TM MP2104 1.7MHz, 600mA Synchronous Step-Down Converter The Future of Analog IC Technology TM DESCRIPTION FEATURES The MP2104 is a 1.7MHz constant frequency, current mode, PWM step-down converter. The device integrates a main switch and a synchronous rectifier for high efficiency without an external Schottky diode. It is ideal for powering portable equipment that runs from a single cell Lithium-Ion (Li+) battery. The MP2104 can supply 600mA of load current from a 2.5V to 6V input voltage. The output voltage for the MP2104DJ can be regulated as low as 0.6V, while the output voltages of the MP2104DJ-1.5 and MP2104DJ-1.8 are fixed at 1.5V and 1.8V, respectively. The MP2104 can also run at 100% duty cycle for low dropout applications. • • • • • • • • • • • • The MP2104 is available in a low profile (1mm) 5-pin, TSOT package. • • • • • • ORDERING INFORMATION Part Number MP2104DJ-1.5 MP2104DJ-1.8 MP2104DJ Output Voltage VOUT = 1.5V VOUT = 1.8V VOUT = 0.6V to 6V EVALUATION BOARD REFERENCE Board Number Dimensions EV2104DJ-00A 2.0”X x 2.0”Y x 0.5”Z High Efficiency: Up to 95% 1.7MHz Constant Switching Frequency 600mA Available Load Current 2.5V to 6V Input Voltage Range Output Voltage as Low as 0.6V 100% Duty Cycle in Dropout Current Mode Control Short Circuit Protection Thermal Fault Protection <0.1µA Shutdown Current 1.5V and 1.8V Fixed Output Versions Space Saving 5-Pin TSOT23 Package APPLICATIONS Cellular and Smart Phones Microprocessors and DSP Core Supplies PDAs MP3 Players Digital Still and Video Cameras Portable Instruments “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency vs Load Current 100 4 IN SW 3 MP2104DJ-1.8 OFF ON 1 EN GND OUT 5 2 90 VIN = 3.3V 80 EFFICIENCY (%) INPUT 2.5V - 6V OUTPUT 1.8V 600mA VIN = 4.2V 70 60 50 40 30 20 MP2104_TAC_S01 10 0 10 100 LOAD CURRENT (mA) 1000 MP2104-EC01 MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 1 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE REFERENCE TOP VIEW GND 2 SW 3 5 FB 4 IN EN 1 GND 2 SW 3 MP2104_PD01-TSOT23-5 OUT 4 IN MP2104_PD02-TSOT23-5 Part Number* Package Temperature MP2104DJ TSOT23-5 –40°C to +85°C * 5 MARKING 1 C2YW EN TOP VIEW For Tape & Reel, add suffix –Z (eg. MP2104DJ–Z) For Lead Free, add suffix –LF (eg. MP2104DJ–LF–Z) Part Number** Package Marking Temp MP2104DJ-1.5 TSOT23-5 D7YW MP2104DJ-1.8 TSOT23-5 D8YW –40°C to +85°C ** For Tape & Reel, add suffix –Z (eg. MP2104DJ-1.5–Z) For Lead Free, add suffix –LF (eg. MP2104DJ-1.5–LF–Z) ABSOLUTE MAXIMUM RATINGS (1) Recommended Operating Conditions VIN to GND ..................................–0.3V to +6.5V VSW to GND........................... –0.3V to VIN +0.3V VFB, VEN to GND ..........................–0.3V to +6.5V SW Peak Current ........................................ 1.4A Junction Temperature .............................+150°C (2) Lead Temperature ..............................+260°C Storage Temperature ............. –65°C to +150°C Thermal Resistance (3) Supply Voltage VIN ............................. 2.5V to 6V Output Voltage VOUT .......................... 0.6V to 6V Operating Temperature .............–40°C to +85°C (4) θJA θJC TSOT23-5.............................. 220 .... 110.. °C/W Notes: 1) Exceeding these ratings may damage the device. 2) For recommended IR reflow temperature information, refer to MPS document MP2104_IRRTP. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on approximately 1” square of 1 oz copper. ELECTRICAL CHARACTERISTICS (5) VIN = VEN = 3.6V, TA = +25°C, unless otherwise noted. Parameter Supply Current Shutdown Current IN Under Voltage Lockout Threshold IN Under Voltage Lockout Hysteresis Regulated FB Voltage FB Input Bias Current MP2104 Rev. 1.3 10/4/2005 Symbol Condition VEN = VIN, VFB = 0.65V VEN = 0V, VIN = 6V Min Typ 400 0.01 Max 600 1 Units µA µA Rising Edge 2.10 2.27 2.45 V 55 TA = +25°C, MP2104DJ –40°C ≤ TA ≤ +85°C VFB = 0.65V, MP2104DJ 0.588 0.582 –50 0.600 0.600 0.5 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. mV 0.612 0.618 +50 V nA 2 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS (continued) (5) VIN = VEN = 3.6V, TA = +25°C, unless otherwise noted. Parameter Regulated Output Voltage PFET On Resistance NFET On Resistance SW Leakage Current PFET Current Limit Oscillator Frequency Thermal Shutdown Trip Threshold EN Trip Threshold EN Input Current Symbol Condition MP2104DJ-1.5 IOUT = 50mA –40°C ≤ TA ≤ +85°C MP2104DJ-1.8 IOUT = 50mA –40°C ≤ TA ≤ +85°C ISW = 100mA ISW = –100mA VEN = 0V, VIN = 6V VSW = 0V or 6V Duty Cycle = 100%, Current Pulse Width < 1ms Min Typ Max 1.455 1.500 1.545 V 1.746 1.800 1.854 0.44 0.29 –1 Ω Ω +1 µA 0.7 1.0 1.35 A 1.26 1.70 2.08 MHz °C 145 –40°C ≤ TA ≤ +85°C VEN = 0V to 6V Units 0.3 –1 0.96 1.5 +1 V µA Notes: 5) 100% production test at +25°C. Typical and temperature specifications are guaranteed by design and characterization. MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 3 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.3V, VOUT = 1.8V, L1 = 10µH, C1 = 4.7µF, C3 = 10µF, TA = +25°C, unless otherwise noted. Efficiency vs Load Current 100 90 90 VIN = 3.3V EFFICIENCY (%) VIN = 4.2V 60 50 40 30 1.83 VIN = 4.2V 70 60 50 40 30 1.77 1.75 1.73 1.71 1.69 10 10 1.67 0 0 1.65 100 LOAD CURRENT (mA) 1000 10 100 LOAD CURRENT (mA) 90 90 80 80 EFFICIENCY (%) 100 60 50 40 30 0 10 100 LOAD CURRENT (mA) Output Voltage vs Supply Voltage 70 60 50 40 30 VOUT = 1.8V VIN = 4.2V 10 0 1000 10 MP2104-TPC03 100 LOAD CURRENT (mA) PFET CURRENT LIMIT (A) 0.605 0.600 0.595 0.590 0.585 0.580 -50 -30 -10 10 30 40 70 90 110 130 TEMPERATURE (°C) MP2104-TPC07 1.804 1.802 ILOAD = 200mA 1000 1.3 0.610 1.806 1.800 2 3 4 5 SUPPLY VOLTAGE (V) 1.2 1.1 1.0 0.9 0.8 0.7 -50 -30 -10 10 30 40 70 90 110 130 TEMPERATURE (°C) 6 MP2104-TPC06 Oscillator Frequency vs Supply Voltage PFET Current Limit vs Temperature 0.620 0.615 1.808 MP2104-TPC04 Regulated FB Voltage vs Temperature MP2104 Rev. 1.3 10/4/2005 MP2104-TPC05 1.810 20 VOUT = 1.8V VIN = 3.3V 10 0 100 200 300 400 500 600 700 800 900 LOAD CURRENT (mA) Efficiency vs Load Current 70 VIN = 3.3V MP2104-TPC02 100 20 1000 OUTPUT VOLTAGE (V) 10 Efficiency vs Load Current EFFICIENCY (%) 1.79 20 MP2104-TPC01 REGULATED FB VOLTAGE (V) 1.81 20 OSCILLATOR FREQUENCY (MHz) EFFICIENCY (%) 80 70 1.85 VIN = 3.3V OUTPUT VOLTAGE (V) 100 80 Output Voltage vs Load Current Efficiency vs Load Current 2.05 1.95 1.85 1.75 1.65 1.55 1.45 1.35 1.25 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 SUPPLY VOLTAGE (V) MP2104-TPC08 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. MP2104-TPC09 4 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) VIN = 3.3V, VOUT = 1.8V, L1 = 10µH, C1 = 4.7µF, C3 = 10µF, TA = +25°C, unless otherwise noted. MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 5 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER PIN FUNCTIONS Pin # Name Description 1 2 3 4 5 5 Regulator Enable Control Input. Drive EN above 1.5V to