AP1603 STEP-UP DC/DC CONVERTER General Description Features • • • • • • • A Guaranteed Start-Up from less than 0.9 V High Efficiency Low Quiescent Current Less Number of External Components needed Low Ripple and Low Noise Space Saving Lead-Free Packages: SOT26 Lead Free Finish/RoHS Compliant for Lead Free products (Note 1) The AP1603 is a high efficiency step-up DC/DC converter for applications using as few as a single NiMH or Li-Ion battery cells. Only four external components are required to deliver a fixed output voltage of 3.3V. The AP1603 starts up from less than 0.9V input with 1mA load. Pulse Frequency Modulation scheme brings optimized performance for applications with light output loading and low input voltages. The output ripple and noise are lower compared with the circuits operating in PSM mode. The PFM control circuit operating in 150KHz (max.) switching rate results in smaller passive components. The space saving SOT26 packages make the AP1603 an ideal choice of DC/DC converter for space conscious applications, like pagers, electronic cameras, and wireless microphones. Applications • • • • • • Pagers Cameras Wireless Microphones Pocket Organizers Battery Backup Suppliers Portable Instruments Ordering Information A P 1 6 0 3 X X X Package W : SOT26 Note: Packing L : Lead-Free (Note 2) - 7 : Taping 1. RoHS revision 13.2.2003. Glass and High Temperature Solder Exemptions Applied, see EU Directive Annex Notes 5 and 7. Lead-free Note: Lead-Free Device Package Code Packaging (Note 2) AP1603W W SOT26 7” Tape and Reel Quantity Part Number Suffix 3000/Tape & Reel -7 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. AP1603 Rev. 1 1 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Pin Descriptions Pin Assignments FB 1 GND 2 Name 6 SHDN AP1603 FB Feedback GND Ground 1.2V Reference Voltage. Bypass with a REF 0.1µF capacitor. N-Channel and P-Channel Power MOSFET LX Drain Power Output. OUT provides bootstrap OUT power to the IC. Shutdown Input. Drive high (>80% of VOUT) for operating mode. Drive low (<20% of SHDN V ) for shutdown mode. Connect to OUT OUT for normal operation. 5 OUT 74 LX REF 3 Description SOT26 Block Diagram OUT + EN 0.1uF + Zero Crossing Amplifier - SHDN Minimum Off-Time One-Shot Q TRIG One-Shot 47uF P VIN LX + - Current-Limit Amplifier + TRIG Q One-Shot 47uF GND - Maximum On-Time One-Shot N + + 22uH F/F Q S R FB FB + Error Amplifier REF 0.1uF AP1603 Rev. 1 2 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Absolute Maximum Ratings Symbol Parameter VCC VREF VSW IOUT ISW TST TOP Supply Voltage (OUT to GND) REF to GND Switch Voltage (LX to GND) Output Current (OUT) Switch Current (LX) Storage Temperature Range Operation Temperature Range Rating Unit -0.3 to 5.5 -0.3 to VOUT +0.3 -0.3 to VOUT +0.3 -0.8 to 0.2 -0.8 to 0.2 -65 to +150 -40 to +85 V V V A A o C o C Electrical Characteristics ( VIN = 2V, FB = VOUT, RL = ∞, TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C ) Symbol Parameter Minimum Input Voltage Operating Voltage VIN Min. 1.1 Typ. 0.9 - Max. 5.5 Unit V V - 0.9 1.1 V 2 100 -4 150 5.5 - mV/°C V - 80 - 1.196 3.17 4.8 - 1.22 3.3 5 0.05 1.244 3.43 5.2 - mV/°C IREF = 0 to 20 µA - 15 80 mV VIN = 1.1V to 3.6V - 0.08 1.5 mV/V ILX = 100mA - 0.6 1.0 Ω 0.3 0.35 0.4 A SHDN = GND VOUT = 3.3V, ILOAD = 100mA 3 1.0 0.05 16 0.1 90 4 1.2 1 35 1 7 1.4 µA µA µA % µs µs SHDN Input Current V SHDN = 0 or VOUT - 0.07 50 nA SHDN Input Voltage Based on VOUT