MP2102DK-LF-P

MP2102 1.5MHz, 800mA Dual-Output Synchronous Step-Down Converter The Future of Analog IC Technology DESCRIPTION FEATURES The MP2102 is a dual-output, internally compensated, 1.5MHz fixed frequency PWM step-down converter. It is ideal for powering portable equipment from a single cell LithiumIon (Li+) Battery. Each channel of the MP2102 can supply 800mA of load current from a 2.5V to 6V input voltage. Both output voltages can be regulated as low as 0.6V. • • • • • • • • • • • • • • The device features integrated high-side switches and synchronous rectifiers for high efficiency step-down conversion without the need for external Schottky diodes. With peak current mode control and internal compensation, the MP2102 can be stabilized with ceramic capacitors and small inductors. Fault condition protection includes cycle-bycycle current limiting and thermal shutdown. The MP2102 is available in small 10-pin QFN with exposed pad and 10-pin MSOP packages. EVALUATION BOARD REFERENCE Board Number Dimensions EV2102DQ-00B 2.2”X x 2.2”Y x 0.4”Z Dual 800mA Outputs Internal Power MOSFET Switches Up to 95% Efficiency 1.5MHz Switching Frequency 1µA Shutdown Current Stable with Low ESR Output Ceramic Capacitors Thermal Shutdown Cycle-by-Cycle Over Current Protection Short Circuit Protection Power-On Reset with Programmable Delay 2.5V to 6V Operating Input Range Output Adjustable from 0.6V to 5.4V Input Undervoltage Lockout Available in 10-Pin QFN with Exposed Pad and 10-Pin MSOP Packages. APPLICATIONS • • • • • DVD+/-RW Drive Smart Phones PDAs Digital Cameras Portable Instruments “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency vs Load Current 3 2 7 VOUT2 1.2V / 800mA 6 10 DLY VIN C4 1nF EN1 EN2 PWROK MP2102 SW2 FB2 SW1 GND 5 FB1 100 9 8 4 1 90 VOUT=1.8V PWROK VOUT1 1.8V / 800mA EFFICIENCY (%) VIN 2.4V to 6V 80 70 VOUT=1.2V 60 50 40 30 20 MP2102 Rev. 1.0 11/8/2006 10 100 LOAD CURRENT (mA) www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 1000 1 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE REFERENCE TOP VIEW TOP VIEW FB1 1 10 FB2 EN1 2 9 DLY FB1 1 10 FB2 PWROK EN1 2 9 DLY VIN 3 8 PWROK SW1 4 7 EN2 GND 5 6 SW2 VIN 8 3 SW1 4 7 EN2 GND 5 6 SW2 EXPOSED PAD ON BACKSIDE CONNECT TO GROUND (PIN 5) Part Number* Package Temperature Part Number* Package Temperature MP2102DQ QFN10 (3mm x 3mm) –40°C to +85°C MP2102DK MSOP10 –40°C to +85°C * For Tape & Reel, add suffix –Z (eg. MP2102DQ–Z) For RoHS Compliant Packaging, add suffix –LF (eg. MP2102DQ–LF–Z) * For Tape & Reel, add suffix –Z (eg. MP2102DK–Z) For RoHS Compliant Packaging, add suffix –LF (eg. MP2102DK–LF–Z) ABSOLUTE MAXIMUM RATINGS (1) Recommended Operating Conditions VIN to GND .................................–0.3V to +6.5V SW1/2 to GND ..................... –0.3V to VIN + 0.3V FB1/2, OUT1/2, EN1/2 to GND...–0.3V to +6.5V Operating Temperature............. –40°C to +85°C Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature.............. –65°C to +150°C Supply Voltage VIN ............................. 2.5V to 6V Output Voltage VOUT ....................... 0.6V to 5.4V Operating Temperature .............–40°C to +85°C Thermal Resistance (3) θJA (2) θJC QFN10 .................................... 50 ...... 12... °C/W MSOP10 ................................ 150 ..... 65... °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its operating conditions. 