Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsPMICsPMIC - OR controller, electrical elements n-channel DFN 14 N+1 OR controller

LTC4358

4358fa

FEATURES

APPLICATIONS

DESCRIPTION

5A Ideal Diode

The LTC

4358 is a 5A ideal diode that uses an internal

20mΩ N-channel MOSFET to replace a Schottky diode

when used in diode-OR and high current diode applica-

tions. The LTC4358 reduces power consumption, heat

dissipation, and PC board area.

The LTC4358 easily ORs power supplies together to in-

crease total system reliability. In diode-OR applications,

the LTC4358 regulates the forward voltage drop across

the internal MOSFET to ensure smooth current transfer

from one path to the other without oscillation. If the power

source fails or is shorted, a fast turnoff minimizes reverse

current transients.

12V, 5A Diode-OR

Replaces a Power Schottky Diode

Internal 20mΩ N-Channel MOSFET

0.5μs Turn-Off Time Limits Peak Fault Current

Operating Voltage Range: 9V to 26.5V

Smooth Switchover without Oscillation

No Reverse DC Current

Available in 14-Pin (4mm × 3mm) DFN and

16-Lead TSSOP Packages

N+1 Redundant Power Supplies

High Availability Systems

Telecom Infrastructure

Automotive Systems

Power Dissipation vs Load Current

4358 TA01

LTC4358

GND

IN DRAIN

OUT

INA

= 12V

OUT

5A LOAD

LTC4358

GND

IN DRAIN

OUT

INB

= 12V

CURRENT (A)

POWER DISSIPATION (W)

0.5

1.0

1.5

2.0

2.5

3.0

24 6 8

4358 TA01b

DIODE (B530C)

POWER SAVED

FET (LTC4358)

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

All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

Summary of content (12 pages)

