3
LTC1645
1645fa
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
TM
TIMER Pin Voltage Threshold ● 1.212 1.230 1.255 V
∆V
TM
TIMER Pin Threshold Line Regulation V
CC1
= 2.375V to 12V ● 19 mV
I
TM
TIMER Pin Current Timer On, V
TIMER
= 0.6V, V
CC1
= 5V ● –2.3 –2 –1.7 µA
Timer Off, V
TIMER
= 1.5V 12 mA
V
CB1
Circuit Breaker Trip Voltage 1 V
CB1
= (V
CC1
– V
SENSE1
) ● 46 50 56 mV
V
CB2
Circuit Breaker Trip Voltage 2 V
CB2
= (V
CC2
– V
SENSE2
) ● 46 50 56 mV
t
CBD
n
Circuit Breaker Trip Delay V
CB
n
= (V
CC
n
– V
SENSE
n
) > 60mV 1.5 µs
I
CP
GATE
n
Pin Output Current ON = 2.2V, V
GATE
n
= V
CC
n
, V
CC1
= 5V, V
CC2
= 3.3V ● –12.5 –10 –7.5 µA
ON = 0.7V, V
GATE
n
= V
CC
n
, V
CC1
= 5V, V
CC2
= 3.3V ● 30 40 50 µA
ON = 0.3V, V
GATE
n
= V
CC
n
, V
CC1
= 5V, V
CC2
= 3.3V 12 mA
I
SENSE
SENSE Pin Current V
CC
n
– 0.3V ≤ V
SENSE
n
≤ V
CC
n
+ 0.3V ● –10 10 µA
∆V
GATE
n
External N-Channel Gate Drive ∆V
SENSE
= V
CC
– 0.5V ● 4.5 16 V
V
ONFPD
ON Pin Fast Pull-Down Threshold Low to High ● 0.375 0.4 0.425 V
High to Low, Fast Pull-Down Engaged ● 0.35 0.375 0.4 V
V
ON1
ON Pin Threshold #1 Low to High, GATE1 Turns On ● 0.8 0.825 0.85 V
High to Low, GATE1 Turns Off ● 0.775 0.8 0.825 V
V
ON2
ON Pin Threshold #2 Low to High, GATE2 Turns On ● 2 2.025 2.050 V
High to Low, GATE2 Turns Off
● 1.975 2 2.025 V
V
ONHYST
ON Pin Hysteresis 25 mV
I
ON
ON Pin Input Current V
CC1
= 5V, V
CC2
= 3.3V ● ±0.01 ±2 µA
V
OL
Output Low Voltage RESET, FAULT, COMPOUT, I
OUT
= 1.6mA, V
CC1
= 5V ● 0.16 0.4 V
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
2.375V ≤ V
CC1
≤ 12V, 1.2V ≤ V
CC2
≤ 12V unless otherwise noted (Note 2).
Note 3: An internal zener on the GATE
n
pins clamps the charge pump
voltage to a typical maximum operating voltage of 22V. External overdrive
of a GATE pin (for example, from capacitive coupling of V
CC
n
glitches)
beyond the internal zener voltage may damage the device. If a lower
GATE
n
pin clamp voltage is desired, use an external zener diode.
V
CC1
Supply Current vs Voltage V
CC2
Supply Current vs Voltage
V
CC1
(V)
0
I
CC1
(mA)
1.0
2.0
3.0
0.5
1.5
2.5
46810
1645 G01
123257911
T
A
= 25°C
V
CC2
= 1.5V
V
CC2
= 12V
V
CC2
(V)
0
I
CC2
(mA)
0.5
1.5
2.0
2.5
3.5
1
5
7
1645 G02
1.0
3.0
4
9
10 11 12
2
3
68
T
A
= 25°C
V
CC1
= 2.375V
V
CC1
= 12V
Supply Current vs Temperature
TEMPERATURE (°C)
–40
0.8
1.0
1.4
20 60
1645 G03
0.6
0.4
–20 0
40 80 100
0.2
0
1.2
I
CC
n
(mA)
V
CC1
= 5V
V
CC2
= 3.3V
I
CC1
I
CC2
ELECTRICAL CHARACTERISTICS
TYPICAL PERFOR A CE CHARACTERISTICS
UW
