LM2772SD/NOPB

LM2772 www.ti.com SNVS486B – DECEMBER 2006 – REVISED MAY 2013 LM2772 Low-Ripple Switched Capacitor Step-Down Regulator Check for Samples: LM2772 FEATURES DESCRIPTION • • • • • • • • • • • • The LM2772 is a switched capacitor step-down regulator that produces a 1.2V output. It is capable of supplying loads up to 150mA with 3% output voltage regulation over line, load, and temperature. The LM2772 operates with an input voltage from 3.0V to 5.5V, accommodating 1-cell Li-Ion batteries and chargers. 1 2 Low-Noise Fixed Frequency Operation 1.2V Output Voltage 3% Output Voltage Regulation Li-Ion (3.6V) to 1.2V with 80% Efficiency Very Low Output Ripple: 8mV @ 150mA Output Currents up to 150mA 2.7V to 5.5V Input Voltage Range Shutdown Disconnects Load from VIN 1.1MHz Switching Frequency No Inductors…Small Solution Size Short Circuit and Thermal Protection WSON-10 Package (3mm × 3mm × 0.8mm) APPLICATIONS • • • The LM2772 utilizes a highly efficient regulated multigain charge pump. Pre-regulated 1.1MHz fixedfrequency switching results in very low ripple and noise on both the input and the output. When output currents are low, the part automatically switches to a low-ripple PFM regulation mode to maintain high efficiency over the entire load range. The LM2772 is available in TI’s WSON-10 Package (WSON-10). DSP, Memory, and Microprocessor Power Supplies Mobile Phones and Pagers Portable Electronic Devices Typical Application Circuit VOUT: 1.2V VIN = 3.0V to 5.5V IOUT up to 150 mA VIN VOUT CIN COUT 1 µF 4.7 µF C1+ GND LM2772 C1 1 µF High: ON Low: Shutdown C1C2+ EN C3+ C3 1 µF C2 1 µF C3- C2- Capacitors: 1 µF - TDK C1005X5R0J105K 4.7 µF - TDK C1608X5R0J475K or equivalent Figure 1. Figure 2. LM2772 Efficiency vs. Low-Dropout Linear Regulator (LDO) Efficiency 1 2 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2006–2013, Texas Instruments Incorporated LM2772 SNVS486B – DECEMBER 2006 – REVISED MAY 2013 www.ti.com Connection Diagram VIN 1 10 EN EN 10 1 VIN GND 2 9 C1+ C1+ 9 2 GND VOUT 3 8 C1- C1- 8 3 VOUT C3- 4 7 C2+ C2+ 7 4 C3- C3+ 5 6 C2- C2- 6 5 C3+ Die-Attach Pad: GND Die-Attach Pad: GND Top View Bottom View 10-Pin WSON Package (WSON-10) See Package Number DSC0010A PIN DESCRIPTIONS Pin # Name 1 VIN Description 2 GND Ground 3 VOUT Output Voltage 4 C3- Flying Capacitor 3: Negative Terminal 5 C3+ Flying Capacitor 3: Positive Terminal 6 C2- Flying Capacitor 2: Negative Terminal 7 C2+ Flying Capacitor 2: Positive Terminal 8 C1- Flying Capacitor 1: Negative Terminal 9 C1+ Flying Capacitor 1: Positive Terminal 10 EN Enable Pin Logic Input. Applying a logic HIGH voltage signal enables the part. A logic LOW voltage signal places the the device in shutdown. Input Voltage: Recommended VIN operating range 3.0V to 5.5V. These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 2 Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 LM2772 www.ti.com SNVS486B – DECEMBER 2006 – REVISED MAY 2013 Absolute Maximum Ratings (1) (2) (3) VIN Pin Voltage -0.3V to 6.0V EN Pin Voltage -0.3V to (VIN+0.3V) w/ 6.0V max Continuous Power Dissipation (4) Internally Limited Junction Temperature (TJ-MAX) 150ºC Storage Temperature Range Maximum Lead Temperature -65ºC to +150º C (5) 265ºC ESD Rating (6) Human Body Model: (1) (2) (3) (4) (5) (6) 2.0kV Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of the device is ensured. Operating Ratings do not imply ensured performance limits. For ensured performance limits and associated test conditions, see the Electrical Characteristics tables. If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications. All voltages are with respect to the potential at the GND pins. Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ=150ºC (typ.) and disengages at TJ=140ºC (typ.). For detailed information on soldering requirements and recommendations, please refer to Texas Instruments' Application Note 1187 (SNOA401): Leadless Leadframe Package (LLP). The Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. MIL-STD-883 3015.7 Operating Ratings (1) (2) Input Voltage Range 2.7V to 5.5V Recommended Load Current Range 0mA to 150mA Junction Temperature (TJ) Range -30°C to +110°C Ambient Temperature (TA) Range (3) (1) (2) (3) -30°C to +85°C Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation of the device is ensured. Operating Ratings do not imply ensured performance limits. For ensured performance limits and associated test conditions, see the Electrical Characteristics tables. All voltages are with respect to the potential at the GND pins. Maximum ambient temperature (TA-MAX) is dependent on the maximum operating junction temperature (TJ-MAX-OP = 110ºC), the maximum power dissipation of the device in the application (PD-MAX), and the junction-to ambient thermal resistance of the part/package in the application (θJA), as given by the following equation: TA-MAX = TJ-MAX-OP – (θJA × PD-MAX). Thermal Properties Junction-to-Ambient Thermal Resistance (θJA), WSON-10 Package (1) (1) 55°C/W Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists, special care must be paid to thermal dissipation issues. Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 3 LM2772 SNVS486B – DECEMBER 2006 – REVISED MAY 2013 www.ti.com Electrical Characteristics (1) (2) Limits in standard typeface are for TJ = 25ºC. Limits in boldface type apply over the full operating junction temperature range (-30°C ≤ TJ ≤ +110°C) . Unless otherwise noted, specifications apply to the LM2772 Typical Application Circuit (pg. 1) with: VIN = 3.6V; V(EN) = 1.8V, CIN = C1 = C2 = C3 = 1.0µF, COUT = 4.7µF. (3) Symbol VOUT Parameter 1.2V Output Voltage Regulation Typ Max 3.0V ≤ VIN ≤ 5.5V 0mA ≤ IOUT ≤ 150mA Condition 1.164 (−3%) Min 1.2 1.236 (+3%) 0mA ≤ IOUT ≤ 150mA 1.178 (−1.8%) 1.2 1.236 (+3.0%) 0mA ≤ IOUT ≤ 150mA Units V VOUT/IOUT Output Load Regulation VOUT/VIN Output Line Regulation E Power Efficiency IOUT = 150mA 80 IQ Quiescent Supply Current IOUT = 0mA (4) 47 VR Fixed Frequency Output Ripple 40mA ≤ IOUT ≤ 150mA 8 VR–PFM PFM–Mode Output Ripple IOUT < 40mA 12 ISD Shutdown Current V(EN) = 0V 0.01 0.3 µA FSW Switching Frequency 3.0V ≤ VIN ≤ 5.5V 1.15 1.50 MHz ICL Output Current Limit VIN = 5.5V 0V ≤ VOUT ≤ 0.2V tON Turn-on Time VIL Logic-low Input Voltage 3.0V ≤ VIN ≤ 5.5V 0 VIH Logic-high Input Voltage 3.0V ≤ VIN ≤ 5.5V 1.1 IIH Logic-high Input Current V(EN) = 1.8V (5) 5 µA IIL Logic-low Input Current Logic Input = 0V 0.01 µA (1) (2) (3) (4) (5) 4 0.80 0.15 mV/mA 0.2 %/V % 50 µA mV mV 500 mA 150 µs 0.63 VIN V V All voltages are with respect to the potential at the GND pins. Min and Max limits are specified by design, test, or statistical analysis. Typical numbers are not ensured, but do represent the most likely norm. CIN, COUT, C1, C2, C3: Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics. VOUT is set to 1.3V during this test (Device is not switching). There is a 350kΩ pull-down resistor connected internally between the EN pin and GND. Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 LM2772 www.ti.com SNVS486B – DECEMBER 2006 – REVISED MAY 2013 BLOCK DIAGRAM LM2772 VIN C1+ C11.04M SWITCH ARRAY GAIN CONTROL 950k SWITCH CONTROL 1 2 C2+ 1 G =2, 5,3 C2C3+ C3- 775k PFM Control GND VOUT Current sense 1.1 MHz OSC. 1.25V Ref. EN Enable/ Shutdown Control EN Soft-Start Ramp 0.8V Ref. Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 5 LM2772 SNVS486B – DECEMBER 2006 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics Unless otherwise specified: VIN = 3.6V, CIN = C1 = C2 = C3 = 1.0µF, COUT = 4.7µF, TA = 25ºC. Capacitors are low-ESR multilayer ceramic capacitors (MLCC's). Output Voltage vs. Input Voltage Output Voltage vs. Output Current Figure 3. Figure 4. Efficiency vs. Input Voltage Operating Supply Current Figure 5. Figure 6. Input and Output Voltage Ripple, Load = 150mA Load Step 10mA to 150mA, VIN = 3.6V CH1: VIN, Scale: 50mV/Div, AC Coupled CH3: VOUT, Scale: 10mV/Div, AC Coupled Time scale: 1µs/Div Figure 7. 6 Submit Documentation Feedback CH3: VOUT; Scale: 50mV/Div, AC Coupled CH4: IOUT; Scale: 100mA/Div Time scale: 40µs/Div Figure 8. Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 LM2772 www.ti.com SNVS486B – DECEMBER 2006 – REVISED MAY 2013 Typical Performance Characteristics (continued) Unless otherwise specified: VIN = 3.6V, CIN = C1 = C2 = C3 = 1.0µF, COUT = 4.7µF, TA = 25ºC. Capacitors are low-ESR multilayer ceramic capacitors (MLCC's). Load Step 10mA to 150mA, VIN = 4.7V CH3: VOUT; Scale: 50mV/Div, AC Coupled CH4: IOUT; Scale: 100mA/Div Time scale: 40µs/Div Figure 9. Line Step 3.5V to 4.0V with Load = 150mA CH2: VIN; Scale: 1V/Div, DC Coupled CH3: VOUT; Scale: 20mV/Div, AC Coupled Time scale: 400µs/Div Figure 10. Line Step 4.0V to 3.5V with Load = 150mA CH2: VIN; Scale: 1V/Div, DC Coupled CH3: VOUT; Scale: 20mV/Div, AC Coupled Time scale: 400µs/Div Figure 11. Oscillator Frequency vs. Input Voltage Figure 12. Startup Behavior, Load = 150mA CH1: VOUT; Scale: 200mV/Div, DC Coupled Time scale: 20µs/Div Figure 13. Submit Documentation Feedback Copyright © 2006–2013, Texas Instruments Incorporated Product Folder Links: LM2772 7 LM2772 SNVS486B – DECEMBER 2006 – REVISED MAY 2013 www.ti.com OPERATION DESCRIPTION Overview The LM2772 is a switched capacitor converter that produces a regulated, low voltage output. The core of the part is a highly efficient charge pump that utilizes fixed frequency pre-regulation and Pulse Frequency Modulation to minimize ripple and power losses over wide input voltage and output current ranges. A description of the principal operational characteristics of the LM2772 is detailed in the Circuit Description, and Efficiency Performance sections. These sections refer to details in the Block Diagram. Circuit Description The core of the LM2772 is a two-phase charge pump controlled by an internally generated non-overlapping clock. The charge pump operates by using external flying capacitors C1, C2, and C3 to transfer charge from the input to the output. At input voltages below 3.5V (typ.) the LM2772 operates in a 1/2x Gain, with the input current being equal to 1/2 of the load current. At input voltages between 3.5V to 4.6V(typ.) the part utilizes a gain of 2/5x, resulting in an input current equal to 2/5 times the load current. At input voltages above 4.6V (typ.), the part is in a gain of 1/3, with the input current being 1/3 of the load current. The two phases of the switched capacitor switching cycle will be referred to as the "charge phase" and the "discharge phase". During the charge phase, the flying capacitor is charged by the input supply. After half of the switching cycle [ t = 1/(2×FSW) ], the LM2772 switches to the discharge phase. In this configuration, the charge that was stored on the flying capacitors in the charge phase is transferred to the output. The LM2772 uses fixed frequency pre-regulation to regulate the output voltage to 1.2V during moderate to high load currents. The input and output connections of the flying capacitors are made with internal MOS switches. Pre-regulation limits the gate drive of the MOS switch connected between the voltage input and the flying capacitors. Controlling the on resistance of this switch limits the amount of charge transferred into and out of each flying capacitor during the charge and discharge phases, and in turn helps to keep the output ripple very low. When output currents are low (