PAGE 1
LTC4358 5A Ideal Diode FEATURES DESCRIPTION n The LTC®4358 is a 5A ideal diode that uses an internal 20mΩ N-channel MOSFET to replace a Schottky diode when used in diode-OR and high current diode applications. The LTC4358 reduces power consumption, heat dissipation, and PC board area. n n n n n n Replaces a Power Schottky Diode Internal 20mΩ N-Channel MOSFET 0.5μs Turn-Off Time Limits Peak Fault Current Operating Voltage Range: 9V to 26.
PAGE 2
LTC4358 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Supply Voltages IN, OUT, VDD, DRAIN Voltage ................. –0.3V to 28V Output Voltage GATE (Note 3) .......................... VIN – 0.2V to VIN + 6V Operating Ambient Temperature Range LTC4358C ................................................ 0°C to 70°C LTC4358I.............................................. –40°C to 85°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) FE Package ..........................
PAGE 3
LTC4358 ELECTRICAL CHARACTERISTICS The l denotes the speciﬁcations which apply over the full operating temperature range, otherwise speciﬁcations are at TA = 25°C. VOUT = VDD, VDD = 9V to 26.5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS VDD Operating Supply Range l IDD Operating Supply Current l IIN IN Pin Current VIN = VOUT ± 1V, No Load l IOUT OUT Pin Current VIN = VOUT ± 1V, No Load l IDRAIN DRAIN Pin Current VIN = 0V, VOUT = VDD = VDRAIN = 26.
PAGE 4
LTC4358 TYPICAL PERFORMANCE CHARACTERISTICS VDD Current (IDD vs VDD) 400 500 IN Current (IIN vs VIN) VIN = VOUT = VDD VIN = VOUT = VDD 400 VIN = VOUT = VDD 80 300 IOUT (μA) 300 IIN (μA) IDD (μA) OUT Current (IOUT vs VOUT) 100 200 200 60 40 100 20 100 0 0 0 20 10 30 0 20 10 0 30 0 VDD (V) 30 VOUT (V) 4358 G03 4358 G02 4358 G01 FET Turn-Off Time vs Final Overdrive FET Turn-Off Time vs Initial Overdrive MOSFET RDS(ON) vs Temperature 30 2000 400 IIN = 5A VIN = 12V $VSD =
PAGE 5
LTC4358 PIN FUNCTIONS (DE/FE PACKAGES) DRAIN: The exposed pad is the drain of the internal N-channel MOSFET. This pin must be connected to OUT (Pin 9/Pin 10). GATE: Gate Drive Output. If reverse current ﬂows, a fast pulldown circuit quickly connects the GATE pin to the IN pin, turning off the MOSFET. Leave open if unused. GND: Device Ground. IN: Input Voltage and Fast Pulldown Return. IN is the anode of the ideal diode.
PAGE 6
LTC4358 OPERATION High availability systems often employ parallel-connected power supplies or battery feeds to achieve redundancy and enhance system reliability. ORing diodes have been a popular means of connecting these supplies at the point of load. The disadvantage of this approach is the forward voltage drop and resulting efﬁciency loss. This drop reduces the available supply voltage and dissipates signiﬁcant power.
PAGE 7
LTC4358 APPLICATIONS INFORMATION ORing Two Supply Outputs Where LTC4358s are used to combine the outputs of two supplies, the power supply with the highest output voltage sources most or all of the current. If this supply’s output is quickly shorted to ground while delivering load current, the current temporarily reverses and ﬂows backwards through the LTC4358. When reverse current ﬂows the LTC4358 ideal diode is quickly turned off.
PAGE 8
LTC4358 APPLICATIONS INFORMATION VDD Hold-Up Circuit In the event of an input short, parasitic inductance between the input supply of the LTC4358 and the load bypass capacitor may cause VDD to glitch below its minimum operating voltage. This causes the turn-off time (tOFF) to increase. To preserve the fast turn-off time, local output bypassing of 39μF or more is sufﬁcient or a 100Ω, 0.1μF RC hold-up circuit on the VDD pin can be used as shown in Figure 2a and Figure 2b.
PAGE 9
LTC4358 APPLICATIONS INFORMATION VIN GND VOUT Figure 4. DFN Layout Considerations for 1” × 1” Single Sided PCB 10 TA = AREA (INCH2) 85oC 70oC 50oC 25oC 1 0.1 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 DIODE CURRENT (A) 4358 F05 Figure 5.
PAGE 10
LTC4358 PACKAGE DESCRIPTION DE Package 14-Lead Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1708) 0.70 ±0.05 3.30 ±0.05 3.60 ±0.05 2.20 ±0.05 1.70 ± 0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 3.00 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R = 0.115 TYP 4.00 ±0.10 (2 SIDES) R = 0.05 TYP 3.00 ±0.10 (2 SIDES) 8 0.40 ± 0.10 14 3.30 ±0.10 1.70 ± 0.10 PIN 1 NOTCH R = 0.20 OR 0.
PAGE 11
LTC4358 PACKAGE DESCRIPTION FE Package 16-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG # 05-08-1663) Exposed Pad Variation BC 4.90 – 5.10* (.193 – .201) 3.58 (.141) 3.58 (.141) 16 1514 13 12 1110 6.60 ±0.10 9 2.94 (.116) 4.50 ±0.10 6.40 2.94 (.252) (.116) BSC SEE NOTE 4 0.45 ±0.05 1.05 ±0.10 0.65 BSC 1 2 3 4 5 6 7 8 RECOMMENDED SOLDER PAD LAYOUT 4.30 – 4.50* (.169 – .177) 0.09 – 0.20 (.0035 – .0079) 0.50 – 0.75 (.020 – .030) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2.
PAGE 12
LTC4358 TYPICAL APPLICATION Plug-In Card Input Diode for Supply Hold-Up BACKPLANE PLUG-IN CARD CONNECTORS CONNECTOR 1 IN 12V OUT HOT SWAP CONTROLLER VOUT1 100Ω + LTC4358 GND CHOLDUP VDD 0.1μF GND IN OUT HOT SWAP CONTROLLER VOUT2 100Ω LTC4358 GND + CHOLDUP VDD 0.