Voltage 0.8 - 0.2 - VOUT Start-Up Voltage Conditions TA = +25°C TA = +25°C, RL = 3kΩ (Note 3) Start-Up Voltage Tempco Output Voltage Range IOUT Steady-State Output Current (Note 4) VREF Reference Voltage VOUT Output Voltage TEMPCO Reference Voltage Tempco Reference Voltage Load Regulation Reference Voltage Line Regulation Internal NFET, PFET On-Resistance LX Switch Current Limit (NFET) LX Leakage Current Operating Current into OUT Shutdown Current into OUT Efficiency LX Switch On-Time LX Switch Off-Time VREF_LOAD VREF_LINE RDS (ON) ILIM ILEAK tON tOFF ISHDN VIL VIH FB = VOUT = 3.3V VIN = 2.4V, FB = GND, VOUT = 5V IREF = 0 FB = VOUT FB = GND VLX = 0, 5.5V; VOUT = 5.5V VOUT = 3.3V mA V V Note: 3. Start-up voltage operation is guaranteed with the addition of a Schottky 1N5819 external diode between the input and output. 4. Steady-state output current indicates that the device maintains output voltage regulation under load. AP1603 Rev. 1 3 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Typical Application Circuit (1) VOUT = 5V 1.1V to 5.5V VIN 22uH + 47uF ON OFF LX OUT SHDN REF GND 0.1uF + 47uF FB Fixed Output ( 5V ) (2) VOUT = 3.3V 1.1V to 3.6V VIN 22uH + 47uF ON OFF LX SHDN OUT REF GND 0.1uF + 47uF Fixed Output ( 3.3V ) FB (3) VOUT = Adj 1.1V to 5.5V V IN 22uH + 47uF ON OFF LX OUT SHDN REF GND 0.1uF FB + R2 Output 47uF R1 V OUT = V REF (1+ AP1603 Rev. 1 R2 R1 ) 4 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Typical Performance Characteristics 1.23 400 1.22 STEADY STATE OUTPUT CURRENT (mA) 1.21 1.2 1.19 320 240 160 80 0 1.18 -40 -20 0 20 40 60 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 80 INPUT VOLTAGE (V) o TEMPERATURE ( C) 175 2 with diode 1N5819 1.8 NO LOAD INPUT CURRENT (uA) without diode 1.6 1.4 1.2 NO LOAD INPUT CURRENT vs. INPUT VOLTAGE 150 125 100 75 1 99 AP1603 Rev. 1 3 2 2.8 79 2.6 59 2.4 39 2.2 18 1.8 9 1.6 3 LOAD CURRENT (mA) 1.2 0 1 50 0.8 0.89 START-UP VOLTAGE (V) START-UP VOLTAGE vs. LOAD CURRENT 1.4 REFERENCE VOLTAGE (V) STEADY STATE OUTPUT CURRENT vs. INPUT VOLTAGE REFERENCE VOLTAGE vs. TEMPERATURE INPUT VOLTAGE (V) 5 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Typical Performance Characteristics ( Continued ) EFFICIENCY vs. INPUT VOLTAGE = 2.4V EFFICIENCY vs. INPUT VOLTAGE = 1.2V 91.00 89.00 EFFICIENCY (%) EFFICIENCY (%) 90.00 88.00 87.00 86.00 85.00 84.00 83.00 2. 91 27 .9 57 .9 87 .6 11 7. 6 14 7. 6 17 7. 5 20 8 23 8 26 8 29 8 2. 89 7. 94 17 .8 6 27 .9 37 .9 47 .9 57 .9 67 .9 77 .6 87 .7 97 .6 82.00 92.00 91.00 90.00 89.00 88.00 87.00 86.00 85.00 84.00 83.00 82.00 81.00 80.00 INPUT VOLTAGE = 2.4 (V) SHUTDOWN THRESHOLD VOLTAGE vs. SUPPLY VOLTAGE SHUTDOWN CURRENT vs. SUPPLY VOLTAGE 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 SHUTDOWN THRESHOLD VOLTAGE (V) SHUTDOWN CURRENT (uA) INPUT VOLTAGE = 1.2 (V) 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 1 2 3 4 SUPPLY VOLTAGE (V) AP1603 Rev. 1 1 1.5 2 2.5 3 3.5 4 SUPPLY VOLTAGE (V) 6 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Function Description General Description AP1603 PFM (Pulse Frequency Modulation) converter IC series combine a switch mode converter, power MOSFET, and precision voltage reference in a single monolithic device. They offer both extreme low quiescent current, high efficiency, and very low gate threshold voltage to ensure start-up with low battery voltage (0.9V typ.). Designed to maximize battery life in portable products, and minimize