19-2712; Rev 0; 1/03 KIT ATION EVALU E L B A AVAIL Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Features ♦ Step-Up DC-to-DC Converter 95% Efficient 3.3V (Fixed) or 2.7V to 5.5V (Adjustable) Output Voltage ♦ Step-Down DC-to-DC Converter Operate from Battery for 95% Efficient Buck Combine with Step-Up for 90% Efficient BuckBoost Adjustable Output Down to 1.25V ♦ Three Auxiliary PWM Controllers ♦ Up to 1MHz Operating Frequency ♦ 1µA Shutdown Mode ♦ Internal Soft-Start Control ♦ Overload Protection ♦ Compact 32-Pin, 5mm x 5mm Thin QFN Package Ordering Information PART MAX1565ETJ TEMP RANGE PIN-PACKAGE -40°C to +85°C 32 Thin QFN The MAX1565 is available in a space-saving 32-pin thin QFN package. Pin Configuration CORE +1.5V AUX1 MOTOR +5V AUX2 CCD +15V/-7.5V AUX3 LCD, LED +15V GND DL1 DL2 DL3 OUTSUB FB3 26 25 24 COMP3 FB1 2 23 SDOK PGNDA 3 22 OUTSUA LXSD 4 INSD 5 ONSD 6 19 OSC COMPSD 7 18 FBSEL1 FBSD 8 17 FBSELSD 21 LXSU MAX1565 9 10 20 PGNDB 11 12 13 14 15 16 FBSELSU STEP-DOWN 27 COMPSU ON2 0N3 MAIN +3.3V 28 FBSU ON/OFF CONTROLS ONSU ONSD ON1 STEP-UP 29 REF MAX1565 30 ONSU INPUT +0.7V TO +5.5V 31 1 ON3 Typical Operating Circuit 32 COMP1 ON2 PDAs COMP2 Digital Video Cameras FB2 TOP VIEW Digital Still Cameras ON1 Applications 5mm x 5mm THIN QFN ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX1565 General Description The MAX1565 provides a complete power-supply solution for digital still and video cameras through the integration of ultra-high-efficiency step-up/step-down DC-to-DC converters along with three auxiliary step-up controllers. The MAX1565 is targeted for applications that use either 2 or 3 alkaline or NiMH batteries as well as those using a single lithium-ion (Li+) battery. The step-up DC-to-DC converter accepts inputs from 0.7V to 5.5V and regulates a resistor-adjustable output from 2.7V to 5.5V. It uses internal MOSFETs to achieve 95% efficiency. Adjustable operating frequency facilitates design for optimum size, cost, and efficiency. The step-down DC-to-DC converter can produce output voltages as low as 1.25V and also utilizes internal MOSFETs to achieve 95% efficiency. An internal softstart ramp minimizes surge current from the battery. The converter can operate from the step-up output providing buck-boost capability with up to 90% compound efficiency, or it can run directly from the battery if buckboost operation is not needed. The MAX1565 features auxiliary step-up controllers that power CCD, LCD, motor actuator, and backlight circuits. The device also features low-cost expandability by supplying power, an oscillator signal, and a reference to the MAX1801 SOT23 slave controller that supports step-up, SEPIC, and flyback configurations. MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply ABSOLUTE MAXIMUM RATINGS OUTSU_, INSD, SDOK, ON_, FB_, FBSEL_ to GND ....................................................-0.3V to +6V PGND to GND .......................................................-0.3V to +0.3V DL_ to PGND...........................................-0.3V to OUTSU + 0.3V LXSU Current (Note 1) ..........................................................3.6A LXSD Current (Note 1) ........................................................2.25A REF, OSC, COMP_ to GND.....................-0.3V to OUTSU + 0.3V Continuous Power Dissipation (TA =+70°C) 32-Pin Thin QFN (derate 22mW/°C above +70°C).............................................................1700mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Note 1: LXSU has internal clamp diodes to OUTSU and PGND, and LXSD has internal clamp diodes to INSD and PGND. Applications that forward bias these diodes should take care not to exceed the devices power dissipation limits. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VOUTSU = 3.3V, TA = 0°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS 5.5 V 1.1 V GENERAL Input Voltage Range (Note 2) Minimum Startup Voltage ILOAD < 1mA, TA = +25°C, startup voltage tempco is -2300ppm/°C (typ) (Note 3) 0.7 0.9 100,000 OSC cycles Thermal Shutdown 160 °C Thermal-Shutdown Hysteresis 20 °C Overload Protection Fault Interval Shutdown Supply Current into OUTSU ONSU = ONSD = ON1 = ON2 = ON3 = 0; OUTSU = 3.6V 0.1 5 µA Step-Up DC-to-DC Supply Current into OUTSU ONSU = 3.35V, FBSU = 1.5V (does not include switching losses) 290 400 µA Step-Up Plus 1 AUX Supply Current into OUTSU ONSU = ON_ = 3.35V, FBSU = 1.5V, FB_ = 1.5V (does not include switching losses) 420 600 µA Step-Up Plus Step-Down Supply Current into OUTSU ONSU = ONSD = 3.35V, FBSU = 1.5V, FBSD = 1.5V (does not include switching losses) 470 650 µA Reference Output Voltage IREF = 20µA 1.25 1.27 V Reference Load Regulation 10µA < IREF < 200µA 4.5 10 mV Reference Line Regulation 2.7 < OUTSU < 5.5V mV OSC Discharge Trip Level Rising edge OSC Discharge Resistance OSC = 1.5V, IOSC = 3mA 1.23 1.225 OSC Discharge Pulse Width OSC Frequency ROSC = 40kΩ, COSC = 100pF 1.3 5 1.25 1.275 V 52 80 Ω 300 ns 400 kHz STEP-UP DC-TO-DC CONVERTER Step-Up Startup-to-Normal Operating Threshold Step-Up Startup-to-Normal Operating Threshold Hysteresis 2 Rising or falling edge (Note 4) 2.30 2.5 80 _______________________________________________________________________________________ 2.60 V mV Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply (VOUTSU = 3.3V, TA = 0°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS Step-Up Voltage Adjust Range MIN TYP MAX UNITS 5.5 V 1.231 1.25 1.269 V 2.7 FBSU Regulation Voltage OUTSU Regulation Voltage FBSELSU = GND 3.296 3.35 3.404 V FBSU to COMPSU Transconductance FBSU = COMPSU 80 135 185 µS FBSU Input Leakage Current FBSU = 1.25V -100 +1 +100 nA Idle-Mode™ Trip Level (Note 6) 150 200 265 mA Current-Sense Amplifier Transresistance 0.3 Step-Up Maximum Duty Cycle FBSU = 1V 85 90 % OUTSU Leakage Current VLX = 0V, OUTSU = 5.5V 0.01 20 µA LXSU Leakage Current VLXSU = VOUT = 5.5V µA Switch On-Resistance 80 V/A 0.01 20 N-channel 95 150 P-channel 150 250 2 2.4 N-Channel Current limit 1.6 P-Channel Turn-Off Current mΩ A 20 mA mA Startup Current Limit OUTSU = 1.8V (Note 5) 800 Startup tOFF OUTSU = 1.8V 700 ns Startup Frequency OUTSU = 1.8V 200 kHz STEP-DOWN DC-TO-DC CONVERTER FBSD Regulation Voltage 1.231 1.25 1.269 V OUTSD Regulation Voltage FBSELSD = GND 1.48 1.5 1.52 V FBSD to COMPSD Transconductance FBSD = COMPSD 80 135 185 µS FBSD Input Leakage Current FBSD = 1.25V -100 +1 +100 nA Idle-Mode Trip Level (Note 6) 110 160 190 mA Current-Sense Amplifier Transresistance LXSD Leakage Current Switch On-Resistance 0.60 VLXSD = 5.5V, OUTSU = 5.5V 0.01 20 VLXSD = 0V, OUTSU = 5.5V 0.01 20 N-channel 95 150 P-channel 150 250 0.79 1.0 P-Channel Current Limit 0.7 N-Channel Turn-Off Current Soft-Start Interval SDOK Output Low Voltage V/A FBSD = 0.4V; 0.1mA into SDOK pin SDOK Operating Voltage Range mΩ A 20 mA 4096 OSC cycles 0.002 1.0 µA 0.1 V 5.5 V Idle Mode is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ 3 MAX1565 ELECTRICAL CHARACTERISTICS (continued) MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply ELECTRICAL CHARACTERISTICS (continued) (VOUTSU = 3.3V, TA = 0°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS AUXILIARY DC-TO-DC CONTROLLERS (AUX 1, 2, AND 3) Maximum Duty Cycle FB_ = 1V 80 85 90 % FB_ Regulation Voltage FB_ = COMP_ 1.231 1.25 1.269 V FB_ to COMP_ Transconductance FB_ = COMP_ 80 135 185 µS FB_ Input Leakage Current FB_ = 1.25V -100 +1 +100 nA AUX1 Output Regulation Voltage FBSEL1 = GND, FB1 connected directly to AUX1 output 4.93 V DL_ Driver Resistance DL_ Drive Current 5 5.07 Output high 3 10 Output low 2 5 Sourcing or sinking Soft-Start Interval Ω 0.5 A 4096 OSC cycles LOGIC INPUTS (ON_ , FBSEL_) Input Low Level Input High Level 1.1V < OUTSU < 1.8V (ONSU only) 0.2 1.8V < OUTSU < 5.5V 0.4 1.1V < OUTSU < 1.8V (ONSU only) 1.8V < OUTSU < 5.5V FBSEL_ Input Leakage Current ON_ Impedance to GND VOUTSU - 0.2 V V 1.6 FBSEL = 3.6V, OUTSU = 3.6V -100 0 +100 FBSEL = GND, OUTSU = 3.6V -100 0 +100 ON_ = 3.35V 330 nA kΩ ELECTRICAL CHARACTERISTICS (VOUTSU = 3.3V, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS 5.5 V 1.1 V 5 µA GENERAL Input Voltage Range (Note 2) Minimum