MP2101DQ

TM MP2101 1.6MHz Synchronous Step-Down plus 200mA LDO The Future of Analog IC Technology TM DESCRIPTION The MP2101 is an internally compensated 1.6MHz fixed-frequency PWM step-down switcher with a 200mA low dropout (LDO) linear regulator. It is ideal for portable equipment powered by a single cell Lithium-Ion (Li+) Battery. The MP2101 can provide 800mA and 200mA of load current from a 2.5V to 6V input voltage. Both output voltages can be regulated as low as 0.6V. The 800mA output channel features an integrated high-side switch and synchronous rectifier for high efficiency without an external Schottky diode. With peak current mode control and internal compensation, the MP2101 can be stabilized with ceramic capacitors and small inductors. The high-side switch can maintain 100% duty cycle in dropout condition. The 200mA LDO output is used to power noise sensitive circuitry. It has a separate input supply to reduce power dissipation and noise from the main switcher. Dropout voltage is 280mV under a 150mA load. Fault condition protection includes cycle-by-cycle current limiting and thermal shutdown. The MP2101 is available in small 3mm x 3mm 10-pin QFN packages. FEATURES • • • • • • • • • • • • • • • • • • • 0.8A Switcher Output and 0.2A LDO Output VIN1 Range for Switcher: 2.5V to 6V VIN2 Range for LDO: 1.2V to VIN1 Internal Power MOSFET Switches Stable with Low ESR Output Ceramic Capacitors Up to 93% Efficiency 0.01µA Shutdown Current 1.6MHz Fixed Switching Frequency Up to 100% Switcher Duty Cycle Thermal Shutdown Cycle-by-Cycle Over Current Protection Short Circuit Protection Power On Reset Output Available in 3x3 10-Pin QFN Packages DVD+/-RW Drives Smart Phones PDAs Digital Cameras Portable Instruments APPLICATIONS “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency vs Load Current 100 OFF ON VIN 2.5V - 6V OUT1 1.8V @ 600mA 2 3 EN1 IN1 EN2 PWROK 9 8 7 10 5 POWER OK 90 VIN=3.3V EFFICIENCY (%) L1 80 70 60 50 40 10 100 LOAD CURRENT (mA) 1000 VIN=4.2V VIN=5.0V 4 6 1 SW1 MP2101 OUT2 IN2 FB1 FB2 GND OUT2 1.2V @ 200mA MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 1 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO PACKAGE REFERENCE ABSOLUTE MAXIMUM RATINGS (1) IN1, OUT1/2 to GND ................. –0.3V to + 6.5V IN2 to GND ......................... –0.3V to VIN1 + 0.3V SW1 to GND....................... –0.3V to VIN1 + 0.3V PWROK to GND ......................... –0.3V to +6.5V FB1/2, 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 TOP VIEW FB1 EN1 IN1 SW1 GND 1 2 3 4 5 10 9 8 7 6 FB2 EN2 PWROK OUT2 IN2 Recommended Operating Conditions (2) EXPOSED PAD ON BACKSIDE Supply Voltage VIN1 ........................... 2.5V to 6V Supply Voltage VIN2 ..........................1.2V to VIN1 Output Voltage VOUT1/2 ....................... 0.6V to 6V Operating Temperature .............–40°C to +85°C Thermal Resistance Part Number* MP2101DQ * Package QFN10 (3mm x 3mm) Temperature –40°C to +85°C (3) QFN10 (3mm x 3mm) ............. 50 ...... 12... °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. θJA θJC For Tape & Reel, add suffix –Z (eg. MP2101DQ–Z) For RoHS compliant packaging, add suffix –LF (eg. MP2101DQ–LF–Z) ELECTRICAL CHARACTERISTICS (4) VIN1/2 = VEN1/2 = 3.6V, TA = +25°C, unless otherwise noted. Parameters No Load Supply Current Condition VFB1/2 = 0.62V VEN1 = 0V, VEN2 = 3.6V VEN1 = 3.6V, VEN2 = 0V VEN1/2 = 0V, VIN1/2 = 6V Hysteresis = 20°C FB1/2 with respect to the Nominal Value FB1/2 with respect to the Nominal Value ISINK = 5mA Switching Regulator LDO –40°C ≤ TA ≤ +85°C Min Typ 400 80 300 0.01 150 10 –10 50 150 0.96 900 2.0 100 0.600 –2 Max 550 100 400 1 Units µA µA µA µA °C % % V µs 1.5 V kΩ V mV V nA 2 Shutdown Current Thermal Shutdown Trip Threshold PWROK Upper-Trip Threshold PWROK Lower-Trip Threshold PWROK Output