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JANUARY 18, 2013 |DATA SHEET |    Rev 3.5

13

IR3897 

4A Highly Integrated SupIRBuck

Single‐Input Voltage, Synchronous Buck Regulator  

PD‐97663

4.4

4.6

4.8

5

5.2

5.4

5.6

25

30

35

40

45

50

55

60

65

70

75

80

85

TAmb

0 LFM

Lout-3.3uH,6.5mΩ(Wurth Elektronik 7443340330)

4.4

4.6

4.8

5

5.2

5.4

5.6

25

30

35

40

45

50

55

60

65

70

75

80

85

TAmb

0 LFM

Lout-1.5uH,6.7mΩ(Cyntec PCMB065T-1R5MS)

THERMAL DERATING CURVES 

 

Measurement done on Evaluation board of IRDC3897.PCB is 4 layer board with 2 oz Copper, FR4 material, size 2.23"x2" 

 

PVin = 12V, Vout=1.2V, Vcc = Internal LDO (6.4V), Fs = 600kHz 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PVin = 12V, Vout=3.3V, Vcc = Internal LDO (6.4V), Fs = 600kHz 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: International Rectifier Corporation specifies current rating of SupIRBuck devices conservatively. The continuous current

load capability might be higher than the rating of the device if input voltage is 12V typical and switching frequency is below

750 kHz.The above derating curves are generated at 12V input ,600kHz with 0-200LFM air flow and ambient temperature up

to 85°C.Detailed thermal derating information can be found in the Application Note AN-1174 “Thermal Derating of DC DC

Convertors using IR3899/98/97”. However, the maximum current is limited by the internal current limit and designers need to

consider enough guard bands between load current and minimum current limit to guarantee that the device does not trip at

steady state condition.