switching losses by only switching as needed to service the load. PFM converters transfer a discrete amount of energy per cycle and regulate the output voltage by modulating switching frequency with the constant turn-on time. Switching frequency depends on the load, input voltage, and inductor value, and it can range up to 150KHz. The SW on resistance is typically 1 to 1.5 W to minimize switch losses. When the output voltage drops, the error comparator enables 150KHz oscillator that turns on the MOSFET around 7.5us and 2.5ms off time. Turning on the MOSFET allows inductor current to ramp up, storing energy in a magnetic field and when MOSFET turns off that force inductor current through the diode to the output capacitor and load. As the stored energy is depleted, the current ramp down until the diode turns off. At this point, inductor may ring due to residual energy and stray capacitance. The output capacitor stores charge when current flow through the diode is high, and release it when the current flow is low, thereby maintaining a steady voltage across the load. As the load increases, the output capacitor discharges faster and the error comparator initiates cycles sooner, increasing the switching frequency. The maximum duty cycle ensures adequate time for energy transfer to output during the second half of each cycle. Depending on the circuit, PFM converter can operate in either discontinuous mode or continuous conduction mode. Continuous conduction mode means that the inductor current does not ramp to zero during each cycle. Inductor Selection To operate as an efficient energy transfer element, the inductor must fulfill three requirements. First, the inductance must be low enough for the inductor to store adequate energy under the worst-case condition of minimum input voltage and switch ON time. Second, the inductance must also be high enough so the maximum current rating of AP1603 and inductor are not exceeded at the other worst-case condition of maximum input voltage and ON time. Lastly, the inductor must have sufficiently low DC resistance so excessive power is not lost as heat in the windings. But unfortunately this is inversely related to physical size. Minimum and Maximum input voltage, output voltage and output current must be established before an inductor can be selected. Capacitor Selection A poor choice for an output capacitor can result in poor efficiency and high output ripple. Ordinary aluminum electrolyzers, while inexpensive, may have unacceptably poor ESR and ESL. There is a low ESR aluminum capacitor for switch mode DC-DC converters which work much better than the general purpose unit. Tantalum capacitors provide still better performance at more expense. OS-CON capacitors have extremely low ESR in a small size. If capacitance is reduced, the output ripple will increase. Most of the input supply is supplied by the input bypass capacitor. The capacitor voltage rating should be at least 1.25 times greater than a maximum input voltage. Marking Information (1) SOT26 5 4 7 6 XX : Identification code XX Y M Y : Year: 0-9 M : Month: A~L 1 Part Number AP1603W AP1603 Rev. 1 2 3 Package SOT26 7 of 8 www.diodes.com Identification Code EY NOVEMBER 2006 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Package Information Package Type: SOT26 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. AP1603 Rev. 1 8 of 8 www.diodes.com NOVEMBER 2006 © Diodes Incorporated