Startup Voltage ILOAD < 1mA, TA = +25°C, startup voltage tempco is -2300ppm/°C (typ) (Note 3) Shutdown Supply Current into OUTSU ONSU = ONSD = ON1 = ON2 = ON3 = 0 OUTSU = 3.6V Step-Up DC-to-DC Supply Current into OUTSU ONSU = 3.35V, FBSU = 1.5V (does not include switching losses) 400 µA Step-Up Plus 1 AUX Supply Current into OUTSU ONSU = ON_ = 3.35V, FBSU = 1.5V, FB_ = 1.5V (does not include switching losses) 600 µA Step-Up Plus Step-Down Supply Current into OUTSU ONSU = ONSD = 3.35V, FBSU = 1.5V, FBSD = 1.5V (does not include switching losses) 650 µA Reference Output Voltage IREF = 20µA Reference Load Regulation 10µA < IREF < 200µA 4 0.7 1.23 _______________________________________________________________________________________ 1.27 V 10 mV Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply (VOUTSU = 3.3V, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS Reference Line Regulation 2.7V < OUTSU < 5.5V OSC Discharge Trip Level Rising edge OSC Discharge Resistance OSC = 1.5V, IOSC = 3mA MIN 1.225 TYP MAX UNITS 5 mV 1.275 V 80 Ω 2.30 2.60 V 2.7 5.5 V STEP-UP DC-TO-DC CONVERTER Step-Up Startup-to-Normal Operating Threshold Rising or falling edge (Note 4) Step-Up Voltage Adjust Range FBSU Regulation Voltage 1.225 1.275 V OUTSU Regulation Voltage FBSELSU = GND 3.283 3.417 V FBSU to COMPSU Transconductance FBSU = COMPSU 80 185 µS FBSU Input Leakage Current FBSU = 1.25V -100 +100 nA Idle-Mode Trip Level (Note 6) 150 275 mA Step-Up Maximum Duty Cycle FBSU =1V 80 90 % OUTSU Leakage Current VLX = 0V, OUTSU = 5.5V 20 µA LXSU Leakage Current VLXSU = VOUT = 5.5V 20 µA N-channel 150 P-channel 250 Switch On-Resistance N-Channel Current limit mΩ 1.6 2.4 A STEP-DOWN DC-TO-DC CONVERTER FBSD Regulation Voltage 1.225 1.275 V OUTSD Regulation Voltage FBSELSD = GND 1.47 1.53 V FBSD to COMPSD Transconductance FBSD = COMPSD 80 185 µS FBSD Input Leakage Current FBSD = 1.25V -100 +100 nA Idle-Mode Trip Level (Note 6) 110 195 mA LXSD Leakage Current Switch On-Resistance VLXSD = 5.5V, OUTSU = 5.5V 20 VLXSD = 0V, OUTSU = 5.5V 20 N-channel 150 P-channel 250 P-Channel Current Limit SDOK Output Low Voltage 0.7 mΩ 1.0 A 0.1 V 1 5.5 V 80 90 % 1.225 1.275 V FBSD = 0.4V; 0.1mA into SDOK pin SDOK Operating Voltage Range µA AUXILIARY DC-TO-DC CONTROLLERS (AUX 1, 2, AND 3) Maximum Duty Cycle FB_ = 1V FB_ Regulation Voltage FB_ = COMP_ _______________________________________________________________________________________ 5 MAX1565 ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (VOUTSU = 3.3V, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS 80 185 µS FB_ to COMP_ Transconductance FB_ = COMP_ FB_ Input Leakage Current FB_ = 1.25V -100 +100 nA AUX1 Output Regulation Voltage FBSEL1 = GND, FB1 connected directly to AUX1 output 4.90 5.10 V DL_ Driver Resistance Output high 10 Output low 5 Ω LOGIC INPUTS (ON_, FBSEL_) Input Low Level 1.1V < OUTSU < 1.8V (ONSU only) 0.2 1.8V < OUTSU < 5.5V 0.4 VOUTSU -0.2 1.1V < OUTSU < 1.8V (ONSU only) Input High Level 1.8V < OUTSU < 5.5V FBSEL_ Input Leakage Current V V 1.6 FBSEL = 3.6V, OUTSU = 3.6V -100 +100 FBSEL = GND, OUTSU = 3.6V -100 +100 nA The IC is powered from the OUTSU output. Since the part is powered from OUTSU, a Schottky rectifier, connected from the input battery to OUTSU, is required for low-voltage startup. The step-up regulator operates in startup mode until this voltage is reached. Do not apply full load current during startup. The step-up current limit in startup refers to the LXSU switch current limit, not an output current limit. The idle-mode current threshold is the transition point between fixed-frequency PWM operation and idle-mode operation (where switching rate varies with load). The spec is given in terms of inductor current. In terms of output current, the idlemode transition varies with input/output voltage ratio and inductor value. For the step-up, the transition output current is approximately 1/3 the inductor current when stepping from 2V to 3.3V. For the step-down, the transition current in terms of output current is approximately 3/4 the inductor current when stepping down from 3.3V to 1.8V. Note 2: Note 3: Note 4: Note 5: Note 6: Typical Operating Characteristics (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) STEP-UP EFFICIENCY vs. LOAD CURRENT (3.3V OUTPUT) 60 50 VIN = 4V VIN = 3.6V VIN = 3V VIN = 2V VIN = 1.5V 40 30 20 70 60 50 VIN = 3.6V VIN = 3V VIN = 2V VIN = 1.5V 40 30 VOUT = 5V 0 10 100 LOAD CURRENT (mA) 1000 90 VIN = 4.2V VIN = 3.6V VIN = 3V 80 70 60 50 40 30 20 10 1 80 EFFICIENCY (%) 70 90 EFFICIENCY (%) 80 100 MAX1565 toc02 90 6 100 MAX1565 toc01 100 STEP-DOWN EFFICIENCY vs. LOAD CURRENT INSD CONNECTED TO BATTERY VOUT = 1.5V DOES NOT INCLUDE CURRENT USED BY THE STEP-UP TO POWER THE IC 20 10 VOUT = 3.3V 0 1 MAX1565 toc03 STEP-UP EFFICIENCY vs. LOAD CURRENT (5V OUTPUT) EFFICIENCY (%) MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply 10 100 LOAD CURRENT (mA) 1000 10 0 1 10 100 LOAD CURRENT (mA) _______________________________________________________________________________________ 1000 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply 70 50 40 60 50 30 30 20 20 VOUTSD = 1.5V VOUTSU = 3.3V 100 1000 MAX1565 toc06 2.0 1.5 2.5 3.0 3.5 4.0 INPUT VOLTAGE (V) BUCK-BOOST EFFICIENCY vs. INPUT VOLTAGE (3.3V OUTPUT, VOUTSU = 5V) BOOST AND BUCK-BOOST COMBINED EFFICIENCY vs. INPUT VOLTAGE AUX_ EFFICIENCY vs. LOAD CURRENT (5V OUTPUT) IOUTSD = 500mA IOUTSD = 100mA 90 EFFICIENCY (%) 70 100 60 50 40 100 80 70 MAX1565 toc09 80 90 80 70 VIN = 3.6V VIN = 3V VIN = 2V VIN = 1.5V 60 50 40 30 30 VOUTSU = 3.3V, 200mA VOUTSD = 1.5V, 200mA EFF% = [(VSUISU) + (VSDISD)]/(VINIIN) 60 VOUTSD = 3.3V VOUTSU = 5V 10 20 10 2.5 3.0 3.5 1.5 1.0 4.5 4.0 2.0 2.5 3.0 NO-LOAD INPUT CURRENT vs. INPUT VOLTAGE (SWITCHING) 3.0 BUCK-BOOST (STEP-UP AND STEP DOWN) 2.5 2.0 STEP-UP 1.0 0.5 100 1000 LOAD CURRENT (mA) MINIMUM STARTUP VOLTAGE vs. LOAD CURRENT (OUTSU) 3.5 1.5 10 1 3.5 INPUT VOLTAGE (V) INPUT VOLTAGE (V) VOUTSD = 1.5V VOUTSU = 5V 3.5 WITHOUT SCHOTTKY* MINIMUM STARTUP VOLTAGE (V) 2.0 MAX1565 toc10 1.5 VOUTAUX_ = 5V 0 50 0 3.0 WITH SCHOTTKY* 2.5 2.0 1.5 1.0 0.5 0 MAX1565 toc11 20 INPUT CURRENT (mA) EFFICIENCY (%) VOUTSD = 1.5V VOUTSU = 3.3V 10 LOAD CURRENT (mA) IOUTSD = 250mA 90 40 LOAD CURRENT (mA) MAX1565 toc07 100 50 0 10 1 1000 100 60 20 VOUTSD = 3.3V VOUTSU = 5V 0 10 IOUTSD = 250mA IOUTSD = 500mA IOUTSD = 100mA 70 30 10 0 1 80 EFFICIENCY (%) 10 VIN = 4.2V VIN = 3.6V VIN = 3V VIN = 2V VIN = 1.5V 40 90 MAX1565 toc08 60 80 EFFICIENCY (%) VIN = 3V VIN = 2V VIN = 1.5V 90 EFFICIENCY (%) 80 100 MAX1565 toc05 90 EFFICIENCY (%) 100 MAX1565 toc04 100 70 BUCK-BOOST EFFICIENCY vs. INPUT VOLTAGE (1.5V OUTPUT, VOUTSU = 3.3V) BUCK-BOOST EFFICIENCY vs. LOAD CURRENT (3.3V OUTPUT, VOUTSU = 5V) BUCK-BOOST EFFICIENCY vs. LOAD CURRENT (1.5V OUTPUT, VOUTSU = 3.3V) *SCHOTTKY DIODE CONNECTED FROM IN TO OUTSU 0 1 2 3 INPUT VOLTAGE (V) 4 5 0 300 600 900 1200 LOAD CURRENT (mA) _______________________________________________________________________________________ 7 MAX1565 Typical Operating Characteristics (continued) (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) REFERENCE VOLTAGE vs. TEMPERATURE REFERENCE VOLTAGE vs. REFERENCE LOAD CURRENT 1.246 1.245 1.244 1.243 1.249 1.248 1.247 1.246 1.242 1.245 1.241 1.240 -25 0 25 50 75 100 100 150 200 500 400 300 200 250 1 10 WHEN THIS DUTY CYCLE IS EXCEEDED FOR 100,000 CLOCK CYCLES, THE MAX1565 SHUTS DOWN 100 ROSC (kΩ) STEP-UP STARTUP RESPONSE MAX1565 toc16 MAX1565 toc15 MAXIMUM DUTY CYCLE (%) COSC = 470pF COSC = 220pF COSC = 100pF COSC = 47pF 600 REFERENCE LOAD CURRENT (µA) AUX_ MAXIMUM DUTY CYCLE vs. FREQUENCY 87 700 0 50 0 TEMPERATURE (°C) 88 800 100 1.244 -50 MAX1565 toc14 1.250 REFERENCE VOLTAGE (V) 1.247 900 OSCILLATOR FREQUENCY (kHz) 1.248 OSCILLATOR FREQUENCY vs. ROSC MAX1565 toc13 1.251 MAX1565 toc12 1.249 REFERENCE VOLTAGE (V) MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply 0V ONSU 5V/div OUTSU 2V/div 0V IOUTSU 100mA/div 86 85 84 0A 83 82 COSC = 100pF IIN VOUTSO = 3.3V 1A/div VIN = 2V 0A 81 80 100µs/div 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (kHz) BUCK-BOOST STARTUP