ADP2114 Configurable, Dual Output, Synchronous Regulator
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The ADP2114 is a configurable dual output synchronous regulator that provides high efficiency power conversion for point-of-load applications. It offers design flexibility with two independent outputs, configurable output voltages and currents, and synchronization capabilities. The device aims to meet the important requirements of flexibility, versatility, ease-of-use, high efficiency, and low noise for powering demanding loads in communications, industrial, and consumer applications.
ADP2114 Configurable, Dual Output, Synchronous Regulator
- 1. ADP2114 Configurable, Dual Output, Synchronous Regulator Source: ANALOG DEVICES
- 2. Introduction Purpose To introduce the ADP2114 DC/DC converter with its key features and typical application circuits. Outline ADP2114 Overview Key Features Application circuits Summary Content 15 pages
- 3. Terminology and Acronyms Switching Controller Switching MOSFETs are external to the device Generally used for high current loads >5A Switching Regulator Switching MOSFETs are internal to the device Generally used for low-medium currents 0.5A-5A The ADP2114 has integrated power MOSFETs providing a high-efficiency, compact solution Point of Load (POL) Voltage regulator or controller located directly next to the load No further steps of power conversion are required Switching Controller Switching Regulator
- 4. Market Overview Point-of-Load (POL) Applications Communications Infrastructure Industrial & Instrumentation Healthcare High-end Consumer Important Application Requirements Flexibility, Versatility, Configurability Simple, Ease-to-Use, with design tool support Low noise for high-performance, sensitive applications High Conversion Efficiency
- 5. ADP2114 Overview Flexible output configuration Two independent outputs 2A/2A or 3A/1A Single 4A output – PWMs 180°phase shifted Gate-drive optimized to support high performance, noise sensitive converters Current mode control for fast transient 95% peak efficiency Light load, pulse-skip mode for improved efficiency Bi-directional synchronization Independent Enable & Power Good Fixed & Programmable V OUT options Adjustable: 0.8V, 1.2V, 1.5V, 1.8V, 2.5V, 3.3V Programmable frequency options 300kHz, 600kHz, and 1.2MHz Input Voltage Guaranteed Output Current Output Voltage Accuracy Package Options Junction Temp. Range 2.7V to 5.5V 2A/2A, 1A/3A, or 4A 1.5% LFCSP-32L 5mm x 5mm -40°C to 125°C
- 6. Simplified Block Diagram ADP2114 Block Diagram
- 7. Typical Application (2A/2A) 3 resistor-selectable fixed switching frequencies fsw 6 selectable output voltages with a single resistor Programmable Soft-Start Time Independent PGOOD outputs Configurable outputs (2A/2A or 3A/1A) Configurable Clock output
- 8. Configurability for Broad Market Applications Figure 3 Four power Rails, Phase-shifted Outputs Figure 1 Two synchronized Phase-shifted Step-down DC-DC Converters Figure 2 Single synchronized Dual-phase Output ADP 2114 + 3 . 3 V 2 A + 1 . 8 V 2 A + 5 . 0 V L 1 L 2 Cin 1 Cin 2 Cout 1 Cout 2 SYNC ADP 2114 + 1 . 2 V 3 A + 3 . 3 V 1 A + 5 . 0 V ADP 2114 + 1 . 8 V 2 A + 2 . 5 V 2 A Cin 1 Cin 2 Cin 3 Cin 4 Cout 1 Cout 2 Cout 3 Cout 4 SYNC L 1 L 2 L 3 L 4
- 9. Interleaved Configuration Single 4A Output 2 Interleaved Phases 2 Inductors Effective output ripple frequency is doubled which halves the required output bypass capacitor value Output inductor & capacitor can be smaller than a traditional single inductor output scheme Dual-Phase Combined Output The current sharing mismatch at 4A load Is 200mA = 5%.
