manualshive.com logo in svg

Linear Technology LTC1624, Manual

Share
Download
Linear Technology LTC1624 Manual Download Page 28

28

LTC1624

1624f LT/TP 0198 4K • PRINTED IN USA

 

LINEAR TECHNOLOGY CORPORATION 1997

Linear Technology  Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417 

●

 (408) 432-1900

FAX: (408) 434-0507 

● 

TELEX: 499-3977 

●  

www.linear-tech.com

TYPICAL APPLICATIO

N

U

PART NUMBER

DESCRIPTION

COMMENTS

LTC1147

High Efficiency Step-Down Controller

100% DC, Burst Mode Operation, 8-Pin SO
and PDIP

LTC1148HV/LTC1148

High Efficiency Synchronous Step-Down Controllers

100% DC, Burst Mode Operation, V

IN 

< 20V

LTC1149

High Efficiency Synchronous Step-Down Controller

100% DC,Std Threshold  MOSFETs, V

IN 

< 48V

LTC1159

High Efficiency Synchronous Step-Down Controller

100% DC, Logic Level MOSFETs, V

IN 

< 40V

LTC1174

Monolithic 0.6A Step-Down Switching Regulator

100% DC, Burst Mode Operation, 8-Pin SO

LTC1265

1.2A Monolithic High Efficiency Step-Down Switching Regulator

100% DC, Burst Mode Operation, 14-Pin SO

LTC1266

High Efficiency Synchronous Step-Down Controller, N-Channel Drive

100% DC, Burst Mode Operation, V

IN 

< 20V

LT

®

1375/LT1376

1.5A, 500kHz Step-Down Switching Regulators

High Frequency

LTC1433/LTC1434

Monolithic 0.45A Low Noise Current Mode Step-Down Switching Regulators

16- and 20-Pin Narrow SSOP

LTC1435

High Efficiency Low Noise Synchronous Step-Down Controller,

Burst Mode Operation, 16-Pin Narrow SO

N-Channel Drive

LTC1436/LTC1436-PLL

High Efficiency Low Noise Synchronous Step-Down Controllers,

Adaptive Power

TM

 Mode, 20- and 24-Pin SSOP

N-Channel Drive

LTC1474/LTC1475

Ultralow Quiesent Current Step-Down Monolithic Switching Regulators

100% DC, 8-Pin MSOP, V

IN

 < 20V

Adaptive Power is a trademark of Linear Technology Corporation.

RELATED PARTS

Figure 23. 5V to 3.3V/10A Converter (Surface Mount)

+

SENSE

–

I

TH

/RUN

V

FB

GND

V

IN

BOOST

TG

SW

LTC1624

D1

10k

Q2

C

B

0.1

µ

F

C2
100pF

C

IN

100

µ

F

10V

×

 4

C4, 0.1

µ

F

C3, 0.033

µ

F

8

7

6

5

1

2

3

4

R

SENSE

0.0082

Ω

R

C

6.8k

C

C

820pF

M1

C

OUT

470

µ

F

6.3V

×

 2

L1

1.68

µ

H

+V

OUT

3.3V
10A

+V

IN

4.5V TO
5.5V

V

OUT

RTN

1624 F23

C

IN

 (

×

 4) = KEMET T495D107M010AS

C

OUT

 (

×

 2) = AVX TPSV477M006R0055

D1 = MOTOROLA MBRB2515L
D2 = MOTOROLA MBR0520

L1 = PULSE ENGINEERING PE53691
M1 = INTERNATIONAL RECTIFIER IRL3803S
Q2 = MOTOROLA MMBTA14LT1 
R

SENSE

 = IRC OAR3-R0082

R3, 10

Ω

C8
100pF

D2

+

R1
20k

R2
35.7k

Summary of Contents for LTC1624

Page 1: ...oost step down inverting and SEPIC Burst ModeTM operation provides high efficiency at low load currents A maximum highdutycyclelimitof95 provideslowdropoutoperation whichextendsoperatingtimeinbattery...

