ACT6330_08

ACT6330 Rev0, 02-Apr-08 Dual PWM Step-Up DC/DCs in TQFN33 FEATURES • Multiple Patents Pending • Two Integrated Regulators − PWM Step-Up DC/DC with OVP for WLED Bias − PWM Step-Up DC/DC Converter with OVP GENERAL DESCRIPTION The patent-pending ACT6330 integrates two stepup DC/DC into a single, thin, space-saving package to provide a cost-effective, highly-efficient ActivePMUTM power management solution. This device is ideal for a wide range of portable handheld equipment that can benefit from the advantages of ActivePMU technology but does not require a high level of integration. REG1 and REG2 are fixed-frequency, current mode PWM step-up DC/DC converter. REG1 is optimized for high-efficiency WLED bias applications. REG2 is optimized for voltage regulation applications, while together these output can provide a complete TFT bias and backlighting solution for portable handheld equipment. The ACT6330 is available in a tiny 3mm x 3mm 16 pin Thin-QFN package that is just 0.75mm thin. • Independent Enable/Disable Control • Minimal External Components • 3×3mm, Thin-QFN (TQFN33-16) Package − Only 0.75mm Height − RoHS Compliant APPLICATIONS • • • • Portable Devices and PDAs MP3/MP4 Players Wireless Handhelds GPS Receivers SYSTEM BLOCK DIAGRAM Battery REG1 Step-Up DC/DC System Control OUT1 WLED Bias Up to 18 LEDs ON1 ON2 Pb-free REG2 ACT6330 Active Step-Up DC/DC OUT2 Up to 20V PMU TM Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -1- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 FUNCTIONAL BLOCK DIAGRAM Rev0, 02-Apr-08 ACT6330 IN UVLO To Battery SW1 OVP1 OUT1 ON1 REG1 FB1 GP12 ON2 SW2 OVP2 REG2 FB2 GP12 To Battery OUT2 GA Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -2- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 ORDERING INFORMATION PART NUMBER ACT6330QK-T Rev0, 02-Apr-08 PACKAGE TQFN33-16 PINS 16 TEMPERATURE RANGE -40°C to +85°C All Active-Semi product are offered in lead-free RoHS Compliant packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS (Restriction of Hazardous Substances) standards. PIN CONFIGURATION TOP VIEW GA 16 GA GA GA FB1 1 2 3 4 5 6 15 ACT6330 EP 7 8 GA SW1 14 GA 13 12 11 10 9 ON1 ON2 FB2 OVP2 IN Thin - QFN (TQFN 33-16) OVP1 SW2 GP12 Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -3- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 PIN DESCRIPTIONS PIN 1, 2, 3, 14, 15, 16 4 5 6 7 8 9 10 11 12 13 EP Rev0, 02-Apr-08 NAME GA FB1 OVP1 SW1 GP12 SW2 OVP2 FB2 ON2 ON1 IN EP DESCRIPTION Analog Ground. Connect GAs directly to a quiet ground node. Connect GAs and GP12 together at a single point as close to the IC as possible. Feedback Sense for REG1. Connect this pin to the LED string current sense resistor to sense the LED current. Over-Voltage Protection Input for REG1. Connect this pin directly to the output node to sense and prevent over-voltage conditions. Switching Node Output for REG1. Connect this pin to the switching end of the inductor. Power Ground for REG1, REG2. Connect GP12 directly to a power ground plane. Connect GAs and GP12 together at a single point as close to the IC as possible. Switching Node Output for REG2. Connect this pin to the switching end of the inductor. Over-Voltage Protection Input for REG2. Connect this pin directly to the output node to sense and prevent over-voltage conditions. Feedback Sense for REG2. Connect this pin to the center point of a resistive voltage divider to sense output voltage. Enable Control Input for REG2. Drive ON2 to IN or to a logic high for normal operation, drive to GA or a logic low to disable REG2. Enable Control Input for REG1. Drive ON1 to IN or to a logic high for normal operation, drive to GA or a logic low to disable REG1. Power Input for the IC. Bypass IN to GA with a capacitor placed as close as possible to the IC. Exposed Pad. Must be soldered to ground on the PCB. Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -4- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 ABSOLUTE MAXIMUM RATINGS PARAMETER IN, ON1, ON2, FB1, FB2 to GA OVP1, OVP2, SW1, SW2 to GP12 GP12 to GA Junction to Ambient Thermal Resistance (θJA) Operating Temperature Range Junction Temperature Store Temperature Lead Temperature (Soldering, 10 sec) Rev0, 02-Apr-08 VALUE -0.3 to +6 -0.3 to +25 -0.3 to +0.3 33.3 -40 to 85 125 -55 to 150 300 UNIT V V V °C/W °C °C °C °C : Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability. Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -5- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 WLED BIAS DC/DC CONVERTER (REG1) ELECTRICAL CHARACTERISTICS ( VIN = 3.6V, TA = 25°C, unless otherwise specified.) Rev0, 02-Apr-08 PARAMETER IN Operating Voltage Range UVLO Voltage Threshold UVLO Hysteresis Supply Current FB1 Feedback Voltage FB1 Input Current Oscillator Frequency Minimum On-Time Maximum Duty Cycle Switch Current Limit Switch On-Resistance Switch Leakage Current Logic High Input Voltage Logic Low Input Voltage ON1 Leakage Current Over-Voltage Threshold Thermal Shutdown Temperature Thermal Shutdown Hysteresis TEST CONDITIONS IN Voltage Rising IN Voltage Falling ON1 = IN, VFB1 = 0.3V ON1 = GA, ILOAD = 0mA MIN 3.1 2.9 TYP 3 100 75 0.1 MAX 6 3.1 UNIT V V mV 150 1 0.275 µA µA V nA 0.235 0.255 50 1.35 1.6 100 1.85 MHz ns % mA 87 Duty = 83%, L1 = 22uH, COUT1 = 4.7uF ISW1 = 100mA VSW1 = 25V, ON1 = GA ON1 ON1 VON1 = 0V to 5.5V 21 Temperature rising Temperature falling 1.4 500 92 750 0.67 1.1 10 Ω µA V 0.4 1 22 160 20 23 V µA V °C °C Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -6- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 WLED BIAS DC/DC CONVERTER (REG1) FUNCTIONAL DESCRIPTION General Description REG1 is highly efficient step-up DC/DC converter that employs a fixed frequency, current-mode, PWM architecture. This regulator is optimized for white-LED bias applications consisting of up to six white-LEDs. Rev0, 02-Apr-08 Inductor Selection REG1 has been designed to provide excellent performance across a wide range of applications, allowing a design to be optimized for both a small footprint as well as for achieving the highest possible efficiency. REG1 was designed for operation with inductor in the 10µH to 22µH range, in order to achieve a small footprint , although larger inductor values of up to 68µH can be used in order to optimize a design to achieve the highest possible efficiency. Optimizing for Smallest Footprint REG1 is capable of operating with very low inductor values in order to achieve the smallest possible footprint . When solution size is of primary concern, best results are achieved when an inductance value that ensures discontinuous conduction mode (DCM) operation over the full load current range is used. Optimizing for Highest Efficiency REG1 achieves excellent efficiency in applications that demand the longest possible battery life. When efficiency is the primary design consideration, best results are achieved when an inductance value that both results in continuous conduction mode (CCM) operation and achieves a very small inductor ripple current is chosen. Over-Voltage Protection REG1 features internal over-voltage protection (OVP) circuitry which protects the system from LED open-circuit fault conditions. The ACT6330’s OVP threshold is set at 22V, and if necessary, regulates the voltage at the top of the LED string to ensure that it never exceeds this voltage. REG1 requires a 10kΩ resistor connected from output capacitor to OVP1 pin. Thermal Shutdown Protection The ACT6330 integrates thermal shutdown protection circuitry to prevent damage resulting from excessive thermal stress, as may be encountered under fault conditions. This circuitry disables all regulators if the ACT6330 die temperature exceeds 160°C, and prevents the regulators from being enabled until the IC temperature drops by 20°C (typ). Enabling and Disabling REG1 REG1 is enabled or disabled using ON1. Drive ON1 to a logic-high to enable REG1. Drive ON1 to a logic-low to disable REG1, reducing supply current to less than 1µA. As with all non-synchronous stepup DC/DC converter, REG1’s application circuit procedures a DC current path between the input and the