RESPONSE AUX_ STARTUP RESPONSE MAX1565 toc17 0V MAX1565 toc18 ONSD = ONSU 5V/div OUTSU 1V/div 0V OUTSD 500mA/div 0V ON1 5V/div OUT1 2V/div IOUT1 200mA/div 0V 0V VOUTSU = 3.3V VOUTSD = 1.5V VIN = 2.5V 0A 4ms/div 8 IOUTSD 200mA/div VOUT1 = 5V VIN = 2.5V 0A 2ms/div _______________________________________________________________________________________ 1000 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply STEP-UP LOAD TRANSIENT RESPONSE STEP-DOWN LOAD TRANSIENT RESPONSE MAX1565 toc19 MAX1565 toc20 IOUTSD 100mA/div IOUTSU 200mA/div 0A 0A 0V VOUTSU = 3.3V VIN = 2.5V VOUTSU AC-COUPLED 100mV/div 0V VOUTSD = 1.5V VOUTSU = 3.3V VIN = 2.5V 400µs/div VOUTSD AC-COUPLED 50mV/div 400µs/div Pin Description PIN NAME FUNCTION 1 COMP1 Auxiliary Controller 1 Compensation Node. Connect a series RC from COMP1 to GND to compensate the control loop. COMP1 is actively driven to GND in shutdown and thermal limit. Auxiliary Controller 1 Feedback Input. For 5V output, short FBSEL1 to GND and connect FB1 to the output voltage. For other output voltages, connect FBSEL1 to OUTSU and connect a resistive voltage-divider from the step-up converter output to FB1 to GND. The FB1 feedback threshold is then 1.25V. This pin is high impedance in shutdown. 2 FB1 3 PGNDA 4 LXSD Step-Down Converter Power-Switching Node. Connect LXSD to the step-down converter inductor. LXSD is the drain of the P-channel switch and N-channel synchronous rectifier. LXSD is high impedance in shutdown. 5 INSD Step-Down Converter Input. INSD can connect to OUTSU, effectively making OUTSD a buck-boost output from the battery. Bypass to GND with a 1µF ceramic capacitor if connected to OUTSU. INSD may also be connected to the battery, but should not exceed OUTSU by more than a Schottky diode forward voltage. Bypass INSD with a 10µF ceramic capacitor when connecting to the battery input. A 10kΩ internal resistance connects OUTSU and INSD. 6 ONSD Step-Down Converter On/Off Control Input. Drive ONSD high to turn on the step-down converter. This pin has an internal 330kΩ pulldown resistor. ONSD does not start until OUTSU is in regulation. 7 Power Ground. Connect PGNDA and PGNDB together and to GND with short trace as close to the IC as possible. Step-Down Converter Compensation Node. Connect a series RC from COMPSD to GND to compensate the COMPSD control loop. COMPSD is pulled to GND in normal shutdown and during thermal shutdown (see the StepDown Compensation section). _______________________________________________________________________________________ 9 MAX1565 Typical Operating Characteristics (continued) (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply MAX1565 Pin Description (continued) PIN NAME 8 FBSD Step-Down Converter Feedback Input. For a 1.5V output, short FBSELSD to GND and connect FBSD to OUTSD. For other voltages, short FBSELSD to OUTSU and connect a resistive voltage-divider from OUTSD to FBSD to GND. The FBSD feedback threshold is 1.25V. This pin is high impedance in shutdown. 9 ON1 Auxiliary Controller 1 On/Off Control Input. Drive ON1 high to turn on. This pin has an internal 330kΩ pulldown resistor. ON1 cannot start until OUTSU is in regulation. 10 ON2 Auxiliary Controller 2 On/Off Control Input. Drive ON2 high to turn on. This pin has an internal 330kΩ pulldown resistor. ON2 cannot start until OUTSU is in regulation. 11 ON3 Auxiliary Controller 3 On/Off Control Input. Drive ON3 high to turn on. This pin has an internal 330kΩ pulldown resistor. ON3 cannot start until OUTSU is in regulation. 12 ONSU 13 REF 14 10 FBSU FUNCTION Step-Up Converter On/Off Control. Drive ONSU high to turn on the step-up converter. All other control pins are locked out until 2ms after the step-up output has reached its final value. This pin has an internal 330kΩ resistance to GND. Reference Output. Bypass REF to GND with a 0.1µF or greater capacitor. The maximum allowed load on REF is 200µA. REF is actively pulled to GND when all converters are shut down. Step-Up Converter Feedback Input. To regulate OUTSU to 3.35V, connect FBSELSU to GND. FBSU may be connected to OUTSU or GND. For other output voltages, connect FBSELSU to OUTSU and connect a resistive voltage-divider from OUTSU to FBSU to GND. The FBSU feedback threshold is 1.25V. This pin is high impedance in shutdown. 15 Step-Up Converter Compensation Node. Connect a series RC from COMPSU to GND to compensate the COMPSU control loop. COMPSD is pulled to GND in normal shutdown and during thermal shutdown (see the StepDown Compensation section). 16 FBSELSU Step-Up Feedback Select Pin. With FBSELSU = GND, OUTSU regulates to 3.35V. With FBSELSU = OUTSU, FBSU regulates to a 1.25V threshold for use with external feedback resistors. This pin is high impedance in shutdown. 17 FBSELSD Step-Down Feedback Select Pin. With FBSELSD = GND, FBSD regulates to 1.5V. With FBSELSD = OUTSU, FBSD regulates to 1.25V for use with external feedback resistors. This pin is high impedance in shutdown. 18 FBSEL1 Auxiliary Controller 1 Feedback Select Pin. With FBSEL1 = GND and FB1 regulates to 5V. With FBSEL1 = OUTSU, FB1 regulates to 1.25V for use with external feedback resistors. This pin is high impedance in shutdown. 19 OSC 20 PGNDB 21 LXSU 22 OUTSUA 23 SDOK Oscillator Control. Connect a timing capacitor from OSC to GND and a timing resistor from OSC to OUTSU to set the oscillator frequency between 100kHz and 1MHz. This pin is high impedance in shutdown. Power Ground. Connect PGNDA and PGNDB together and to GND with short trace as close to the IC as possible. Step-Up Converter Power-Switching Node. Connect LXSU to the step-up converter inductor. LXSU is high impedance in shutdown. Step-Up Converter Output. OUTSUA is the power output of the step-up converter. Connect OUTSUA to OUTSUB at the IC. This open-drain output goes high impedance when the step-down has successfully completed soft-start. ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply PIN NAME FUNCTION 24 COMP3 25 FB3 Auxiliary Controller 3 Feedback Input. Connect a resistive voltage-divider from the output voltage to FB3 to GND. The FB3 feedback threshold is 1.25V. This pin is high impedance in shutdown. 26 OUTSUB Step-Up Converter Output. OUTSUB powers the MAX1565 and is the sense input when FBSELSU is GND and the output is 3.3V. Connect OUTSUA to OUTSUB. 27 DL3 Auxiliary Controller 3 Gate-Drive Output. Connect the gate of an N-channel MOSFET to DL3. DL3 swings from GND to OUTSU and supplies up to 500mA. DL3 is driven to GND in shutdown and thermal limit. 28 DL2 Auxiliary Controller 2 Gate-Drive Output. Connect the gate of an N-channel MOSFET to DL2. DL2 swings from GND to OUTSU and supplies up to 500mA. DL2 is driven to GND in shutdown and thermal limit. 29 DL1 Auxiliary Controller 1 Gate-Drive Output. Connect the gate of an N-channel MOSFET to DL1. DL1 swings from GND to OUTSU and supplies up to 500mA. DL1 is driven to GND in shutdown and thermal limit. 30 GND Quiet Ground. Connect GND to PGND as close to the IC as possible. 