3
LT1111
E
LECTR
IC
AL C CHARA TERIST
ICS
V
IN
= 3V, Military or Commercial Version
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Reference Line Regulation 5V ≤ V
IN
≤ 30V ● 0.02 0.075 %/V
2V ≤ V
IN
≤ 5V 0.20 0.400 %/V
A
V
Gain Block Gain R
L
= 100k (Note 3) ● 1000 6000 V/V
I
LIM
Current Limit 220Ω from I
LIM
to V
IN
400 mA
Current Limit Temperature Coefficient ● –0.3 %/°C
Switch OFF Leakage Current Measured at SW1 Pin, V
SW1
= 12V 1 10 µA
Maximum Excursion Below GND I
SW1
≤ 10µA, Switch OFF –400 –350 mV
LT1111M
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Switch OFF ● 300 500 µA
f
OSC
Oscillator Frequency ● 45 72 100 kHz
DC Duty Cycle: Step-Up Mode Full Load ● 40 50 62 %
Step-Down Mode
● 20 55 %
t
ON
Switch ON Time: Step-Up Mode I
LIM
Tied to V
IN
● 5711 µs
Step-Down Mode V
OUT
= 5V, V
IN
= 12V ● 39µs
Reference Line Regulation 2V ≤ V
IN
≤ 5V, 25°C ≤ T
A
≤ 125°C 0.2 0.4 %/V
2.4V ≤ V
IN
≤ 5V, T
A
= –55°C 0.8 %/V
V
SAT
SW Saturation Voltage, Step-Up Mode 0°C ≤ T
A
≤ 125°C, I
SW
= 500mA, 0.5 0.65 V
T
A
= –55°C, I
SW
= 400mA
SW Saturation Voltage, Step-Down Mode V
IN
= 12V, 0°C ≤ T
A
≤ 125°C 1.5 V
I
SW
= 500mA T
A
= –55°C 2.0 V
V
IN
= 3V, –55°C ≤ T
A
≤ 125°C unless otherwise noted.
LT1111C
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Quiescent Current Switch OFF ● 300 450 µA
f
OSC
Oscillator Frequency ● 54 72 95 kH
DC Duty Cycle: Step-Up Mode Full Load ● 43 50 59 %
Step-Down Mode
● 24 34 50 %
t
ON
Switch ON Time: Step-Up Mode I
LIM
Tied to V
IN
● 5.0 7 9.0 µs
Step-Down Mode V
OUT
= 5V, V
IN
= 12V ● 3.3 5 7.8 µs
Reference Line Regulation 2V ≤ V
IN
≤ 5V ● 0.2 0.7 %/V
V
SAT
SW Saturation Voltage, Step-Up Mode V
IN
= 3V, I
SW
= 650mA ● 0.5 0.65 V
SW Saturation Voltage, Step-Down Mode V
IN
= 12V, I
SW
= 650mA ● 1.1 1.50 V
V
IN
= 3V, 0°C ≤ T
A
≤ 70°C unless otherwise noted.
The ● denotes specifications which apply over the full operating
temperature range.
Note 1: This specification guarantees that both the high and low trip points
of the comparator fall within the 1.20V to 1.30V range.
Note 2: The output voltage waveform will exhibit a sawtooth shape due to
the comparator hysteresis. The output voltage on the fixed output versions
will always be within the specified range.
Note 3: 100k resistor connected between a 5V source and the A0 pin.
