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LINEAR TECHNOLOGY LTC4217 User Guide

Summary

The LTC4217 is a highly integrated hot swap controller designed to ensure safe power insertion and removal into live backplanes. This manual details its functionality, covering essential features like wide operating voltage range, adjustable current limit control, inrush current management, and overtemperature protection. It is specifically engineered for demanding high-reliability applications, such as enterprise RAID systems and server I/O cards, where precise and safe power sequencing is critical.

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Page 1 Text Content

LTC4217

2A Integrated Hot Swap

Controller

FEATURES DESCRIPTION n Small Footprint

The LTC®4217 is an integrated solution for Hot Swap™

n 25mΩ MOSFET and 7.5mΩ RSENSE

applications that allows a board to be safely inserted and

n Wide Operating Voltage Range: 2.9V to 26.5V

removed from a live backplane. The part integrates a Hot

n Adjustable, 5% Accurate Current Limit

Swap controller, power MOSFET and current sense resistor

n Current and Temperature Monitor Outputs

in a single package for small form factor applications. A

n Overtemperature Protection

dedicated 12V version (LTC4217-12) contains preset 12V

n Adjustable Current Limit Timer Before Fault

specifi c thresholds, while the standard LTC4217 allows

n Powergood and Fault Outputs

adjustable thresholds.

n Adjustable Inrush Current Control

The LTC4217 provides separate inrush current control

n 2% Accurate Undervoltage and Overvoltage

and an accurate (5%) 2A current limit with current fold-

Protection

back limiting. The current limit threshold can be adjusted

n Available in 20-Lead TSSOP and 16-Lead

dynamically using an external pin. Additional features

5mm × 3mm DFN Packages

include a current monitor output that amplifi es the sense resistor voltage for ground referenced current sensing

APPLICATIONS and a MOSFET temperature monitor output. Thermal limit,

overvoltage, undervoltage and powergood monitoring are

n RAID Systems

also provided.

n Server I/O Cards

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Hot Swap

n Industrial

is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

TYPICAL APPLICATION 12V, 1.5A Card Resident Application Power-Up Waveforms

12V VDD OUT

12V VIN

UV 330μF 1.5A

10V/DIV

LTC4217DHC-12

RETRY 10k IIN

0.1A/DIV

TIMER

VOUT 10V/DIV

INTVCC IMON ADC 0.1μF GND

20k PG

4217 TA01a 10V/DIV

4217 TA01b

25ms/DIV

4217fb

Page Summary Contents For LINEAR TECHNOLOGY LTC4217 User Guide

Page 1 LTC4217 2A Integrated Hot Swap Controller FEATURES DESCRIPTION n Small Footprint The LTC®4217 is an integrated solution for Hot Swap™ n 25mΩ MOSFET and 7.5mΩ RSENSE applications that allows a board to...
Page 2 LTC4217 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Supply Voltage (VDD) ................................. –0.3V to 28V GATE (Note 3) ........................................ –0.3V to 33V Input Voltages Ope...
Page 3 LTC4217 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4217CDHC-12#PBF LTC4217CDHC-12#TRPBF 16-Lead (5mm × 3mm) Plastic DFN 0°C to 70°C LTC4217...
Page 4 LTC4217 ELECTRICAL CHARACTERISTICS The l denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VDD = 12V unless otherwise noted...
Page 5 IM IT LTC4217 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VDD = 12V unless otherwise noted. UV Low-High Threshold vs IDD vs VDD INTVCC Load Regulation Temperature VDD = 5V 85°C VDD = 3.3V IM -U IM ...
Page 6 IV (V LTC4217 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VDD = 12V unless otherwise noted. RON vs VDD and Temperature MOSFET SOA Curve PG, FLT VOUT Low vs ILOAD VDD = 3.3V, 12V, 24V FLTPG 1ms 10ms...
Page 7 LTC4217 PIN FUNCTIONS Exposed Pad: SENSE. comparator monitors an internal resistive divider between the OUT pin and GND. FB: Foldback and Power Good Input. Connect this pin to an external resistive di...
Page 8 LTC4217 FUNCTIONAL DIAGRAM SENSE (EXPOSED PAD) GATE INTERNAL 7.5mΩ INTERNAL 20mΩ SENSE RESISTOR MOSFET VDD OUT CLAMP CHARGE ISET INRUSHCS AND GATE 0.6V POSITIVE +– DRIVER 0.3V/ms TEMPERATURE COEFFICIE...
Page 9 LTC4217 OPERATION The Functional Diagram displays the main circuits of the for many applications to use an internal 2ms overcurrent device. The LTC4217 is designed to turn a board’s supply timer with ...
Page 10 LTC4217 APPLICATIONS INFORMATION 12V VDD OUT is a graph of the Safe Operating Area for the MOSFET. It is LTC4217FE 0.8V 150k +R3 evident from this graph that the power dissipation at 12V, 140k FB R6 3...
Page 11 LTC4217 APPLICATIONS INFORMATION LTC4217 Tying the TIMER pin to INTVCC will force the part to use the internally generated (circuit breaker) delay of 2ms. *OPTIONAL CP In either case the FLT pin is pu...
Page 12 LTC4217 APPLICATIONS INFORMATION a resistor between the ISET pin and ground. As shown in tor that is charged with this current. When the capacitor the Functional Diagram the voltage at the ISET pin (v...
Page 13 LTC4217 APPLICATIONS INFORMATION 12V Fixed Version Use the equation for RSHUNT1 for increasing the OV and FB thresholds. Likewise use the equation for RSHUNT2 for In the LTC4217-12 the UV, OV and FB p...
Page 14 LTC4217 APPLICATIONS INFORMATION invoked by tying the TIMER pin to INTVCC. After the 2ms There are two VDD pins on opposite sides of the package timeout the FLT pin needs to pull-down on the UV pin to...
Page 15 LTC4217 PACKAGE DESCRIPTION DHC Package 16-Lead Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) (2 SIDES) 3.00 ±0.10 (2 SIDES) 1.65 ±0.05 1.65 ± 0.10 (2 SIDES) PACKAGE (2 SIDES) 2.20 ±0.05 OU...
Page 16 LTC4217 TYPICAL APPLICATION 24V, 1.5A Card Resident Application 24V VDD OUT VOUT LTC4217FE 158k 200k FB 3.24k FLT OV 10k TIMER INTVCC IMON ADC GND 20k 4217 TA02 *DIODES INC. SMAJ24A RELATED PARTS PART...

Manual Details

Brand Linear
Pages 16
File Size 180.70 KB
Published June 17, 2026
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Frequently Asked Questions

What is the recommended operating temperature range for the LTC4217DHC-12?

The operating temperature range for the standard LTC4217C package is 0°C to 70°C, while the improved version (LTC4217I) can handle -40°C to 85°C.

How does the device provide current monitoring capabilities?

The part integrates a MOSFET and an accurate 5% adjustable current limit controller. Additional packages offer a current monitor output that amplifies the sense resistor voltage for ground-referenced sensing.

What is the maximum operating voltage range for this component?

The LTC4217 can operate across a wide voltage range, from 2.9V up to 26.5V (specific to the LTC4218 part).

Can I adjust the current limit settings or sense resistor thresholds?

Yes, the device includes an adjustable current limit and provides configurable Powergood and Fault Outputs with adjustable thresholds.