Datasheet

2
LTC1624
ABSOLUTE MAXIMUM RATINGS
W
WW
U
Input Supply Voltage (V
IN
).........................36V to –0.3V
Topside Driver Supply Voltage (BOOST)....42V to –0.3V
Switch Voltage (SW)..................................36V to –0.6V
Differential Boost Voltage
(BOOST to SW) ....................................7.8V to –0.3V
SENSE
–
Voltage
V
IN
< 15V.................................. (V
IN
+ 0.3V) to –0.3V
V
IN
≥ 15V .......................... (V
IN
+0.3V) to (V
IN
–15V)
I
TH
/RUN, V
FB
Voltages ............................ 2.7V to – 0.3V
Peak Driver Output Current < 10µs (TG) .................... 2A
Operating Temperature Range
LTC1624CS ............................................ 0°C to 70°C
LTC1624IS......................................... –40°C to 85°C
Junction Temperature (Note 1)............................. 125°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
PACKAGE/ORDER INFORMATION
W
U
U
ORDER PART
NUMBER
S8 PART MARKING
TOP VIEW
V
IN

BOOST
TG
SW
SENSE
–

I
TH
/RUN
V
FB

GND
S8 PACKAGE
8-LEAD PLASTIC SO
1
2
3
4
8
7
6
5
T
JMAX
= 125°C, θ
JA
= 110°C/ W
LTC1624CS8
LTC1624IS8
1624
1624I
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
T
A
= 25°C, V
IN
= 15V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
I
IN
V
FB
Feedback Current (Note 2) 10 50 nA
V
FB
Feedback Voltage (Note 2) ● 1.1781 1.19 1.2019 V
∆V
LINE REG
Reference Voltage Line Regulation V
IN
= 3.6V to 20V (Note 2) 0.002 0.01 %/V
∆V
LOAD REG
Output Voltage Load Regulation (Note 2)
I
TH
Sinking 5µA ● 0.5 0.8 %
I
TH
Sourcing 5µA ● –0.5 –0.8 %
V
OVL
Output Overvoltage Lockout 1.24 1.28 1.32 V
I
Q
Input DC Supply Current (Note 3)
Normal Mode 550 900 µA
Shutdown V
ITH/RUN
= 0V 16 30 µA
V
ITH/RUN
Run Threshold 0.6 0.8 V
I
ITH/RUN
Run Current Source V
ITH/RUN
= 0.3V –0.8 –2.5 –5.0 µA
Run Pullup Current V
ITH/RUN
= 1V –50 –160 –350 µA
∆V
SENSE(MAX)
Maximum Current Sense Threshold V
FB
= 1.0V 145 160 185 mV
TG Transition Time
TG t
r
Rise Time C
LOAD
= 3000pF 50 150 ns
TG t
f
Fall Time C
LOAD
= 3000pF 50 150 ns
f
OSC
Oscillator Frequency ● 175 200 225 kHz
V
BOOST
Boost Voltage SW = 0V, I
BOOST
= 5mA, V
IN
= 8V 4.8 5.15 5.5 V
∆V
BOOST
Boost Load Regulation SW = 0V, I
BOOST
= 2mA to 20mA 3 5 %
T
J
= T
A
+ (P
D
• 110°C/W)
Note 2: The LTC1624 is tested in a feedback loop which servos V
FB
to
the midpoint for the error amplifier (V
ITH
= 1.8V).
Note 3: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
The
● denotes specifications which apply over the full operating
temperature range.
LTC1624CS: 0°C ≤ T
A
≤ 70°C
LTC1624IS: –40°C ≤ T
A
≤ 85°C
Note 1: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula: