KB3426 (Kingbor Technology) - 800mA Synchronous Step-Down Regulator (KB3426.pdf)

Kingbor Technology

Description
Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3426 1.5MHz, 800mA Synchronous Step-Down Regulator in SOT23-5 FEATURES High Efficiency: Up to 96% Very Low Quiescent Current: Only 20µA www.DataSheet4U.com During Operation ■ 800mA Output Current ■ 2.5V to 6.5V Input Voltage Range ■ 1.5MHz Constant Frequency Operation ■ No Schottky Diode Required ■ Low Dropout Operation: 100% Duty Cycle ■ 0.6V Reference Allows Low Output Voltages ■ Shutdown Mode Draws 1µA Supply Current ■ Current Mode Operation for Excellent Line and Load Transient Response ■ Overtemperature Protected ■ Low Profile (1mm) SOT23-5 Package ■ ■ DESCRIPTION The KB3426 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.8V and 3.3V. Supply current during operation is only 20µA and drops to 1µA in shutdown. The 2.5V to 5.5V input voltage range makes the KB3426 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The KB3426 is available in a low profile (1mm) SOT23-5 package. APPLICATIONS ■ ■ ■ ■ ■ ■ Cellular Telephones Personal Information Appliances Wireless and DSL Modems Digital Still Cameras MP3 Players Portable Instruments TYPICAL APPLICATION 95 90 VIN 3.6V TO 6.5V 4.7µH COUT 10µF CER 5 VOUT 3.3V 800mA VIN = 3.6V 85 EFFICIENCY (%) 4 + CIN 4.7µF Tan 1 VIN SW 3 VIN = 3.8V 80 VIN = 4.2V 75 70 65 60 0.1 VOUT = 3.3V 1 10 100 OUTPUT CURRENT (mA) 1000 KB3426-3.3 RUN VOUT 2 GND Figure 1a. High Efficiency Step-Down Converter Figure 1b. Efficiency vs Load Current 1 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3426 Peak SW Sink and Source Current ........................ 1.3A Operating Temperature Range (Note 2) .. – 40°C to 85°C Junction Temperature (Note 3) ............................ 125°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage .................................. – 0.3V to 6.5V RUN, VFB Voltages ..................................... – 0.3V to VIN SW Voltage .................................. – 0.3V to (VIN + 0.3V) P-Channel Switch Source Current (DC) ............. 800mA N-Channel Switch Sink Current (DC) ................. 800mA www.DataSheet4U.com PACkAGE/ORDER INFORMATION TOP VIEW RUN 1 GND 2 SW 3 5 VFB 4 VIN ORDER PART NUMBER KB3426-ADJ Top Marking TOP VIEW RUN 1 GND 2 SW 3 5 VOUT 4 VIN ORDER PART NUMBER KB3426B-3.3 Top Marking Marking S5 PACKAGE 5-LEAD PLASTIC SOT-23 Marking JA = 250°C/ W, TJMAX = 125°C, JC = 90°C/ W A17x A16x x: date code S5 PACKAGE 5-LEAD PLASTIC SOT-23 TJMAX = 125°C, JA = 250°C/ W, JC = 90°C/ W A33x KB3426B-1.8 Top Marking A37x x: date code ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. VIN = 3.6V unless otherwise specified. SYMBOL IVFB VFB PARAMETER Feedback Current Regulated Feedback Voltage KB3426 (Note 4) T A = 25°C KB3426 (Note 4) 0 °C TA 85°C