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RT7297B

14

DS7297B-02   September  2012

www.richtek.com

Richtek Technology Corporation

5F, No. 20, Taiyuen Street, Chupei City

Hsinchu, Taiwan, R.O.C.

Tel: (8863)5526789

Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should

obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot

assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be

accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third

parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.

Outline Dimension

A

B

J

F

H

M

C

D

I

Y

X

EXPOSED THERMAL PAD
(Bottom of Package)

8-Lead SOP (Exposed Pad) Plastic Package

Dimensions In Millimeters 

Dimensions In Inches 

Symbol 

Min Max Min Max 

A 4.801 

5.004 

0.189 

 

0.197 

3.810 4.000 0.150 0.157 

1.346 1.753 0.053 0.069 

0.330 0.510 0.013 0.020 

1.194 1.346 0.047 0.053 

0.170 0.254 0.007 0.010 

0.000 0.152 0.000 0.006 

5.791 6.200 0.228 0.244 

0.406 1.270 0.016 0.050 

2.000 2.300 0.079 0.091 

Option 1 

2.000 2.300 0.079 0.091 

2.100 2.500 0.083 0.098 

Option 2 

3.000 3.500 0.118 0.138 

Summary of Contents for RT7297B

Page 1: ...nd loads Cycle by cycle current limit provides protection against shorted outputs and soft start eliminates input current surge during start up The RT7297B also provides under voltage protection and t...

Page 2: ...trol loop Connect a series RC network from COMP to GND In some cases an additional capacitor from COMP to GND is required 7 EN Enable Input Pin A logic high enables the converter a logic low forces th...

Page 3: ...istered trademark of Richtek Technology Corporation Function Block Diagram UV Comparator Oscillator Foldback Control 0 4V Internal Regulator Shutdown Comparator Current Sense Amplifier BOOT VIN GND SW...

Page 4: ...usceptibility Note 3 HBM Human Body Model 2kV Recommended Operating Conditions Note 4 Supply Input Voltage VIN 4 5V to 18V Junction Temperature Range 40 C to 125 C Ambient Temperature Range 40 C to 85...

Page 5: ...l Shutdown TSD 150 C Note 1 Stresses beyond those listed Absolute Maximum Ratings may cause permanent damage to the device These are stress ratings only and functional operation of the device at these...

Page 6: ...oltage vs Load Current 3 20 3 22 3 24 3 26 3 28 3 30 3 32 3 34 3 36 3 38 3 40 0 0 5 1 1 5 2 2 5 3 Load Current A Output Voltage V VOUT 3 3V VIN 12V VIN 17V Switching Frequency vs Temperature 1 10 1 11...

Page 7: ...nt Limit vs Input Voltage 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 0 5 5 6 0 4 5 7 9 5 12 14 5 17 Input Voltage V Current Limit A VIN 4 5V to 17V VOUT 3 3V Time 100 s Div Load Transient Response VOUT 100mV D...

Page 8: ...ration Power On from VIN Time 10ms Div VIN 12V VOUT 3 3V IOUT 3A IL 2A Div VOUT 2V Div VIN 5V Div Power Off from VIN Time 10ms Div IL 2A Div VOUT 2V Div VIN 5V Div VIN 12V VOUT 3 3V IOUT 3A Power On f...

Page 9: ...ing the EN pin low 0 4V will shutdown the device During shutdown mode the RT7297B quiescent current drops to lower than 3 A Driving the EN pin high 2 7V 18V will turn on the device again For external...

Page 10: ...6 5 TAIYO YUDEN NR8040 8 x 8 x 4 OUT OUT L MAX IN MAX V V L 1 f I V The inductor s current rating caused a 40 C temperature rising from 25 C ambient should be greater than the maximum load current and...

Page 11: ...lied by a wall adapter through long wires a load step at the output can induce ringing at the input VIN At best this ringing can couple to the output and be mistaken as loop instability At worst a sud...

Page 12: ...a Copper Area 2 3 x 2 3 mm2 JA 75 C W b Copper Area 10mm2 JA 64 C W c Copper Area 30mm2 JA 54 C W 0 0 0 2 0 4 0 6 0 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 0 25 50 75 100 125 Ambient Temperature C Power Dissip...

Page 13: ...06 COUT TDK C3225X5R0J476M 47 1210 COUT MURATA GRM32ER71C226M 22 1210 COUT TDK C3225X5R1C22M 22 1210 SW node is with high frequency voltage swing and should be kept at small area Keep analog component...

Page 14: ...reliable However no responsibility is assumed by Richtek or its subsidiaries for its use nor for any infringements of patents or other rights of third parties which may result from its use No license...

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