Lower Voltage PWROK Deglitch Timer (FB1) PWROK Deglitch Timer (FB2) EN1/2 Trip Threshold EN1/2 Pull-Down Resistor Switching Regulator IN1 Under Voltage Lockout Threshold Rising Edge IN1 Under Voltage Lockout Hysteresis TA = +25°C Regulated FB1Voltage –40°C ≤ TA ≤ +85°C FB1 Input Bias Current VFB1 = 0.62V MP2101 Rev. 1.0 8/18/2006 0.3 0.3 1.5 0.588 0.582 –50 2.5 0.612 0.618 +50 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO ELECTRICAL CHARACTERISTICS (4) (continued) VIN1/2 = VEN1/2 = 3.6V, TA = +25°C, unless otherwise noted. Parameters SW1 PFET On Resistance SW1 NFET On Resistance SW1 Leakage Current SW1 PFET Peak Current Limit Oscillator Frequency Linear Regulator LDO IN2 Input Range Regulated FB2 Voltage FB2 Input Bias Current OUT2 Short Circuit Foldback OUT2 Output Current Dropout Voltage (5) Condition ISW1 = 100mA ISW1 = –100mA VEN1 = 0V, VIN = 6V VSW1 = 0V or 6V Duty Cycle = 100%, Current Pulse Width < 1ms Min Typ 0.35 0.25 Max Units Ω Ω µA A MHz V V nA mA mA mV –2 0.9 1.2 1.4 1.6 +2 2.0 2.0 VIN1 0.612 0.618 +50 ILOAD = 10mA, VOUT2=VFB2 TA = +25°C –40°C ≤ TA ≤ +85°C VFB2 = 0.6V VOUT2 = 0V VOUT = 1.2V ILOAD = 150mA, VOUT2 = 1.2V 1.2 0.588 0.582 –50 200 0.600 –2 180 280 Notes: 4) Production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization. 5) The dropout voltage is equal to VIN2 – VOUT2 when VOUT2 is 100mV below the nominal value. PIN FUNCTIONS Pin # 1 2 3 4 5 6 7 Name FB1 EN1 Description Feedback 1. Feedback Input for the switcher output (OUT1). Enable 1. Enable input for the switcher. Pull high to turn on the switcher; low to turn it off. Input 1. Main input supply for both the switcher and the auxiliary low dropout (LDO) linear IN1 regulator. SW1 Switcher Switch Node. Output for the 800mA switcher channel. GND Ground. IN2 Input 2. Input supply for the auxiliary linear regulator LDO output power device. Output 2. Output of the 200mA LDO. The LDO is designed to be stable with an external OUT2 minimum 1µF ceramic capacitor at 200mA of load current. Power On Reset Open Drain Output. A high output indicates that both outputs are within ±10% of the regulation value. A low output indicates that the output is outside of the ±10% PWROK window. PWROK is pulled down if EN1 and/or EN2 is low. The PWROK window comparators have a 50µs deglitch timer for the switcher and 150µs deglitch timer for the linear regulator LDO to avoid a false trigger during load transient. Enable 2. Enable input for the linear regulator LDO. Pull high to turn on the LDO; low to turn it EN2 off. FB2 Feedback 2. Feedback input for the linear regulator output (OUT2). 8 9 10 MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, VOUT1 = 1.8V, VOUT2 = 1.2V, CIN1 = 4.7µF, CIN2 = 1µF, CO1 = 10µF, CO2 = 1µF, L = 2.2µH, TA = +25°C, unless otherwise noted. Efficiency vs Load Current 90 80 95 85 VIN=3.3V VIN=4.2V VIN=5.0V Efficiency vs Load Current 95 85 Efficiency vs Load Current EFFICIENCY (%) EFFICIENCY (%) 60 50 40 30 20 10 10 100 LOAD CURRENT (mA) 1000 VIN=4.2V VIN=5.0V 65 55 45 35 25 10 EFFICIENCY (%) 70 VIN=3.3V 75 75 65 55 45 35 25 VIN=4.2V VIN=5.0V 100 LOAD CURRENT (mA) 1000 10 100 LOAD CURRENT (mA) 1000 Efficiency vs Load Current 95 85 VIN=3.3V 100 90 Efficiency vs Load Current 100 VIN=3.3V 90 Efficiency vs Load Current VIN=4.2V VIN=5.0V EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 1000 75 65 55 45 35 25 10 100 LOAD CURRENT (mA) 1000 VIN=4.2V 80 70 60 50 40 10 100 LOAD CURRENT (mA) VIN=4.2V VIN=5.0V 80 70 60 50 40 30 10 VIN=5.0V 100 LOAD CURRENT (mA) 1000 Output Voltage vs Load Current 1.82 2.52 Output Voltage vs Load Current VIN=4.2V 3.33 Output Voltage vs Load Current 3.32 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.81 1.80 1.79 1.78 1.77 1.76 0 VIN=4.2V VIN=3.3V VIN=5.0V 2.50 2.48 2.46 2.44 2.42 2.40 0 VIN=3.3V VIN=5.0V 3.31 3.30 3.29 