KB3426 (Note 4) –40 °C TA 85°C VIN = 2.5V to 5.5V (Note 4) KB3426-1.8, I OUT = 100mA KB3426-3.3, I OUT = 100mA VIN = 2.5V to 5.5V VIN = 3V, VFB = 0.5V or VOUT = 90%, Duty Cycle < 35% ● CONDITIONS ● MIN 0.5880 0.5865 0.5850 1.746 3.234 0.75 TYP 0.6 0.6 0.6 0.04 1.800 3.300 0.04 1 0.5 MAX ±30 0.6120 0.6135 0.6150 0.4 1.854 3.366 0.4 1.25 UNITS nA V V V %/V V V %/V A % ● ● ● ● ● VFB VOUT VOUT IPK VLOADREG VIN IS Reference Voltage Line Regulation Regulated Output Voltage Output Voltage Line Regulation Peak Inductor Current Output Voltage Load Regulation Input Voltage Range Input DC Bias Current Active Mode Sleep Mode Shutdown Oscillator Frequency RDS(ON) of P-Channel FET RDS(ON) of N-Channel FET SW Leakage 2.5 300 20 0.1 6.5 400 35 1 1.8 0.5 0.45 ±1 V µA µA µA MHz kHz (Note 5) VFB = 0.5V or VOUT = 90%, ILOAD = 0A VFB = 0.62V or VOUT = 103%, ILOAD = 0A VRUN = 0V, VIN = 4.2V VFB = 0.6V or VOUT = 100% VFB = 0V or VOUT = 0V ISW = 100mA ISW = –100mA VRUN = 0V, VSW = 0V or 5V, VIN = 5V ● fOSC RPFET RNFET ILSW 1.2 1.5 210 0.4 0.35 ±0.01 µA 2 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3426 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. VIN = 3.6V unless otherwise specified. SYMBOL VRUN IRUN PARAMETER RUN Threshold RUN Leakage Current CONDITIONS ● ● MIN 0.3 TYP 1 ±0.01 MAX 1.5 ±1 UNITS V µA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. www.DataSheet4U.com Note 2: The KB3426E is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: KB3426: T J = TA + (PD)(250°C/W) Note 4: The KB3426 is tested in a proprietary test mode that connects VFB to the output of the error amplifier. Note 5: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. TYPICAL PERFORMANCE CHARACTERISTICS (From Figure1a Except for the Resistive Divider Resistor Values) Efficiency vs Input Voltage 100 95 90 IOUT = 100mA IOUT = 10mA Efficiency vs Output Current 95 90 85 EFFICIENCY (%) Efficiency vs Output Current 95 VOUT = 1.5V VIN = 2.7V VIN = 4.2V 80 VIN = 3.6V 75 70 65 60 0.1 90 85 VOUT = 1.2V VIN = 2.7V EFFICIENCY (%) 85 IOUT = 1mA 80 75 70 65 60 55 50 VOUT = 1.8V 2 3 4 5 INPUT VOLTAGE (V) 6 IOUT = 0.1mA IOUT = 650mA 80 75 70 65 60 0.1 VIN = 4.2V VIN = 3.6V 1 10 100 OUTPUT CURRENT (mA) 1000 EFFICIENCY (%) 1 10 100 OUTPUT CURRENT (mA) 1000 Efficiency vs Output Current 100 95 90 EFFICIENCY (%) Reference Voltage vs Temperature 0.614 VIN = 3.6V 0.609 1.65 1.60 0.604 0.599 0.594 0.589 0.584 –50 –25 1.70 Oscillator Frequency vs Temperature VIN = 3.6V VOUT = 2.5V VIN = 2.7V REFERENCE VOLTAGE (V) VIN = 3.6V FREQUENCY (MHz) 50 25 75 0 TEMPERATURE (°C) 100 125 85 80 75 70 65 60 0.1 1 10 100 OUTPUT CURRENT (mA) 1000 VIN = 4.2V 1.55 1.50 1.45 1.40 1.35 1.30 –50 –25 50 25 75 0 TEMPERATURE (°C) 100 125 3 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3426 TYPICAL PERFORMANCE CHARACTERISTICS (From Figure1a