turn on the MP2104. Drive EN below 0.3V to turn it off (shutdown current < 0.1µA). GND Ground. SW Power Switch Output. Inductor connection to drains of the internal PFET and NFET switches. IN Supply Input. Bypass to GND with a 2.2µF or greater ceramic capacitor. Feedback Input (MP2104DJ). Connect FB to the center point of the external resistor divider. The FB feedback threshold voltage is 0.6V. Output Voltage Sense Input (MP2104DJ-1.5 and MP2104DJ-1.8). An internal resistor divider is OUT connected to this pin to set the proper output voltage. EN OPERATION The MP2104 is a constant frequency current mode PWM step-down converter. The MP2104 is optimized for low voltage, Li-Ion battery powered applications where high efficiency and small size are critical. The MP2104 uses an external resistor divider to set the output voltage from 0.6V to 6V. The device integrates both a main switch and a synchronous rectifier, which provides high efficiency and eliminates an external Schottky diode. The MP2104 can achieve 100% duty cycle. The duty cycle D of a step-down converter is defined as: D = TON × fOSC × 100% ≈ VOUT × 100% VIN Where TON is the main switch on time, fOSC is the oscillator frequency (1.7MHz), VOUT is the output voltage and VIN is the input voltage. IN EN ICS 0.6V + FB + IAMP 10X -CURRENT SENSE AMP BIAS & VOLTAGE REFERENCE SLOPE COMP FEEDBACK ERROR EAMP AMP -- CC 17pF EAO + + PWMCMP PWM DH MAIN SWITCH (PCH) -- 1.7MHz OSCILLATOR OSC PWM CONTROL LOGIC SW SYNCHRONOUS RECTIFIER (NCH) DL GND MP2104_BD01 Figure 1—Functional Block Diagram (MP2104) MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 6 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER IN EN ICS 0.6V SLOPE COMP + OUT + IAMP 10X -CURRENT SENSE AMP BIAS & VOLTAGE REFERENCE FEEDBACK ERROR EAMP AMP -- CC 17pF EAO + + PWMCMP PWM DH MAIN SWITCH (PCH) -- 1.7MHz OSCILLATOR OSC PWM CONTROL LOGIC SW SYNCHRONOUS RECTIFIER (NCH) DL GND MP2104_BD01 Figure 2—Functional Block Diagram (MP2104DJ-1.5 / MP2104DJ-1.8) 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 MP2104 switches at a constant frequency (1.7MHz) 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 either the next cycle starts. Dropout Operation The MP2104 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 continuously to deliver current to the output up to MP2104 Rev. 1.3 10/4/2005 the PFET current limit. The output voltage then is the input voltage minus the voltage drop across the main switch and the inductor. Short Circuit Protection The MP2104 has 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. The PFET current limit 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 MP2104 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. © 2005 MPS. All Rights Reserved. 7 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER APPLICATION INFORMATION Output Voltage Setting (MP2104DJ) The external resistor divider sets the output voltage (see Figure 3). The feedback resistor R1 also sets the feedback loop bandwidth with the internal compensation capacitor (see Figure 1). Choose R1 around 300kΩ for optimal transient response. R2 is then given by: R2 = R1 VOUT −1 0 .6 V Inductor Selection 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 <200mΩ. See Table 2 for recommended inductors and manufacturers. For most designs, the inductance value can be derived from the following equation: L= Table 1—Resistor Selection vs. Output Voltage Setting VOUT R1 R2 