3.28 3.27 3.26 VIN=4.2V VIN=5.0V 200 400 600 800 LOAD CURRENT (mA) 1000 200 400 600 800 LOAD CURRENT (mA) 1000 3.25 0 200 400 600 800 LOAD CURRENT (mA) 1000 MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.6V, VOUT1 = 1.8V, VOUT2 = 1.2V, CIN1 = 4.7µF, CIN2 = 1µF, CO1 = 10µF, CO2 = 1µF, L = 2.2µH, TA = +25°C, unless otherwise noted. Output Voltage vs Load Current 1.56 VOUT2 = 1.5V 2.53 Output Voltage vs Load Current VOUT2 = 2.5V 1.206 Output Voltage vs Load Current OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.54 OUTPUT VOLTAGE (V) 2.52 1.205 1.52 VIN=3.3V 1.50 LDO 1.48 0 40 80 120 160 LOAD CURRENT (mA) 200 2.51 VIN=3.3V 1.204 VIN=1.8V LDO 1.202 0 40 80 120 160 LOAD CURRENT (mA) 200 2.50 LDO 2.49 0 40 80 120 160 LOAD CURRENT (mA) 200 1.203 PSRR vs Frequency 100 90 80 70 1.8 1.7 1.6 1.5 1.4 Frequency vs Input Voltage 0.62 Feedback Voltage vs Temperature FEEDBACK VOLTAGE (V) FREQUENCY (MHz) 0.61 PSRR (dB) 60 50 40 30 20 10 0 10 100 1K 10K 100K FREQUENCY (Hz) 1M 0.60 FB2 FB1 0.59 1.3 4.0 4.4 4.8 5.2 5.6 INPUT VOLTAGE (V) 6.0 0.58 -40 -10 +20 +50 +80 +110 +140 TEMPERATURE (°C) LDO Dropout vs Load Current 0.5 Enable Turn On EN = 3.6V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load EN 5V/div. PWROK 5V/div. Enable Turn Off EN = 3.6V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load DROPOUT VOLTAGE (V) 0.4 0.3 0.2 0.1 0.0 EN 2V/div. PWROK 2V/div. VOUT1 1V/div. VOUT2 1V/div. VOUT1 1V/div. VOUT2 1V/div. 0 50 100 150 200 LOAD CURRENT (mA) 250 MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 5 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.6V, VOUT1 = 1.8V, VOUT2 = 1.2V, CIN1 = 4.7 µF, CIN2 = 1µF, CO1 = 10µF, CO2 = 1µF, L = 2.2µH, TA = +25°C, unless otherwise noted. Input Ramp Up EN = 4V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load Input Ramp Down EN = 4V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load VOUT1 10mV/div. VIN 2V/div. VOUT1 1V/div. VSW 2V/div. IL 0.5A/div. Heavy Load Ripple EN1 = VIN = 5V, IOUT1 = 0.8A Resistive Load VIN 2V/div. VOUT1 2V/div. VOUT2 1V/div. VOUT2 1V/div. 1ms/div. 400ns/div. PWROK Off vs VOUT1 Shorted EN = 4V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load PWROK Off vs VOUT2 Shorted Over Current Protection IOUT1 = 0.3A Resistive Load EN = 4V, IOUT1 = 0.3A, IOUT2 = 0.1A Resistive Load PWROK 2V/div. VOUT1 1V/div. VOUT2 1V/div. PWROK 2V/div. VOUT1 1V/div. VOUT1 2V/div. VSW 5V/div. VOUT2 1V/div. IL 0.5A/div. Switcher Load Transient IOUT1 = 0.8A Resistive Load LDO Load Transients VIN2 = 3.3V, VOUT2 = 1.2V, IOUT2 = 0.02A to 0.15A Resistive Load LDO Over Current Protection VIN2 = 3.3V, VOUT2 = 2.5V VOUT1 0.1V/div. VOUT2 50mV/div. VOUT2 1V/div. IL 0.5A/div. IOUT2 0.1A/div. IOUT2 0.1A/div. MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 6 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO OPERATION The MP2101 is a fixed-frequency 1.6MHz, 800mA current mode PWM step-down switcher with a 200mA low dropout (LDO) linear regulator. The MP2101 is optimized for low voltage, Li-Ion battery powered applications where high efficiency and small size are critical. The MP2101 uses an external resistor divider to set both the switcher and LDO output voltage from 0.6V to 6V. IN1 3 BIAS & VOLTAGE REFERENCE ICS SLOPE COMP EAO1 + IAMP 10X -CURRENT SENSE AMP PWM DH MAIN SWITCH (PCH) OSC PWM CONTROL LOGIC 4 SW1 SYNCHRONOUS RECTIFIER (NCH) DL EN1/2 2/9 0.6V + FEEDBACK ERROR EAMP1 AMP -- + + PWMCMP -- FB1 1 CC 17pF 1.6MHz OSCILLATOR 5 GND FB2 10 + EAMP2 0.6V -EAO2 6 IN2 7 OUT2 FB1/2 0.66V + -- OUT_Hi NO GOOD 8 PWROK POWER ON RESET WINDOW COMPARATORS 0.54V + -OUT_Lo Figure 1—MP2101 Function Diagram MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 7 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO Short Circuit Protection When the output is shorted to ground, the oscillator