QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 863 500MA LOW NOISE, HIGH EFFICIENCY CHARGE PUMP LTC3203B, LTC3203-1, and LTC3203B-1 DESCRIPTION Demonstration circuit 863 is a 500mA low noise, high Burst Mode operation at light load to achieve low efficiency charge pump converter with LTC3203 in supply current whereas DC863A-A and DC863A-C 3mmx3mm DFN package. It comes with three as- operate in constant frequency to achieve low noise at sembly versions, DC863A-A, DC863A-B and DC863A- the input. Also, the built-in soft-start prevents exces- C, featuring the LTC3203B, LTC3203-1, and sive inrush current at turn-on, and short-circuit cur- LTC3203B-1 respectively. The DC863A-A is pro- rent limit/thermal protection help the part survive a grammed to generate a regulated 3.3V output, and continuous short-circuit. All these features make the DC863A-B/DC863A-C generate a user selectable fixed circuit a powerful solution to the applications that output voltage of 4.5V or 5V, all from a 2.7V to 5.5V demand high current with a constrained space in a input. The output current can reach up to 500mA with battery powered portable system. an input voltage above 2.9V (for 4.5V output), 3.1V (for 5V output) or full input range (for 3.3V output). Design files for this circuit board are available. Call the LTC factory. By choosing the proper operation modes, the LTC is a trademark of Linear Technology Corporation DC863A circuit optimizes conversion efficiencies and maintains the maximum output current at each output voltage. Additionally, DC863A-B features Automatic Table 1. Performance Summary (T = 25C) A PARAMETER CONDITION MINIMUM TYPICAL MAXIMUM Input Voltage Range 2.7V 5.5V DC863A-A: V > 2.9V DC863A-B: V > 3.1V IN IN Maximum Output Current 500mA DC863A-C: V > 2.7V IN V > 2.9V, I < 500mA IN OUT 4.32 4.5 4.68 DC863A-B 2.7V < V < 2.9V, I < 250mA IN OUT Output Voltage V DC863A-C V > 3.1V, I < 500mA OUT IN OUT 4.8 5 5.2 2.7V < V < 3.1V, I < 150mA IN OUT DC863A-A V > 2.7V, I < 500mA 3.168 3.3 3.432 IN OUT V = 5V 50mV PP OUT I = 500mA DC863A-B/-C, OUT Output Ripple V V = 4.5V 50mV OUT PP OUT (20MHz BW) DC863A-A, V = 3.3V 53mV PP OUT Nominal Switching Frequency 0.9M or 1MHz V = 5V, V = 2.7V, I = 150mA 89.5% IN OUT DC863A-B OUT DC863A-C Efficiency V = 4.5V, V = 3.8V, I = 500mA 77.4% IN OUT OUT DC863A-A V = 3.3V, V = 3.0V, I = 500mA 71.4% IN OUT OUT 1 QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 863 500MA LOW NOISE, HIGH EFFICIENCY CHARGE PUMP QUICK START PROCEDURE Demonstration circuit 863 is easy to set up to evalu- NOTE: Make sure that the input voltage does not ex- ate the performance of the LTC3203BEDD, ceed 5.5V. LTC3203EDD-1 and LTC3203BEDD-1. Refer to 5. Check for the proper output voltages. For DC863A- Figure 1 for proper measurement equipment setup B and DC863A-C, Vout should measure either a 5V and follow the procedure below: (could vary from 4.8V to 5.2V) or 4.5V (could vary NOTE: When measuring the input or output voltage from 4.32V to 4.68V) depending on the position of ripple, care must be taken to avoid a long ground lead JP2. For DC863A-A, Vout is typically 3.3V, varying on the oscilloscope probe. Measure the input or out- from 3.168V to 3.432V. put voltage ripple by touching the probe tip directly NOTE: If there is no output, temporarily disconnect across the Vin or Vout and GND terminals. See the load to make sure that the load is not set too Figure 2 for proper scope probe technique. high. 1. Place jumpers in the following positions: 6. Connect the JP1 jumper to the off position to JP1 On turn off the LTC3203. Returning the jumper to the on position will turn on the LTC3203. JP2 5V (or 4.5V) 7. Once the proper output voltages are established, 2. With power off, connect a 2.7V-5.5V, 1A power adjust the loads within the operating range and ob- supply to Vin and GND. serve the output voltage regulation, ripple voltage, 3. Connect a load to Vout and GND. efficiency and other parameters. 4. Turn on the power at the input. Figure 1. Proper Measurement Equipment Setup 2