L1

22uH

L2

22uH

CCUK

1uF

CIN

10uF

COUT

22uF

CFF1

1000pF

RFB1

29.4k

RFB2

1k

D

LM2611A

VIN

5

SW

1

NFB

3

SHDN

4

GND

2

VOUT

-5V

CIN: TAIYO YUDEN X5R JMK325BJ106MN

CCUK: TAIYO YUDEN X5R TMK316BJ105ML

COUT: TAIYO YUDEN X5R JMK325BJ226MM

D: ON SEMICONDUCTOR MBR0520

L1, L2: SUMIDA CDRH6D28-220

CFF2

1uF

RFB3

9k

2.7V

VIN

d

14V

d

LM2611

www.ti.com

SNOS965J – JUNE 2001 – REVISED DECEMBER 2015

Typical Application (continued)

8.2.7 High Duty Cycle and Load Current

Figure 35. LM2611 High Current Schematic

8.2.7.1 Design Requirements

Follow the design requirements in Cuk Converter With Integrated Switch.

8.2.7.2 Detailed Design Procedure

8.2.7.2.1

High Duty Cycle and Load Current Operation

The circuit in Figure 35 is used for high duty cycles (D > 0.5) and high load currents. The duty cycle begins to

increase beyond 50% as the input voltage drops below the absolute magnitude of the output voltage. RFB3 and

CFF2 are added to the feedback network to introduce a low frequency lag compensation (pole-zero pair)

necessary to stabilize the circuit under the combination of high duty cycle and high load currents.

9 Power Supply Recommendations

The power supply must never exceed the absolute maximum rating of the device given in Absolute Maximum

Ratings. If the regulator is connected to the input supply through long wires or PCB traces, special care is

required to achieve good performance. The parasitic inductance and resistance of the input cables can have an

adverse effect on the operation of the regulator. The parasitic inductance, in combination with the low ESR

ceramic input capacitors, can form an under-damped resonant circuit. This circuit may cause overvoltage

transients at the VIN pin, each time the input supply is cycled on and off.

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