AP1603 STEP-UP DC/DC CONVERTER Description Pin Assignments The AP1603 is a high efficiency step-up DC/DC converter for ( Top View ) applications using as few as a single NiMH or Li-Ion battery cells. Only four external components are required to deliver a FB 1 fixed output voltage of 3.3V. The AP1603 starts up from less 6 SHDN than 0.9V input with 1mA load. Pulse Frequency Modulation scheme brings optimized performance for applications with GND 2 light output loading and low input voltages. The output ripple AP1603 5 OUT and noise are lower compared with the circuits operating in 74 LX REF 3 PSM mode. SOT26 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. 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 Package: SOT26 • Lead Free Finish/ RoHS Compliant (Note 1) Notes: Applications • • • • • • Pagers Cameras Wireless Microphones Pocket Organizers Battery Backup Suppliers Portable Instruments 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. AP1603 Document number: DS31131 Rev. 3 - 2 1 of 10 www.diodes.com June 2010 © 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 + 47uF REF GND 0.1uF 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 R2 V OUT = V REF (1+ AP1603 Document number: DS31131 Rev. 3 - 2 R1 ) 2 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Pin Descriptions Pin Name Description FB Feedback. GND Ground. REF 1.2V Reference Voltage. Bypass with a 0.1μF capacitor. LX N-Channel and P-Channel Power MOSFET Drain. OUT SHDN Power Output. OUT provides bootstrap power to the IC. Shutdown Input. Drive high (>80% of VOUT) for operating mode. Drive low (<20% of VOUT) for shutdown mode. Connect to OUT for normal operation. Functional Block Diagram VOUT Zero Crossing Amplifier 0.1uF EN + Q TRIG One-Shot + - SHDN Minimum Off-Time One-Shot 47uF P VIN LX F/F Q R + Current-Limit Amplifier -+ TRIG Q One-Shot N - S Maximum On-Time One-Shot 47uF FB connects to Vcc or GND + Error Amplifier FB connects to external feedback resistors GND FB 0.1uF AP1603 Document number: DS31131 Rev. 3 - 2 3 of 10 www.diodes.com June 2010 © Diodes Incorporated + + 22uH AP1603 STEP-UP DC/DC CONVERTER Absolute Maximum Ratings Symbol VCC VREF VSW IOUT ISW TST TOP Parameter 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 VIN Parameter Minimum Input Voltage Operating Voltage Start-Up Voltage Conditions TA = +25°C TA = +25°C, RL = 3kΩ (Note 2) Start-Up Voltage Tempco Output Voltage Range IOUT VREF VOUT TEMPCO VREF_LOAD VREF_LINE RDS (ON) ILIM ILEAK tON tOFF ISHDN VIL VIH Notes: FB = VOUT = 3.3V Steady-State Output Current VIN = 2.4V, FB = GND, (Note 3) VOUT = 5V Reference Voltage IREF = 0 FB = VOUT Output Voltage FB = GND Reference Voltage Tempco Reference Voltage Load IREF = 0 to 20μA Regulation Reference Voltage Line VIN = 1.1V to 3.6V Regulation Internal NFET, PFET OnILX = 100mA Resistance LX Switch Current Limit (NFET) LX Leakage Current VLX = 0, 5.5V; VOUT = 5.5V Operating Current into OUT VOUT = 3.3V Shutdown Current into OUT SHDN = GND Efficiency VOUT = 3.3V, ILOAD = 100mA LX Switch On-Time LX Switch Off-Time V SHDN = 0 or VOUT SHDN Input Current SHDN Input Voltage Based on VOUT Voltage 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 - 15 80 mV - 0.08 1.5 mV/V - 0.6 1.0 Ω 0.3 0.35 0.4 A 3 1.0 0.05 16 0.1 90 4 1.2 1 35 1 7 1.4 μA μA μA % μs μs - 0.07 50 nA 0.8 - 0.2 - VOUT mA V V 2. Start-up voltage operation is guaranteed with the addition of a Schottky 1N5819 external diode between the input and output. 3. Steady-state output current indicates that the device maintains output voltage regulation under load. AP1603 Document number: DS31131 Rev. 3 - 2 4 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Typical Performance Characteristics Steady Stage Output Current vs. Input Voltage Reference Voltage vs. Temperature 400 Steady Stage Output Current (mA) Reference Voltage (V) 1.23 1.22 1.21 1.20 1.19 320 240 160 80 1.18 -40 -20 0 20 40 60 80 0 1.0 1.2 1.4 Input 1.6 1.8Voltage 2.0 2.2 2.4 (V) 2.6 2.8 3.0 Temperature (°C) No Load Input Current vs. Input Voltage Start-up Voltage vs. Load Current 175 with diode 1N5819 without diode 1.8 No Load Input Current (uA) 1.6 1.4 1.2 1.0 150 125 100 75 Document number: DS31131 Rev. 3 - 2 2. 80 3. 00 Input Voltage (V) Load Current (mA) AP1603 2. 60 99 2. 40 79 2. 20 59 2. 00 39 1. 60 18 1. 80 9 1. 40 3 1. 20 0 1. 00 50 0.8 0. 89 Start-up Voltage (V) 2.0 5 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Typical Performance Characteristics (Continued) Efficiency vs. Load Current Efficiency vs. Load Current 91 Efficiency (%) 89 VIN = 1.2V VOUT = 3.3V Efficiency (%) 90 88 87 86 85 84 83 VIN = 2.4V VOUT = 3.3V 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 7. 94 17 .8 6 27 .9 37 .9 47 .9 57 .9 67 .9 77 .6 87 .7 97 .6 2. 89 82 92 91 90 89 88 87 86 85 84 83 82 81 80 Load Current (mA) Load Current (mA) Shoutdown Current vs. Supply Voltage Shutdown Threshold Voltage 1.6 0.8 Shutdow n Thr eshold Voltage (V) Shutdown Current (uA) 1.0 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 1 2 3 4 Supply Voltage (V) AP1603 Document number: DS31131 Rev. 3 - 2 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Supply Voltage (V) 6 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Functions 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. AP1603 Document number: DS31131 Rev. 3 - 2 7 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Ordering Information AP1603 W L - 7 Device Package Lead Free Packing W : SOT26 L : Lead Free 7 : Tape & Reel AP1603WL-7 Notes: Packaging (Note 4) SOT26 Package Code W 7” Tape and Reel Quantity Part Number Suffix 3000/Tape & Reel -7 4. 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. Marking Information (1) SOT26 ( Top View ) 4 7 5 7 6 XX Y W X 1 2 Part Number AP1603W AP1603 Document number: DS31131 Rev. 3 - 2 3 XX : Identification code Y : Year 0~9 W : Week : A~Z : 1~26 week; a~z : 27~52 week; z represents 52 and 53 week X : a~z : Lead Free Package SOT26 8 of 10 www.diodes.com Identification Code EY June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER Package Outline Dimensions (All Dimensions in mm) (1) Package Type: SOT26 AP1603 Document number: DS31131 Rev. 3 - 2 9 of 10 www.diodes.com June 2010 © Diodes Incorporated AP1603 STEP-UP DC/DC CONVERTER IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). 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