MPQ28164GD-P

MPQ28164 High-Efficiency, Single-Inductor, Buck-Boost Converter with 4.2A Switches DESCRIPTION FEATURES The MPQ28164 is a high-efficiency, lowquiescent current, buck-boost converter that operates from an input voltage above, equal to, or below the output voltage. The MPQ28164 provides a compact solution for products powered by one-cell Lithium-ion or multi-cell alkaline batteries where the output voltage is within the battery voltage range.      The MPQ28164 uses current-mode control with a fixed PWM frequency for optimal stability and transient response. The fixed 2MHz switching frequency and integrated low RDS(ON) MOSFETs minimize the solution footprint while maintaining high efficiency.         To ensure the longest possible battery life, the MPQ28164 uses an optional pulse-skipping mode that reduces the switching frequency under light-load conditions. For other low-noise applications where pulse-skipping mode may cause interference, a high-logic input on the MODE/SYNC pin guarantees fixed-frequency PWM operation under all load conditions.   1.8V Minimum Start-Up Input Voltage 1.2V to 5.5V Input Work Range 1.5V to 5V Output Range 4.2A Switching Current Limit 3.3V/2A Load Capability from a 2.5V to 5.5V Input Supply 2MHz Fixed or External Synchronous Switching Frequency Selectable PSM and PWM Mode Typical 25μA Quiescent Current High Efficiency up to 95% Load Disconnect during Shutdown Internal Soft Start (SS) and Compensation Power Good Indicator Hiccup Mode for Short-Circuit Protection (SCP) Over-Temperature Protection (OTP) Available in a Small QFN-11 (2mmx3mm) Package APPLICATIONS     The MPQ28164 operates with an input voltage from 1.2V to 5.5V to provide an adjustable output voltage from 1.5V to 5V. With an input from 2.5V to 5.5V, the device can supply 2A of current to the load with a 3.3V output voltage. Battery-Powered Devices Portable Instruments Tablet PCs Super-Cap Chargers All MPS parts are lead-free, halogen-free, and adhere to the RoHS directive. For MPS green status, please visit the MPS website under Quality Assurance. “MPS”, the MPS logo, and “Simple, Easy Solutions” are trademarks of Monolithic Power Systems, Inc. or its subsidiaries. The MPQ28164 is available in a small QFN-11 (2mmx3mm) package. TYPICAL APPLICATION L1 1µH SW1 VIN VIN C1 22µF EN SW2 R1 560kΩ FB VCC C3 1µF MODE/SYNC AGND VOUT=3.3V VOUT C2 22µFx2 R2 100kΩ PG PGND MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 1 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES ORDERING INFORMATION Part Number* MPQ28164GD Package QFN-11 (2mmx3mm) Top Marking See Below * For Tape & Reel, add suffix –Z (e.g. MPQ28164GD–Z). TOP MARKING ANA: Product code of MPQ28164GD Y: Year code W: Week code LLL: Lot number PACKAGE REFERENCE TOP VIEW EN MODE/ SYNC PG VCC AGND FB 1 11 VIN 10 SW1 9 PGND 8 SW2 7 VOUT 2 3 4 5 6 QFN-11 (2mmx3mm) MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 2 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES PIN FUNCTIONS Pin # 1 2 3 4 5 6 7 8 9 10 11 Name Description On/off control. Pull EN high to enable the MPQ28164. Pull EN low or leave EN EN floating to disable all of the internal circuits. EN is pulled down to AGND with a 1.5MΩ resistor internally. Operation mode selection. If MODE/SYNC is low, the MPQ28164 switches between PSM and fixed frequency PWM automatically according to the load level. If MODE/SYNC is high, the MPQ28164 works in fixed-frquency PWM mode MODE/SYNC continuously. An external clock can be applied to MODE/SYNC for switching frequency synchronization. MODE/SYNC is pulled down to AGND with a 1MΩ resistor internally. MODE/SYNC should be pulled high or low through a resistor smaller than 10kΩ. PG Power good indicator. PG switches high and low based on the feedback voltage. Supply voltage for control stage. VCC is powered by the higher value of either VIN VCC or VOUT. Decouple VCC with a 1μF capacitor. AGND Signal ground. Output voltage feedback. Keep FB and its associated traces far away from noise FB sources like SW. Buck-boost converter output. An output capacitor should be placed close to VOUT VOUT and PGND. Switch. Internal switches are connected to SW2. Connect an inductor between SW1 SW2 and SW2. PGND Power ground. Switch. Internal switches are connected to SW1. Connect an inductor between SW1 SW1 and SW2. VIN Supply voltage for