3) Measured on approximately 1” square of 1 oz copper. ELECTRICAL CHARACTERISTICS (4) VIN = VEN = 3.6V, TA = +25°C, unless otherwise noted. Parameter Symbol Condition Supply Current Shutdown Current IN Under Voltage Lockout Threshold IN Under Voltage Lockout Hysteresis Output Line Regulation Output Load Regulation MP2102 Rev. 1.0 11/8/2006 Min VEN = VIN, VFB = 0.62V VEN = 0V, VIN = 6V Rising Edge VIN = 2.5V to 6V ILOAD = 50mA to 500mA 1.7 Typ Max Units 750 0.01 1 µA µA 2.0 2.3 V 100 mV 0.03 0.05 %/V %/mA www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 2 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS (4) (continued) VIN = VEN = 3.6V, TA = +25°C, unless otherwise noted. Parameter Symbol Condition TA = +25°C Regulated FB Voltage –40°C ≤ TA ≤ +85°C FB Input Bias Current VFB = 0.62V SW PFET On Resistance ISW = 100mA SW NFET On Resistance ISW = –100mA VEN = 0V, VIN = 6V SW Leakage Current VSW = 0V or 6V Duty Cycle = 100%, SW PFET Peak Current Current Pulse Width < 1ms Limit Oscillator Frequency Thermal Shutdown Trip Threshold PWROK Upper Trip FB1/2/OUT1/2 with respect to the Threshold nominal value PWROK Lower Trip FB1/2/OUT1/2 with respect to the Threshold nominal value PWROK Output Lower ISINK = 5mA Voltage PWROK Deglitch Timer C4 open PWROK Startup Delay C4 = 1nF DLY Pull-Down Resistor EN1/2 Trip Threshold EN1/2 Trip Threshold –40°C ≤ TA ≤ +85°C EN Pull-Down Resistor Min 0.588 0.582 –50 Typ 0.600 0.600 –2 0.4 0.3 –2 Max 0.612 0.618 +50 Units +2 µA V nA Ω Ω 0.9 1.5 2.1 A 1.2 1.5 1.7 MHz 150 °C 10 % –10 % 0.3 10 0.40 0.30 45 0.5 0.8 0.98 0.96 0.8 1.40 1.50 V µs ms MΩ V V MΩ Note: 4) Production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization. PIN FUNCTIONS Pin # Name Description 1 2 3 4 FB1 EN1 VIN SW1 Feedback Input 1. Feedback input for output 1. Enable Input 1. “High” input enables the switcher. It has an internal 800kΩ pull-down resistor. Input Supply Pin. Switch Node 1. Switch node to the inductors. 5 6 7 8 GND SW2 EN2 PWROK 9 DLY 10 FB2 Ground Pin. Switch Node 2. Switch node to the inductors. Enable Input 2. “High” input enables the switcher. It has an internal 800kΩ pull-down resistor. Power-On Reset Open Drain Output. Open drain output indicating that both outputs are within 10% of the final regulation value. “Low” output indicates output is out of ±10% window. PWROK is pulled down in shutdown. Delay Set. The startup power on reset delay is proportional to the value of C4 connected to this pin. It has an internal 800kΩ pull-down resistor. Feedback Input 2. Feedback input for output 2. MP2102 Rev. 1.0 11/8/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VOUT1 = 1.8V, VOUT2 = 1.2V, C1 = C2 = C3 = 10µF, C4 = 1nF, L1 = L2 = 2.2µH, TA = +25°C, unless otherwise noted. Efficiency vs Efficiency vs Load Current Load Current 100 100 VIN=3.3V 90 VOUT=1.8V 80 EFFICIENCY (%) EFFICIENCY (%) 90 70 60 VIN=6.0V 50 40 30 20 70 10 100 LOAD CURRENT (mA) 50 40 20 1000 90 VOUT=1.8V 70 60 50 40 1000 1.5 1.2 0.9 0.6 0.3 30 20 10 100 LOAD CURRENT (mA) 0.