- 10. Reducing System Noise Synchronization The ADP2114 can be synchronized to an external clock or another ADP2114 Synchronization eliminates ‘beat’ or difference frequencies Optimized Gate-Drive slew rate Reduced slew-rate minimizes EMI emissions without compromising conversion efficiency Phase Shift between Phases ADP2114 output switching is shifted 180° between phases reducing stress on the input capacitors and filters Synchronized to an external clock Synchronization between ADP2114s
- 11. ADP2114 – Improving Energy Efficiency High conversion efficiency ~95% with a 5V input and a 3.3V output ADP2114 features a high switching frequency, up to 1.2MHz, to reduce capacitor and inductor sizes. Optional pulse-skip mode reduces the switching losses at light load current or during periods of system inactivity Efficiency: with/without Pulse-Skip enabled Pulse-Skip at Light Load for Higher Efficiency
- 12. Additional Features Soft Start Reduces inrush current at power-up and enables voltage tracking Hiccup Mode Provides output protection under short circuit conditions Periodically performs re-entry or retry to start normal operation Independent Power Good Outputs and Enable Inputs Simple & reliable sequencing ‘ Daisy Chain’ sequencing Soft-Start Hiccup Mode: Shorted-Output Protection
- 13. Powering the High Speed ADC
- 14. ADP2114 Evaluation Board ADP2114-EVALZ The ADP2114 evaluation board comes in two versions: ADP2114-EVALZ : 3.3 V at 2 A and 1.8 V at 2 A outputs, 600 kHz, and pulse skip enabled ADP2114-2PH-EVALZ : Interleaved 1.2 V at 4 A single output, switching frequency set to 1.2 MHz, and forced PWM mode
- 15. Summary Product Performance and Key Features Design flexibility, versatility, & configurability Simple, ease-to-use, with design tool support High conversion efficiency ~95% from light to heavy loads Enable inputs & power good outputs for reliable sequencing Low noise for high-performance, sensitive applications
- 16. Additional Resource For ordering the ADP2114, please click the part list or Call our sales hotline For more product information go to http://www.analog.com/ADP2114 Visit Element 14 to post your question www.element-14.com For additional inquires contact our technical service hotline or even use our “Live Technical Chat” online facility Newark Farnell
Editor's Notes
- #2: Welcome to the training module on ADP2114 Configurable, Dual Output, Synchronous Regulator .
- #3: This training module introduces the ADP2114 DC/DC converter with its key features and typical application circuits.
- #4: Both switching controllers and switching regulators convert the DC input voltage to a fixed output voltage. In a switching controller, the output voltage is applied to external MOSFET or BJT (BIPOLAR JUNCTION TRANSISTOR ) switch, but the MOSFETs are integrated into a switching regulator. No mater which method is used, the filtered switch output voltage is fed back to a circuit that controls the power switch on and off, so that the output voltage remains constant regardless of input voltage or load current changes. Normally, the switching controller is used for loads current greater than 5A applications, and the switching regulator is suitable for low or medium currents from 0.5A to 5A. Point of Loads are voltage regulators or controllers that are located directly next to the load. Therefore, there is no further steps of power conversion required.
- #5: The switch regulator features high conversion efficiency, flexibility, and configurability. With design tool support, it is easy to use. Its low noise characteristic make it suitable for high performance and sensitive applications. The switch regulator benefits point-of-load applications such as digital signal processors, ASICs, FPGAs, microprocessors and microcontrollers used in communications, networking, industrial, healthcare and a wide variety of other applications. Next we will introduce the ADP2114 which satisfies a wide range of customer POL requirements.
- #6: The ADP2114 is a synchronous step-down switching regulator. It can be configured to deliver independent outputs at 2A and 2A (or 3A/1A) or can be configured as a single output capable of delivering 4A. The device operates over an input voltage range of 2.75V to 5.5V. Each output channel provides an adjustable output down to 0.6V and delivers up to 2A of load current. The integrated high-side, P-channel power MOSFET and the low-side, N-channel power MOSFET yield high efficiency at medium to heavy loads. Pulse skip mode is available for improved efficiency at light loads. The ADP2114 provides high efficiency and operates at switching frequencies of up to 2 MHz.
- #7: The ADP2114 consists of two step-down, dc-to-dc converters that deliver regulated output voltages, V1 and V2, by modulating the duty cycle at which the internal high-side, P-channel power MOSFET and the low-side, N-channel power MOSFET are switched on and off. The output of the PWM comparator modulates the duty cycle by adjusting the trailing edge of the PWM that switches the power devices
- #8: Here is one typical application circuit of the ADP2114. From the diagram, we can see the device is configured to deliver two outputs at 2A and 2A, and its output voltage is set to 1.8V and 3.3V. Changing the resistors (R SET2 and R SET1 ) value will change the output voltage correspondingly. The resistor R FREQ connected FREQ pin and GND is used to set the switching frequency. In order to set the output current to 2A/2A, a 4.7K Ω resistor (R OPCFG ) has to be connected with OPCFG pin and ground. Two open-drain, power-good outputs (PGOOD1 and PGOOD2) indicate the health of the converter output voltage. This schematic can be used to power DSPs and FPGAs.