Except for the Resistive Divider Resistor Values) Oscillator Frequency vs Supply Voltage 1.8 OSCILLATOR FREQUENCY (MHz) Output Voltage vs Load Current 1.844 1.834 VIN = 3.6V RDS(ON) vs Input Voltage 0.7 0.6 0.5 RDS(ON) ( ) 1.7 OUTPUT VOLTAGE (V) www.DataSheet4U.com 1.6 1.5 1.4 1.3 1.2 1.824 1.814 1.804 1.794 1.784 1.774 0.4 0.3 0.2 0.1 0 0 1 MAIN SWITCH SYNCHRONOUS SWITCH 2 3 4 5 SUPPLY VOLTAGE (V) 6 0 100 200 300 400 500 600 700 800 900 LOAD CURRENT (mA) 5 4 2 3 INPUT VOLTAGE (V) 6 7 RDS(ON) vs Temperature 0.7 VIN = 2.7V 0.6 VIN = 4.2V 0.5 RDS(ON) ( ) Supply Current vs Supply Voltage 50 45 40 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) Supply Current vs Temperature 50 VIN = 3.6V 45 VOUT = 1.8V = 0A I 40 LOAD VOUT = 1.8V ILOAD = 0A VIN = 3.6V 35 30 25 20 15 10 35 30 25 20 15 10 5 0.4 0.3 0.2 0.1 0 –50 –25 MAIN SWITCH SYNCHRONOUS SWITCH 50 25 75 0 TEMPERATURE (°C) 100 125 5 0 2 4 3 5 SUPPLY VOLTAGE (V) 6 0 –50 –25 50 25 0 75 TEMPERATURE (°C) 100 125 Switch Leakage vs Temperature 300 VIN = 5.5V RUN = 0V 250 SWITCH LEAKAGE (nA) Switch Leakage vs Input Voltage 120 100 SWITCH LEAKAGE (pA) 80 60 40 20 0 SYNCHRONOUS SWITCH RUN = 0V SW 5V/DIV VOUT 100mV/DIV AC COUPLED IL 200mA/DIV Burst Mode Operation 200 150 100 50 0 –50 –25 MAIN SWITCH SYNCHRONOUS SWITCH 50 25 75 0 TEMPERATURE (°C) 100 125 MAIN SWITCH VIN = 3.6V VOUT = 1.8V ILOAD = 50mA 0 1 2 3 4 INPUT VOLTAGE (V) 5 6 4µs/DIV 4 Kingbor Technology Co.,Ltd TEL:(86)0755-26508846 FAX:(86)0755-26509052 KB3426 TYPICAL PERFORMANCE CHARACTERISTICS (From Figure 1a Except for the Resistive Divider Resistor Values) Start-Up from Shutdown RUN 2V/DIV VOUT 2V/DIV VOUT 100mV/DIV AC COUPLED IL 500mA/DIV Load Step VOUT 100mV/DIV AC COUPLED Load Step www.DataSheet4U.com ILOAD 500mA/DIV IL 500mA/DIV ILOAD 500mA/DIV VIN = 3.6V 20µs/DIV VOUT = 1.8V ILOAD = 0mA TO 800mA ILOAD 500mA/DIV VIN = 3.6V VOUT = 1.8V ILOAD = 800mA 40µs/DIV VIN = 3.6V 20µs/DIV VOUT = 1.8V ILOAD = 50mA TO 800mA Load Step VOUT 100mV/DIV AC COUPLED Load Step VOUT 100mV/DIV AC COUPLED IL 500mA/DIV IL 500mA/DIV ILOAD 500mA/DIV VIN = 3.6V 20µs/DIV VOUT = 1.8V ILOAD = 100mA TO 800mA ILOAD 500mA/DIV VIN = 3.6V 20µs/DIV VOUT = 1.8V ILOAD = 200mA TO 800mA PIN FUNCTIONS RUN (Pin 1): Run Control Input. Forcing this pin above 1.5V enables the part. Forcing this pin below 0.3V shuts down the device. In shutdown, all functions are disabled drawing <1µA supply current. Do not leave RUN floating. GND (Pin 2): Ground Pin. SW (Pin 3): Switch Node Connection to Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches. VIN (Pin 4): Main Supply Pin. Must be closely decoupled to GND, Pin 2, with a 2.2µF or greater ceramic capacitor. VFB (Pin 5) (kB3426): Feedback Pin. Receives the f

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KB3426

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