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 INPUT VOLTAGE (V) 1000 Frequency vs Temperature Feedback Voltage vs Temperature 0.610 FEEDBACK VOLTAGE (V) 1.8 FREQUENCY (MHz) 100 LOAD CURRENT (mA) 1.8 VOUT=2.5V 80 10 Frequency vs Input Voltage FREQUENCY (MHz) 100 1.5 1.2 0.9 0.6 0.3 0.0 -40 MP2102 Rev. 1.0 11/8/2006 VOUT=1.2V 60 30 Efficiency vs Load Current EFFICIENCY (%) 80 -10 20 50 80 110 TEMPERATURE (°C) 140 0.606 0.602 0.598 0.594 0.590 -40 -15 10 35 60 85 110 135 TEMPERATURE (°C) www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VOUT1 = 1.8V, VOUT2 = 1.2V, C1 = C2 = C3 = 10µF, C4 = 1nF, L1 = L2 = 2.2µH, TA = +25°C, unless otherwise noted. Output Voltage vs Output Voltage vs Load Current Load Current 1.84 2.52 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 2.54 2.50 2.48 2.46 2.44 0 200 400 600 800 LOAD CURRENT (mA) 1.82 1.80 1.78 1.76 1000 Output Voltage vs Load Current 1000 1.6 SWITCH CURRENT (A) OUTPUT VOLTAGE (V) 200 400 600 800 LOAD CURRENT (mA) Peak Switch Current vs Temperature 1.22 1.20 1.18 1.16 1.14 0 0 200 400 600 800 LOAD CURRENT (mA) 1.5 1.4 1.3 1.2 -40 1000 0 +40 +80 TEMPERATURE (OC) +120 Current Limit vs Duty Cycle CURRENT LIMIT (A) 1.6 1.5 1.4 1.3 1.2 1.1 1.0 MP2102 Rev. 1.0 11/8/2006 30 40 50 60 70 80 DUTY CYCLE (%) 90 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 5 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VOUT1 = 1.8V, VOUT2 = 1.2V, C1 = C2 = C3 = 10µF, C4 = 1nF, L1 = L2 = 2.2µH TA = +25°C, unless otherwise noted. Enable Turn On Enable Turn Off VIN = 3.6V, EN = EN1 = EN2 = 4V, ILOAD1 = ILOAD2 = 0.3A with Resistive Load VIN = 3.6V, EN = EN1 = EN2 = 4V, ILOAD1 = ILOAD2 = 0.3A with Resistive Load PWROK 2V/div. VOUT1 1V/div. VOUT1 1V/div. VOUT2 1V/div. VOUT2 1V/div. VIN = EN1 = 4.2V, ILOAD1 = 0.8A VOUT1 10mV/div. EN 2V/div. EN 2V/div. PWROK 2V/div. Heavy Load Ripple VSW1 2V/div. IL 0.5A/div. 400ns/div. Input Ramp Up Input Ramp Down VIN = 4.2V, EN = EN1 = EN2 = 4V, ILOAD1 = ILOAD2 = 0.3A with Resistive Load VIN = 4.2V, EN = EN1 = EN2 = 4V, ILOAD1 = ILOAD2 = 0.3A with Resistive Load VSW 5V/div. VOUT2 2V/div. VOUT1 1V/div. VOUT1 1V/div. 1ms/div. VIN = 3.6V, ILOAD1 = 0.45A, with Resistive Load VOUT1 2V/div. VIN 2V/div. VIN 2V/div. VOUT2 2V/div. Over Current Protection IL 0.5A/div. 1ms/div. PWROK Off vs. Short Output Load Transient VIN = 4.2V, ILOAD1 = ILOAD2 = 0.3A with Resistive Load and VOUT2 Forced to Short VIN = 4.2V, ILOAD1 = 0A to 0.8A Step with Resistive Load VOUT1 0.1V/div. PWROK 2V/div. VOUT1 1V/div. IOUT1 0.5A/div. VOUT2 0.5V/div. MP2102 Rev. 1.0 11/8/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 6 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER OPERATION The MP2102 is a dual-channel constant frequency current mode PWM step-down converter. The MP2102 is optimized for low voltage, Li-Ion battery powered applications where high efficiency and small size are critical. The MP2102 uses an external resistor divider to set the output voltage from 0.6V to 5.4V. The device integrates both a main switch and a synchronous rectifier which provides high efficiency and eliminates the need for an external Schottky diode. Current Mode PWM Control Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limit for superior load and line response and protection of the internal main switch and synchronous rectifier. The MP2102 switches at a constant frequency (1.5MHz) and regulates the output voltage. During each cycle the PWM comparator modulates the power transferred to the load by changing the inductor peak current based on the feedback error voltage. During normal operation, the main switch is turned on for a certain time to ramp the inductor current at each rising edge of the internal