output in shutdown mode. Although the forward drop of the WLEDs makes this leakage current very small in most applications, it is important to consider the effect that this may have in your application particularly when using fewer than three WLEDs. Output Capacitor Selection REG1 is designed to operate with output capacitors ranging from 1µF to 10µF, providing design flexibility. A 1µF output capacitor is suitable for most applications, although larger output capacitors may be used to minimize output voltage ripple, if needed. Ceramic capacitors are recommended for most applications. Rectifier Selection REG1 requires a Shottky diode to rectify the inductor current. Select a low forward voltage drop Shottky diode with a forward current (IF) rating that is sufficient to support the maximum switch current and a sufficient peak repetitive reverse voltage (VRRM) to support the output voltage. Compensation and Stability REG1 utilizes current-mode control and an internal compensation network to optimize transient performance, ease compensation, and improve stability over a wide range of operating conditions. REG1 is a flexible regulator, and with just a simple component, choice can be optimized to achieve minimum total solution size in applications that require the smallest possible footprint, or can be optimized to achieve the highest possible efficiency. Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -7- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 WLED BIAS DC/DC CONVERTER (REG1) Setting the LED Bias Current The LED bias current is set by a resistor connected from FB1 and ground, and regulator is satisfied when the LED current is sufficient to generate 250mV across this resistor. Once the bias current is programmed, the LED current can be adjusted using the ACT6330’s Direct-PWM feature. REG1 is also compatible with a variety of well-know LED dimming circuit, such as with a DC control voltage and a filtered PWM signal. Rev0, 02-Apr-08 Board Layout Typical for all switching power supplies, the layout is an important step in design, especially at high peak current and switching frequencies, please refer to PCB Layout Consideration for more information. Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -8- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 WLED BIAS DC/DC CONVERTER (REG1) TYPICAL PERFORMANCE CHARACTERISTICS (ACT6330QK, VIN = 3.6V, L = 22µH, CIN = 2.2µF, COUT= 2.2µF, TA = 25°C, unless otherwise specified.) Rev0, 02-Apr-08 REG1 Efficiency vs. Output Current Normalized Output Current (%) 100 4 LEDs 90 100 90 80 70 60 50 40 30 20 10 0 0 ACT6330-001 PWM Output Current Adjustment ACT6330-002 ON1 PWM Frequency = 1kHz Efficiency (%) 6 LEDs 80 70 60 50 1 5 9 13 17 21 25 31 10 20 30 40 50 60 70 80 90 100 Output Current (mA) ON1 Duty Cycle (%) REG1 RDSON 900 800 700 ACT6330-003 REG1 Over-Voltage Protection ACT6330-004 CH1 RDSON (mΩ) 600 500 400 300 200 2.5 3.0 3.5 4.0 4.5 5.0 5.5 CH1: VOUT1, 10V/div CH2: VFB1, 200mV/div TIME: 2ms/div CH2 0V IN Voltage (V) REG1 Startup Waveform ACT6330-005 CH1 0V CH2 0V CH1: VOUT1, 10V/div CH2: VON1, 1V/div TIME: 100µs/div Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. -9- www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 STEP-UP DC/DC CONVERTER (REG2) ELECTRICAL CHARACTERISTICS ( VIN = 3.6V, TA = 25°C, unless otherwise specified.) Rev0, 02-Apr-08 PARAMETER IN Operating Voltage Range UVLO Voltage Threshold UVLO Hysteresis Supply Current FB2 Feedback Voltage FB2 Input Current Oscillator Frequency Minimum On-Time Maximum Duty Cycle Switch Current Limit Switch On-Resistance Switch Leakage Current Logic High Input Voltage Logic Low Input Voltage ON2 Leakage Current Over-Voltage Threshold Thermal Shutdown Temperature Thermal Shutdown Hysteresis TEST CONDITIONS IN Voltage Rising IN Voltage Falling ON2 = IN, VFB2 = 0.3V ON2 = GA, ILOAD = 0mA MIN 3.1 2.9 TYP 3 100 75 0.1 MAX 6 3.1 UNIT V V mV 150 1 1.27 µA µA V nA 1.23 1.25 50 1.35 1.6 100 1.85 MHz ns % mA 87 Duty = 83%, L2 = 22uH, COUT2 = 4.7uF ISW2 = 100mA VSW2 = 25V, ON2 = GA ON2 ON2 