- #9: The ADP2114 can be designed into a broad range of application due to its versatile nature. In figure 1, the device is configured to provide two independent channel outputs, each at 2A but different output voltages, 3.3V and 1.8V. In figure 2, the ADP2114 is configured as single output. We will introduce it in detail in next page. In figure 3, the device is configured as a 4-phase solution.
- #10: In the interleaved configuration, the outputs of the two channels are connected together, and they generate a single DC output voltage. For this single combined dual-phase output, only Mode 2 in the OPCFG options can be used. The two channels are 180º phase shifted to reduce input ripple current and to reduce input capacitance. Effective output ripple frequency can be doubled which halves the required output bypass capacitor value. Another advantage is the output inductor & capacitor can be smaller than a traditional single inductor output scheme.
- #11: Normally the noise comes from two sources: noise coupled directly into the converter through supply ripple and noise due to magnetic coupling effects. There are three mechanism used to reduce system noise. The first is to synchronize the ADP2114 by an external clock or another ADP2114. This clock distribution approach synchronizes all DC-DC converters in the system and prevents beat harmonics that can lead to EMI issues. The slew rate of the switch node is controlled by the size of the driver devices. Fast slewing of the switch node is desirable to minimize transition losses but can lead to serious EMI issues due to parasitic inductance. Therefore, reduced slew-rate minimizes EMI emissions without compromising conversion efficiency. The last is the output switching shifted 180° between phases to reduce stress on the input capacitors and filters.
- #12: The ADP2114 can achieve high power conversion efficiency up to 95 percent with a 5V input and a 3.3V output. The ADP2114 has built-in, pulse skip circuitry that turns on during light loads, switching only as necessary to maintain the output voltage within regulation. This allows the converter to maintain high efficiency during light load operation by reducing the switching loss. The high switching frequency of ADP2114 allows for minimal output voltage ripple even with small inductors. The sizing of the inductor is a trade-off between efficiency and transient response.
- #13: The ADP2114 also includes undervoltage lockout (UVLO) with hysteresis, soft start, and power good, as well as protection features such as output short-circuit protection and thermal shutdown. These features are externally programmable with tiny resistors and capacitors. The ADP2114 soft start feature allows the output voltage to ramp up in a controlled manner, eliminating output voltage overshoot during startup. The hiccup mode current limit feature provide output protection under short circuit conditions and periodically performs re-entry or retry to start normal operation. The ADP2114 features open-drain, power-good outputs that indicate when the converter output voltage is within regulation.
- #14: Here is the schematic for powering the AD9268 ADC using ADP2114. One of its output supplies AVDD; the second output supplies DRVDD. The analog input of the ADC was supplied through a double balun input network, which converts the single-ended output from the signal generator for differential input for the ADC. The sample clock source was a low jitter Wenzel oscillator, which was also supplied through a balun circuit for single-ended to differential conversion. The ADP2114 can run asynchronously or it can be synchronized to the converter’s sample clock without affecting the ADC’s performance. Synchronization allows for additional freedom in applications where it may be advantageous.
- #15: The ADP2114 evaluation / demo board is a complete, dual, step-down, dc-to-dc converter design based on the ADP2114, a configurable, dual 2 A/single 4 A, synchronous step-down, dc-to-dc regulator. The ADP2114 is a versatile step-down switching regulator that satisfies a wide range of user point-of-load requirements. The two PWM channels are 180° phase shifted and provide ±1.5% accurate regulated output voltages
- #16: In summary, the ADP2114 is a highly versatile, synchronous step-down, switching regulator that can be configured to satisfy a wide range of customer point of load requirements. With the design tool support, it is ease to use. Designed for noise-sensitive point-of-load applications, the ADP2114 achieves high-power conversion efficiency up to 95 per cent, enabling designers to reduce time to market and provide higher reliability for medical, consumer, communications infrastructure and industrial system applications.
- #17: Thank you for taking the time to view this presentation on “ ADP2114 Configurable, Dual Output, Synchronous Regulator ” . If you would like to learn more or go on to purchase some of these devices, you may either click on the part list link, or simply call our sales hotline. For more technical information you may either visit the Analog Devices site, or if you would prefer to speak to someone live, please call our hotline number, or even use our ‘live chat’ online facility. You may visit Element 14 e-community to post your questions.