oscillator, and switched off when the peak inductor current is above the error voltage. When the main switch is off, the synchronous rectifier will be turned on immediately and stay on until the next cycle starts. The maximum duty cycle of the MP2102 is around 90%, therefore the maximum achievable output voltage is 90% of the input voltage minus the voltage drop across the main switch and the inductor. MP2102 Rev. 1.0 11/8/2006 Short Circuit Protection The MP2102 has an independent short circuit protection for each channel. When the output is shorted to ground, the valley current limit control is activated; the next cycle of turning on the main switch will not start until the inductor current has dropped to below 300mA. The control mechanism will return to normal once the feedback voltage reaches 0.3V. Output Power Good Indication The open-drain pin PWROK is used to monitor the output condition. When the voltages of both outputs are within ±10% of the expected value, the open-drain device will turn off, floating the PWROK pin. When at least one of the outputs is outside of ±10% window, the PWROK will be pulled “LOW”. Power-On Reset Delay The MP2102 has a programmable power on reset delay. Changing the value of the capacitor at the DLY pin sets the delay time. See Programming PWROK Delay in the Applications Information section. Maximum Load Current The MP2102 can operate down to 2.5V input voltage; however the maximum load current decreases at lower input due to large IR drop on the main switch and synchronous rectifier. The slope compensation signal reduces the peak inductor current as a function of the duty cycle to prevent sub-harmonic oscillations at duty cycles greater than 50%. Conversely, the current limit increases as the duty cycle decreases. www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 7 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER BLOCK DIAGRAMS BUCK1 DLY PWROK DC-DC CORE PGD MONITOR EN1 POR EN2 BG REFERENCE BUCK2 OSC DC-DC CORE SHORT DETECTION Figure 1—Dual Buck Functional Block Diagram VIN EN1/2 ICS 0.6V SLOPE COMP + EAMP FB1/2 + IAMP 10X -CURRENT SENSE AMP BIAS & VOLTAGE REFERENCE EAO PWMCMP + + PWM DH -- MAIN SWITCH (PCH) -PWM CONTROL LOGIC RC 17pF 1.5MHz OSCILLATOR OSC SW1/2 SYNCHRONOUS RECTIFIER (NCH) DL GND Figure 2—DC-DC Core Functional Block Diagram MP2102 Rev. 1.0 11/8/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 8 MP2102 – 1.5MHz, 800mA DUAL-OUTPUT SYNCHRONOUS STEP-DOWN CONVERTER APPLICATION INFORMATION Output Voltage Setting Please reference the schematic on the front page. The external resistor divider sets the output voltage. The top feedback resistor RTOP also sets the feedback loop bandwidth with the internal compensation capacitor (see Typical Application circuit). Choose RTOP around 300kΩ for optimal transient response. The bottom feedback resistor RBOT is then given by: R BOT = R TOP VOUT −1 0 .6 V Where RTOP is either R1 or R3, and RBOT is either R2 or R4. Table 1—Resistor Selection vs. Output Voltage Setting VOUT RTOP RBOT 1.2V 300kΩ (1%) 300kΩ (1%) 1.5V 300kΩ (1%) 200kΩ (1%) 1.8V 300kΩ (1%) 150kΩ (1%) 2.5V 300kΩ (1%) 95.3kΩ (1%) Inductor Selection (L1, L2) A 1µH to 10µH inductor with DC current rating at least 25% higher than the maximum load current is recommended for most applications. For best efficiency, the inductor DC resistance shall be