® SP6650 Evaluation Board Manual ■ High efficiency synchronous stepdown converter with up to 95% efficiency ■ Ideal for cellular telephones, wireless modems, PDAs, digital cameras ■ Programmable inductor peak current limit, 2.7V-6.5V input voltage range ■ MSOP package & SMT components for small, low profile power supply ■ Easy evaluation for different distributed power systems and batterypowered portable equipment DESCRIPTION The SP6650 Evaluation Board is designed to help the user evaluate the performance of the SP6650 for use as a single Li-Ion battery input to +5V output DC-DC Converter. The SP6650 operates from 2.7V to 6.5V input, with the highest efficiency in the range 3.0V to 4.2V where the Li-Ion battery has the most energy. The SP6650UEB evaluation board is a complete power supply circuit to provide ease of evaluation for the DC/DC Converter performance. The evaluation board is a completely assembled and tested surface mount board which provides easy probe access points to all SP6650 inputs and outputs so that the user can quickly connect and measure electrical characteristics and waveforms. The next two sections describe the SP6650 board layout and using the SP6650 evaluation boards. A table of SP6650 pin assignments is also included with details on input/output pin function. A SP6650 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 SP6650. BOARD SCHEMATIC AND LAYOUT The SP6650 Evaluation Board has been designed for easy and convenient access to all Inputs and Outputs of the SP6650 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 SP6650 MSOP, labeled U1 in the center of the board, and surrounding it the capacitors CIN, CVIN, CF, COUT and resistors forming the switched DC-DC Converter circuit. Rev. 3/23/01 SP6650 Evaluation Board Manual 1 © Copyright 2001 Sipex Corporation VIN 2.7-6.5 VDC CIN 47µF RB 100k RVIN 10.0 ® L1 22µH 1 2 3 3 2 4 1 5 3 2 1 PVIN LX VIN PGND SP6650 BLON GND ILIM VOUT SHDN FB VOUT 3.3V 10 9 RF OPEN 8 7 6 COUT 47µF D1* MBR0540TI CVIN 1.0µF R1 100k Figure 1. SP6650 Evaluation Board Schematic The SP6650 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. 2) I LIM Programming Connect pin 4 of the SP6650 to VIN for 0.8 A peak Inductor current limit (pins 2,3 of the Jumper J2). Connect pin 4 of the SP6650 to GND for 0.35 A peak Inductor current limit (pins 1,2 of the Jumper J2). 3) VOUT Programming To control the output voltage externally connect the appropriate resistors (Table 1) From pin 6 SP6650 FB to VOUT and to the GND. Tie Pin 6 FB to the 100k resistor or to the GND and controller will use the internal network for a preset output Voltage of 3.3V. For VOUT different from shown in the Table 1, use equation: USING THE EVALUATION BOARD 1) Powering Up the SP6650 Circuit The SP6650 Evaluation Board can be powered from a single Li-Ion battery or a +2.7 to +6.5V power supply. Connect with short leads directly to the “VIN” and “GND” posts. Note the SP6650 will remain in “shutdown” until pin 2 of the Jumper J2 is applied to the GND. RF = ( VOUT 1.25 ) – 1 R1 (For VOUT > 3.3V, RF = 50k recommended) Rev. 3/23/01 SP6650 Evaluation Board Manual 2 © Copyright 2001 Sipex Corporation Figure 2: SP6650UEB Component Placement Figure 3: SP6650UEB PC layout Top Side Figure 4: SP6650UEB PC Layout Bottom Side Rev. 3/23/01 SP6650 Evaluation Board Manual 3 © Copyright 2001 Sipex Corporation TABLE 1: SP6650UEB LIST OF MATERIALS Component VOUT = 3.3V, Int FB VOUT = 2.5V, Ext FB VOUT = 1.25V, Ext FB L1 22µH,CDRH6D28 Sumida 22µH,CDRH6D28 Sumida 22µH,CDRH6D28 Sumida CIN 47µF, AVX TPSD 47µF, AVX TPSD 47µF, AVX TPSD COUT 47µF, AVX TPSD 47µF, AVX TPSD 47µF, AVX TPSD RB 100k 5% 100k 5% 100k 5% RVIN 10Ω 5% 10Ω 5% 10Ω 5% CVIN 1µF ceramic 1µF ceramic 1µF ceramic RI 100k 1% 100k 1% 100k 1% RF open 100k 1% short CF open 470pF ceramic open U1 SP6650 SP6650 SP6650 Rev. 3/23/01 SP6650 Evaluation Board Manual 4 © Copyright 2001 Sipex Corporation PIN DESCRIPTION PIN NUMBER PIN NAME 1 PVIN Input voltage power pin. Inductor charging current passes through this pin. 2 VIN Internal supply voltage. Control circuitry powered from this pin. 3 BLON Open drain battery low output. VIN below battery low threshold pulls this node to ground. VIN above threshold, this node is open. 4 ILIM Inductor current limit programming pin. Tie pin to VIN for 0.8A peak inductor current limit. Tie pin to ground for 0.4A peak inductor current limit. TTL input threshold. 5 SHDN Shutdown control input. Tie to VIN for normal operation, tie to ground for shutdown. TTL input threshold. 6 FB External feedback network input connection. Connect a resistor from FB to ground and FB to VOUT to control the output voltage externally. This pin regulates to the internal bandgap reference voltage of 1.25V. Tie FB to ground to use the internal divider for a preset output voltage of 3.3V. 7 VOUT Output voltage sense pin. Used for internal feedback divider and timing circuit. 8 GND Internal ground pin. Control circuitry returns current to this pin. 9 PGND 10 LX Rev. 3/23/01 DESCRIPTION Power ground pin. Synchronous rectifier current returns through this pin. Inductor switching node. Inductor tied between this pin and the output capacitor to create regulated output voltage. SP6650 Evaluation Board Manual 5 © Copyright 2001 Sipex Corporation ORDERING INFORMATION Part Number Temperature Range Package SP6650UEB .............................................................................................................. SP6650 Evaluation Board SP6650EU ........................................................... -40°C to +85°C ............................................... 10-pin MSOP Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Rev. 3/23/01 SP6650 Evaluation Board Manual 6 © Copyright 2001 Sipex Corporation