LTC4213
1
DESCRIPTION
Demonstration circuit DC872A features the LTC4213
NoRsense Electronic Circuit Breaker, which provides
over-current protection without a sense resistor. The
Board allows evaluation of the LTC4213 over its full op-
erating voltage range, at all three over-current protection
levels and with ON and RESET functionality.
Design files for this circuit board are available. Call
the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT and
PowerPath are trademarks of Linear Technology Corporation.
PERFORMANCE SUMMARY
Specification s are at T
A
= 25°C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC
Supply Voltage Range
2.6 6.0 V
V
SENSEP
SENSEP Voltage Range V
SENSEP
≤
V
CC
0 6.0 V
V
CC(URLR)
V
CC Undervoltage Lockout Release
V
CC
Rising
1.8 2.1 2.23 V
V
CB
Circuit Breaker Trip Voltage
V
CB
=V
SENSEP
-V
SENSEN
at slow comparator Trips
V
SENSEP
= V
CC
, I
OSEL
= 0V
V
SENSEP
= V
CC,
I
OSEL
= Floated
V
SENSEP
= V
CC,
I
OSEL
= V
CC
22.5
45
90
25
50
100
23
55
110
mV
V
CB(FAST)
Circuit Breaker Trip Voltage
V
CB(FAST)
=V
SENSEP
-V
SENSEN
at fast comparator
Trips
V
SENSEP
= V
CC
, I
OSEL
= 0V
V
SENSEP
= V
CC,
I
OSEL
= Floated
V
SENSEP
= V
CC,
I
OSEL
= V
CC
100
175
325
mV
mV
mV
I
GATE(UP)
Gate Pin Pull Up Current V
GATEN
= 0V, –50 -100 -150 µA
I
GATE(DN)
Gate Pin Pull Down Current
V
ON
=1V,
∆=
V
SENSEP
−
V
SENSEN
=200
mV,
V
GATE
= 8V
10 40 80 mA
V
ON(TH)
ON Pin High Threshold ON Rising, Gate Pulls Down 0.76 0.8 0.84 V
V
ON(RST)
ON Pin Reset Threshold ON Falling, Fault Reset, Gate Pulled Down
0.36
0.4 0.44
V
OPERATING PRINCIPLES
The LTC4213 is an Electronic Circuit Breaker that has a 0V
to 6.0V operating range and a 10V absolute maximum
operating voltage for the V
CC
pin. In low voltage applica-
tions where the rail voltage is lower than 2.6V, the V
CC
pin
must have a separate supply.
The circuit Breaker function is based on sensing the volt-
age across the drain and source of an external N-
channel MOSFET. The LTC4213 provides dual level over-
current protection. The slow comparator has 15µs re-
sponse time while the fast comparator trips in 1µs.
One of three Circuit Breaker thresholds, 25mV, 50mV, or
100mV is selected by connecting ISEL pin to GND, leav-
ing it floating, or connecting to Vcc, respectively. The cor-
responding fast comparator thresholds are 100mV,
175mV, and 325mV.
When the ON pin signal increases above 0.8V, the device
starts up and the GATE pulls up with a 100µA current
source. When the ON pin signal drops below 0.76V, the
GATE pulls down. To reset a circuit breaker fault, the ON
pin must go below 0.4V.
LTC4213
Electronic Circuit Breaker
