Datasheet

LT1173
2
WU
U
PACKAGE
/
O
RDER I FOR ATIO
LT1173CN8
LT1173CN8-5
LT1173CN8-12
A
U
G
W
A
W
U
W
ARB
S
O
LU
T
EXI T
I
S
Supply Voltage (V
IN
)................................................ 36V
SW1 Pin Voltage (V
SW1
) .......................................... 50V
SW2 Pin Voltage (V
SW2
) .............................–0.5V to V
IN
Feedback Pin Voltage (LT1173) ................................. 5V
Sense Pin Voltage (LT1173, -5, -12) ....................... 36V
Maximum Power Dissipation ............................. 500mW
Maximum Switch Current ....................................... 1.5A
Operating Temperature Range ..................... 0°C to 70°C
Storage Temperature Range .................. –65°C to 150°C
Lead Temperature, (Soldering, 10 sec.)................300°C
Consult factory for Industrial and Military grade parts
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Switch Off ● 110 150 µA
I
Q
Quiescent Current, Boost No Load LT1173-5 135 µA
Mode Configuration
LT1173-12 250 µA
V
IN
Input Voltage Step-Up Mode ● 2.0 12.6 V
Step-Down Mode ● 30 V
Comparator Trip Point Voltage LT1173 (Note 1) ● 1.20 1.245 1.30 V
V
OUT
Output Sense Voltage LT1173-5 (Note 2) ● 4.75 5.00 5.25 V
LT1173-12 (Note 2) ● 11.4 12.0 12.6 V
Comparator Hysteresis LT1173 ● 510 mV
Output Hysteresis LT1173-5 ● 20 40 mV
LT1173-12 ● 50 100 mV
f
OSC
Oscillator Frequency ● 18 23 30 kHz
Duty Cycle Full Load ● 43 51 59 %
t
ON
Switch ON Time I
LIM
tied to V
IN
● 17 22 32 µs
Feedback Pin Bias Current LT1173, V
FB
= 0V ● 10 50 nA
Set Pin Bias Current V
SET
= V
REF
● 20 100 nA
V
OL
Gain Block Output Low I
SINK
= 100µA, V
SET
= 1.00V ● 0.15 0.4 V
Reference Line Regulation 2.0V ≤ V
IN
≤ 5V ● 0.2 0.4 %/V
5V ≤ V
IN
≤ 30V ● 0.02 0.075 %/V
V
SAT
SW
SAT
Voltage, Step-Up Mode V
IN
= 3.0V, I
SW
= 650mA ● 0.5 0.65 V
V
IN
= 5.0V, I
SW
= 1A 0.8 1.0 V
● 1.4 V
T
A
= 25°C, V
IN
= 3V, unless otherwise noted.
E
LECTR
IC
AL C CHARA TERIST
ICS
1
2
3
4
8
7
6
5

TOP VIEW
I
LIM

V
IN

SW1
SW2
FB (SENSE)*
SET
AO
GND
N8 PACKAGE
8-LEAD PLASTIC DIP
*FIXED VERSIONS
T
JMAX
= 90°C, θ
JA
= 130°C/W
TOP VIEW
S8 PACKAGE
8-LEAD PLASTIC SOIC
*FIXED VERSIONS
1
2
3
4
8
7
6
5
I
LIM

V
IN

SW1
SW2
FB (SENSE)*
SET
AO
GND
T
JMAX
= 90°C, θ
JA
= 150°C/W
LT1173CS8
LT1173CS8-5
LT1173CS8-12
ORDER PART
NUMBER
S8 PART MARKING
1173
11735
117312