31 COMP2 32 FB2 Auxiliary Controller 2 Feedback Input. Connect a resistive voltage-divider from the output voltage to FB2 to GND to set the output voltage. The FB2 feedback threshold is 1.25V. This pin is high impedance in shutdown. Exposed Pad EP Exposed Underside Metal Pad. This pad must be soldered to the PC board to achieve package thermal and mechanical ratings. The exposed pad is electrically connected to GND. Auxiliary Controller 3 Compensation Node. Connect a series resistor-capacitor from COMP3 to GND to compensate the control loop. COMP3 is actively driven to GND in shutdown and thermal limit. Auxiliary Controller 2 Compensation Node. Connect a series resistor-capacitor from COMP2 to GND to compensate the control loop. COMP2 is actively driven to GND in shutdown and thermal limit. ______________________________________________________________________________________ 11 MAX1565 Pin Description (continued) MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply VIN +1.5V TO +4.2V -7.5V 20mA -CCD BIAS 1µF 20µF 2µH T1 MAX1565 5V 500mA AUX1 DL1 V-MODE STEP-UP PWM 20µF AUX3 V-MODE DL3 STEP-UP PWM FB3 FB1 90.9kΩ 1MΩ +15V 20mA +CCD BIAS 1µF REF 0.1 µF +1.25V REF TO OUTSU TO VIN 1µF 4.7µH AUX2 V-MODE DL2 STEP-UP PWM +15V 100mA LCD 10µF 36.5kΩ 1MΩ FB2 90.9kΩ OSC 100pF OUTSUB COMPSU COMPSD COMP1 COMP2 CURRENTCOMP3 MODE STEP-UP 47kΩ 25kΩ 20kΩ 6800pF 10kΩ 3300pF OUTSUA LXSU 3.3µH TO VIN 1µF 10kΩ 0.01µF 3.35V 600mA MAIN SYSTEM 47µF PGNDB FBSU 1000pF 1000pF INSD ONSU ONSD ON1 ON2 ON3 FBSELSU FBSELSD 10µF CURRENTMODE STEPDOWN LXSD 4.7µH 22µF +1.5V 350mA CORE PGNDA FBSD SDOK FBSEL1 GND Figure 1. Typical Application Circuit 12 ______________________________________________________________________________________ TO VIN TO STEP-DOWN DIRECT FROM BATTERY Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply MAX1565 INTERNAL POWER OK VOUTSU NORMAL MODE STARTUP OSCILLATOR 2.35V ONSU VREF REFOK DIE OVER TEMP 1V ONSU FLTALL 100,000 CLOCK CYCLE FAULT TIMER FAULT IN TO INTERNAL POWER CLK OUTSUB OSC REF 1.25V REFERENCE REF 300ns ONE-SHOT GND COMPSU OUTSUA FBSU FAULT STEP-UP TIMER DONE (SUSSD) STARTUP TIMER CURRENTMODE DC-TO-DC STEP-UP LXSU TO VREF PGND ONSU FLTALL COMPSD INSD FBSD FAULT SOFT-START RAMP GENERATOR ONSD CURRENTMODE DC-TO-DC STEP-DOWN TO VREF LXSD PGND SUSSD FLTALL SDOK COMP_ FB_ FAULT SOFT-START RAMP GENERATOR ON_ TO VREF ONE OF 3 VOLTAGE-MODE DC-TO-DC CONTROLLERS AUX_ DL_ SUSSD FLTALL Figure 2. MAX1565 Functional Diagram ______________________________________________________________________________________ 13 MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Detailed Description The MAX1565 is a complete digital still camera powerconversion IC. It can accept input from a variety of sources including single-cell Li+ batteries, 2-cell alkaline or NiMH batteries, as well as systems designed to accept both battery types. The MAX1565 includes five DC-to-DC converter channels to generate all required voltages: 1) Synchronous rectified step-up DC-to-DC converter with on-chip MOSFETs—This typically supplies 3.3V for main system power. 2) Synchronous rectified step-down DC-to-DC converter with on-chip MOSFETs—Powering the stepdown from the step-up output provides efficient (up to 90%) buck-boost functionality that supplies a regulated output when the battery voltage is above or below the output voltage. The step-down can also be powered from the battery. 3) Auxiliary DC-to-DC Controller 1—Typically used for 5V output for motor, strobe, or other functions as required. 4) Auxiliary DC-to-DC Controller 2—Typically supplies LCD bias voltages with either a multi-output flyback transformer, or boost converter with chargepump inverter. Alternately may power white LEDs for LCD backlighting. 5) Auxiliary DC-to-DC Controller 3—Typically supplies CCD bias voltages with either a multi-output flyback transformer, or boost converter with chargepump inverter. The MAX1565 can also operate with MAX1801 slave DCto-DC controllers if additional DC-to-DC converter channels are required. All MAX1565 DC-to-DC converter channels employ fixed-frequency PWM operation. In addition to multiple DC-to-DC channels, the MAX1565 also includes overload protection, soft-start circuitry, adjustable PWM operating frequency, and a power-OK (POK) output to signal when the step-down converter output voltage (for CPU core) is in regulation. Step-Up DC-to-DC Converter The step-up DC-to-DC converter channel generates a 2.7V to 5.5V output voltage range from a 0.9V to 5.5V battery input voltage. An internal switch and synchronous rectifier allow conversion efficiencies as high as 95% while reducing both circuit size and the number of external components. Under moderate to heavy loading, the converter operates in a low-noise PWM mode with constant frequency. Switching harmonics generated by fixed-frequency operation are consistent and easily filtered. 14 The step-up is a current-mode PWM. An error signal (at COMPSU) represents the difference between the feedback voltage and the reference. The error signal programs the inductor current to regulate the output voltage. At light loads (under 75mA when boosting from 2V to 3.3V), efficiency is enhanced by an idle mode in which switching occurs only as needed to service the load. In this mode, the inductor current peak is limited to typically 200mA for each pulse. Step-Down DC-to-DC Converter The step-down DC-to-DC converter channel is optimized for generating output voltages down to 1.25V. Lower output voltages can be set by adding an additional resistor (see the Applications Information section). An internal switch and synchronous rectifier allow conversion efficiencies as high as 95% while reducing both circuit size and the number of external components. Under moderate to heavy loading, the converter operates in a low-noise PWM mode with constant frequency. Switching harmonics generated by fixed-frequency operation are consistent and easily filtered. The step-down is a current-mode PWM. An error signal (at COMPSD) represents the difference between the feedback voltage and the reference. The error signal programs the inductor current to regulate the output voltage. At light loads (under 120mA), efficiency is enhanced by an idle mode in which switching occurs only as needed to service the load. In this mode, the inductor current peak is limited to 150mA (typ) for each pulse. The step-down remains inactive until the step-up DCto-DC is in regulation. This means that the step-down DC-to-DC on/off pin (ONSD) is overridden by ONSU. The soft-start sequence for the step-down begins 1024 OSC cycles after the step-up output is in regulation. If the step-up, step-down, or any of the auxiliary controllers remains faulted for 200ms, all channels turn off. The step-down also features an open-drain SDOK output that goes low when the output is in regulation. Buck-Boost Operation The step-down input can be powered from the output of the step-up. By cascading these two channels, the stepdown output can maintain regulation even as the battery voltage falls below the step-down output voltage. This is especially useful when trying to generate 3.3V from 1-cell Li+ inputs, or 2.5V from 2-cell alkaline or NiMH inputs, or when designing a power supply that must operate from both Li+ and alkaline/NiMH inputs. Compound efficiencies of up to 90% can be achieved when the step-up and step-down are operated in series. ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Direct Battery Step-Down Operation The step-down converter can also be operated directly from the battery as long as the voltage at INSD does not exceed OUTSU by more than a Schottky diode forward voltage. When using this connection, connect a Schottky diode from the battery input to OUTSU. There is also an internal 10kΩ resistance from OUTSU to INSD, which adds a small additional current drain (of approximately (V OUTSU - V INSD)/10kΩ from OUTSU when INSD is not connected directly to OUTSU. Step-down direct battery operation improves efficiency for the step-down output (up to 95%), but limits the upper limit of the output voltage to 200mV less than the minimum battery voltage. In 1-cell Li+ designs (with a 2.7V min), the output can be set up to 2.5V. In 2-cell alkaline or NiMH designs, the output may be limited to 1.5V or 1.8V, depending on the minimum allowed cell voltage. Auxiliary DC-to-DC Controllers The three auxiliary controllers operate as fixed-frequency voltage-mode PWM controllers. They do not have internal MOSFETs, so output power is determined by external components. The controllers regulate output voltage by modulating the pulse width of the DL_ drive signal to an external N-channel MOSFET switch. Figure 3 shows a functional diagram of an AUX controller channel. A sawtooth oscillator signal at OSC governs timing. At the start of each cycle, DL_ goes high, turning on the external N-FET switch. The switch then turns off when the internally level-shifted sawtooth rises above COMP_ or when the maximum duty cycle is exceeded. The switch remains off until the start of the next cycle. A transconductance error amplifier forms an integrator at COMP_ so that DC high-loop gain and accuracy can be maintained. The auxiliary controllers do not start