the power stage. ABSOLUTE MAXIMUM RATINGS (1) VIN to GND ....................................... -0.3V to 6V SW1/2 to GND .................. -0.3V (-2V for VOUT) When the input voltage is significantly higher than the output voltage, the converter can deliver energy to the load within SWA’s maximum duty cycle by switching SWA and SWB. The converter operates in buck mode. In this condition, SWD remains on and SWC remains off. VC-Buck is compared with the current ramp signal normally and generates a PWM output. Therefore, SWA/SWB are pulse-width modulated to produce the required duty cycle and eventually support the output voltage. Buck-Boost Region (VIN ≈ VOUT) When VIN is close to VOUT, the converter is unable to provide enough energy to the load due to SWA’s maximum duty cycle, so the current ramp signal cannot trigger VC-Buck in the first period, and SWA remains on with 100% duty cycle. If SWB is not turned on in the first period, boost begins working in the secondary period (SWC switches in the secondary period), and an offset voltage is added to the current ramp signal to allow it to reach VC-Buck. SWC turns off when the current ramp signal intersects with VC-Boost in the secondary period, and SWD conducts the inductor current when SWC is off. This is called boost operation. SWA turns off when the current ramp signal intersects with VC-Buck in the secondary period, and SWB turns on to conduct the inductor current after SWA turns off. This is called buck operation. If SWB turns on in the secondary period, the boost operation (SWC on) is disabled in the following cycle. If SWA continues to conduct with 100% duty in the secondary cycle, the boost operation is also enabled in the following duty cycle. SWA/SWB and SWC/SWD switch during this condition simultaneously. This is called buck-boost mode. Boost Region (VIN < VOUT) When the input voltage is significantly lower than the output voltage, the control voltage (VCBuck) is always higher than the current ramp signal. The offset voltage is added to the current signal, so SWB cannot turn on in all cycles. The boost operation (SWC on) is enabled in every cycle based on the logic, so only SWC and SWD switch. This is called boost mode. In this condition, SWC/SWD are pulsewidth modulated to produce the required duty cycle and eventually support the output regulation voltage. Under-Voltage Lockout (UVLO) Under-voltage lockout (UVLO) is used to protect the device from operating at an insufficient supply voltage. The MPQ28164’s UVLO circuit monitors the VCC voltage. During start-up, VIN must rise higher than VIN-UVLO-R to support enough VCC voltage and enable the IC. After the IC is enabled, VCC is powered by VIN or VOUT (depending on which is higher), so the IC can work, even if VIN drops to 1.2V, unless VCC drops to the VCC-UVLO-F threshold. During start-up, if VCC has a bias voltage from another power supply, the MPQ28164 can work with 1.2V of input power. If VIN is much lower than 1.2V, the SWA RDS(ON) is high, and the MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 13 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES MPQ28164 cannot supply high power to the output. If VIN drops to 0.69V, the MPQ28164 stops working. VCC Power Supply When EN is high and VIN ramps up, VIN charges VCC. If VIN is higher than VIN-UVLO-R, the MPQ28164 begins working. All internal circuits of the MPQ28164 are supplied by VCC, and VCC only needs to be decoupled with a ceramic capacitor less than 1µF. After the system starts up, VCC is powered by the higher value of VIN or VOUT internally. If VCC is powered by VOUT, the MPQ28164 does not shut down until VIN drops to the UVLO falling threshold (0.69V) or VCC drops to the VCC UVLO falling threshold (1.56V). It is not suggested to supply the MPQ28164 with an input lower than 1.2V, even if VCC has a bias voltage due to SWA (P-FET) having an RDS(ON) that is too high when VIN is low. Even with 1.2V of input power, the load capability is weaker than the high input condition due to the RDS(ON). Internal Soft Start (SS) When EN is high and VIN is above the UVLO rising threshold, the MPQ28164 starts up with a soft-start (SS) function. The internal soft-start signal ramps up and controls the feedback reference voltage. After 4ms of blank time, if VOUT has not risen to 60% of the normal output voltage or