temperature range -20 to +85 o C -65 to +150 o C Recommended Operating Conditions Symbol Min Max Unit Supply voltage 3.6 20 V VI Amplifier input voltage 1.05 1.45 V VO Collector output voltage Vcc-1.5 V IFB Current into feedback terminal 45 µA RF Feedback resistor 100 CT Timing capacitor 100 6800 pF Oscillator frequency 10 300 KHz VCC FOSC AP2008 Rev. 2 Parameter 3 of 8 www.diodes.com kΩ FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Electrical Characteristics (TA=25ºC, VCC=6V, f=200 Khz) Reference (REF) Symbol Parameter Comp connect to FB VREF Output voltage change with temperature Under voltage lockout (UVLO) Symbol Parameter VUT Upper threshold voltage (VCC) VLWT Lower threshold voltage (VCC) VHT Hysteresis (VCC) Short-circuit protection (SCP) control Symbol Parameter VIT Input threshold voltage VSTB Standby voltage VLT Latched input voltage ISCP Input (source) current Comparator threshold voltage VCT (COMP) Oscillator (OSC) Symbol Parameter FOSC Frequency Standard deviation of frequency ΔFOSC Frequency change with voltage Error-amplifier Symbol Parameter VIO Input offset voltage IIO Input offset current IIB Input bias current VCM AV GBW CMRR VOH VOL IOI IOO AP2008 Rev. 2 Conditions Min 0.755 Typ. 0.770 -0.1 -0.2 Max 0.785 ±1 ±1 Unit V % % Min Typ. 2.9 2.4 500 Max Unit V V mV Min 0.60 100 Typ. 0.67 130 50 -15 Max 0.75 160 100 -20 Unit V mV mV µA TA = -20ºC ~ 25ºC TA = 25ºC ~ 85ºC Conditions IO(REF) = 0.1mA TA = 25ºC Conditions TA = 25ºC No pull up No pull up VI = 0.7V, TA = 25ºC -10 1.5 Conditions CT =270 pF CT =270 pF VCC=3.6V ~ 20V Min Conditions VO (FB)=0.77V VO (FB)=0.77V VO (FB)=0.77V Min Common-mode input voltage range VCC=3.6V ~ 20V 1.05 Open-loop voltage amplification Unity-gain bandwidth Common-mode rejection ratio Max. output voltage Min. output voltage Output (sink) current (COMP) Output (source) current (COMP) RF=200 kΩ Typ. 200 10 1 Max Typ. Max ±6 ±100 500 Unit mV nA nA 1.45 V 160 70 60 Vref-0.1 V % 80 1.5 80 1 VID = -0.1V, VO = 0.77V VID = 0.1V, VO = 0.77V 4 of 8 www.diodes.com 0.5 -45 1.6 -70 Unit KHz dB MHz dB V V mA µA FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Electrical Characteristics Output section Symbol ILEAK IDRV VSAT (Continued) (TA=25ºC, VCC=6V, f=200 Khz) Parameter Conditions VT100 Total device Symbol ICCA Soft Start Symbol Typ. Max Unit 10 µA Leakage current VO = 20V Sink current VIN= 12V 200 mA Source current VIN= 12V 200 mA Output saturation voltage IO = 10 mA 1.0 VO = 6V 120 ISC Short-circuit output current PWM comparator Symbol Parameter VT0 Min Conditions Min Input threshold voltage at f = 10 KHz CT=6800pF (COMP) Maximum duty cycle Parameter Conditions Average supply current Conditions V mA Typ. Max Unit 0.6 0.7 V 1.2 1.3 Min Typ. Max Unit 6 10 mA Typ. Max Unit CT = 270pF Parameter 1.5 Min V VSS Soft-start Voltage 2.3 V ISS Constant Charge Current 20 µA Typical Application Circuit R3 30K Vcc = 12V C2 10nF (Optional) Q1 C1 470uF P mos 1 OUT GND 8 2 VCC CT 7 3 COMP SS 6 FB SCP 5 4 L1 10uH 5A R1 1K Output 1V/5A C4 50nF (Optional) C3 470uF R2 4K C4 270pF C5 50nF C6 220nF Step-Down DC/DC converter AP2008 Rev. 2 5 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Typical Characteristics AVERAGE SUPPLY CURRENT vs. POWER-SUPPLY VOLTAGE 0.785 0.78 0.775 0.77 0.765 0.76 0.755 5 Icc-Average Supply Current (mA) VrefReference Output Voltage (V) REFERENCE OUTPUT VOLTAGE vs. POWER-SUPPLY VOLTAGE 4 6 8 10 12 14 16 18 4 3 2 1 0 0 20 AVERAGE SUPPLY CURRENT vs. AMBIENT TEMPERATURE VCT (V) ICC - Average Supply Current (mA) 6 5 4 3 2 -25 0 25 50 75 0 100 tscp-SCP Time-out Period (ms) fosc - Frequency (KHz) 300 250 200 150 100 50 0 600 1100 1600 2100 2600 3100 3600 4100 4600 5100 5600 6100 6600 20 VCT(min) VCT(max) 100 200 300 SCP TIME-OUT PERIOD vs. SCP CAPACITANCE 35 30 25 20 15 10 5 0 45 90 135 180 225 270 315 360 405 450 495 Cscp - SCP Capacitance (nF) CT-Timing Capacitor (pF) AP2008 Rev. 2 16 Frequency (KHz) OSCILLATOR FREQUENCY vs. TIMING CAPACITANCE 100 12 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 TA - Ambient Temperature (℃) 350 8 VCT vs. FREQUENCY 7 -50 4 Vcc - Power-Supply Voltgae (V) Vcc-Power Supply Voltage (V) 6 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Typical Characteristics (Continued) SOFT-START TIME (Ts) vs. SOFT-START CAPACITOR (Css) 30 Ts (mS) 25 20 15 10 5 0 25 50 75 100 125 150 175 200 Css (nF) Marking Information (1) SOP-8L ( Top View ) 8 5 Logo Part Number AP2008 YY WW X X 1 AP2008 Rev. 2 4 L : Lead Free G : Green YY : Year : 08, 09,10~ WW : Week : 01~52; 52 represents 52 and 53 week X : Internal Code 7 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated AP2008 PWM BUCK CONTROLLER Package Information (All Dimensions in mm) 0.254 0.10/0.20 3.85/3.95 5.90/6.10 (1) Package Type: SOP- 8L Gauge Plane Seating Plane 0.62/0.82 Detail "A" 7°~9° 0.15/0.25 1.30/1.50 1.75max. 0.35max. 45° 7°~9° Detail "A" 0°/8° 0.3/0.5 1.27typ 4.85/4.95 5.4 8x-0.60 8x-1.55 6x-1.27 Land Pattern Recommendation (Unit: mm) IMPORTANT NOTICE Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to any product herein. Diodes Incorporated does not assume any liability arising out of the application or use of any product described herein; neither does it convey any license under its patent rights, nor the rights of others. The user of products in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on our website, harmless against all damages. LIFE SUPPORT Diodes Incorporated products are not authorized for use as critical components in life support devices or systems without the expressed written approval of the President of Diodes Incorporated. AP2008 Rev. 2 8 of 8 www.diodes.com FEBRUARY 2009 © Diodes Incorporated