until the step-up DC-to-DC output is in regulation. If the step-up, stepdown, or any of the auxiliary controllers remains faulted for 100,000 OSC cycles, then all MAX1565 channels latch off. The step-down can only be briefly operated in dropout since the MAX1565 fault protection detects the out-ofregulation condition and activates after 100,000 OSC cycles, or 200ms at 500kHz. At that point, all MAX1565 channels shut down. FB COMP R Q DL_ LEVEL SHIFT REFI SOFTSTART* REF S 0.85 REF CLK OSC *SOFT-START RAMPS REFI FROM 0V TO VREF IN 4096 CLOCK CYCLES. FAULT PROTECTION ENABLE Figure 3. PWM Auxiliary Controller Functional Diagram ______________________________________________________________________________________ 15 MAX1565 Note that the step-up output supplies both the step-up load and the step-down input current when the stepdown is powered from the step-up. The step-down input current reduces the available step-up output current for other loads. MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Maximum Duty Cycle The MAX1565 auxiliary PWM controllers have a guaranteed maximum duty cycle of 80%. That is to say that all controllers can achieve at least 80% and typically reach 85%. In boost designs that employ continuous current, the maximum duty cycle limits the boost ratio such that: 1 - VIN/VOUT ≤ 80% With discontinuous inductor current, no such limit exists for the input/output ratio since the inductor has time to fully discharge before the next cycle begins. Master/Slave Configurations The MAX1565 supports MAX1801 slave PWM controllers that obtain input power, a voltage reference, and an oscillator signal directly from the MAX1565 master. The master/slave configuration allows channels to be easily added and minimizes system cost by eliminating redundant circuitry. The slaves also control the harmonic content of noise since their operating frequency is synchronized to that of the MAX1565 master converter. A MAX1801 connection to the MAX1565 is shown in Figure 11. Fault Protection The MAX1565 has robust fault and overload protection. After power-up, the device is set to detect an out-of regulation state that could be caused by an overload or short. If any DC-to-DC converter channel (step-up, step-down, or any of the auxiliary controllers) remains faulted for 100,000 clock cycles, then ALL outputs latch off until the step-up DC-to-DC converter is reinitialized by the ONSU pin, or by cycling of input power. The fault-detection circuitry for any channel is disabled during its initial turn-on soft-start sequence. Note that output of the step-up, or that of any auxiliary channel set up in boost configuration, does not fall to 0V during shutdown or fault. This is due to the current path from the battery to the output that remains even when the channel is off. This path exists through the boost inductor and the synchronous rectifier body diode. An auxiliary boost channel falls to the input voltage minus the rectifier drop during fault and shutdown. OUTSU falls to the input voltage minus the synchronous rectifier body diode drop during shutdown, and also during fault if the input voltage exceeds 2.5V. If the input voltage is less than 2.5V, OUTSU remains at 2.5V due to operation of the startup oscillator, but can source only limited current. Reference The MAX1565 has an internal 1.250V reference. Connect a 0.1µF ceramic bypass capacitor from REF to GND within 0.2in (5mm) of the REF pin. REF can source up to 200µA and is enabled whenever ONSD is high and OUTSD is above 2.5V. The auxiliary controllers and MAX1801 slave controllers (if connected) each sink up to 30µA REF current during startup. If the application requires that REF be loaded beyond 200µA, it may be buffered with a unity-gain amplifier or op amp. Oscillator All MAX1565 DC-to-DC converter channels employ fixed-frequency PWM operation. The operating frequency is set by an RC network at the OSC pin. The range of usable settings is 100kHz to 1MHz. When MAX1801 slave controllers are added, they operate at the same frequency set by OSC. The oscillator uses a comparator, a 300ns one-shot, and an internal N-FET switch in conjunction with an external timing resistor and capacitor (Figure 4). When the switch is open, the capacitor voltage exponentially approaches the step-up output voltage from zero with a time constant given by the ROSCCOSC product. The comparator output switches high when the capacitor voltage reaches VREF (1.25V). In turn, the one-shot activates the internal MOSFET switch to discharge the capacitor within a 300ns interval, and the cycle repeats. Note that the oscillation frequency changes as the main output voltage ramps upward following startup. The oscillation frequency is constant once the main output is in regulation. VOUTSU ROSC OSC COSC VREF (1.25V) 300ns ONE-SHOT MAX1565 Figure 4. Master Oscillator 16 ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Soft-Start The MAX1565 step-down and AUX_ channels feature a soft-start function that limits inrush current and prevents excessive battery loading at startup by ramping the output voltage to the regulation voltage. This is achieved by increasing the internal reference inputs to the controller transconductance amplifiers from 0V to the 1.25V reference voltage over 4096 oscillator cycles (8ms at 500kHz) when initial power is applied or when a channel is enabled. Soft-start is not included in the step-up converter in order to avoid limiting startup capability with loading. Shutdown The step-up converter is activated with a high input at ONSU. The step-down and auxiliary DC-to-DC converters 1, 2, and 3 activate with a high input at ONSD, ON1, ON2, and ON3, respectively. The auxiliary controllers and step-down cannot be activated until OUTSU is in regulation. For automatic startup, connect ON_ to OUTSU or a logic level greater than 1.6V. Design Procedure Setting the Switching Frequency Choose a switching frequency to optimize external component size or circuit efficiency for any particular MAX1565 application. Typically, switching frequencies between 300kHz and 600kHz offer a good balance between component size and circuit efficiency. Higher frequencies generally allow smaller components and lower frequencies give better conversion efficiency. The switching frequency is set with an external timing resistor (ROSC) and capacitor (COSC). At the beginning of a cycle, the timing capacitor charges through the resistor until it reaches VREF. The charge time, t1, is: t1 = -ROSCCOSC ln [1 - 1.25/VOUTSU] Table 1. Voltage Setting Summary CHANNEL FB_ FB THRESHOLD (FBSEL_ LOW) FBSU 3.35V FBSD 1.5V FB1 FB2 FB2 FB THRESHOLD (FBSEL_ HIGH) 1.25V 5V Always 1.25V (FBSEL is not provided for these channels) The capacitor voltage is then given time (t2 = 300ns) to discharge. The oscillator frequency is fOSC = 1/(t1 + t2) fOSC can operate from 100kHz to 1MHz. Choose COSC between 47pF and 470pF. Determine ROSC from the equation: ROSC = (300ns - 1/fOSC)/(COSC ln [1 - 1.25/VOUTSU]) See the Typical Operating Characteristics for fOSC versus ROSC using different values of COSC. Setting Output Voltages The MAX1565 step-up/step-down converters and the AUX1 controllers have both factory-set and adjustable output voltages. These are selected by FBSEL_ for the appropriate channel. When FBSEL_ is low, the channel output regulates at its preset voltage. When FBSEL_ is high, the channel regulates FB_ at 1.25V for use with external feedback resistors. When setting the voltage for auxiliary channels 2 and 3, or when using external feedback at FBSU, FBSD, or FB1, connect a resistive voltage-divider from the output voltage to the corresponding FB_ input. The FB_ input bias current is less than 100nA, so choose the low-side (FB_to-GND) resistor (RL), to be 100kΩ or less. Then calculate the high-side (output-to-FB_) resistor (RH) using: RH = RL [(VOUT/1.25) - 1] General Filter Capacitor Selection The input capacitor in a DC-to-DC converter reduces current peaks drawn from the battery, or other input power source, and reduces switching noise in the controller. The impedance of the input capacitor