DC1555A Linear Technology, DC1555A Datasheet

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DC1555A

Manufacturer Part Number
DC1555A
Description
LTC4365 High Voltage UV, OV And Reverse Supply Protection Controller
Manufacturer
Linear Technology
Series
-r
Datasheets

Specifications of DC1555A

Design Resources
DC1555 Design Files DC1555A Schematic
Main Purpose
Power Management, Voltage Protection, Over, Under
Embedded
No
Utilized Ic / Part
LTC4365
Primary Attributes
-
Secondary Attributes
-
Kit Application Type
Power Management
Application Sub Type
Overvoltage Protection
Features
Board Intended To Demonstrate Performance Of The LTC4365 High Voltage, Undervoltage Controller
Lead Free Status / Rohs Status
Not applicable / Not applicable
FEATURES
APPLICATIONS
n
n
n
n
TYPICAL APPLICATION
n
n
n
n
n
n
n
n
n
n
n
Portable Instrumentation
Industrial Automation
Laptops
Automotive
Wide Operating Voltage Range: 2.5V to 34V
Overvoltage Protection to 60V
Reverse Supply Protection to –40V
Blocks 50Hz and 60Hz AC Power
No Input Capacitor or TVS Required for Most
Applications
Adjustable Undervoltage and Overvoltage
Protection Range
Charge Pump Enhances External N-Channel MOSFET
Low Operating Current: 125μA
Low Shutdown Current: 10μA
Fault Status Output
Compact 8-Lead, 3mm × 2mm DFN and
TSOT-23 (ThinSOT™) Packages
12V
V
IN
1820k
243k
59k
12V Automotive Application
510k
V
SHDN
UV
OV
IN
LTC4365
Si4946
GATE
GND
FAULT
4365 TA01a
V
OUT
OV = 18V
UV = 3.5V
V
3A
OUT
Supply Protection Controller
DESCRIPTION
The LTC
input voltages may be too high, too low or even negative.
It does this by controlling the gate voltages of a pair of
external N-channel MOSFETs to ensure that the output
stays within a safe operating range.
The LTC4365 can withstand voltages between –40V and
60V and has an operating range of 2.5V to 34V, while
consuming only 125μA in normal operation.
Two comparator inputs allow configuration of the
overvoltage (OV) and undervoltage (UV) set points using an
external resistive divider. A shutdown pin provides external
control for enabling and disabling the MOSFETs as well
as placing the device in a low current shutdown state. A
fault output provides status of the gate pin pulling low. A
fault is indicated when the part is in shutdown or the input
voltage is outside the UV and OV set points.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
ThinSOT, No R
trademarks are the property of their respective owners.
WINDOW
Load Protected from Reverse and Overvoltage at V
10V/DIV
VALID
®
–30V
SENSE
GND
30V
4365 protects applications where power supply
and Hot Swap are trademarks of Linear Technology Corporation. All other
UV = 3.5V
OV = 18V
UV, OV and Reverse
V
IN
V
OUT
1s/DIV
V
V
OUT
LTC4365
IN
4365 TA01b
IN
1
4365f

Related parts for DC1555A

DC1555A Summary of contents

Page 1

... A fault is indicated when the part is in shutdown or the input voltage is outside the UV and OV set points. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT SENSE trademarks are the property of their respective owners. ...

Page 2

LTC4365 ABSOLUTE MAXIMUM RATINGS Supply Voltage (Note 1) V .......................................................... –40V to 60V IN Input Voltages (Note 3) UV, SHDN .............................................. –0.3V to 60V OV ............................................................ –0. ....................................................... –0.3V to 40V OUT Output Voltages (Note 4) FAULT ...

Page 3

ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER OUT V Input Voltage Range IN I Input Supply Current VIN I Reverse Input Supply Current VIN(R) V Input Supply Undervoltage Lockout IN(UVLO ...

Page 4

LTC4365 TYPICAL PERFORMANCE CHARACTERISTICS V Operating Current vs IN Temperature 100 SHDN = 2. OUT 34V 12V 2. –50 – ...

Page 5

TYPICAL PERFORMANCE CHARACTERISTICS UV Threshold vs Temperature 507 12V IN OUT 505.0 502.5 500.0 497.5 495.0 492.5 –50 – 100 TEMPERATURE (°C) 4365 G10 UV/OV Propagation Delay vs Overdrive ...

Page 6

LTC4365 PIN FUNCTIONS Exposed Pad: Connect to device ground. FAULT: Fault Indication Output. This high voltage open drain output is pulled low below its monitor threshold above its monitor threshold, if SHDN is low, ...

Page 7

BLOCK DIAGRAM V IN –40V TO 60V LDO 6.5V INTERNAL V OUT 2.2V UVLO UV – + 25mV OV HYSTERESIS + – 0.5V REVERSE PROTECTION – + CLOSES SWITCH 5V INTERNAL WHEN V IS NEGATIVE SUPPLY IN SUPPLY GATE I ...

Page 8

LTC4365 OPERATION Many of today’s electronic systems get their power from external sources such as a wall wart adapter, batteries and custom power supplies. These power sources are often unreliable, wired incorrectly, out of spec, or just plain wrong. This ...

Page 9

APPLICATIONS INFORMATION Figure 2 highlights the dependence of the gate drive on V and V . When system power is first turned on (SHDN OUT low to high 0V), gate drive maximum for all OUT ...

Page 10

LTC4365 APPLICATIONS INFORMATION Figure 4 shows the timing associated with the UV pin. Once a UV fault propagates through the UV comparator ), the FAULT output is asserted low and a 50mA (t FAULT current sink discharges the GATE pin. ...

Page 11

APPLICATIONS INFORMATION The resistor values can then be solved: 3mV 1. R1 300k 10nA 3mV • • (3.5V – 0.5V) =1.8M 10nA The closest 1% value 1.82M: 300k +1.82M 3. R1 ...

Page 12

LTC4365 APPLICATIONS INFORMATION The trace the other hand, does not respond OUT to the negative voltage demonstrating the desired IN reverse supply protection. The waveforms of Figure 7 were captured using a 40V ...

Page 13

APPLICATIONS INFORMATION Select Between Two Input Supplies With the part in shutdown, the V IN driven by separate power supplies. The LTC4365 then automatically drives the GATE pin just below the lower of the two supplies, thus turning off the ...

Page 14

LTC4365 APPLICATIONS INFORMATION Transients During OV Fault The circuit of Figure 14 was used to display transients during an overvoltage condition. The nominal input supply is 24V and it has an overvoltage threshold of 30V. The parasitic inductance is that ...

Page 15

... SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

Page 16

... V ≤ (0.9)( OUT IN ≤ 14V OUT ≤ 10V, 80μA Quiescent Current OUT ≤ 36V, 120μA Quiescent Current OUT 4V to 24V, 97% Duty Cycle, 4mm × 4mm IN LT 0910 • PRINTED IN USA © LINEAR TECHNOLOGY CORPORA TION 2010 4365f ...

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