SP6680 Evaluation Board Manual § Easy Evaluation for the SP6680 Li-Ion Battery to 5V Inductorless Converter § Ideal for SIMM Card Power Supply Applications in Cellular Phones § High Efficiency: 80 to 95% with Li-Ion Battery § µSOIC Package & SMT components for small, low profile Power Supply DESCRIPTION The SP6680 Evaluation Board is designed to help the user evaluate the performance of the SP6680 for use as a single Li-Ion battery input to +5V output DC-DC Converter. The SP6680 operates from 2.7V to 6.3V input, with the highest efficiency in the range 3.0V to 4.2V where the Li-Ion battery has the most energy. The SP6680UEB evaluation board is a complete power supply circuit with +5V LDO Regulator to provide ease of use to evaluate system DC/DC Converter performance. The evaluation board is a completely assembled and tested surface mount board which provides easy probe access points to all SP6680 Inputs and Outputs so that the user can quickly connect and measure electrical characteristics and waveforms. The next two sections describe the SP6680 Board Layout and Using the SP6680 Evaluation Boards. A table of SP6680 Pin Assignments is also included with details on input/output pin function. A SP6680 Evaluation Board List of Materials table is provided with some manufacturers part numbers to use as a reference. Finally, a schematic and drawings of the PC Layout are included as a design-in tool for the user of the SP6680. BOARD LAYOUT The SP6680 Evaluation Board has been designed for easy and convenient access to all Inputs and Outputs of the SP6680 device under test. Position the board with the silkscreen lettering upright, (also see the drawing on the front page of this manual) and you will see the SP6680 µSOIC, labeled U1 in the left center of the board, and surrounding it the Capacitors Cin, CF1, CF2 and Cout forming the switched capacitor DC-DC Converter circuit. On the right is U2, the LDO, in a small SOT23-5 package providing a low-noise, regulated +5V output. Rev. 6/27/01 SP6680 Evaluation Board Manual 1 © Copyright 2001 Sipex Corporation The SP6680 Evaluation Board provides convenient test points to connect the input to Power Supply or Li-Ion Battery. The Input and Output connections are made with raised female pin receptacles which can accommodate easy-hook connection leads for power and meter connections, as well as scope probe hooks and grounds for waveform measurements. USING THE EVALUATION BOARD 1) Powering Up the SP6680 Circuit The SP6680 Evaluation Board can be powered from a single Li-Ion battery or a +2.7 to +6.3V power supply. Connect with short leads directly to the “Vin” and “Gnd” posts. Note the SP6680 will remain in “shutdown” until a Clock input is applied to the “CLK” input post. 2) Enabling the SP6680 Output with CLK Input The SP6680 output will typically be in low current “shutdown” mode until a Clock Input is applied to the “CLK” post. This input typically is a CMOS level 32.768kHz clock derived from a real-time clock crystal, but any stable square wave function generator with a VIL<0.4V and VIH>1.3V will do. You can now measure the SP6680 pre-regulated output of 5.2V to 6.3V with a voltmeter or scope across the “Vout” and “Gnd” posts. 3) Controlling the Pump Frequency The SP6680 has 3 frequency modes controlled by the presence of a 32.768kHz Clock at “CLK” input, and levels at the digital inputs at posts “CD4” or “CX8”. Basically, the SP6680 will pump at the 32.768kHz Clock input frequency unless a High level is present at CD4 or CX8, as illustrated in the Pump Frequency Control table below. Apply Logic High to “CD4” post and the SP6680 will pump at ¼ frequency or 8.192kHz. Or, apply a Logic High to “CX8” post and the SP6680 will pump at 8 times the Clock frequency or 262.14kHz. Observe the pump frequency by applying a scope probe to CF2P post. TABLE1: PUMP FREQUENCY CONTROL CLK pin not present 32.768kHz 32.768kHz 32.768kHz 32.768kHz CD4 X Low Low High High CX8 X Low High Low High Fpump Frequency 0 32.768kHz 262.14kHz 8.192kHz 262.14kHz Maximum Output 0 20mA 60mA 2mA 60mA As you can see from the table, as pump frequency increases, the capability of the SP6680 maximum output current increases (and quiescent current will rise). See the SP6680 datasheet specification table to compare how the Output Resistance, Output Voltage and Power Efficiency parameters vary with Pump Frequency. 4) Dynamic Charge Pump Action The charge pump configuration dynamically changes to optimize efficiency. At low input voltages the charge pump doubles the input, while at higher inputs the output is 1.5 times the input. You can observe this action by monitoring how the output voltage Rev. 6/27/01 SP66680 Evaluation Board Manual 2 © Copyright 2001 Sipex Corporation changes with input changes. Also, you can see these mode changes by attaching a scope probe to the “CF1P” post and observe how the pump waveform changes from the 2X mode to the 1.5X mode, as shown in the scope traces shown below. As seen in the datasheet specification for Power Efficiency, by dynamically changing modes with input voltages the SP6680 optimizes power efficiency. Ch1 = CF2P Ch2 = CF1P Ch3 = Vin Ch4 = Vout Vin = 3.7V, 2X Mode 32kHz Vin = 4.0V, 1.5X Mode 32kHz TABLE2: SP6680UEB PIN ASSIGNMENTS Pin No. 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 Rev. 6/27/01 Pin Name Pin Function Input/Output Pin Name U1 - SP6680UEB Pin Assignments VOUT PreRegulated 5.2 to 6.3Vout VOUT CFIP Fly Capacitor One Positive CFIP VIN Input Voltage VIN CD4 Digital Input for CLK/4 CD4 CX8 Digital Input for CLK*8 CX8 CLK Clock Input CLK CF2N Fly Capacitor Two Negative GND Ground GND CF1N Fly Capacitor One Negative CF2P Fly Capacitor Two Positive CF2P U2 - SP6200EM5 Pin Assignments VIN LDO Input GND Ground GND ON/OFF_N ON = H or Shutdown =L N/C No Connect VOUT +5V Output +5V SP66680 Evaluation Board Manual 3 © Copyright 2001 Sipex Corporation FIGURE 1: SP6680UEB COMPONENT PLACEMENT FIGURE 2: SP6680UEB PC LAYOUT TOP SIDE FIGURE 3: SP6680UEB PC LAYOUT BOTTOM SIDE Rev. 6/27/01 SP66680 Evaluation Board Manual 4 © Copyright 2001 Sipex Corporation SP6680 EVALUATION BOARD SCHEMATIC CF1P CF2P VOUT CF1 2.2uF Cer. COUT 2.2uF 1 2 3 VIN CIN 4.7uF GND 4 5 VOUT SP6680 CF1P CF1N VIN GND CD4 CX8 Cer. CF2P CF2N U1 CLK Cer. 10 GND 9 CF2 8 2.2uF Cer. 7 6 5V SP1 +5V LDO C5 CD4 1 R1 SP2 2 1M 3 SP6200 VIN VOUT 5 2.2uF Cer. GND ON/OFF_N N/C GND 4 C6 CX8 N/C SP3 R2 1M CLK TABLE3: SP6680EB LIST OF MATERIALS Ref. Des. PCB U1 U2 Cout,Cf1,Cf2,C5 Cin C6 R1,2 TP Qty. Manuf. Sipex Sipex Sipex TDK TDK Manuf. Part Number 146-6386-00 SP6680EU SP6200EM5-5.0 C2012X5R1A225K C3216X5R1C475K Layout Size .85"x1.5" uSO-10 SOT23-5 0805 SM 1206 SM 1 1 1 4 1 0 2 11 Panasonic Mill-Max ERJ-8GEYJ105 3137-3002-10-0080 1206 SM .042 Dia Component SP6680 Eval PCB 5V Reg. Charge Pump 5V LDO Regulator 2.2uF 10V SM X5R 4.7uF 10V SM X5R No Connection 1M Thick Film Res 5% Test Point Female Pin Vendor Phone Number 978-667-7800 978-667-7800 978-667-7800 847-803-6100 847-803-6100 800-344-4539 800-344-4539 ORDERING INFORMATION Model Temperature Range Package Type SP6680UEB ........................................................................... SP6680 Evaluation Board SP6680EU.....................................-40°C to +85°C......................................10-pin µSOIC Rev. 6/27/01 SP66680 Evaluation Board Manual 5 © Copyright 2001 Sipex Corporation