frequency is reduced to prevent the inductor current from increasing beyond the PFET current limit, which is also reduced to lower the short circuit current. The frequency and current limit will return to the normal values once the short circuit condition is removed and the feedback voltage reaches 0.6V. Maximum Load Current The MP2101 can operate down to a 2.5V input voltage. However the maximum load current decreases at lower inputs due to a 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. Power OK The MP2101 provides an open-drain PWROK output that goes high after both channels reach regulation during startup. PWROK goes low after one of the output channels goes out of regulation by ±10% or when the device enters shutdown. There is a built-in deglitch timer to avoid a false PWROK trigger during load transients (50µs for the switcher and 150µs for the LDO). When the output is disabled, Power OK remains low. 200mA Linear Regulator The 200mA low dropout (LDO) linear regulator has separate input (IN2) and output (OUT2) pins for the internal power device. The control circuitry of the LDO takes power from the main input supply (IN1). Both IN1 and IN2 input supplies must be present for the LDO to work properly. The LDO power device input (IN2) can be connected to the switcher output or directly to the main supply (Figure 2). If IN2 is tied to IN1, an optional RC filter can be inserted between IN1 and IN2. The RC filter reduces switching noise coupling from IN1 to IN2 and power dissipation inside the MP2101. The switcher guarantees 800mA output current, but output current to the switcher load will be reduced if the LDO draws current from the switcher output. 800mA Step-Down Switcher The switcher integrates both a main switch and a synchronous rectifier, which provides high efficiency and eliminates the need for an external Schottky diode. This switcher can achieve 100% duty cycle. The duty cycle (D) of a step-down switcher is defined as: D = TON × fOSC × 100% ≈ VOUT × 100% VIN Where TON is the main switch on time and fOSC is the oscillator frequency (1.6MHz). Current Mode PWM Control Slope compensated current mode PWM control provides stable switching and cycle-by-cycle current limiting for superior load and line response in addition to protection of the internal main switch and synchronous rectifier. 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 to ramp the inductor current at each rising edge of the internal oscillator, then switched off when the peak inductor current is above the error voltage. When the main switch is turned off, the synchronous rectifier is immediately turned on and stays on until the next cycle begins. Dropout Operation The MP2101 allows the main switch to remain on for more than one switching cycle and increases the duty cycle while the input voltage is dropping close to the output voltage. When the duty cycle reaches 100%, the main switch is held on to deliver current to the output up to the PFET current limit. The output voltage then becomes the input voltage minus the voltage drop across the main switch and the inductor. MP2101 Rev. 1.0 8/18/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 8 TM MP2101 – 1.6MHz SYNCHRONOUS STEP-DOWN PLUS 200mA LDO APPLICATION INFORMATION Output Voltage Setting The external resistor divider sets the output voltage. The feedback resistor R1 of the switcher also sets the feedback loop bandwidth with the internal compensation capacitor (see Figure 1). R1 of the switcher should be 300kΩ for optimal transient response. R2 is then given by: R2 = R1 VOUT1 −1 0 .6 V Inductor Selection A 1µH to 10µH inductor with a DC current rating of at least 25% higher than the maximum load current is recommended for most applications. For best efficiency, the inductor DC resistance should be