at the switching frequency should be less than that of the input source so that high-frequency switching currents do not pass through the input source. ______________________________________________________________________________________ 17 MAX1565 Low-Voltage Startup Oscillator The MAX1565 internal control and reference-voltage circuitry receive power from OUTSU and do not function when OUTSU is less than 2.5V. To ensure low-voltage startup, the step-up employs a low-voltage startup oscillator that activates at 0.9V. The startup oscillator drives the internal N-channel MOSFET at LXSU until OUTSU reaches 2.5V, at which point voltage control is passed to the current-mode PWM circuitry. Once in regulation, the MAX1565 operates with inputs as low as 0.7V since internal power for the IC is supplied by OUTSU. At low input voltages, the MAX1565 can have difficulty starting into heavy loads. MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply The output capacitor keeps output ripple small and ensures control-loop stability. The output capacitor must also have low impedance at the switching frequency. Ceramic, polymer, and tantalum capacitors are suitable, with ceramic exhibiting the lowest ESR and high-frequency impedance. Output ripple with a ceramic output capacitor is approximately: VRIPPLE = IL(PEAK) [1/(2π fOSC COUT)] If the capacitor has significant ESR, the output ripple component due to capacitor ESR is: VRIPPLE(ESR) = IL(PEAK) ESR Output capacitor specifics are also discussed in the Step-Up Compensation section and the Step-Down Compensation section. Step-Up Component Selection The external components required for the step-up are an inductor, input and output filter capacitor, and compensation RC. Typically, the inductor is selected to operate with continuous current for best efficiency. An exception might be if the step-up ratio, (VOUT/VIN), is greater than 1/(1 - DMAX), where DMAX is the maximum PWM duty factor of 80%. When using the step-up channel to boost from a low input voltage, loaded startup is aided by connecting a Schottky diode from the battery to OUTSU. See the Minimum Startup Voltage vs. Load Current graph in the Typical Operating Characteristics. Step-Up Inductor In most step-up designs, a reasonable inductor value (LIDEAL) can be derived from the following equation, which sets continuous peak-to-peak inductor current at one-half the DC inductor current: LIDEAL = [2 VIN(MAX) D(1 - D)] / (IOUT fOSC) where D is the duty factor given by: D = 1 - (VIN / VOUT) Given LIDEAL, the consistent peak-to-peak inductor current is 0.5 I OUT /(1 - D). The peak inductor current, IIND(PK) = 1.25 IOUT / (1 - D). Inductance values smaller than L IDEAL can be used to reduce inductor size. However, if much smaller values are used, the inductor current rises and a larger output capacitance may be required to suppress output ripple. 18 Step-Up Compensation The inductor and output capacitor are usually chosen first in consideration of performance, size, and cost. The compensation resistor and capacitor are then chosen to optimize control-loop stability. In some cases it may help to readjust the inductor or output capacitor value to get optimum results. For typical designs, the component values in the circuit of Figure 1 yield good results. The step-up converter employs current-mode control, thereby simplifying the control-loop compensation. When the converter operates with continuous inductor current (typically the case), a right-half-plane zero (RHPZ) appears in the loop-gain frequency response. To ensure stability, the control-loop gain should crossover (drop below unity gain) at a frequency (fC) much less than that of the right-half-plane zero. The relevant characteristics for step-up channel compensation are: 1) Transconductance (from FBSU to COMPSU), gmEA (135µS) 2) Current-sense amplifier transresistance, R CS , (0.3V/A) 3) Feedback regulation voltage, VFB (1.25V) 4) Step-up output voltage, VSUOUT, in V 5) Output load equivalent resistance, R LOAD , in Ω = VSUOUT/ILOAD The key steps for step-up compensation are: 1) Place fC sufficiently below the RHPZ and calculate CC. 2) Select RC based on the allowed load-step transient. RC sets a voltage delta on the COMP pin that corresponds to load current step. 3) Calculate the output filter capacitor (C OUT ) required to allow the RC and CC selected. 4) Determine if CP is required (if calculated to be > 10pF). For continuous conduction, the right-plane zero frequency (fRHPZ) is given by: fRHPZ = VOUTSU (1 - D)2 / (2π L ILOAD) where D = the duty cycle = 1 - (VIN/VOUT), L is the inductor value, and ILOAD is the maximum output current. Typically target crossover (fC) for 1/6 the RHPZ. For example, if we assume VIN = 2V, VOUT = 3.35V, and I OUT = 0.5A, then R LOAD = 6.7Ω. If we select L = 3.3µH then: fRHPZ = 3.35 (2/3.35)2 / (2π x 4.7 x 10-6 x 0.5) = 115kHz ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply Choose 6.8nF. Now select RC such that transient droop requirements are met. For example, if 4% transient droop is allowed, the input to the error amplifier moves 0.04 x 1.25V, or 50mV. The error amp output drives 50mV x 135µS, or 6.75µA, across RC to provide transient gain. Since the current-sense transresistance is 0.3V/A, the value of RC that allows the required load step swing: RC = 0.3 IIND(PK)/6.75µA In a step-up DC-to-DC converter, if LIDEAL is used, output current relates to inductor current by: IIND(PK) = 1.25 IOUT/(1 - D) = 1.25 IOUT VOUT/VIN Thus, for a 400mA output load step with VIN = 2V and VOUT = 3.35V: RC = [1.25(0.3 x 0.4 x 3.35)/2)]/6.75µA = 37kΩ Note that the inductor does not limit the response in this case since it can ramp at 2V/3.3µH, or 606mA/µs. The output filter capacitor is then chosen so that the COUT RLOAD pole cancels the RC CC zero: COUT RLOAD = RCCC For example: COUT = 37kΩ x 6.8nF/6.7 = 37.5µF Since a reasonable value for COUT is 47µF rather than 37.5, choose 47µF and rescale RC: RC = 47µF x 6.7/6.8nF = 46.3kΩ which provides a slightly higher transient gain and consequently less transient droop than previously selected. If the output filter capacitor has significant ESR, a zero occurs at: ZESR = 1/(2π COUT RESR) If ZESR > fC, it can be ignored, as is typically the case with ceramic output capacitors. If ZESR is less than fC, it should be cancelled with a pole set by capacitor CP connected from COMPSU to GND: CP = COUT RESR/RC If CP is calculated to be < 10pF, it can be omitted. Step-Down Component Selection Step-Down Inductor The external components required for the step-down are an inductor, input and output filter capacitors, and compensation RC network. The MAX1565 step-down converter provides best efficiency with continuous inductor current. A reasonable inductor value (LIDEAL) can be derived from: LIDEAL = 2 (VIN) D (1 - D)/(IOUT fOSC) which sets the peak-to-peak inductor current at 1/2 the DC inductor current. D is the duty cycle: D = VOUT/VIN Given LIDEAL, the peak-to-peak inductor current variation is 0.5 IOUT. The absolute peak inductor current is 1.25 IOUT. Inductance values smaller than LIDEAL can be used to reduce inductor size. However, if much smaller values are used, inductor current rises and a larger output capacitance may be required to suppress output ripple. Larger values than LIDEAL can be used to obtain higher output current, but with typically larger inductor size. Step-Down Compensation The relevant characteristics for step-down compensation are: 1) Transconductance (from FBSD to COMPSD), gmEA (135µS) 2) Step-down slope compensation pole, P SLOPE = VIN / (πL) 3) Current-sense amplifier transresistance, R CS , (0.6V/A) 4) Feedback regulation voltage, VFB (1.25V) 5) Step-down output voltage, VSD, in V 6) Output load equivalent resistance, R LOAD , in Ω = VOUTSD/ILOAD The key steps for step-down compensation are: 1) Set the compensation RC zero to cancel the RLOAD COUT pole. 2) Set the loop crossover below the lower of 1/5 the slope compensation pole, or 1/5 the switching frequency. If we assume VIN = 3.35V, VOUT = 1.5V, and IOUT = 350mA, then RLOAD = 