if VOUT is pulled down to 60% of the normal output voltage due to an overload, the soft-start signal is pulled down to GND, and hiccup protection is initiated. During start-up or a hiccup recovery condition, an internal SS signal is clamped to VFB + 0.3V if VOUT does not rise up. This limit can prevent a VOUT overshoot if the heavy load disappears suddenly during start-up. During start-up or recovery from hiccup, if there is already some voltage on the output, this voltage is discharged by the negative current limit (-1A when the MPQ28164 operates in PWM mode regardless of the MODE/SYNC setting) to equal the SS voltage. VOUT then rises normally. MODE/SYNC Setting The MPQ28164 can be set in power-save mode (PSM) or fixed-frequency PWM mode in light load through the MODE/SYNC setting. When MODE/SYNC is pulled high, the MPQ28164 operates in fixed-frequency PWM mode. The current conducts while the inductor current direction reverses. In this mode, the VOUT ripple is lower than it is in PSM, but the power loss is higher due to the high-frequency switching. When MODE/SYNC is pulled low, the MPQ28164 enters PSM automatically when the load decreases. In PSM, a group of switching pulses are initiated when the internal VC-Buck rises higher than the PSM threshold (group pulses start with SWA/SWC on and end with SWB/SWD on). SWD is turned off if the SWD current flows from VOUT to SW2 in each period. During start-up or a short-circuit protection (SCP) recovery condition, the MPQ28164 works in fixed-frequency PWM mode, even if MODE/SYNC is low. The negative inductor current is limited to -1A, the same as in constant frequency mode. OCP/SCP and Two Current Limits There are two peak-current limits in the MPQ28164. One is a steady-state switching current limit with a 4.2A typical value, and the other is a start-up switching current limit with a 2.5A typical value. The start-up current limit can control the input inrush current at a lower level when VFB < 60% x VREF during start-up. In overload or short-circuit condition, VOUT drops due to the steady-state switching current limit. If VOUT drops below 60% of its normal output, the MPQ28164 stops switching and recovers after ~8ms with hiccup mode protection. After the switching stops in hiccup protection, the internal soft-start signal is clamped to VFB + 0.3V, where VFB is the divided voltage from the residual VOUT. This smooths the soft start-up when the MPQ28164 recovers from hiccup protection. During the soft-start time, the MPQ28164 blanks during hiccup protection for about 4ms. After the 4ms blank time, if VOUT is still lower than 60% of the normal voltage, the MPQ28164 resumes hiccup mode. If VOUT rises above 60% of the normal value, the MPQ28164 enters normal operation. MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 14 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES Power Good (PG) The MPQ28164 has a power-good (PG) output. PG is the open drain of the MOSFET. Pull PG up to VCC through a resistor (typically 100kΩ) during the application. After the FB voltage reaches 91.5% of the VREF voltage, PG is pulled high. When the FB voltage drops to 76% of the VREF voltage, PG is pulled low. PG has a self-driving capability. If the MPQ28164 is off and PG is pulled up to another DC power source through a resistor, PG can also be pulled low (~0.7V) by the self-driving circuit. Over-Voltage Protection (OVP) If VOUT is higher than the typical 6.3V value, the switching stops. This helps protect the device from high-voltage stress. After the output drops below 5.3V, the switching recovers automatically. Over-Temperature Protection (OTP) An internal temperature sensor continuously monitors the IC junction temperature. If the IC temperature exceeds 160°C, the device stops operating. Once the temperature falls below 140°C, normal operation resumes. MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 15 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES APPLICATION INFORMATION Setting the Output Voltage A resistor divider from VOUT to FB is necessary to set the MPQ28164’s output voltage. The high-side feedback resistor (R1) can be calculated with Equation (1): R1  ( VOUT  1)  R2 VFB (1) Where R2 is the low-side feedback resistor with a recommended value from 60 - 360kΩ to balance the stability and transient response. Selecting an