60V Low IQ, Dual Output Synchronous Step-Down Controller with Adjustable Gate Drive Design Note 562 Victor Khasiev Introduction The LTC ®3892 is a dual output synchronous buck controller featuring a wide input voltage range of 4.5V to 60V and an output voltage of 0.8V to 99% of VIN. The combination of the LTC3892’s built-in FET drivers and external FETs yield high efficiency and high power capability, up to 97% efficiency and over 60A output current 2. Its robust design—an IC operating junction temperature range of –55°C to 150°C—meets the needs of industrial, automotive, telecom, military, aerospace and distributed systems.

and 3.9µA shutdown current, maintaining battery charge as long as possible. The LTC3892’s wide input voltage range satisfies the demanding requirements of industrial and automotive applications, which are distinguished by their lack of stable, high quality voltage sources. For example, in automotive environments, a 12V nominal voltage rail can range from a low 5V to above 50V during cold starts and load dumps. The LTC3892’s ability to sustain the output in the face of high voltage inputs eliminates costly voltage suppressors; its low minimum input

The LTC3892’s low IQ is indispensable in batterypowered applications where idle current must be kept low. It features 29µA no-load quiescent current VIN 6V TO 60V

+

VIN

CINA 5× 2.2µF 100V

CINP 47µF

0.1µF

4.7µF

PGOOD2

VFB2 TRACK/SS2

0.01µF VIN

1nF CINB

VIN

VOUT2 12V AT 5A

8m

+

0.1µF 10µF

Q2

VFB1

0.1µF

0.1µF

TRACK/SS1

ITH2

ITH1

RUN2

RUN1

SENSE2–

SENSE1–

SENSE2+

SENSE1+

2.2µF 100V

L1 Q1 15µH

150µF

35.7k

10k

20k 100pF

INTVCC

INTVCC

EXTVCC

0.1µF

1.8nF

DRVUV DRVSET FREQ PLLIN/MODE

PGOOD1

1M

100k

7.15k

LTC3892EUHF ILIM VPRG1

DRVCC 1M

INTVCC

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners.

VIN

TG1

SW2

SW1

BOOST2 BG2

GND

BOOST1 BG1

100pF

1nF 2.2µF 100V

TG2

CINC

VIN Q3 L2 5.6µH

5m

+

0.1µF Q4

Figure 1. LTC3892, Dual Output DC/DC Converter Schematic 05/17/562

1.8nF

10µF

VOUT1 5V AT 8A 470µF

maintains an uninterrupted logic supply when the input voltage dips far below nominal. Another key feature of the LTC3892 is its programmable gate voltage that can be set from 5V to 10V. This is important for many reasons. A designer can choose a standard (10V) gate drive level and select switching devices from the wide variety of MOSFETs offered by multiple vendors, optimizing the supply efficiency and reducing overall cost. However, if gate driver loss is important, then logic level (5V) FETs can be used. As a compromise, the gate voltage can be programmed to any intermediate value, providing acceptable gate and minimum conduction losses1. The LTC3892 features programmable undervoltage lockout (UVLO) and programmable EXTVCC via the DRVUV pin. Circuit Description Figure 1 shows a single LTC3892, dual-output solution: 12V out at 5A and 5V out at 8A. The LTC3892 controls two power trains, each with a pair of switching MOSFETs, inductor and output filter. This circuit demonstrates the ability for VOUT1 to be set to a fixed level by programming the VPRG1 pin. In this schematic it’s set to 5V 1; consequently VOUT1 is connected directly to the FB1 pin. The standard gate drive level is selected by tying the DRVSET pin to the INTVCC pin. In the solution of Figure 1, the VIN pin and the drains of the top MOSFETs of both outputs are connected to the same input voltage VIN. However, these three