Page 2: ...Regulation VIN 3 6V to 20V Note 2 0 002 0 01 V VLOAD REG Output Voltage Load Regulation Note 2 ITH Sinking 5 A 0 5 0 8 ITH Sourcing 5 A 0 5 0 8 VOVL Output Overvoltage Lockout 1 24 1 28 1 32 V IQ Inpu...

Page 3: ...ge Boost Line Regulation INPUT VOLTAGE V 0 BOOST VOLTAGE V 6 5 4 3 2 1 0 15 25 1624 G04 5 10 20 30 35 IBOOST 1mA VSW 0V BOOST LOAD CURRENT mA 0 BOOST VOLTAGE V 6 5 4 3 2 1 0 15 25 1624 G06 5 10 20 30...

Page 4: ...0 10 60 85 1448 G12 15 35 110 135 VOUT IN REGULATION VFB 0V PIN FUNCTIONS U U U SENSE Pin 1 Connects to the input for the current comparator Built in offsets between the SENSE and VIN pinsinconjunctio...

Page 5: ...charged during each off cycle The dropout detector counts the number of oscillator cycles that the top MOSFET remains on and periodically forces a brief off period to allow CB to recharge Themaincontr...

Page 6: ...RIVER TG SW D1 L1 N CHANNEL MOSFET N CHANNEL MOSFET INTV CC R SENSE SENSE D B 5 6V INTV CC REG V IN 0 8V 1 19V 200kHz 200kHz 1 19V I TH RUN 1 28V 1 19V 180k 1 5V 3 A 30k 8k 2 3 4 5 6 7 GND 1624 FD 2 5...

Page 7: ...esults in higher output voltage ripple and greater core losses A reasonable starting point for setting ripple current is IL 0 4 IMAX Remember the maximum IL occurs at the maximum input voltage The ind...

Page 8: ...eterm 1 isgenerallygivenforaMOSFETintheform of a normalized RDS ON vs Temperature curve but 0 005 C can be used as an approximation for low voltageMOSFETs CRSSisusuallyspecifiedintheMOSFET APPLICATION...

Page 9: ...will be scaled by a factor of Duty Cycle Efficiency For 5V regulators this simply means connecting the BOOST monlyusedfordesignbecauseevensignificantdeviations donotoffermuchrelief Notethatcapacitorma...

Page 10: ...at approximately 10mV RSENSE at VITH RUN 1 4V and ends at 160mV RSENSE VITH RUN 2 4V The output current thus ramps up slowly charging the outputcapacitor Thepeakinductorcurrentandmaximum output curren...

Page 11: ...ed in the sense resistor only when the topside MOSFET is on The I2R loss is thus reduced by the duty cycle For example at 50 DC if RDS ON 0 05 RL 0 15 and RSENSE 0 05 then the effective total resistan...

Page 12: ...Note that the transient suppressor should not conduct during double battery operation but must still clamptheinputvoltagebelowbreakdownoftheconverter Although the LTC1624 has a maximum input voltage o...

Page 13: ...VIN In this case the worst case dissipation rises to P I V V V V D SC AVG D IN IN D APPLICATIONS INFORMATION W U U U With the 0 05 sense resistor ISC AVG 2A will result increasing the 0 5V Schottky di...

Page 14: ...the peak inductor current occuring at VIN MIN and IOUT MAX I V V V V kHz L V V L IN OUT D IN OUT D P P 200 with IL MAX IL P P at VIN VIN MIN Remember boost converters are not short circuit pro tected...

Page 15: ...The input voltage source imped ance determines the size of the capacitor that is typically 10 F to 100 F A low ESR is recommended although not as critical as the output capacitor and can be on the or...

Page 16: ...tional term for transition losses that are highest at high total input plus output voltages For VIN VOUT 20V the high current efficiency generally improves with larger MOSFETs while for VIN VOUT 20V t...

Page 17: ...UT D IN MIN L 1 1 Schottky diodes such as MBR130LT3 are recommended SEPIC Converter Input and Output Capacitors The output capacitor is normally chosen by its effective series resistance ESR because t...