4.3Ω. ______________________________________________________________________________________ 19 MAX1565 Choose fC = 20kHz. Calculate CC: CC = (VFB/VOUT)(RLOAD/RCS)(gm/2π fC)(1 - D) = (1.25/3.35)(6.7/0.3) x (135µS/(6.28 x 20kHz) (2/3.35) = 5.35nF MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply If we select L = 4.7µH and fOSC = 440kHz, PSLOPE = VIN/(πL) = 214kHz, so choose fC = 40kHz and calculate CC: CC = (VFB/VOUT)(RLOAD/RCS)(gm/2π fC) = (1.25/1.5)(4.3/0.6) x (135µS/(6.28 x 40kHz) = 3.2nF Choose 3.3nF. Now select RC such that transient droop requirements are met. For example, if 4% transient droop is allowed, the input to the error amplifier moves 0.04 x 1.25V, or 50mV. The error amp output drives 50mV x 135µS, or 6.75µA across RC to provide transient gain. Since the current-sense transresistance is 0.6V/A, the value of RC that allows the required load step swing: RC = 0.6 IIND(PK)/6.75µA In a step-down DC-to-DC converter, if LIDEAL is used, output current relates to inductor current by: IIND(PK) = 1.25 IOUT Thus, for a 250mA output load step with VIN = 3.35V and VOUT = 1.5V: RC = (1.25 x 0.6 x 0.25)/6.75µA = 27.8kΩ Choose 27kΩ. Note that the inductor does not limit the response in this case since it can ramp at (V IN VOUT)/4.7µH, or (3.35 - 1.5)/4.7µH = 394mA/µs. The output filter capacitor is then chosen so that the COUT RLOAD pole cancels the RC CC zero: COUTRLOAD = RCCC For example: COUT = 27kΩ x 3.3nF/4.3 = 20.7µF Choose 22µF. If the output filter capacitor has significant ESR, a zero occurs at: ZESR = 1/(2π COUTRESR) If ZESR > fC, it can be ignored, as is typically the case with ceramic output capacitors. If ZESR is less than fC, it should be cancelled with a pole set by capacitor CP connected from COMPSD to GND: CP = COUTRESR/RC If CP is calculated to be < 10pF, it can be omitted. 20 Auxiliary Controller Component Selection External MOSFET All MAX1565 auxiliary controllers drive external logiclevel N-channel MOSFETs. Significant MOSFET selection parameters are: 1) On-resistance (RDS(ON)) 2) Maximum drain-to-source voltage (VDS(MAX)) 3) Total gate charge (QG) 4) Reverse transfer capacitance (CRSS) DL_ swings between OUTSU and GND. Use a MOSFET with on-resistance specified at or below the main output voltage. The gate charge, QG, includes all capacitance associated with charging the gate and helps to predict MOSFET transition time between on and off states. MOSFET power dissipation is a combination of on-resistance and transition losses. The on-resistance loss is: PRDSON = D IL2 RDS(ON) where D is the duty cycle, IL is the average inductor current, and RDS(ON) is MOSFET on-resistance. The transition loss is approximately: PTRANS = (VOUT IL fOSC tT)/3 where VOUT is the output voltage, IL is the average inductor current, fOSC is the switching frequency, and tT is the transition time. The transition time is approximately QG/IG, where QG is the total gate charge, and IG is the gate drive current (typically 0.5A). The total power dissipation in the MOSFET is: PMOSFET = PRDSON + PTRANS Diode For most auxiliary applications, a Schottky diode rectifies the output voltage. The Schottky diode’s low forward voltage and fast recovery time provide the best performance in most applications. Silicon signal diodes (such as 1N4148) are sometimes adequate in low-current (<10mA) high-voltage (>10V) output circuits where the output voltage is large compared to the diode forward voltage. Auxiliary Compensation The auxiliary controllers employ voltage-mode control to regulate their output voltage. Optimum compensation somewhat depends on whether the design uses continuous or discontinuous inductor current. ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply To ensure discontinuous operation, the inductor must have a sufficiently low inductance to fully discharge on each cycle. This occurs when: L < [VIN2 (VOUT - VIN)/VOUT3] [RLOAD/(2 fOSC)] A discontinuous current boost has a single pole at: fP = (2VOUT - VIN)/(2π RLOADCOUTVOUT) Choose the integrator capacitor such that the unity-gain crossover (fC) occurs at fOSC/10 or lower. Note that for many auxiliary circuits, such as those powering motors, LEDs, or other loads that do not require fast transient response, it is often acceptable to overcompensate by setting fC at fOSC/20 or lower. CC is then determined by: CC = [2VOUTVIN /((2VOUT - VIN)VRAMP)] [VOUT /(K(VOUT - VIN))]1/2 [(VFB/VOUT) (gM /(2π fC))] where K = 2 L fOSC/RLOAD, and VRAMP is the internal slope compensation voltage ramp of 1.25V. The CCRC zero is then used to cancel the fP pole, so: RC = RLOADCOUTVOUT/[(2VOUT - VIN) CC] Continuous Inductor Current Continuous inductor current can sometimes improve boost efficiency by lowering the ratio between peak inductor current and output current. It does this at the expense of a larger inductance value that requires larger size for a given current rating. With continuous inductor current boost operation, there is a right-plane zero at: fRHPZ = (1 - D)2 RLOAD /(2πL) where (1 - D) = VIN/VOUT (in a boost converter). A complex pole pair is located at: f0 = VOUT/[2π VIN (L COUT)1/2] If the zero due to the output capacitor capacitance and ESR is less than 1/10 the right-plane zero: ZCOUT = 1/(2π COUT RESR) < fRHPZ/10 Choose C C such that the crossover frequency f C occurs at ZCOUT. The ESR zero provides a phase boost at crossover. CC = (VIN/VRAMP)(VFB/VOUT)(gM /(2π ZCOUT)) Choose RC to place the integrator zero, 1/(2π RCCC), at f0 to cancel one of the pole pairs: RC = VIN (L COUT)1/2/(VOUT CC) If ZCOUT is not less than fRHPZ/10 (as is typical with ceramic output capacitors) and continuous conduction is required, then cross the loop over before fRHPZ and f0: fC < f0/10, and fC < fRHPZ/10 In that case: CC = (VIN/VRAMP)(VFB/VOUT)(gM /(2π fC)) Place 1/(2π RCCC) = 1/(2π RLOADCOUT), so that RC = RLOAD COUT/CC or reduce the inductor value for discontinuous operation. Applications Information LED, LCD, and Other Boost Applications Any auxiliary channel can be used for a wide variety of step-up applications. These include generating 5V or some other voltage for motor or actuator drive, generating 15V or a similar voltage for LCD bias, or generating a step-up current source to efficiently drive a series array of white LEDs for display backlighting. Figures 5 and 6 show examples of these applications. TO VBATT 4.7µF 4.7µH 15V 100mA 22µF OUTSU DL_ 1.1MΩ FB_ 100kΩ AUX_ PWM MAX1565 (PARTIAL) Figure 5. Using an AUX_ Controller Channel to Generate LCD Bias ______________________________________________________________________________________ 21 MAX1565 Discontinuous Inductor Current When the inductor current falls to zero on each switching cycle, it is described as discontinuous. The inductor is not utilized as efficiently as with continuous current. This often has little negative impact in light-load applications since the coil losses may already be low compared to other losses. A benefit of discontinuous inductor current is more flexible loop compensation and no maximum duty-cycle restriction on boost ratio. MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply TO VBATT INPUT 1-CELL Li+ 1µF 10µH MAIN OUTSU 1µF IN WHITE LEDs L2 L1 DL_ AUX_ PWM OUTPUT 3.3V DCON DL FB_ D1 C2 Q1 PART OF MAX1565 R1 FB 62Ω (FOR 20mA) MAX1565 (PARTIAL) Figure 6. AUX_ Channel Powering a White LED Step-Up Current Source SEPIC Buck-Boost The MAX1565’s internal switch step-up and step-down can be cascaded to make a high-efficiency buck-boost converter, but it may sometimes be desirable to build a second buck-boost converter with an AUX_ controller. One type of step-up/step-down converter is the SEPIC (Figure 7). Inductors L1 and L2 can be separate inductors or wound on a single core and coupled like a transformer. Typically, a coupled inductor improves efficiency since some power is transferred through the coupling, causing less power to pass through the coupling capacitor (C2). Likewise, C2 should have low ESR to improve efficiency. The ripple current rating must be greater than the larger of the input and output currents. The MOSFET (Q1) drain-to-source voltage rating, and the