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%) VOUT × (VIN − VOUT ) VIN × ∆IL × fOSC Where ∆IL is the inductor ripple current. Choose inductor ripple current approximately 30% of the maximum load current, 600mA. The maximum inductor peak current is: IL(MAX ) = ILOAD + ∆IL 2 Under light load conditions below 100mA, larger inductance is recommended for improved efficiency. Table 3 lists inductors recommended for this purpose. Table 2—Suggested Surface Mount Inductors Manufacturer Part Number Inductance (µH) Max DCR (Ω) Saturation Current (A) Dimensions LxWxH (mm3) Coilcraft Toko Sumida Taiyo Yuden LP1704-222M D312C CDRH3D16 LBC2518 2.2 2.2 2.2 2.2 0.07 0.14 0.072 0.13 1.7 1.0 1.2 0.6 6.5x5.3x2 3.6x3.6x1 4x4x1.8 2.5x1.8x1.8 Table 3—Inductors for Improved Efficiency at 25mA, 50mA, under 100mA Load. Manufacturer Part Number Inductance (µH) Max DCR (Ω) Saturation Current (A) IRMS (A) Coilcraft Murata Sumida Sumida Sumida DO1605T-103MX LQH4C100K04 CMD4D06-100 CR32-100 CR54-100 10 10 10 10 10 0.3 0.2 0.3 0.2 0.1 1.0 1.2 0.7 1.0 1.2 0.9 0.8 0.5 0.7 1.4 MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 8 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. For most applications, a 4.7µF capacitor is sufficient. PC Board Layout The high current paths (GND, IN and SW) should be placed very close to the device with short, direct and wide traces. Input capacitor C1 needs to be as close as possible to the IN and GND pins. The external feedback resistors shall be placed next to the FB pin. Keep the switching node SW short and away from the feedback network. Figure 3 illustrates an example of PCB layout and signal routing. Output Capacitor Selection The output capacitor keeps output voltage ripple small and ensures regulation loop stable. The output capacitor impedance shall be low at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended. The output ripple ∆VOUT is approximately: ∆VOUT ≤ ⎞ VOUT × (VIN − VOUT ) ⎛ 1 ⎟ × ⎜⎜ ESR + ⎟ VIN × fOSC × L 8 × f × C 3 OSC ⎠ ⎝ Figure 3—MP2104 Suggested Layout For the fixed output versions (MP2104DJ-1.5 and MP2104-1.8), R1 is shorted and R2 is open. Efficiency vs Load Current 100 IN SW 3 MP2104 1 OFF ON EN GND FB OUTPUT 1.8V 600mA 5 2 90 VIN = 3.3V 80 EFFICIENCY (%) 4 INPUT 2.5V - 6V VIN = 4.2V 70 60 50 40 30 20 10 MP2104_F04 0 10 100 LOAD CURRENT (mA) 1000 MP2104-EC02 Figure 4—VIN = 2.5V to 6V, VOUT = 1.8V, ILOAD = 600mA Step-Down Circuit (L = 10µH for Higher Light-Load Efficiency) NOTICE: MPS believes the information in this document to be accurate and reliable. However, it is subject to change without notice. Contact MPS for current specifications. MPS encourages users of its products to ensure that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS cannot assume any legal responsibility for any said applications. MP2104 Rev. 1.0 10/4/05 © 2004 MPS, Inc. Monolithic Power Systems, Inc. 983 University Avenue, Building A, Los Gatos, CA 95032 USA Tel: 408-357-6600 ♦ Fax: 408-357-6601 ♦ www.MonolithicPower.com 9 TM MP2104 – 1.7MHz 600mA SYNCHRONOUS STEP-DOWN CONVERTER PACKAGE INFORMATION TSOT23-5 2.90 BSC 3 0.950 TYP . 10°TYP. (2 plcs) C L 2.80 BSC 1.60 BSC 3 0.950 TYP . + 4° - 0° 0° 0.25 BSC. ±0.10 Gauge Plane C L 0.87±0.03 1.00 Max. 0.300(Min) 0.500(Max) (5 PLCS) 0.400 0.00-0.10 SEATING PLANE 0.127 TYP. 10° TYP. (2 plcs) NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP2104 Rev. 1.3 10/4/2005 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. 10