ports can be connected to different voltages or power supplies if needed. Designers can bias the LTC3892 through the VIN pin and apply a voltage from different sources to the drains of Q1 or Q3. Figures 2 and 3 illustrate the efficiency of the converter in Figure 1 at various input voltages. Demonstration circuits2 are available from the factory, designed to display a variety of load capabilities. Incorporating current mode control, a LTC3892 supply can be wired as a dual output supply as on the DC1998A demo board, as a 2-phase single output supply delivering 12V at 30A (DC2190A-B), or as a 4-phase single output supply generating 12V at 60A (DC2190A-A). Conclusion The LTC3892 is a versatile 60V input, dual output buck controller, optimized for high efficiency DC/ DC solutions in automotive, industrial and telecom fields. Other salient features include programmable gate voltage, extremely low no-load and shutdown quiescent current, programmable frequency, internal bootstrap diodes and easy current sharing for high current designs. References 1. http://cds.linear.com/docs/en/datasheet/ 38921fb.pdf, LTC3892 Family Data Sheet 2. http://www.linear.com/product/LTC3892# demoboards, LTC3892 Family Demo Circuits

96

98

94

96 EFFICIENCY (%)

EFFICIENCY (%)

92 90 88 86

16VIN 24VIN 36VIN 48VIN

84 82 0.5

1.5

2.5 3.5 4.5 5.5 6.5 OUTPUT CURRENT (A)

7.5 DN6VK F02

Figure 2. LTC3892, VOUT1, 5V Efficiency Curves Data Sheet Download

www.linear.com/LTC3892

94 92 90 16VIN 24VIN 36VIN 48VIN

88 86 0.5

1

1.5

2 2.5 3 3.5 4 OUTPUT CURRENT (A)

4.5

5

DN6VK F03

Figure 3. LTC3892, VOUT2, 12V Efficiency Curves For applications help, call (408) 432-1900, Ext. 3161 DN562 LT/AP 0517 71K • PRINTED IN THE USA

 LINEAR TECHNOLOGY CORPORATION 2017

DN562 - 60V Low IQ, Dual Output Synchronous ... - Linear Technology

150°C—meets the needs of industrial, automotive, telecom, military, aerospace and distributed systems. The LTC3892's low IQ is indispensable in battery-.

300KB Sizes 1 Downloads 260 Views

Recommend Documents

1µA IQ Synchronous Boost Converter Extends ... - Linear Technology
For applications help, call (408) 432-1900, Ext. 3788. IOUT (mA). 0.1 ... To simulate a real battery-operated application, the circuit in Figure 1 was tested with 1Ω ...

High Efficiency 100mA Synchronous Buck ... - Linear Technology
Design Note 532. Charlie Zhao. 11/14/ ... the cost of design and manufacture. The LTC3639 ... Figure 3 shows an application example of a 24V output,. 100mA ...

DN551 - Ultrathin Triple Output µModule ... - Linear Technology
Design Note 551. Sam Young and Afshin Odabaee. 06/16/551. Figure 1. Typical LTM4632 DDR3 Application. Introduction. Delivering the highest RTR (random ...

DN1040 - 60V Input Monolithic Converter Powers ... - Linear Technology
important housekeeping tasks, such as data reten- ... is lost. Typical hold-up solutions employ dedicated controllers and large storage capacitors [1, 2] thus.

DN1040 - 60V Input Monolithic Converter Powers ... - Linear Technology
tion, for a short period before all available energy ... registered trademarks of Linear Technology Corporation. ... But if the required hold-up energy is relatively.

60V 2MHz Buck-Boost Controllers Regulate High ... - Linear Technology
more than 45°C above room temperature. At 7V input, the hottest component rises less than 55°C with a. Figure 1. 2MHz 12V, 4A Buck-Boost Voltage Regulator ...

DN554 6A Monolithic Synchronous DC/DC Step ... - Linear Technology
down converter with digital power monitoring and ... (for the Circuit in Figure 1). Data Sheet Download ... free LTpowerPlay® software, an easy to use PC-based.