rectifier (D1) reverse-voltage rating must exceed the sum of the input and output voltages. Other types of step-up/step-down circuits are a flyback converter and a step-up converter followed by a linear regulator. Multiple Output Flyback Circuits Some applications require multiple voltages from a single converter channel. This is often the case when generating voltages for CCD bias or LCD power. Figure 8 shows a two-output flyback configuration with AUX_. The controller drives an external MOSFET that switches the transformer primary. Two transformer secondaries generate the output voltages. Only one positive output voltage can be fed back, so the other voltages are set by the turns ratio of the transformer secondaries. The load stability of the other secondary voltages depends on transformer leakage inductance and winding resistance. Voltage regulation is best when the load on the 22 R2 Figure 7. Auxiliary SEPIC Configuration secondary that is not fed back is small when compared to the load on the one that is. Regulation also improves if the load current range is limited. Consult the transformer manufacturer for the proper design for a given application. Boost with Charge Pump for Positive and Negative Outputs Negative output voltages can be produced without a transformer, using a charge-pump circuit with an auxiliary controller as shown in Figure 9. When MOSFET Q1 turns off, the voltage at its drain rises to supply current to VOUT+. At the same time, C1 charges to the voltage VOUT+ through D1. TO VBATT 1µF 1µF +15V 30mA CCD+ 1.1MΩ 100kΩ AUX_ PWM 1µF OUTSU DL_ -7.5V 20mA CCD*(SEE NOTE) FB_ MAX1565 (PARTIAL) *LOAD RESISTOR REQUIRED IF -7.5V OPERATES WITH NO LOAD Figure 8. +15V and -7.5V CCD Bias with Transformer ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply D2 TO VBATT VOUT+ +15V 20mA C2 1µF 1µF R1 1MΩ FB_ AUX_ PWM OUTSU Q1 DL_ C1 1µF R2 90.9kΩ D3 C3 1µF D1 VOUT-15V 10mA Adding a MAX1801 Slave The MAX1801 is a 6-pin SOT slave DC-to-DC controller that can be connected to generate additional output voltages. It does not generate its own reference or oscillator. Instead, it uses the reference and oscillator of the MAX1565 (Figure 11). The MAX1801 controller operation and design are similar to that of a MAX1565 AUX controller. All comments in the Auxiliary Controller Component Selection section also apply to add-on MAX1801 slave controllers. For more details, refer to the MAX1801 data sheet. MAX1565 (PARTIAL) Figure 9. ±15V Output Using a Boost with Charge-Pump Inversion 10µH +15V 20mA TO VBATT 1µF 1µF 1MΩ FB_ AUX_ PWM 90.9kΩ OUTSU Q1 1µF -7.5V 20mA DL_ 1µF 110kΩ 1µF MAX1565 (PARTIAL) 549kΩ IN SHDN GND OUT FB_ +1.25V MAX1616 Figure 10. +15V and -7.5V CCD Bias without Transformer ______________________________________________________________________________________ 23 MAX1565 L1 10µH When the MOSFET turns on, C1 discharges through D3, thereby charging C3 to V OUT - minus the drop across D3 to create roughly the same voltage as VOUT+ at VOUT- but with inverted polarity. If different magnitudes are required for the positive and negative voltages, a linear regulator can be used at one of the outputs to achieve the desired voltages. One such connection is shown in Figure 10. This circuit is somewhat unique in that a positive output linear regulator is able to regulate the negative output. It does this by controlling the charge to the flying capacitor rather than directly regulating at the output. MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply TO BATT OUTSU VOUT DL IN OSC MAX1801 OSC MAX1565 (PARTIAL) FB COMP GND REF REF DCON Figure 11. Connecting the MAX1801 Slave PWM Controller to the MAX1565 Using SDOK for Power Sequencing SDOK goes low when the step-down reaches regulation. Some microcontrollers with low-voltage cores require that the high-voltage (3.3V) I/O rail not be powered up until the core has a valid supply. The circuit in Figure 12 accomplishes this by driving the gate of a PFET connected between the 3.3V output and the microcontroller I/O supply. Alternately, power sequencing may be implemented by connecting RC networks to the appropriate converter ON_ inputs. MAX1565 (PARTIAL) OUTSUB OUTSUA LXSU STEP-UP Setting OUTSD Below 1.25V where VSD is the output voltage, VFBSD is 1.25V, and VSU is the step-up output voltage. Note that any available voltage that is higher than 1.25V can be used as the connection point for R3 in Figure 13 and for the VSD term in the equation. Since there are multiple solutions for R1, R2, and R3, the above equation cannot be written in terms of one resistor. The best method for determining resistor values is to enter the above equation into a spreadsheet and test estimated resistors’ values. A good starting point is with 100kΩ at R2 and R3. 24 10µH 3.3V TO CPU 10µF The step-down feedback voltage is 1.25V when FBSELSD is high. With a standard two-resistor feedback network, the output voltage may be set to values between 1.25V and the input voltage. If a step-down output voltage less than 1.25V is desired, it can be set by adding a third feedback resistor from FB to a voltage higher than 1.25V (the step-up output is a convenient voltage for this) as shown in Figure 13. The equation governing output voltage shown in Figure 13 is: 0 = [(VSD - VFBSD)/R1] + [(0 - VFBSD)/R2] + [(VSU - VFBSD)/R3] 3.35V TO VBATT PGNDB 1MΩ FBSU 1MΩ SDOK INSD TO VBATT OR OUTSU 10µF LXSD STEP-DOWN 4.7µH VCORE 1.5V 10µF FBSD PGNDA Figure 12. Using SDOK to Gate 3.3V Power to CPU After the Core Voltage is OK ______________________________________________________________________________________ Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply VSU 3.3V OUTSUA OUTSUB FBSELSD MAX1565 (PARTIAL) INSD 10µF LXSD CURRENT-MODE STEP-DOWN 4.7µH VSD 0.8V 22µF PGNDA FBSD R3 100kΩ VFBSD 1.25V R1 56kΩ R2 100kΩ Figure 13. Setting OUTSD for Outputs Below 1.25V Chip Information TRANSISTOR COUNT: 9420 PROCESS: BiCMOS ______________________________________________________________________________________ 25 MAX1565 Designing a PC Board Good PC board layout is important to achieve optimal performance from the MAX1565. Poor design can cause excessive conducted and/or radiated noise. Conductors carrying discontinuous currents, and any high-current path should be made as short and wide as possible. A separate low-noise ground plane containing the reference and signal grounds should connect to the power-ground plane at only one point to minimize the effects of power-ground currents. Typically, the ground planes are best joined right at the IC. Keep the voltage feedback network very close to the IC, preferably within 0.2in (5mm) of the FB_ pin. Nodes with high dV/dt (switching nodes) should be kept as small as possible and should be routed away from high-impedance nodes such as FB_. Refer to the MAX1565EVKIT evaluation kit data sheet for a full PC board example. Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) D2 0.15 C A D b CL 0.10 M C A B D2/2 D/2 PIN # 1 I.D. QFN THIN.EPS MAX1565 Small, High-Efficiency, Five-Channel Digital Still Camera Power Supply k 0.15 C B PIN # 1 I.D. 0.35x45 E/2 E2/2 CL (NE-1) X e E E2 k L DETAIL A e (ND-1) X e CL CL L L e e 0.10 C A C 0.08 C A1 A3 PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE 16, 20, 28, 32L, QFN THIN, 5x5x0.8 mm APPROVAL COMMON DIMENSIONS DOCUMENT CONTROL NO. REV. 21-0140 C 1 2 EXPOSED PAD VARIATIONS NOTES: 1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994. 2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 3. N IS THE TOTAL NUMBER OF TERMINALS. 4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE. 5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm FROM TERMINAL TIP. 6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY. 7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION. 8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS. 9. DRAWING CONFORMS TO JEDEC MO220. 10. WARPAGE SHALL NOT EXCEED 0.10 mm. PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE 16, 20, 28, 32L, QFN THIN, 5x5x0.8 mm APPROVAL DOCUMENT CONTROL NO. REV. 21-0140 C 2 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.