VON2 = 0V to 5.5V 21 Temperature rising Temperature falling 1.4 500 92 750 0.67 1.1 10 Ω µA V 0.4 1 22 160 20 23 V µA V °C °C Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. - 10 - www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 STEP-UP DC/DC CONVERTER (REG2) FUNCTIONAL DESCRIPTION General Description REG2 is a highly efficient step-up DC/DC converter that employs a fixed frequency, current-mode, PWM architecture. This regulator is optimized for use in a wide range of applications including generation constant voltage of up to 20V. Rev0, 02-Apr-08 nent, choice can be optimized to achieve minimum total solution size in applications that require the smallest possible footprint, or can be optimized to achieve the highest possible efficiency. Figure 1: REG2 Startup Waveform into no load ACT6330-006 CH2 Over-Voltage Protection REG2 features internal over-voltage protection (OVP) circuitry which protects the system from fault conditions. The ACT6330’s OVP threshold is set at 22V, and if necessary, regulates the output voltage to ensure that it never exceeds this voltage. ACT6330 requires a 10kΩ resistor connected from output capacitor to OVP2 pin. CH1 CH1: VON2, 2V/div CH2: VOUT2, 5V/div TIME: 250µs/div Thermal Protection The Thermal shutdown protection prevents excessive thermal stress, please refer to Thermal Shutdown Protection for more information. Figure 2: REG2 Startup Waveform into full load ACT6330-007 CH2 Enabling and Disabling REG2 REG2 is enabled or disabled using ON2. Drive ON2 to a logic-high to enable REG2. Drive ON2 to a logic-low to disable REG2, reducing supply current to less than 1µA. As with all non-synchronous stepup DC/DC converter, REG2’s application circuit procedures a DC current path between the input and the output in shutdown mode. It is important to consider the effect that this may have in your application. CH1 CH1: VON2, 2V/div CH2: VOUT2, 5V/div TIME: 250µs/div Output Voltage Selection Figure 3 shows the feedback network necessary to set the output voltage when using the adjustable voltage option. Select components as follows: Set RFB2 = 51kΩ, then caculate RFB1 using the following equation: ⎛ R⎞ VOUT 2 = VFB2 ⎜1 + FB1 ⎟ ⎜R⎟ FB2 ⎠ ⎝ Soft-start REG2 includes soft-start circuitry. When enabled, the output voltage of REG2 tracks an internal 80µs soft-start ramp. As seen in Figure 1 and Figure 2, the output tracks the internal soft-start ramp and powers up in a monotonic maner that is independent of loading. This circuitry ensures that the output powers up in a controlled maner, greatly simplifying power turn-on design considerations. (1) Where VFB2 is 1.25V. Figure 3: Output Voltage Setting V OUT2 ACT6330 FB2 R FB2 R FB1 Compensation and Stability REG2 utilizes current-mode control and an internal compensation network to optimize transient performance, ease compensation, and improve stability over a wide range of operating conditions. REG2 is a flexible regulator, and with just a simple compoInnovative PowerTM ActivePMUTM is a trademark of Active-Semi. - 11 - www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 STEP-UP DC/DC CONVERTER (REG2) FUNCTIONAL DESCRIPTION CONT’D Inductor Selection REG2 has been designed to provide excellent performance across a wide range of applications, allowing a design to be optimized for both a small footprint as well as for achieving the highest possible efficiency. Optimizing for Smallest Footprint REG2 is capable of operating with very low inductor values in order to achieve the smallest possible footprint . When solution size is of primary concern, best results are achieved when an inductance value that ensures discontinuous conduction mode (DCM) operation over the full load current range is used. Optimizing for Highest Efficiency REG2 achieves excellent efficiency in applications that demand the longest possible battery life. When efficiency is the primary design consideration, best results are achieved when an inductance value that both results in continuous conduction mode (CCM) operation and achieves a very small