DN554 6A Monolithic Synchronous DC/DC Step ... - Linear Technology
Lower current applications, with up to. 6A load current ... down converter with digital power monitoring and ... Figure 1 shows a typical application with an input.

DN511 - 20V, 2.5A Monolithic Synchronous Buck ... - Linear Technology
20V Maximum Input, 2.5A, 2MHz Buck Regulator with Current and Temperature Monitoring. VOUT. 1.8V. 2.5A. IOUT. VIOUTMON. PVIN. PVIN. SVIN. RUN. SW.

DN511 - 20V, 2.5A Monolithic Synchronous Buck ... - Linear Technology
and high frequency operation, while yielding fast response to load transients (see Figure 2). It also features mode setting, tracking and synchronization capabilities. ... easy-to-use input and output current and temperature monitor pins, and it can

Optimization of EVM Performance in IQ Modulators - Linear Technology
LTC5598 IQ modulator on Linear Technology demon- ... It is utilized in many wireless communi- .... troduction”, Application Note 1298, Agilent Technologies.

Ultrathin Triple Output µModule Regulator for ... - Linear Technology
of QDR (quad data rate) SRAMs, QDR-IV provides up to. 400Gbps data transfer for ... µModule® regulator specifically designed to support all three voltage rails ...

Monolithic Converter Delivers High Output Voltages - Linear Technology
Design Note 545. Jesus Rosales ... tive rails. When the designer is faced with producing ... This application can output 120V at 25mA to 80mA in a straight boost ...

DN492 - 36V, 3.5A Dual Monolithic Buck with ... - Linear Technology
into spaces where multichip solutions cannot. Neverthe- ... support of high output currents. The LT3692A fills ... performance to rival that of multichip solutions.

Micropower Dual and Quad JFET Op Amps ... - Linear Technology
when driving capacitive loads. For each amplifier, the ... Driving Large Capacitive Loads. Though the LT1462/3/4/5 ... Data Sheet Download www.linear.com/ ...

DN492 - 36V, 3.5A Dual Monolithic Buck with ... - Linear Technology
Monitor and Standalone Comparator Block ... into spaces where multichip solutions cannot. ... The LT3692A provides an on-die temperature monitoring function ...

Dual PowerPath™ Controller Simplifi es Power ... - Linear Technology
Dual PowerPath™ Controller Simplifies Power Management. Design Note 160. Jaime Tseng. 08/97/160_conv. Figure 1. Protected Automatic Switchover ...

DN505 - Dual Controller Provides 2μs Step ... - Linear Technology
The remotely sensed VOUT1 has a voltage regulation ac- curacy of 0.67% ... L, LT, LTC, LTM, Linear Technology, the Linear logo and PolyPhase are registered.

Ultrathin Dual 2.5A or Single 5A μModule ... - Linear Technology
Introduction. The top side of a typical system board, such as a. PCIe card, is densely populated with FPGAs/ASICs/ microprocessors, transceivers, connectors ...

Ultrathin Dual 2.5A or Single 5A μModule ... - Linear Technology
Reliable High Performance Regulation. The LTM4622 features a controlled on-time current mode architecture for a fast transient response and. L, LT, LTC, LTM, ...

DN505 - Dual Controller Provides 2μs Step ... - Linear Technology
Introduction. The LTC®3838 is a dual output, dual phase buck controller that employs a controlled constant on-time, valley current mode architecture to provide ...

DN503 - Dual DC/DC Controller for DDR Power ... - Linear Technology
Design Note 503. Ding Li. Introduction .... of frequent and large load steps—an important design consideration. Test results ... application. VTT Supply. The VTT ...

High Voltage, Low Noise, DC/DC Converters - Linear Technology
Application Note 118. AN118-4 an118fb. Low Noise Switching Regulator Driven Resonant. Royer Converters. Figure 8 examplifies the aforementioned “special ...