Inductor With one buck-boost topology circuit, the inductor must support the buck application with the maximum input voltage and boost application with the minimum input voltage. Two critical inductance values can be determined according to the buck mode and boost mode current ripple, as shown in Equation (2) and Equation (3): L MINBUCK  LMINBOOST  VOUT  ( VIN(MAX )  VOUT ) VIN(MAX )  FREQ  IL VIN(MIN)  ( VOUT  VIN(MIN) ) VOUT  FREQ  IL (2) (3) In addition to the inductance value, the inductor must support the peak current based on Equation (4) and Equation (5) to avoid saturation: IPEAK BOOST  VOUT  (VIN(MAX)  VOUT ) 2  VIN(MAX)  FREQ  L Output capacitors with a minimum 10µF input and 22µF output are required to achieve optimal behavior from the device. The output capacitor affects loop stability. The input and output capacitors must be placed as close to the device as possible. Refer to the Typical Application Circuits section for optimized capacitor selection details. PCB Layout Guidelines Efficient PCB layout of the high-frequency switching power supplies is critical for stable operation. Poor layout can result in reduced performance, excessive EMI, resistive loss, and system instability. For best results, refer to Figure 3 and Figure 4 and follow the guidelines below. 1. Place the input capacitor and output capacitor close to VIN, VOUT, and PGND. 2. Place the VCC decoupling capacitor close to VCC and AGND. Where FREQ is the switching frequency, and ∆IL is the peak-to-peak inductor current ripple. The peak-to-peak ripple can be set to 10 - 30% of the inductor current. The minimum inductor value for the application must be higher than the calculated value from both Equation (2) and Equation (3). IPEAK BUCK  IOUT  Selecting an Input and Output Capacitor It is recommended to use ceramic capacitors with a low ESR as input and output capacitors to filter any disturbance present in the input and output line and to achieve stable operation. 3. Keep the FB resistor divider very close to FB. 4. Keep the FB trace far away from noise sources, such as SW1 and SW2. 5. Ensure that the layout of the copper of GND, VIN, and VOUT is wide enough to conduct high current and lower the die temperature. 6. Place vias in the GND copper around the chip for better thermal performance. (4) VOUT  IOUT VIN(MIN)  (VOUT  VIN(MIN) )  (5)  VIN(MIN) 2  VOUT  FREQ  L Where η is the estimated efficiency. MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 16 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES L1 SW1 1 2 VIN VIN SW2 VOUT VOUT R1 C1 C2 EN FB VIN VOUT R2 VCC C3 MODE /SYNC AGND GND EN PG GND Top Layer GND PG PGND Figure 4: Reference Circuit for PCB Guide Design Example Table 1 shows a design example following the application guidelines for the specifications below. Table 1: Design Example 1.8 - 5.5 Start-Up VIN (V) 1.2 - 5.5 Operation VIN (V) 3.3 VOUT (V) The detailed application schematic is shown in Figure 5 and the performance can be found in the Typical Performance Characteristics section. Bottom Layer Figure 3: Recommended Layout MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 17 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES TYPICAL APPLICATION CIRCUITS L1 1µH SW1 VIN=1.8-5.5V C1 22µF R3 100kΩ SW2 VIN U1 VOUT=3.3V VOUT R1 560kΩ MPQ28164 C2A C2B FB EN EN PG MODE AGND PGND MODE/ SYNC PG R4 100kΩ VCC 22µF R2 100kΩ 22µF C3 1µF Figure 5: 3.3V Output Application Circuit L1 1.5µH SW1 VIN=1.8-5.5V EN VIN U1 VOUT=5V VOUT MPQ28164 R1 560kΩ C2A C2B FB EN PG MODE/ SYNC PGND MODE R3 100kΩ AGND C1 22µF SW2 PG R4 100kΩ VCC 22µF R2 63.4kΩ 22µF C3 1µF Figure 6: 5V Output Application Circuit MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 18 MPQ28164 – SINGLE-INDUCTOR, BUCK-BOOST CONVERTER W/ 4.2A SWITCHES PACKAGE INFORMATION QFN-11 (2mmx3mm) PIN 1 ID 0.125X45º TYP PIN 1 ID MARKING PIN 1 ID INDEX AREA BOTTOM VIEW TOP VIEW SIDE VIEW 0.125X45º NOTE: 1) ALL DIMENSIONS ARE IN MILLIMETERS. 2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH. 3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETERS MAX. 4) JEDEC REFERENCE IS MO-220. 5) DRAWING IS NOT TO SCALE. RECOMMENDED LAND PATTERN 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. MPQ28164 Rev. 1.0 www.MonolithicPower.com 11/13/2018 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2018 MPS. All Rights Reserved. 19