inductor ripple current is chosen. Table 1 provides recommended inductance values. Table 1: Recommended Inductance Values Output Voltage (V) 9 12 18 L (µH) 10 15 22 Rev0, 02-Apr-08 Rectifier Selection REG2 requires a Shottky diode to rectify the inductor current. Select a low forward voltage drop Shottky diode with a forward current (IF) rating that is sufficient to support the maximum switch current and a sufficient peak repetitive reverse voltage (VRRM) to support the output voltage. PCB Layout Considerations High switching frequencies and large peak currents make PC board layout a very important part of the design. Good design minimizes excessive EMI on the feedback paths and voltage gradients in the ground plane, both of which can result in instability or regulation errors. Step-up DC/DCs exhibit continuous input current, so there is some amount of flexibility in placing vias in the input capacitor circuit. The input capacitor should be placed as close as possible to the input pin for good input voltage filtering. The inductor, input filter capacitor, rectifier, and output filter capacitor should be connected as close together as possible, with short, direct, and wide traces. Avoid using vias in the high-current path. If vias are unavoidable , use many vias in parallel to reduce resistance and inductance. Place all feedback voltage-divider resistor as close as possible to their respective feedback pins. Connect the ground nodes together in a star configuration, with a direct connection to the exposed pad. Route high-speed switching nodes away from the sensitive analog areas. Finally, the exposed pad should be directly connected to the backside ground plane using multiple vias to achieve low electrical and thermal resistance. Note that since the LED string is a low, DC-current path, it does not generally require special layout consideration. Output Capacitor Selection REG2 is designed to operate with output capacitor ranging from 1µF to 10µF. A 2.2µF output capacitor is suitable for most applications, although lager output capacitor may be used to minimize output ripple, if need. Ceramic capacitors are recommended for most applications. Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. - 12 - www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 STEP-UP DC/DC CONVERTER (REG2) TYPICAL PERFORMANCE CHARACTERISTICS (ACT6330QK, VIN = 3.6V, L = 22µH, CIN = 2.2µF, COUT = 2.2µF, TA = 25°C, unless otherwise specified.) Rev0, 02-Apr-08 REG2 Efficiency vs. Output Current 100 VOUT2 = 12V 90 4.2V ACT6330-008 Efficiency (%) 80 3.6V 70 60 50 40 30 0 50 100 150 200 Output Current (mA) REG2 RDSON 900 800 700 ACT6330-009 RDSON (mΩ) 600 500 400 300 200 2.5 3.0 3.5 4.0 4.5 5.0 5.5 3.0 3.5 4.0 4.5 5.0 IN Voltage (V) REG2 Over-Voltage Protection ACT6330-010 CH1 CH2 0V CH1: VOUT2, 10V/div CH2: VFB2, 200mV/div TIME: 2ms/div Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. - 13 - www.active-semi.com Copyright © 2008 Active-Semi, Inc. ACT6330 PACKAGE INFORMATION PACKAGE OUTLINE TQFN33-16 PACKAGE OUTLINE AND DIMENSIONS Rev0, 02-Apr-08 D SYMBOL A A1 E DIMENSION IN MILLIMETERS MIN 0.700 0.000 0.153 2.900 2.900 1.600 1.600 0.180 DIMENSION IN INCHES MIN 0.028 0.000 0.006 0.114 0.114 0.063 0.063 0.007 MAX 0.800 0.050 0.253 3.100 3.100 1.800 1.800 0.300 MAX 0.031 0.002 0.010 0.122 0.122 0.071 0.071 0.012 A3 D E D2 E2 b e 0.500 TYP 0.300 0.200 0.500 0.400 0.020 TYP 0.012 0.008 0.020 0.016 e L K E2 Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use as critical components in lifesupport devices or systems. Active-Semi, Inc. does not assume any liability arising out of the use of any product or circuit described in this datasheet, nor does it convey any patent license. Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact sales@activesemi.com or visit http://www.active-semi.com. For other inquiries, please send to: 1270 Oakmead Parkway, Suite 310, Sunnyvale, California 94085-4044, USA Innovative PowerTM ActivePMUTM is a trademark of Active-Semi. - 14 - www.active-semi.com Copyright © 2008 Active-Semi, Inc.