Page 18: ...h Duty Cycle V V OUT IN with VOUT being the absolute value of VOUT The MOSFET power dissipation and maximum switch current are given by that the voltage across C1 is constant such that VC1 VIN at full...

Page 19: ...N I I V V V V I L PEAK OUT MAX IN OUT D IN L 2 The ripple current in the inductor IL is typically 20 to 50 of the peak inductor current occuring at VIN MIN and IOUT MAX to minimize output ripple Maxim...

Page 20: ...624 ground pin referenced to VOUT the nonimal range on the ITH RUN pin is VOUT in shutdown to VOUT 2 4V at Max IOUT Referring to Figure15 M2 M3andR3providealevelshiftfromtypical TTL levels to the LTC1...

Page 21: ...8 7 6 5 1 2 3 4 R2 35 7k 1 R1 11k 1 COUT 100 F 10V 2 M1 Si4412DY L1 10 H RSENSE 0 033 CIN 22 F 35V 2 VOUT 5V 3A VIN 5 3V TO 28V 1624 F10 COILTRONICS CTX10 4 0 1 F Figure 10 5V 3A Converter with Outpu...

Page 22: ...ST TG SW LTC1624 1000pF 100pF CC 470pF RC 6 8k D1 MBRS140T3 CB 0 1 F 8 7 6 5 1 2 3 4 R2 35 7k 1 R1 3 92k 1 COUT 100 F 16V 2 M1 Si4412DY L1 47 H RSENSE 0 068 CIN 22 F 35V 2 VOUT 12V 1A VIN 12 3V TO 28V...

Page 23: ...F 8 7 6 5 1 2 3 4 R2 35 7k 1 R1 20k 1 COUT 100 F 10V 2 M1 Si6426DQ L1 20 H RSENSE 0 068 CIN 22 F 35V 2 VOUT 3 3V 1 5A VIN 3 5V TO 18V 1624 F16 COILTRONICS CTX20 4 0 1 F Figure 16 Low Dropout 3 3V 1 5A...

Page 24: ...12V 10A Buck Converter with Output Derived Boost Voltage SENSE ITH RUN VFB GND VIN BOOST TG SW LTC1624 CIN1 CIN2 1000 F 35V 2 VIN 13V TO 28V D1 CB 0 1 F C5 3 3 F 50V C4 0 1 F 8 7 6 5 1 2 3 4 RSENSE2...

Page 25: ...MOTOROLA MBR2535CT L1 MAGNETICS CORE 55930AZ WINDING 8T 14BIF M1 INTERNATIONAL RECTIFIER IRL 3803 RSENSE IRC OAR 3 0 005 5 BOTH D1 AND Q1 MOUNTED ON THERMALLOY MODEL 6399 HEAT SINK SENSE ITH RUN VFB...

Page 26: ...RRENT ADJ R2 35 7k RC 10k CC 330pF M1 COUT 100 F 16V 2 L1 27 H R4 0 025 VOUT 12V 3A 1624 F21 CIN1 CIN2 KEMET T495X226M035AS L1 SUMIDA CDRH127 270 RSENSE IRC LR2010 01 R033 F R4 IRC LR2010 01 R025 F M1...

Page 27: ...2 0 014 0 019 0 355 0 483 0 004 0 010 0 101 0 254 0 050 1 270 TYP DIMENSION DOES NOT INCLUDE MOLD FLASH MOLD FLASH SHALL NOT EXCEED 0 006 0 152mm PER SIDE DIMENSION DOES NOT INCLUDE INTERLEAD FLASH IN...

Page 28: ...LT 1375 LT1376 1 5A 500kHz Step Down Switching Regulators High Frequency LTC1433 LTC1434 Monolithic 0 45A Low Noise Current Mode Step Down Switching Regulators 16 and 20 Pin Narrow SSOP LTC1435 High...

Reviews:

No comments

Brands by name

Popular brands

Load more brands